Design and Build Paper - Final Paper

Spring 2013 Group Members

Andrew Hilty Nicholas Fenton Faculty Advisor Mohammad Alhassan, Ph. D

DESIGN OF A STEEL BRIDGE FOR THE 2013 ASCE GREAT LAKES

REGIONAL CONFERENCE STEEL BRIDGE COMPETITION

Indiana University Purdue University Fort Wayne Civil Engineering Department – Department of Engineering

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Contents

Table of Figures ................................................................................................. 5

Table of Tables ................................................................................................... 7

Abstract ............................................................................................................ 8

Section 1: Introduction ..................................................................................... 9

1.1 – Problem Statement .......................................................................................................... 9

1.2 – Scope of Project ............................................................................................................... 9

1.3 – Objectives ...................................................................................................................... 10

1.4 – Past Bridge Competition Performances ....................................................................... 10

1.5 – Project Specifications ..................................................................................................... 11

1.5.1 – Bridge Specifications .............................................................................................. 11

1.5.2 – Member Specifications .......................................................................................... 13

1.5.3 – Connection Specifications ...................................................................................... 14

1.6 – Competition Schedule .................................................................................................... 17

1.7 – Competition Scoring ..................................................................................................... 19

1.7.1 – Display .................................................................................................................... 19

1.7.2 – Construction Speed ................................................................................................ 20

1.7.3 – Lightness ................................................................................................................. 20

1.7.4 – Stiffness .................................................................................................................. 21

1.7.5 – Construction Economy .......................................................................................... 22

1.7.6 – Structural Efficiency .............................................................................................. 22

1.8 – Design Constraints ........................................................................................................ 22

1.8.1 – Actual Project Cost ................................................................................................. 23

1.8.2 – Material Selection .................................................................................................. 24

1.8.3 – Fabrication ............................................................................................................. 24

1.9 – Penalties in Competition .............................................................................................. 24

1.9.1 – Weight Penalties ..................................................................................................... 24

1.9.2 – Time Penalties ........................................................................................................ 25

1.9.3 – Load Test Penalties ................................................................................................ 25

1.9.4 – Disqualifications .................................................................................................... 25

Section 2: Conceptual Design .......................................................................... 26

2.1 – Design Constants .......................................................................................................... 26

2.2 – Design Concepts ........................................................................................................... 26

2.2.1 – Structural Design .................................................................................................. 26

2.2.2 – Experimental Design............................................................................................. 27

Section 3: Design Alternatives and Selection .................................................. 28

3.1 – Alternative Designs Results .......................................................................................... 28

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3.2 – Alternative 0 – Do Nothing .......................................................................................... 28

3.2.1 – Advantages ............................................................................................................ 28

3.2.2 – Disadvantages ....................................................................................................... 29

3.3 – Alternative 1 – Basic Bridge ......................................................................................... 29

3.3.1 – Advantages ............................................................................................................ 30

3.3.2 – Disadvantages ....................................................................................................... 30

3.4 – Alternative 2 – Spider-web Bridge .............................................................................. 31

3.4.1 – Advantages ............................................................................................................ 32

3.4.2 – Disadvantages ....................................................................................................... 32

3.5 – Alternative 3 – Lightweight Design ............................................................................. 33

3.5.1 – Advantages ............................................................................................................. 34

3.5.2 – Disadvantages ....................................................................................................... 34

3.6 – Alternative Selection .................................................................................................... 35

3.6.1 – Design Criteria ....................................................................................................... 35

3.6.2 – Decision Matrix ..................................................................................................... 36

Section 4: Selected Alternative Refinement ..................................................... 37

4.1 – Refinement .................................................................................................................... 37

4.1.1 – Reducing Weight .................................................................................................... 37

4.1.2 – Reducing Construction Time ................................................................................ 37

4.1.3 – Increase Rigidity ................................................................................................... 38

4.2 – Final Design .................................................................................................................. 38

4.2.1 – Bridge Dimensions ................................................................................................ 38

4.2.2 – Member Dimensions ............................................................................................. 40

4.2.3 – Connection Design and Dimensions .................................................................... 42

4.3 – Analysis ......................................................................................................................... 44

4.3.1 – Modeling Using Structural Analysis Program 2000 .......................................... 44

4.3.2 – Lateral Loading and Deflection ........................................................................... 46

4.3.3 – Vertical Loading and Deflection .......................................................................... 47

Section 5: Fabrication ..................................................................................... 49

5.1 – Pre-Fabrication ............................................................................................................. 49

5.1.1 – Shop Drawing......................................................................................................... 49

5.1.2 – Locating Fabricator ............................................................................................... 50

5.1.3 – Purchasing Material .............................................................................................. 50

5.2 – Fabrication .................................................................................................................... 50

Section 6: Load Testing .................................................................................... 52

6.1 – Loading Expectations ................................................................................................... 52

6.1.1 – Safety ...................................................................................................................... 52

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6.2 – Stage One ...................................................................................................................... 53

6.3 – Stage Two ...................................................................................................................... 53

6.4 – Stage Three ................................................................................................................... 54

Section 7: Construction .................................................................................... 55

7.1 – Construction Team Alternatives ................................................................................... 55

7.1.1 – Team 1 ..................................................................................................................... 56

7.1.2 – Team 2 .................................................................................................................... 57

7.1.3 – Team 3 .................................................................................................................... 58

7.1.4 – Team 4 .................................................................................................................... 59

7.1.5 – Team 5 .................................................................................................................... 60

7.2 – Construction Practice Results ...................................................................................... 62

Section 8: Aesthetics ....................................................................................... 63

8.1 – Display Criteria ............................................................................................................. 63

8.1.1 – Poster ...................................................................................................................... 63

8.1.2 – Bridge Finishing .................................................................................................... 64

8.2 – Paint Ideas .................................................................................................................... 64

8.2.1 – In-Home Painting .................................................................................................. 64

8.2.2 – Professional Painting ............................................................................................ 65

8.3 – Final Product ................................................................................................................ 66

Section 9: Competition ..................................................................................... 67

9.1 – Captains Meeting .......................................................................................................... 67

9.2 – Display .......................................................................................................................... 67

9.3 – Construction ................................................................................................................. 68

9.3.1 – Preparation ............................................................................................................ 69

9.3.2 – Construction .......................................................................................................... 69

9.3.3 – Repair .................................................................................................................... 72

9.4 – Loading ......................................................................................................................... 73

9.4.1 – Lateral Load .......................................................................................................... 73

9.4.2 – Back span Load ..................................................................................................... 74

9.4.3 – Cantilever Load ..................................................................................................... 75

9.5 – Results ........................................................................................................................... 76

Section 10: Sponsors and Special Thanks ......................................................... 77

Section 11: Future Project Recommendations .................................................. 78

11.1 – Rulebook and Clarifications ........................................................................................ 78

11.2 – Bridge Design .............................................................................................................. 78

11.3 – Connection Design ...................................................................................................... 78

11.4 – Fabrication ................................................................................................................... 79

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11.4.1 – Material................................................................................................................. 79

11.4.2 – Welding ................................................................................................................. 79

11.5 – Load Testing ................................................................................................................ 79

11.5.1 – Materials Needed .................................................................................................. 79

11.6 – Practice ........................................................................................................................ 79

11.7 – Competition ................................................................................................................ 80

11.8 – Sponsors and Donations ............................................................................................ 80

Section 12: Conclusions ................................................................................... 81

Section 13: References .................................................................................... 82

Section 14: Appendices ................................................................................... 83

Appendix A: 2013 ASCE / AISC Steel Bridge Competition Rulebook ................................. 83

Appendix B: The Current Rule Clarifications ...................................................................... 115

Problem statement ............................................................................................................ 116

Dimensions and Support Specifications .......................................................................... 116

Materials and Component Specifications ....................................................................... 121

Construction Regulations ................................................................................................ 122

Load Test .......................................................................................................................... 124

Appendix C: The SAP2000 Analysis Tables ....................................................................... 125

Base Reactions ................................................................................................................. 126

Frame Section Assignments ............................................................................................ 126

Steel Design Summary – Strength Ratio ....................................................................... 130

Appendix D: Hand Calculations .......................................................................................... 134

Appendix E: Shop Drawings ................................................................................................ 138

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Table of Figures

Figure 1: The 2010 steel bridge. .............................................................................................. 10 Figure 2: The 2011 steel bridge. .............................................................................................. 10 Figure 3: The 2012 steel bridge. .............................................................................................. 11 Figure 4: The site dimensions for the bridge competition. ................................................... 12 Figure 5: The side view of the dimensioned bridge profile. ................................................... 12 Figure 6: Front view of dimensioned bridge profile. ............................................................. 13 Figure 7: A dovetail connection that violates the specification. ............................................ 15 Figure 8: An example of a permissible connection (top) and a violation (bottom). ............. 15 Figure 9: An example of a connection violation ..................................................................... 16 Figure 10: A violation due to lack of bolts and faying surfaces that are not flat. .................. 16 Figure 11: Permissible connections.. ....................................................................................... 17 Figure 12: The plan locations of the decking for loading and targets.. ................................. 18 Figure 13: A visual representation of the loading the back span.. ......................................... 21 Figure 14: A visual representation of the Cantilever load. .................................................... 21 Figure 15: A 3D rendering of alternative 1. ............................................................................ 29 Figure 16: The connection design problem area in alternative 1. ......................................... 30 Figure 17: A 3D rendering of alternative 2. ............................................................................ 31 Figure 18: The connection design problem area in alternative 2. ......................................... 33 Figure 19: A 3D rendering of alternative 3. ............................................................................ 33 Figure 20: The major dimensions for the span of the bridge. ............................................... 38 Figure 21: The major dimension for the width of the bridge. ............................................... 39 Figure 22: The dimensions of the main truss members running the span on the bridge. ... 40 Figure 23: The dimensions of the cross members. ................................................................ 40 Figure 24: The dimensions of the end member of the cantilever. ........................................ 40 Figure 25: The dimensions of the end cross member. ........................................................... 41 Figure 26: The dimension of the leg members. ..................................................................... 41 Figure 27: The connection design for the main members and cross members. ................... 42 Figure 28: The zoomed view of the main members and cross members connection........... 43 Figure 29: The dimensions of the main gusset plates being used.. ....................................... 43 Figure 30: The main members, cross member, and leg connection. .................................... 44 Figure 31: The dimensions of leg gusset plates, including hole spacing. .............................. 44 Figure 32: The rendered version of the final design in SAP2000. ........................................ 45 Figure 33: The rendered version of the final design, side profile. ........................................ 45 Figure 34: The rendered version of the final design, front profile. ....................................... 45 Figure 35: The back span lateral load set-up. ........................................................................ 46 Figure 36: The cantilever lateral load set-up. ........................................................................ 46 Figure 37: The deflection caused by the back span case 1. .................................................... 47 Figure 38: The deflection caused by the back span case 2. ................................................... 48 Figure 39: The deflection caused by the cantilever case 1. .................................................... 48 Figure 40: The deflection caused by the cantilever case 2. ................................................... 48 Figure 41: Example of a shop drawing page. ......................................................................... 49 Figure 42: Mike welding a main truss member. .................................................................... 51 Figure 43: Andrew grinding a connection. ............................................................................ 51 Figure 44: Nicholas grinding a plate to size........................................................................... 51 Figure 45: Load testing possible locations and worst case. ................................................... 52 Figure 46: Stage two, load testing set-up. .............................................................................. 53 Figure 47: Stage 3, the bridge fully loaded with random lab material. ................................. 54 Figure 48: Span deflection under the full load. ..................................................................... 54 Figure 49: Team 1 consisting of 6 builders. ........................................................................... 56 Figure 50: Team 2 consisting of 5 builders. ........................................................................... 57

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Figure 51: Team 3 consisting of 4 builders. ........................................................................... 58 Figure 52: Team 4 consisting of 4 builders. ........................................................................... 59 Figure 53: Team 5 consisting of 3 builders. ........................................................................... 60 Figure 54: The final poster design for competition. .............................................................. 63 Figure 55: The name plate as a member of the bridge. ......................................................... 64 Figure 56: Paint scheme 1. ...................................................................................................... 65 Figure 57: Paint scheme 2. ...................................................................................................... 65 Figure 58: Paint scheme 3. ..................................................................................................... 65 Figure 59: The taped members before painting. ................................................................... 66 Figure 60: The final product as shown at competition. ........................................................ 66 Figure 61: The bridge, ready for display construction. .......................................................... 67 Figure 62: The completed display area. ................................................................................. 68 Figure 63: Carrying the bridge to the construction site. ....................................................... 68 Figure 64: Disassembly in the staging yard. .......................................................................... 69 Figure 65: Final preparations being finished......................................................................... 69 Figure 66: Judges asking question about the construction team. ........................................ 69 Figure 67: Last group meeting before construction. ............................................................. 69 Figure 68: Running a member and the pier to the construction site.................................... 70 Figure 69: Passing members across the river. ....................................................................... 70 Figure 70: Construction the left span of the bridge starting at the cantilever. ...................... 71 Figure 71: Continuing to build the left span to the back span leg. ......................................... 71 Figure 72: Placing the first back span leg. ............................................................................... 71 Figure 73: Constructing the right span of the bridge. ............................................................. 71 Figure 74: Placing the last leg on the back span abutment. ................................................... 71 Figure 75: Adding cross-members throughout. ...................................................................... 71 Figure 76: Tightening the fasteners with impact wrenches. ................................................. 72 Figure 77: The last finishing touches. ..................................................................................... 72 Figure 78: The lateral load test. .............................................................................................. 73 Figure 79: The back span loading. .......................................................................................... 74 Figure 80: The cantilever loading. ......................................................................................... 75

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Table of Tables

Table 1: Showing the determination of M and TB for the first roll of the die. ...................... 18 Table 2: Showing the determination of TC for the second roll of the die. ............................. 18 Table 3: The donations the group has been pursuing throughout the semester. .................. 23 Table 4: The weight penalties applied when the violation (V). .............................................. 24 Table 5: Analysis Result of all three alternatives. ................................................................... 28 Table 6: The alternative design criteria. ................................................................................. 36 Table 7: The alternative decision matrix. ................................................................................ 36 Table 8: The lateral deflection of the final design. ................................................................. 47 Table 9: The vertical deflections for all load cases. ................................................................ 48 Table 10: Time needed to keep the construction cost below $2.5M...................................... 55 Table 11: Team 1 initial practice times in run number order. ................................................ 56 Table 12: Team 2 initial practice times in run number order. ............................................... 57 Table 13: Team 3 initial practice times in run number order. ............................................... 58 Table 14: Team 3 secondary practice times in run number order. ........................................ 58 Table 15: Team 4 initial practice times in run number order. ............................................... 59 Table 16: Team 5 initial practice times in run number order. ............................................... 60 Table 17: Team 5 secondary practice times in run number order. ........................................ 61 Table 18: Team 5 refining practice times in run number order. ........................................... 61 Table 19: All practice runs sorted by lowest construction cost. ............................................. 62 Table 20: A summary of the conference results. .................................................................... 76

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Abstract

The American Society of Civil Engineers (ASCE) Great Lakes Regional Conference has quickly become an important opportunity for IPFW Civil Engineering Students to showcase their abilities while representing the caliber of learning that IPFW offers. The steel bridge competition, hosted by the American Institute of Steel Construction (AISC), is one of the most time-intensive and design-oriented competitions that the conference offers. The bridges submitted in this competition will be judged on display, construction speed, lightness, stiffness, construction economy, and structural efficiency. As a result of examining different material choices, analyzing several design alternatives, and developing unique connections, a bridge will be constructed to best satisfy the strongly weighted categories of construction economy and structural efficiency. The objective of this design will be to compete at the same level as the renowned universities that will be at the competition.

Throughout the first semester of the project, Fall 2012, the group will design a steel bridge according to the 2013 Steel Bridge Competition Rulebook. The design process will consist of truss selection, detailed member design, detailed connection design, and design analysis. The project will be designed with knowledge gained throughout the courses of structural engineering including statics, structural analysis, design of concrete structures, and design of steel structures.

Throughout the second semester of the project, Spring 2013, the group will purchase the necessary steel material and fabricate the previously designed bridge to the exact designed dimensions. After fabrication completes, construction will be practiced in accordance to the competition rules with every possible configuration to achieve the best possible competition score.

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Section 1: Introduction

The following section summarizes most of the forty page AISC rulebook and goes through the project goals and constraints.

1.1 – Problem Statement

Every year, AISC and ASCE host a competition at 18 different regional locations throughout the United States in which universities within the region may compete if they meet the ASCE eligibility requirements.

Several competing firms (other universities) are to submit bids to construct a steel bridge spanning a river and having a cantilever at one end over a historic billiard parlor. Steel is the only material that may be used because fast erection of the bridge is essential. Steel also offers high durability and a high level of recycled content which contribute to sustainability. The congested urban site restricts the location and size of the staging area as well as the dimensions and weight of the materials and tools used for construction. There may be no barges or abutments in the river however; a temporary cofferdam is permitted to allow for safe construction.

Each competing firm is required to submit a 1:10 scale model to demonstrate its concept. Each model will be erected under simulated field conditions and tested for stability, strength, and serviceability under scaled lateral and vertical loads. The firm with the model and construction simulation that best satisfies the specified requirements and achieves all of the project objectives while following all of the rules in the 2013 Rulebook while be given the contract.

Therefore, a bridge is to be designed and built for competition to win the contract at the designated regional conference. This group’s submitted bridge is to compete at Trine University in Auburn, IN on Saturday, April 20th, 2013.

1.2 – Scope of Project

The responsibility of the group is to design the bridge, each member of the bridge, and all of the connections in accordance to the 2013 Rulebook. After design is completed, fabrication and coordinated construction will be the focus until competition. At competition, it is the responsibility of the group to construct the bridge under timed conditions and load the constructed bridge under safe parameters to the specified load limits while being judged by professional engineers throughout.

The scope of the project does not include design of foundations, approaches, deck panels, or cofferdams. The construction portion of the competition may consist of builders outside the senior design group.

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1.3 – Objectives

The following items are objectives that the group is basing their design on. The objectives have been determined based on past experience with the bridge competition and will be used to direct the design semester in the direction that will lead to the most success at competition. The objectives this semester include:

1) To design a bridge that does not fail any of the deflection requirements by a safety factor of two.

2) To design connections that result in the fastest possible construction. 3) To pass all dimensional specifications without taking a single weight penalty. 4) To record as much information and data as possible so IPFW bridge teams can

reference this project for advice in future competitions.

1.4 – Past Bridge Competition Performances

IPFW has competed in the ASCE/AISC Steel Bridge Competition for 3 years at the following host sites: Rose-Hulman Institute of Technology, the University of Wisconsin Milwaukee, and Bradley University. Of the three competitions, IPFW has not been able to pass the deflection criteria under loading. The school’s highest finish was in 2012, tying for 5th place with 2 other schools. In the 2010 and 2011 competitions, IPFW finished 7th and 8th respectfully. Figures 1 – 3 below show the previous bridges entered in competition.

Figure 1: The 2010 steel bridge.


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Andrew was a member of the 2011 bridge team and both Nicholas and Andrew were captains of the 2012 bridge team. Despite the time devoted in previous years, neither has been involved in the design process of the steel bridge project.

1.5 – Project Specifications

A bridge must be designed to meet all of the following specifications precisely. If any specification is ignored or violated, a bridge may be penalized or disqualified from competition. At competition, all final dimensions are measured after the timed construction portion of the competition. Member dimensions are checked just before timed construction starts after all of the members are placed in the staging area. The following subsections will cover bridge, member, and connection specifications.

1.5.1 – Bridge Specifications

There are several requirements the bridge must meet to satisfy the problem statement. The following bridge dimensions are detailed in Figures 4 – 6 to follow:

1) The back span of the bridge must span a 12’-0” river without touching the water at any time during or after timed construction.

2) The entire back span of the bridge, that is every portion over the river, must maintain a minimum clearance above the river of 1’-7”.

3) There must be a cantilevered portion of the bridge and it must have a minimum span length or 3’-6” measured from the end of the cantilever toward the back span that maintains the 1’-7” ground clearance.

4) The bridge may be no longer that 17’-0” in total length in the span direction. 5) The bridge may be no taller than 5’-0” at any point measured from the ground up. 6) There must be two, continuous decking supports that span the length of the

bridge. Nothing may extend past the ends of these decking supports. 7) The top of the decking support (shown in figure 6) may be no taller than 3’-0”

measured from the ground up.

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8) The top of each decking support must maintain no less than ½” flat thickness the entire span of the bridge

9) The two decking supports may be no more than 3’-2” apart measured perpendicular to the span from the insides of each decking support.

10) The two decking support may be no less than 2’-6” apart measured perpendicular to the span from the outsides of each decking support.

11) The bridge must accommodate a vertical vehicle clearance of no less than 1’-6” measured from the top of the decking support surfaces up and must maintain this clearance at all points above the decking support.

12) The bridge must accommodate a horizontal vehicle clearance of no less than 3’-8” measured perpendicular to the span of the bridge starting above the decking support surfaces and must maintain this clearance at all points above the decking support.

Figure 4: The site dimensions for the bridge competition.

Figure 5: The side view of the dimensioned bridge profile.

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Figure 6: Front view of dimensioned bridge profile.

1.5.2 – Member Specifications

The member specifications apply to each member individually and a penalty may be applied for each violation occurrence. The member specifications are as follows:

1) Any one member may not weight more than 20 lbs. 2) A member must be able to fit inside a box with an opening of 4”x6” and a length

of 36” 3) No member may contain any of the following devices:

a) Electronic, electric, fluidic, or other non-mechanical sensor or control system.

b) A non-mechanical energy transmission device such as a wire, duct, or tube.

c) An energy conversion or storage device such as an electromagnet, electric cell, motor, hydraulic or pneumatic piston, turbine, chemical reactor, pressure vessel, pre-loaded spring, or triggering device.

4) All members must be rigid; meaning they must retain their shape, dimensions, and rigidity during construction and loading.

a) Hinged, jointed, articulated, and telescoping members are prohibited. Nothing about any member should be able to move.

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1.5.3 – Connection Specifications

The following definitions will be helpful to know before reading the through the connection specifications:

1) A member-to-member connection is a point of contact between members in which a bolt and nut connect the members in such a way that they cannot be taken apart without first unscrewing the nut from the bolt and then sliding the bolt out of each member.

2) A fastener is a bolt that is not part of a member that is fitted with a single nut that is also not part of a member. The nut of a fastener must match the bolt wherein the nominal size is the same as the bolt and permits the nut to be turned onto the bolt. Fasteners must be commercially available with hexagonal heads on the bolt and the nut. Custom fabricated bolts and mechanically altered fasteners such as Nylock nuts are prohibited.

3) A faying surface is a pair of surfaces that are, or will be, in contact at a connection.

The connection specifications apply to every single connection on the bridge

without exception. The following specifications detail member-to member connection requirements and violations:

1) There must be a member-to-member connection at every place where a member contacts another member by the end of timed construction and repairs.

2) Every member must contain at least one faying surface at each connection. 3) Faying surfaces must be flat and smooth, and must not have protrusions, ridges,

studs, teeth, threads, or sockets that lock connecting members together. 4) Every faying surface must be penetrated by a fastener. 5) The bolts are required to be no more than 1.5” in nominal length. That is from the

bottom of the head to the end of the bolt. 6) The bolt must penetrate completely through a hole in each member that it

connected. The hole must be large enough for the bolt to pass through but small enough so that the bolt head and the nut may not pass through it.

7) The hole for the fastener may not be threaded and a fastener may not be welded to a member. It must be possible to install and remove a bolt without turning it.

8) The bolt must fully engage the threads of the nut.

In Figures 7 – 11 there are several examples of member-to-member connections that violate the connection specifications and examples that meet the connection specifications.

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Figure 7: A dovetail connection that violates the specification stating that each faying

surface must be penetrated by a fastener.

Figure 8: An example of a permissible connection (top) and a violation (bottom).

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Figure 9: An example of a connection violation (top) and permissible connections

(bottom two).

Figure 10: A violation due to lack of bolts and faying surfaces that are not flat.

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Figure 11: Permissible connections. The faying surfaces are all flat and there is a

fastener penetrating each faying surface.

1.6 – Competition Schedule

The Saturday of competition follows a very strict schedule in order for each school to have a chance to represent their bridges. That day, the following schedule will be followed and applies to all competing schools at the competition without exclusion:

1) Bridges are erected in a casual setting for display judging. Teams have roughly 2 hours to set up their display area. The display area should contain the bridge and a poster. There should not be any electronic advertising or display in the display area.

2) Display judging begins. Once display judging starts, no school’s bridge may be altered or modified in any way except for disassembly to timed construction.

3) Bridges are disassembled. 4) A meeting involving all team captains and the head judge takes place where all

rules are clarified and all questions are answered.

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5) With all captains still present, the head judge selects the location of the load on the back span, the locations of the deflections targets on the back span, the locations of the load on the cantilever, and the locations of the deflection targets on the cantilever. The selection is decided by rolling a die twice. The following tables refer to Figure 12 following this text. Table 1 shows the possible results for the first roll (S1) where M is the positioning of the load and TB is the positioning of the vertical deflection target on the back span. Table 2 shows the possible results of the second roll (S2) where TC is the positioning for the vertical deflection target on the cantilever. The same locations will be used for all bridges competing.

Figure 12: The plan locations of the decking for loading and targets for measuring

deflection.

Table 1: Showing the determination of M and TB for the first roll of the die.

Table 2: Showing the determination of TC for the second roll of the die.

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6) In a random process, the head judge determines the order in which the teams will compete.

7) Bridges members, fasteners, tools, and temporary pier are then moved to the staging area and are to be inspected by a judge before timed construction begins.

8) Timed construction. 9) Repair if needed. 10) Judges inspect the assembled bridge for all dimension specifications. If the

bridge passes all dimension specifications, it is approved for load testing. 11) Bridges are weighed whether it is approved for loading or not. This is the final

step of competition for bridges that are not approved for load testing. 12) Lateral load testing. If lateral load testing is passed, the bridge is then approved

for vertical load testing. This is the last step of competition for bridges that are not approved for vertical load testing.

13) Vertical load testing. 14) Scores are then determined using the official scoring spreadsheet and are verified

and signed by the team captains.

1.7 – Competition Scoring

All of the competing bridges are scored in several categories. These categories of competition are display, construction speed, lightness, stiffness, construction economy, and structural efficiency. An overall performance rating is then calculated bridge with the lowest total cost wins the overall competition. The total cost is calculated based on the formerly mentioned categories. Each category is explained in the following subsections.

1.7.1 – Display

Display is the tie-breaker for all categories of competition and there will not be a tie in the display category. The bridges must be displayed exactly as it will be at the end of timed construction. Display is judged on the following:

1) Appearance of the bridge. This includes balance, proportion, elegance, and finish. Welding and fabrication are not to be judged as to fairly judged schools that have their bridges fabricated professionally vs. those that do not.

2) Permanent identification of the bridge must consist of the school name as shown on the ASCE student website. The letters of the school name must be formed of steel, or be applied via paint or decals and must be a minimum of 1” high.

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3) There must be a poster on display meeting the following requirements: a. It must be flat with maximum dimensions of 2’-0” x 3’-0”. All of the

information must appear on only one side of the poster and there may not be any loose pages that need to be turned.

b. The school name must appear on the bridge as the same name displayed on the bridge itself.

c. It must contain a dimensioned illustration of the side profile of the bridge.

d. It must contain a brief explanation of why this design was selected. e. It must contain a brief computation demonstrating design for a one

limit state. f. It must discuss provisions for sustainability, if any. g. It must contain acknowledgement of university technicians, faculty,

and other persons who may have helped in the design or build of the bridge.

h. It must be in English. 4) Financial sponsors are optional and may be on a second poster to contain

their logos if needed. 5) Electronic displays are not allowed.

1.7.2 – Construction Speed

The bridge with the lowest total time will in the construction speed category. Total time is equal to the time it takes to construct the bridge plus all time penalties plus repair time. Time penalties are discussed in Section 1.9.2. Repair time is equal to 2 minutes plus double the repair time. Repair is optional as mentioned before. There are upper limits to construction time and repair time (penalties not included) that are 30 minutes and 5 minutes respectively. During the design semester of this project, the group can only indirectly affect the construction speed of the bridge. This can be done by simplifying the member-to-member connections so that when timed construction is underway, the connections take as little time as possible. The build semester of the project will focus on improving construction speed by repeated practice.

1.7.3 – Lightness

The bridge with the least total weight will win the lightness category. Total weight is equal to the weight of the bridge plus any weight penalties. Weight penalties will be discussed in Section 1.9.1. The decking used, all tools, the temporary pier, any lateral restraint devises and posters are not considered when calculating total weight.

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1.7.4 – Stiffness

The bridge with the lowest aggregate deflection will win the stiffness category. Aggregate deflection is defined as the sum of DCA, DCB, and the larger of DB1 and DB2. DCA is the vertical deflection that occurs under the cantilever loading during step 2 (loading the cantilever with the back span load in place). DCB is the vertical deflection measured at the end of the cantilever during step 2. DB1 is the vertical deflection on the back span that occurs during step 1 (loading of the back span with the cantilever preload in place). DB2 is the vertical deflection on the back span that occurs during step 2. All deflections measured are absolute values of the measured displacement in inches. Figures 13 – 14 below show the location of the deflection targets.

Figure 13: The location of DB1. Also a visual representation of the loading the back

span of the bridge with cantilever preload in place.

Figure 14: The location of DB2, DCA, and DCB. Also a visual representation of the

Cantilever load with the back span load remaining in place.

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1.7.5 – Construction Economy

The bridge with the lowest construction cost (CC) will win the construction economy category. This category will be the main focus of the build semester and will be refined and improved mostly by practice. Construction cost is defined as shown below: CC = [total time (min.)] x [number of builders] x [50,000 ($/builder - min)] + load test penalties ($)

Total time is defined in Section 1.7.2. The number of builders is defined as the team members physically assisting in the timed construction of the bridge and does not include any members who were involved in the design process. The load test penalties will be defined and discussed in Section 1.9.3.

1.7.6 – Structural Efficiency

The bridge with the lowest structural cost (CS) will win the structural efficiency category. This category is the main focus of the design semester. Structural cost has two different definitions; these are based on the total weight of the bridge. For a bridge with a total weight 400 lbs CS = [total weight (lbs)] x [10,000 ($/lbs)] + [aggregate deflection (in)] x [1,000,000 ($/in)] + load test penalties ($)

For a bridge with a total weight 400 lbs

CS = [total weight (lbs)]2 x [25 ($/lbs2)] + [aggregate deflection (in)] x [1,000,000 ($/in)] + load test penalties ($)

Total weight is defined in Section 1.7.3. Aggregate deflection is defined in Section 1.7.4. Load test penalties will be defined and discussed in Section 1.9.3.

1.8 – Design Constraints

Throughout the design and build semesters, there will be several design constraints that continuously interfere and change how concepts and ideas are presented. The major constraints include, but are not limited to, actual project cost, material selection, and fabrication.

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1.8.1 – Actual Project Cost

Although it would be ideal for the group to be able to spend thousands of dollars on the project to ensure the highest quality of materials, tools, and fabrication, this is not feasible for the Department of Engineering at IPFW nor for the students in the group. For this reason, it has been the goal of the group to fundraise materials, fabricating professionals, and tools. The group has even sought out monetary donations. In Table 3 below, all of the donations that the group has received throughout the semester are shown.

Table 3: The donations the group has been pursuing throughout the semester.

Donations, Senior Design ProjectCompany Donated Description for use Stipulations

Cash Value

Status

Best Buy, Appleglen

$1000 cash to ASCE of

IPFW

Will be used to by the steel and any nuts and bolts for

the project.

Andrew must volunteer 40 hours or more of his time to

benefit the non‐profit organization of ASCE

$1,000 Received

Metal Supermarket

(Teresa Starnes)

All steel members

and plates @ 50%

discount.

The bridge material.

The logo of the donating company must be placed on the poster and t‐shirt of the

bridge team.

$180 Received

Spangle Fasteners

All grade 8 bolts and

nuts donated (210 of each)

The fasteners that hold the members

together.


bridge team.

$75 Received

Soap ‐N‐ Suds Auto Detailing

The shop, paint, and

labor to paint the bridge.

Will be used to paint the bridge the desired color as

competition nears.


bridge team.

? Wouldn't Return Calls

American Institute of

Steel Construction

$250 cash to ASCE of IPFW

Used for materials, specifically paint and grinding

materials if needed.

Participate in the Steel bridge Competition.

$250 Received

Berry's Welding

Custom name plate.

Name plate as last member on bridge.


bridge team.

$50 Received

Fabrication

The welding shop,

professional welder, and time needed to fabricate.

To fabricate the bridge as designed to the utmost

quality.


bridge team.

$1,000 Received

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1.8.2 – Material Selection

The material used for the project must be steel. Due to cost restraints previously mentioned, the group will be limited to readily available steel unless custom steel sections are to be donated. Due to the business relationship established with Metal Supermarkets of Fort Wayne, there is a chance to receive the steel needed at a discounted price however nothing has been finalized with the owner as of yet.

1.8.3 – Fabrication

Fabrication has been the downfall of two past bridges (2011 and 2012) due to lack of experience and time constraints. IPFW does not have a certified lab to weld in which causes large time constraints on the project. The fabricator that donates his time, Mike Pettit, works up to 12 hours a day and then offers his evenings to fabricate our bridge to completion; despite the generosity he offers, fabricating the bridge in this manner takes much longer than it would if IPFW had a lab that the students could use.

1.9 – Penalties in Competition

Throughout competition, there are several ways in which the group can be penalized. There are 4 major penalty categories: Weight penalties, time penalties, load penalties, and disqualifications. Each type of penalty occurs at different times in the competition and this section will summarize the formerly stated penalties.

1.9.1 – Weight Penalties

Weight penalties are assessed when dimension specifications are violated. All project specifications are outlined in Section 1.5. The weight penalties are distributed as shown in Table 4 below. Table 4: The weight penalties applied when the violation (V) is within the dimensional

violation parameters.

Weight Penalties

Weight Added

Dimensional Violation

(lbs.) (in.) 50 0 < V ≤ 0.5 150 ½ < V ≤ 1.0 300 1.0 < V ≤ 2.0

All of the weight penalties will be added to the total weight as defined previously in Section 1.7.3 before scoring for any category relating to weight is assessed. It was previously mentioned in Section 1.3 that an objective of the group was to pass all dimension specifications and receive zero weight penalties.

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1.9.2 – Time Penalties

Time penalties occur during timed construction and repair when errors or accidents occur such as dropping a bolt, or stepping in the river. Time penalties will be further addressed and discussed in the build semester. It can also be noted that time penalties affect the total time which is defined in Section 1.7.2 affecting two scoring categories: Construction speed and construction economy.

1.9.3 – Load Test Penalties

Load test penalties may occur during any of the following stages of competitions: Lateral load test of the back span, lateral load test of the cantilever, vertical load test of the back span, vertical load test of the cantilever, or unloading. Load test penalties occur when a bridge fails under loading or deflects above the required deflections limit. Load test penalties are extreme and if a bridge receives a load test penalty, it is ineligible for any awards. These penalties will be discussed and addressed further in the build semester of the project.

1.9.4 – Disqualifications

There are numerous times throughout competition in which a bridge may be disqualified to compete in the competition. Disqualifications can occur based on specification violations, safety violations, or construction violations. Below is a list of specification violations; the bridge will be disqualified if:

1) The back span of the constructed bridge does not completely span the river. 2) The cantilever is constructed toward the staging area instead of across the river. 3) The bridge does not contain decking support surfaces. 4) The decking is anchored or attached to the bridge in any way and is used to

distort the bridge in any way. 5) The bridge is anchored to the floor. 6) Any dimensional violation shown in Section 1.9.1 is greater than 2 inches. 7) A member weighs more than 20 pounds. 8) A member violates the specifications outlined in Section 1.5.2, items 1 and 3. Below is a list of safety violations; the bridge will be disqualified if: 1) The bridge does not provide access for safe placing of decking or load. 2) It is not possible to construct or load the bridge safely using the site, equipment,

or floor surfaces provided by the host student organization. 3) A team cannot construct the bridge completely using safe practices. 4) A weld fractures that reduced the bridge strength. 5) A member is missing or broken.

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Section 2: Conceptual Design

Before bridge designs could be drawn, analyzed, and discussed it was important to do necessary research first to set up the major design parameters that needed to be followed. This would help steer the design group in the right direction by creating guidelines. These guidelines were created using information from the competition rule book, past competition experience, and knowledge gained from courses taken at IPFW. The guidelines are composed of two major areas including design constants and design concepts.

2.1 – Design Constants

Since each member of the design team would be working independently on their own alternative designs it was important to set up design constants in order to keep some unity between designs and to avoid violating any major rules. Using the rule book provided for this competition the following design constants were set up for this project:

The bridge must:

o Have a span of no less than 12 feet 6 inches o Have a cantilevered end of no less than 3 foot 8 inches o Have a height of no more than 4 foot 10 inches o Have a decking support height of no more than 2 foot 10 inches o Have no member that is more than 3.5”x5.5”x35.5” in

dimension

These dimensions were selected to be either slightly more or less than the requirements. This done because of past experience of designing member that meet exact dimension but failed at competition due to errors cause from cutting members or during welding. This over designing should eliminate the chance of this happening.

2.2 – Design Concepts

When designing a bridge anyone can come up with a creative idea and draw it on a piece of paper, but that doesn’t mean it would work. To keep the design team from blindly attempting to come up with designs that may or may not work they called on their knowledge and experience. By revisiting ideas learned in courses and from past competitions experiences the team would be able to work realistic designs.

2.2.1 – Structural Design

From Structural Analysis it is known that a truss design is ideal for this situation due to its ability to transfer load and its lightness compared to a solid member. This also makes analysis easier due to the fact that the truss will hold axial loads only. Implementing this key idea was important when developing alternative designs.

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2.2.2 – Experimental Design

The idea of experimental design come from past competition experience. Both members combine to have a total of 3 years of experience in this competition which included working on two different bridges. Both bridge utilized vary different connect and member designs, and both bridges failed for very different reasons. The first failed to pass lateral deflection mostly due to fabrication while the other bridge failed under loading which was caused by poor connection design. These two experiences displayed the importance of scheduling enough time to correctly and properly cut and weld members and the importance of performing an analysis on the proposed connection before fabrication. While these are the more important things learned there are more minor things that were discovered by participating in past years.

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Section 3: Design Alternatives and Selection

The following section covers all of the design alternatives and concepts as well as the alternative selection process.

3.1 – Alternative Designs Results

Table 5 shows the results of building and analyzing the three main alternatives in SAP2000. It displays the total weight and deflections of each bridge in all possible load cases. This table will be referred to throughout the follow subsections of section 3.

Table 5: Analysis Result of all three alternatives.

Alternative Weight (lbs.)

Maximum Deflection (in.) Lateral

1 Lateral

2 Backspan

1 Backspan

2 Cantilever

1 Cantilever

2

Basic Truss 322 0.036 0.121 0.05 0.062 0.033 0.039

Spider‐web 287.1 0.903 1.15 0.585 0.512 0.117 0.111

Lightweight 208 0.476 1.45 0.189 0.217 0.168 0.209

Final 197.7 0.155 0.231 0.467 0.486 0.328 0.393

3.2 – Alternative 0 – Do Nothing

With this alternative design the project team was able to examine the benefits and down falls for simply not doing anything for the Steel Bridge Competition. Since previous year bridges cannot be reused from year to year this means the IPFW student chapter of ASCE couldn’t modify a previous year’s bridge and take it to competition. As a result of this the student chapter would not be able to compete in this year’s competition.

3.2.1 – Advantages

As an organization that is trying to become stable and is still in the development stages funding is very important and extremely limited. Knowing this, by not designing and building a bridge the contracted design team is saving the student organization an estimated $1,000.00 in materials and fabrication cost. Along with this cost the organization would still have to invest in entrance fees, transportation cost, and hotel reservations in order to get the bridge and construction crew to the competition. Selecting this proposed alternative would allow for the saved money could be reinvested into other student activities throughout the year. This would also allow for the organization to have more time to acquire more investors and funding for the 2014 competition.

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3.2.2 – Disadvantages

One expressed goal of the IPFW ASCE is to win first place at the Great Lakes Regional Conference which requires at least a top 5 finish in all major competitions. One of these major competitions is the Steel Bridge Competition which actually accounts for 25% of the final conference score. Incidentally, if this alternative is selected then the organization will not be able to win first place or even finish in the top five schools. This would result in a failure to accomplish a major goal and would keep the group from improving on their third place finish in the 2012 competition.

Although finances are currently tight for this group, a majority of the funding that is obtained is donated with the intentions of helping the organization improve their performance at the Great Lakes Regional Conference. Donors like the IPFW Student Government (IPSG) provide funds because they see this as a perfect investment opportunity to help promote the city of Fort Wayne and IPFW campus. A poor performance would most likely negatively impact the willingness of the IPSG to invest in the group. This would surely affect the IPFW ASCE’s ability to grow and continue to compete at this conference.

3.3 – Alternative 1 – Basic Bridge

The idea behind this bridge is to design the simplest bridge as far as member design and fabrication. All members are made up of only HSS tubing that is cut to the required length which helps insures that all members will meet the set requirements. This design idea also is aimed at trying to eliminate the need for welding as much as possible, with the point being to reduce fabrication time and increase time to practice. Figure 15 shows what the final product would look like if this alternative as selected.

Figure 15: A 3D rendering of alternative 1.

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The main advantage for this bridge design is the number of members needed to construct it. With this competition speed of construction is very important, so by using fewer members there is less time spent transporting and connecting members which in return will reduce the time of construction. Along with the decreased assembly time due to the number of members, this also decreases the amount of fabrication needed. This would reduce the amount of time spent fabricating and allow for more time spend practicing constructing the bridge.


First, since none of the members are welded together this causes any members to not be perpendicular or parallel to each other at connection locations. This would require gusset plates welded onto members to meet these exact angles. Due to lack of resources and time this would become very difficult to accomplish with enough time for students to practice construction before competition.

Although the design of this bridge is basic and straight forward the connection design and construction would both be frustrating and extremely challenging. The connection design would be difficult due to the number of members meeting at connections and because the angles at which members meet. First off, in many locations there are always at least 3 members meeting and in some cases up to 8 members coming together Figure 16. Attempting to have this many members share a gusset plate would be near impossible and require for a very large plate thickness and area to support all the connected members. Along with this, due to the size of the members needed and the bolt length restriction, it’s impossible to connect members with together without plates. As result of this members cant share bolts to help reduce the total number of bolts needed.

Figure 16: The connection design problem area in alternative 1.

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Finally, even if the first two problems were solved the construction itself would be a difficult process. The connection design would require builders to insert anywhere from 3 to 8 bolts per connection with would waste a great amount of time and increase the probably of getting penalized for dropping bolts. Also during construction it is very helpful for the bridge to be able to support itself as much as possible. With all members being independent of each other and only being connected with one bolt will be hard to accomplish. Members would be able to rotate and wouldn’t be able to support weight until a significant amount of construction is finished.

3.4 – Alternative 2 – Spider-web Bridge

The goal of this alternative is to design a bridge that isn’t simply structurally sound but also aesthetically pleasing. When Figure 17 was shown to the student organization they all thought this alternative was more attractive than the other two designs. This is important because many schools at this competition show up with dull and boring bridges that simply do their intended job but are quickly forgotten. The design team wanted to design a bridge that wouldn’t only be successful when loaded but that would also grab the attention of judges and other students. This would help IPFW ASCE stand out in this competition and help them build a reputation for being creative.


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This strongest quality of this bridge is its ability to resist side sway caused by horizontal loading. When loaded using the SAP2000 software to analyze the bridge it was determined that it would pass side sway (Table 5) without using any cross members for support. This is due to the design of the cross members which in return would save time during construction and reduce the weight of the final product. This is also very important because during competition if a team’s bridge deflects more than .5 inches during horizontal loading they are disqualified.

Another advantage is the number of connections there are throughout the design. This bridge is set up so that multiple members can be connected by a single bolt. Aside from this there are more welded members that help simplify and reduce the number of connections needed. This also allows for a majority of the gusset plates to be smaller, lighter, and easier to design.

The last significant advantage of this bridge is the aesthetic quality of the design. Although aesthetics are only important in a tie breaker situation, it does help a school standout and get more attention by bringing a unique bridge to competition. This is important as IPFW ASCE starts to build a reputation at the Great Lakes Region Conference and helps build the confidence of students.


The first major disadvantage was the weight of this design, as seen in Table 5. The contributing factor of the higher weight was the size of the HSS tubing needed to resist the loading, along with the complexity of the members. The main members required a large amount of steel rod in order to keep the members from failing which unfortunately also increased the weight of the members. Also just like the main members the complicated cross members, which are the reason for the reduced side sway, were large and required a significant amount of rod to construct.

The other down fall to this design is similar to the connection problem with the first alternative. The connection design becomes a problem where the cross members meet because there are four members sharing one connection. This issue is due to the fact that all four of these members would be meeting the connection at an angle that isn’t parallel or perpendicular to any other members. This problem is highlighted with a red circle in Figure 18. With the resources available it would be hard to create a connection that would be as precise as needed to make this successful.

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Figure 18: The connection design problem area in alternative 2.

3.5 – Alternative 3 – Lightweight Design

This design was developed based on previous years of experience in this competition. By adopting the successful aspects of the 2012 bridge design and discarding the areas of the bridge that were wasteful or failed the design team hoped to end up with a much more successful bridge. On one hand this meant trying to utilizing the idea of having welded members made up of HSS tubing and steel rod that made it possible to get the most out of the member restrictions while making construction easier. On the other hand this meant removing the large overdesigned truss from the 2012 bridge and stressing the importance of connection design. The final product shown in Figure 19 below (when compared to Figure 3) is a much smaller and lighter design while still having as much strength.


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The first advantage that sticks out for this design is the overall weight of the bridge, which can be seen in Table 5. Of the three alternative designs this bridge is the lightest, by far, giving it the lowest cost in the Structural Efficiency category of the competition. This was accomplished using larger HSS members with a small wall thickness. Also the design of the individual members’ required very little steel rod with a much smaller diameter than in Alternative 2 which resulted in a loss of weight.

When it comes to connection design this bridge is simple and easy to work with. All members in the design meet parallel or perpendicularly to each other at the connections, with the exception to the truss running along both the sides of the span of the bridge. Even though these truss members are meeting at an angle the connection design is still simple and can be done by using a simple flat gusset plate.

The next positive side to this design is it’s constructability during competition. While under construction members are able to support themselves without rotating or falling even though they are only being held by one bolt. This makes it easier to construct different areas of the bridge at the same time instead of being forced to start at one end and work towards the other. This will save time and possibly laborers need during construction which in return will reduce the cost acquired in the Construction Economy portion of the competition.


The first disadvantage, and a very severe one, is the deflection the bridge experiences under loading. In Table 5, it can be seen that barely passed lateral deflection and had a higher deflection in all other categories compared to that of Alternative 1. The cased a problem because the software only gives a close approximation as to what the deflection will be under loading. Since the bridge will be loaded slowly during competition relaxation and creep must be taken into account. When thinking about these factors it is very possible this design will fail while being loading.

The only other significant disadvantage is the number of members required to construct this bridge. Since builders are only able to move one member of the staging area at a time this means there would be more trips made between the staging and construction areas. This increased amount of trips would result in more time needed to construct the bridge.

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3.6 – Alternative Selection

Once the four alternatives were discussed, designed, and analyzed the next major step was to determine the criteria that were important in selecting the one that would result in the final design. Before this was done though Alternative 0 was pitched to IPFW ASCE so they could decide if it was the course of attraction they would like to take. After explaining this option to them they came to the conclusion that it was important to them that a bridge be designed and taken to competition. This immediately eliminated this option from the selection process. From here the design team needed to select important design criteria and create a decision matrix to help select the best of the three designs left.

3.6.1 – Design Criteria

In order to select the appropriate bridge from the three alternative designs available the design team had to come up with design criteria that would determine what was important in being a successful bridge design. Both group members started by individually creating their own list of important criteria. After this was done the members compared and contrasted their list and defended why they listed things the way they did. This discussion was followed by combining the list with the criteria that both members could agree on. The list of criteria that was created from this process was as follows:

A) Connection Design B) Estimated Construction Time C) Weight D) Deflection E) Number of Members

From here the group had to weight these criteria against each other in order to

rank them in order of importance. This was done by creating a table in excel that would be used to compare the criteria to each other. The table was composed of a row of the criteria across the top and a column of the criteria along the left side. Next the design team took the first criteria listed in the top row and compared it to each criteria in the column. The criteria in the row were ranked based on how important it was compared to the criteria in the column. The ranking system is listed below.

1 – More Important 0.5 – Equally Important 0 – Not As Important

The next step was to add up the total points for each criteria along with the

overall total points. Then each criteria’s total was divide by the overall total to give a

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factor of importance which can be seen in Table 6 shown. These factors of importance would be used during the selection process in the next section.

Table 6: The alternative design criteria.

3.6.2 – Decision Matrix

After the criteria and the weights of those criteria were established the next step was to determine how well each bridge met those criteria. This was done by creating a Decision Matrix with listed each design criteria across the top and the design alternatives along the left side. Each bridge was then ranked on how well the group felt it met the criteria using the following scale:

o 1 – Horrible o 2 – Poor o 3 – Average o 4 – Good o 5 – Great

Looking at Table 7 it can be seen that the group then multiplied the rank by the

factor of importance for to get a score for each category. The scores of each category were added together to get a total score for each bridge. When using this method the highest score is the winner and in this case Alternative 3 had the highest final score.

Table 7: The alternative decision matrix.

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Section 4: Selected Alternative Refinement

After the design of the alternatives was done and the best design was selected using the decision matrix, the design team started taking a more detailed look at the final design. This started with refinement which involved revisiting the design as a whole to see what could be changed, discarded, or improved. From here the next steps consisted of designing the actual connection designs and performing a more detailed analysis. All of these steps contributed to creating and finalizing the final design for the bridge competition.

4.1 – Refinement

After selecting from the three alternatives the next step taken was to reevaluate the design selected. This was important because during the alternative design process the team was only able to spend a limited amount of time working on one design. As a result the bridges could only be analyzed and little time could be used to make improvements. So to make up for this fact the group took the best design and attempted to try to improve it in areas of weight, estimated construction time, and increase its rigidity.

4.1.1 – Reducing Weight

Weight is not only one of the most important aspects of the competition but also one of the easiest factors to alter. That is why the design team started the refinement process by starting with the weight of the bridge. In an attempt to reduce the total weight the large truss running along the outside of the bridge was removed. In order for this to be successful all the other members would have to be increased in size to resist the loading while also not increasing the weight back to where it was before the truss was removed. This was done by selecting different member sizes and rerunning the analysis until all members passed. Once all the members passes the required loading the self-weight of the bridge was determined to be lighter than the original alternative which is shown in Table 5.

4.1.2 – Reducing Construction Time

Reducing construction time is a rather hard time to design more during this stage of the project. Since it’s hard to analysis this factor without actually putting the bridge together anything done this semester is simply assuming that it will reduce construction time. Logical conclusions could be made though as to what will potentially cut back on time. The first assumption is that by reducing the amount of members used to construct the bridge. This was accomplished by removing the truss members when trying to reduce the total weight of the bridge. Also it is assumed that the simpler the connections are the quicker construction will progress. As a result the team set out to come up with connection designs that would be simple to use.

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4.1.3 – Increase Rigidity

Since Alternative 3 performed poorly with lateral deflection it was necessary to try to improve this in the final design due to the importance of this area during the competition. This was done by redesigning the cross members to be more like the ones used in Alternative 2. Once the cross members were redesigned the group reran the analysis. The results improved but the team still wasn’t impressed. To try to improve it even more, M bracing was added to the design that would connect to the cross members. This greatly improved the rigidity of the design and even though it did add more members and increased the weight it still has fewer members and was lighter than the original design.

4.2 – Final Design

Once the long and detailed steps of creating alternatives, selecting the best design, and refining the selected design were completed the design team finally had the final design that would be fabricated and taken to competition. The final design was drawn in AutoCAD to help with connection design and to make it easier to obtain the final dimensions of the bridge. This subsection will show rendered models of the bridge along with major dimensions of final design, individual members, and connections.

4.2.1 – Bridge Dimensions

Figures 20 – 21 show the major dimensions of the bridge when fully constructed. All dimensions are show in decimal feet. In order to convert the decimal units into inches simply multiply it by 12.

Figure 20: The major dimensions for the span of the bridge.

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Figure 21: The major dimension for the width of the bridge.

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4.2.2 – Member Dimensions

Figures 21 – 26 show the dimensions of all the members being used to construct the bridge. All dimensions are show in decimal feet. In order to convert the decimal units into inches simply multiply it by 12.

Figure 22: The dimensions of the main truss members running the span on the bridge.

Figure 23: The dimensions of the cross members.

Figure 24: The dimensions of the end member of the cantilever.

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Figure 25: The dimensions of the end cross member.

Figure 26: The dimension of the leg members.

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4.2.3 – Connection Design and Dimensions

Figures 27 – 31 show the connection details for the final bridge design. The connections were designed to be as strong yet and simple as possible. They were overdesigned slighting to help account for uneven loading and relaxation during competition. Hand calculations where done on the connection that would experience the greatest amount of load. This helped ensure the plate and bolt sizes were strong enough along with helped determine that the plates must have a distance of half an inch from the center of the bolt holes to the edge of the plates. This clear distance was then applied to all plates being using in the design. The hand calculations can be seen in Appendix D.

Figure 27: The connection design for the main members and cross members.

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Figure 28: The zoomed view of the main members and cross members connection.

Figure 29: The dimensions of the main gusset plates being used, including the hole

spacing.

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Figure 30: The main members, cross member, and leg connection.

Figure 31: The dimensions of leg gusset plates, including hole spacing.

4.3 – Analysis

After the final design has been selected and refined, it is analyzed to calculate maximum deflections, maximum stresses on members, and necessary sectional areas needed to resist specified loading within specified deflection requirements.

4.3.1 – Modeling Using Structural Analysis Program 2000

The final design was drawn in a program called SAP2000. SAP2000 is used to design trusses and simple structures. This powerful software, when used correctly, can determine necessary section properties needed under circumstances given. For instance, for constructability the group wanted to use Square HSS sections; once the section type

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was selected, the bridge was drawn, the loads applied, the bridge analyzed, and finally the software shows what minimum sections that are needed to withstand the loads within the deflection requirements provided.

In Figures 32 – 34, the final design is shown in the SAP2000 software.

Figure 32: The rendered version of the final design in SAP2000.

Figure 33: The rendered version of the final design, side profile.

Figure 34: The rendered version of the final design, front profile.

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4.3.2 – Lateral Loading and Deflection

There are two lateral load situations that will occur during bridge loading. The first is a 50lb load shown in Figure 35 below.

Figure 35: The back span lateral load set-up.

The force applied and sway targets are located as close to the decking support

surfaces as possible. The sway target is located at 6’-6” from the back span supports and the lateral force shall be applied from no more than 4” away from the target. “SEE NOTE” refers to the lateral restraints needing to be applied close to the ground and may not restrain rotation, uplift, or translation in other than the lateral direction.

The second lateral force is also a 50lb load shown below in Figure 36.

Figure 36: The cantilever lateral load set-up.

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This lateral sway target is located as close to the end of the decking support surface as possible and again, the force shall be applied from no more than 4” away from the target.

The maximum allowable lateral deflection at either sway target is 0.5” and must remain less than that to avoid a load test penalty as described in Section 1.9.3. When using SAP2000, the maximum lateral deflections are as shown in Table 8 below.

Table 8: The lateral deflection of the final design.

Lateral Deflection

Location Force Applied Maximum Deflection

(lbs) (in) Back Span 50 0.155 Cantilever 50 0.231

According to the software, the group meets the objective to keep the deflection failure mode within a safety factor of 2 and would be approved for vertical load testing.

4.3.3 – Vertical Loading and Deflection

The vertical loading on the bridge happens in two steps. The first step is to load the back span with 1500 lbs and the second is to load the cantilever with 1000 lbs. The back span load from step one is to remain in place during the loading that occurs in step two. Steps one and two refer to Figures 13 – 14 in Section 1.7.4 which discuss how the deflections are measured.

The maximum allowable vertical deflection of the back span is 1.5” and of the cantilever is 1.0” and both must remain less than that to avoid a load test penalty as described in Section 1.9.3. There are two possible load cases that can occur based on the dice rolls discussed in Section 1.6: The back span load can move between two different locations where the cantilever load remains constant. Back span case 1 and back span case 2 refer to the two possible location of the back span load: 3’-6” and 7’-0” from the end respectfully. The cantilever cases are based on where the back span load is located as just mentioned.

Figures 37 – 40 show all of the possible load cases’ vertical deflections.

Figure 37: The deflection caused by the back span case 1.

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Figure 38: The deflection caused by the back span case 2.

Figure 39: The deflection caused by the cantilever case 1.

Figure 40: The deflection caused by the cantilever case 2.

When using SAP2000, the maximum vertical deflections are as shown in Table 9

below. Table 9: The vertical deflections for all load cases.

Vertical Deflection

Location Force Applied Maximum Deflection

(lbs) (in) Back Span Case 1 1500 0.467 Back Span Case 2 1500 0.486 Cantilever Case 1 1000 0.328 Cantilever Case 2 1000 0.393

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Section 5: Fabrication

5.1 – Pre-Fabrication

Before the fabrication process could start there were many steps that needed to be taken first, which included creating shop drawings, finding a fabricator, and purchasing materials. All of these things needed to be dealt with before the scheduled fabrication start date of February 4th. During the pre-fabrication process it was important to accomplish each of these tasks on time and in their respective order.

5.1.1 – Shop Drawing

The first step was to take the final design and calculations from the design semester and transform that information into readable and understandable shop drawings. Shop drawings are detail sheets that break down the bridge into all of its individual parts that will be welded together. It takes each part and provides all the dimensions, material descriptions, and weld sizes that are required to put it together to make a finished piece. These shop drawings are then not only presented to the fabricator for the project but are also used to help ensure that the right amount and type of material is purchased. An example of one page of the shop drawings is show if Figure 41 and more examples of shop drawing can be seen in Appendix E.

Figure 41: Example of a shop drawing page.

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5.1.2 – Locating Fabricator

During the 2012 steel bridge project the build team was able to find a local fabricator by the name of Mike Pettit to help fabricate the bridge. This help included providing the team with his 35 years of welding experience along with allowing the group to use the equipment in the shop where he worked which is owned by National Recreation Systems. This was where this year’s senior design team started. The design team contacted Mr. Pettit and asked him if he would be interested in helping out with this year’s project. The conversation included discussing the time frame in which fabrication needed to be done, along with setting up a day to meet with him to go over this year’s design. During this meeting the design team presented the shop drawing to Mr. Pettit. This was done in order to guarantee he would be able to weld the pieces together as needed along with approving the material type that was selected for the project. After this it as decided between Mike and the group that fabrication would start on February 4th and that Mike would provide the team with 4 to 5 hours of his time two to three times a week until the project was completed.

5.1.3 – Purchasing Material

After the shop drawings were approved by the fabricator the time came to purchase the material needed for the project. The group started this task by researching local steel companies in the Fort Wayne area. During the research process the group discovered that prices varied very little from company to company, so to reduce travel time and gas cost the group selected a business close to IPFW campus. Metal Supermarket proved to be the closes location to campus so the group went there first to see if they had the material the group needed. The design team took their order request to Metal Supermarket and met with Teresa, the owner of the business. She quoted our purchase order at approximately $360.00 for all the steel needed, but Andrew was able to talk Teresa into having Metal Supermarket become a sponsor of the senior design project by giving a 50% discount on all the steel purchased. This brought the final cost of all the steel down to $180.00. Teresa also offered to have her business cut all the HSS tubes, rods, and plates down to the required sizes (within a 1/16” tolerance).

From here Andrew was also able to use his marketing skills to convince Spangle Fasteners to donate all the Grade 8 ¼” diameter fasteners needed for the project. Also he was able to get Berry’s Welding (a local fabrication shop) to plasma cut the name plate for the bridge free of charge.

5.2 – Fabrication

After the order for the steel was picked up the group was ready to start the fabrication process. Due to a delay in ordering the steel long with scheduling conflicts with the fabricator the start date for fabrication was pushed back to February 11th after work hours. On this date the group transferred all the steel from the Civil Engineering materials lab to the shop at National Recreation Systems, where all the fabricating would take place. During the fabrication process Mike was in charge of all the welding (Figure 42), Andrew took on the task of drilling holes and grinding (Figure 43), while Nicholas had the duty of cutting members, grinding, and helping Mike (Figure 44). To help simplify how the fabrication process was done a list, following the figures, shows the dates of fabrication and what was accomplished by each person during those dates.

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Figure 42: Mike welding a main truss member.

Figure 43: Andrew grinding a

connection.

Figure 44: Nicholas grinding a plate to

size.

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February 11th, 2013 – 6pm to 9pm o Mike – Welded one main span member and created template off that member o Andrew – Started drilling holes in HSS tubes using a drill press o Nicholas – Grinded members and helped Mike assemble first member

February 13th, 2013 – 5pm to 10pm

o Mike – Used template to tack weld together the rest of the typical span members

o Andrew – Finished drilling holes in all HSS members and started on plates o Nicholas – Used shop tools to cut rods

February 15th, 2013 – 6:30pm to 9pm

o Mike – Altered template in order to tack weld together members meeting at cantilever leg connection

o Andrew – Finished drilling holes in all bridge plates o Nicholas – Used shop tool to cut and notch out plates

February 20th, 2013 – 5pm to 10pm

o Mike – Tack welded together members meeting at the back span legs o Nicholas – Grinded members and prepared cantilever pieces

February 22nd, 2013 – 4:30pm to 9pm

o Mike – Welded one main span member and created template off that member o Andrew – Grinded HSS tubes

DUE TO ILLNESS MIKE HAD TO TAKE A WEEK OFF

March 4th, 2013 – 6pm to 8pm

o Mike – Tack Welded together the cantilever pieces o Andrew & Nicholas – Hand drilled bolt holes that couldn’t be done using drill

press

March 6th, 2013 – 6:30pm to 9pm o Mike – Fully welded all tack welded members o Andrew – Grinded welds after Mike finished full welding o Nicholas – Prepared cross member pieces

March 8th, 2013 – 5:30pm to 10pm

o Mike – Created template for cross members and tack welded them together o Andrew – Bolted to together finished members in order to grind together

uneven surfaces o Nicholas – Reamed bolt holes to insure they could move through connection

easily

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March 11th, 2013 – 6:30pm to 9pm o Mike – Fully welded cross members and weld leg together o Andrew – Grinded welds after Mike finished full welding o Nicholas – Reamed bolt holes and marked members

March 12th, 2013 – 2pm to 4:30pm

o Nicholas & Andrew – Cut M-Bracing member and drilled bolt holes

March 14th, 2013 – 8am to 3pm o Nicholas & Andrew – Finished M-Bracing o Berry’s Welding – Plasma cut end member name plate

March 14th marked the date that the bridge was completely fabricated and ready

for load testing and construction practice. After this date only minor changes or corrections would need to be made which would require Mike help and the use of his shop.

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Section 6: Load Testing

To help ensure that analysis done by SAP2000 was actuate, check weld strength, and test the ¼” bolt size, load testing was done prior to construction practice. This was done by load testing the bridge in three different stages which included loading 500 pounds to the span one day, loading 500 pounds on both the span and cantilever along with preforming a 50 pound sway test another day, and finally fully loading the bridge a few days prior to competition. In all three stages the bridge was loaded based on the worse load case as seen in Figure 45.

Figure 45: Load testing possible locations and worst case.

6.1 – Loading Expectations

The expectations set by the name of the senior design course is to fully load the bridge to what is stated in the competition rulebook. This could be done prior to competition to ensure a successful bridge before competing or the full load could be saved for competition risking a bridge failure as is IPFW’s custom. The group decided to load the bridge prior to leaving for competition.

6.1.1 – Safety

With the goal expectation being to fully load the bridge, the primary expectation is to remain safe while doing so. Throughout the loading processes, safety glasses, hardhats, and steel-toed boots were to be worn at all times. If at any time the loading process became cumbersome or looked as though a problem was arising, loading would be ceased immediately.

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6.2 – Stage One

The first stage of load testing involved loading 500 pounds onto the span of the

bridge to test immediate deflection and ensure the bridge was safe to construct. This was done by first measuring out the load location on the span of the bridge based on Figure 45. From here, the team placed a wooden pallet at this location which would serve as a surface to place the load. Next the team safely started loading the bridge using weighed concrete bags and pieces of concrete blocks until the load equaled 500 pounds. Afterwards the deflection was deflection was measured to be 1/8” and the team concluded that the bridge as safe for construction.

6.3 – Stage Two

The next stage of load testing happened a few weeks after the team had ran a few practices. This stage took stage one and added testing the cantilever along with testing lateral deflection. This time both the span and the cantilever load locations were measured out along with the sway test points. The group first tested the sway by tying a plumb bob onto the sway location and then a quarter was centered under the plumb bob. Next 50 pounds was tied to the bridge by a rope, then the weight was draped over a 2x4 at the same height as the bridge and roughly 2 feet from the bridge, and finally the weight was lowered until the weight was fully supported by the bridge. The plumb bod was then checked to see if it was still over the area of the quarter. If the plumb bob wasn’t over the quarter the team would have considered that a failure and would have to make changes to the bridge. Since the plumb bob was still over the quarter, in both locations, no changes were needed. Next the span was loaded in the same manner as stage one along with adding the loading of the cantilever. Figure 46 shows where the pallets were placed on the bridge which also is where the loading would be placed. After 500 pounds was added to both locations the deflection was measured under both the span and the cantilever, and the bridge did not deflect over 1/8” in either locations.

Figure 46: Stage two, load testing set-up.

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6.4 – Stage Three

In this stage the bridge was to be fully loaded to make sure it would not fail during competition. Since the team already knew the bridge would pass the sway test based on the stage two results there was no need to test it again in this stage. Therefore the team focused on fully loading the span and the cantilever. To ensure safety this would be done in the lab and done using multiple people. Since the group was very limited on material to load the bridge with they had to use concrete blocks that were approximately 100 pounds each along with concrete ready-mix bags once there were no more blocks left. The team first loaded 1500 pounds to the span of the bridge in the worst case scenario and checked the deflection of the bridge. After this, 1000 pounds was loaded on the cantilever. The final result of this load testing can be seen in Figure 47. After the bridge was fully loaded the design team looked it over to pin point where the most amount of deflection was located. As seen in Figure 48, the bridge was deflecting the most in the middle of the span. To combat this deflection the team decided to add fasteners to two connections on both sides of the bridge located at the middle of the bridge.

Figure 47: Stage 3, the bridge fully loaded with random lab material.

Figure 48: Span deflection under the full load.

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Section 7: Construction

To begin the construction process, several variables were taken into consideration to come up with the lowest construction cost as shown below (also refer to section 1.7.5).

CC = [total time (min.)] x [number of builders] x [50,000 ($/builder - min)] + load test penalties ($)

To ensure the lowest possible construction cost, figuring out the most efficient

use of the number of builders and how long it takes to put the bridge together becomes the focus. This is, however, very difficult to estimate because there are so many variables to consider when building the bridge such as: The number or bolts needed, the amount of connections, the order the members go together, and many others. The best way to figure this out was to actually practice putting the bridge together under competition rules and time each run.

The goal was to have a construction cost of $2,500,000 or less. The possible scenarios to achieve this goal as shown in Table 10 below.

Table 10: Time needed to keep the construction cost below $2.5M. Construction Cost Goal ≤ $2,500,000

Builders Time Needed (min) Price per Builder x Minute

3 16.67 $50,000.00 4 12.50 $50,000.00 5 10.00 $50,000.00 6 8.33 $50,000.00

Obviously, with more builders requires less time in order to keep construction cost down. In order to minimize cost, and find the most efficient team, several construction team alternatives were created.

7.1 – Construction Team Alternatives

The construction site is shown previously in Figure 4 in Section 1.5.1 and will be referred to throughout this topic. Note that there are three possible locations for builders to stand during construction: The staging yard and back span and will be known as ‘runners’, the cofferdam, and the cantilever side of the river. When a builder starts at a particular location, they are to stay in that location throughout the entire construction process; that is, you cannot step into or jump over the river. There are to be five different teams made up of three to six builders. These teams will each be practiced twice. The best two teams will then be practiced three more times. The best team of those practices will then be practiced another five or more times to perfect that particular team for competition. The best team is based on whichever team has the lowest construction cost.

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7.1.1 – Team 1

Team 1 will consist of six builders which is the maximum amount of builders that are allowed by competition rules. The team layout consists of two builders in each of the possible locations. Figure 49 below shows the team layout.

Figure 49: Team 1 consisting of 6 builders.

This team utilizes the most builders and therefore requires the least amount of time to put it together in order to meet the construction cost goal. Table 11 below shows the practice times and construction costs of the first two runs.

Table 11: Team 1 initial practice times in run number order. Team 1

Builders Used = 6

Run # Time (min) Construction Cost

1 16.8 $5,040,000.00

2 16.2 $4,860,000.00

Team 1 did not meet the goal time of 8.33 minutes and had a construction cost of nearly twice the goal cost.

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7.1.2 – Team 2

Team 2 will consist of five builders, two at the cantilever, two runners, and one on the cofferdam. This team will allow the difficult cantilever to be built with the assistance of another and will have two runners to ensure everyone can be building at once. The team set-up is shown in Figure 50 below.


This team was thought to be the team that would most likely compete at competition based on theory and predictions of what would happen during construction. It allowed the most difficult part of the bridge to be constructed by two builders and allowed two runners so no one was ever waiting on a member to be passed. The practice times and construction costs of the first two runs are shown in Table 12 below.


Builders Used = 5


1 16.95 $4,237,500.00

2 15.58 $3,895,000.00

Team 2 did not meet the goal time of 10 minutes and therefore did not meet the goal construction cost.

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7.1.3 – Team 3

Team 3 consists of four builders: A single runner, a builder in the cofferdam, and two builders for the difficult cantilever. This alternative was considered ideal for a four person build due to the fact that the cantilever end is the most difficult part to build and would therefore, theoretically, require more help to build it. Below, in Figure 51, shows the layout of Team 3.


This team performed as expected in the first two runs which has results shown in Table 13 below.

Table 13: Team 3 initial practice times in run number order.

Team 3

Builders Used = 4


1 16.33 $3,266,000.00

2 14.33 $2,866,000.00

The second run produced the second lowest construction cost of all of the initial runs but still did not meet the goal construction cost. This then becomes one of the alternative set-up that would move into secondary practices. Another three runs of this set-up were then conducted and produced the following results as shown in Table 14 below.

Table 14: Team 3 secondary practice times in run number order. Team 3

Builders Used = 4


1 14.13 $2,826,000.00

2 14.13 $2,826,000.00

3 13.33 $2,666,000.00

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The best of these runs still did not produce the goal construction cost and was not the most cost-effective practice compared to the other set-up that moved into the secondary practices.

7.1.4 – Team 4

Team 4 will consist of four builders. However, unlike Team 3, there is only a single builder on the cantilever end and a single runner. There are two builders on the cofferdam. This set-up is shown in Figure 52 below.


This team was theorized to perform just less than that of Team 3. The thought was that if there were two people on the cofferdam, the pier would be less important to use and one of those builders could continuously pass members to the cantilever end as they are needed while also supporting the bridge from falling during construction. Also, the cofferdam position uses the most bolts and comes in contact with nearly every member of the bridge. With this being said, this alternative performed better than the group initially thought it would. The results of the first two runs are shown in Table 15 below.


Builders Used = 4


1 17.33 $3,466,000.00

2 14.93 $2,986,000.00

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7.1.5 – Team 5

Team 5 will consist of three builders, one in each necessary location, as shown Figure 53 below. This team utilizes the least amount of builders you can use to build the bridge within competition rules.


Before the bridge was completely constructed for the first time, this alternative

was thought to be improbable. In years past, at least five builders were always used. In the last few years, six builders were used. To consider building with on three builders wasn’t the group’s favorite alternative due to the amount of coordination and strength that would be needed to achieve the goal cost of $2.5M. Table 16 below shows the first two practice times and construction costs.

Table 16: Team 5 initial practice times in run number order.

Team 5

Builders Used = 3


1 29.5 $4,425,000.00

2 18.1 $2,715,000.00

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This set-up surprisingly produced the lowest construction cost of all initial runs despite its lengthy first trial. It still didn’t meet the construction cost goal but it is the closest of all initial runs. This set-up was then practiced three more times in the secondary practices. The results can be seen on Table 17 below.

Table 17: Team 5 secondary practice times in run number order. Team 5

Builders Used = 3


1 18.17 $2,725,500.00

2 16.33 $2,449,500.00

3 15.53 $2,329,500.00

This alternative produced the lowest construction costs and met our goal of $2.5M. This run was then practiced several more times and produced the following results shown on Table 18 below.

Table 18: Team 5 refining practice times in run number order. Team 5

Builders Used = 3


1 15.25 $2,287,500.00

2 16.63 $2,494,500.00

3 14.4 $2,160,000.00

4 14.82 $2,223,000.00

5 13.67 $2,050,500.00

This team set-up turned out to be extremely successful. With each refining run

achieving the construction cost goal and the final run nearly under $2,000,000.

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7.2 – Construction Practice Results

The practice really paid off; the construction cost is close to $2,000,000 and we are able to build the bridge with only 3 builders. A summary of all of the practices is shown in Table 19 below.

Table 19: All practice runs sorted by lowest construction cost.

Summary of Construction Practice Runs

Team # Run Type Builders Used Time (min) Construction Cost

5 Refining 3 13.67 $2,050,500.00

5 Refining 3 14.4 $2,160,000.00

5 Refining 3 14.82 $2,223,000.00

5 Refining 3 15.25 $2,287,500.00

5 Secondary 3 15.53 $2,329,500.00

5 Secondary 3 16.33 $2,449,500.00

5 Refining 3 16.63 $2,494,500.00

3 Secondary 4 13.33 $2,666,000.00

5 Initial 3 18.1 $2,715,000.00

5 Secondary 3 18.17 $2,725,500.00

3 Secondary 4 14.13 $2,826,000.00

3 Secondary 4 14.13 $2,826,000.00

3 Initial 4 14.33 $2,866,000.00

4 Initial 4 14.93 $2,986,000.00

3 Initial 4 16.33 $3,266,000.00

4 Initial 4 17.33 $3,466,000.00

2 Initial 5 15.58 $3,895,000.00

2 Initial 5 16.95 $4,237,500.00

5 Initial 3 29.5 $4,425,000.00

1 Initial 6 16.2 $4,860,000.00

1 Initial 6 16.8 $5,040,000.00

In conclusion, team five will be used for competition. Our group could be one of the few groups only using three builders.

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Section 8: Aesthetics

Aesthetics is honestly a subjective category for this project. On one hand, it is a judged category for the competition (although it is only a tie-breaker) but on the other hand, it costs a significant sum of money and an even more significant amount of time to commit to. This is generally the last thing the group does before leaving for competition and, in years past, has taken until the day of competition to complete. All of the display criteria for the competition and our ideas and concepts will be covered throughout this section.

8.1 – Display Criteria

In the competition, as talked about throughout Section 1.7.1, display will be judged. This required the creation of a poster meeting specific requirements and the general look of the constructed bridge. Welding and fabrication aspects are not to be judged because some schools have professional fabricators while other schools do everything themselves.

8.1.1 – Poster

The poster required several things as shown in the Section 1.7.1 and will not be discussed here. It was a requirement for the display judging and is something that IPFW has never created which showed pride in the school. This year, the poster was primarily designed by April Bobeck, a graphic designer working at Biomet and a friend. All of the content needed for the poster was given to April in the format she asked for and she organized several different concepts. The final poster design is shown below in Figure 54 and was displayed with the bridge at competition.

Figure 54: The final poster design for competition.

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8.1.2 – Bridge Finishing

The rest of the display score was based on how the bridge looked, that is, the physical appearance of the bridge. The style, the paint, and how dimensionally square the bridge appears. There were several paint and finishing ideas we were working with and they will be discussed throughout Section 8. The bride also needed to display the name of the school on the bridge in one inch lettering. In past years, we have failed the display category due to only displaying the name ‘IPFW’ on the bridge. In order to receive credit for the display category, the full name of the school must appear on the bridge. It took us a few days to come up with a solution to fit the name ‘Indiana University – Purdue University of Fort Wayne’ on the bridge but the final product ended up becoming the final cross member of the back span section as shown in Figure 55 below.

Figure 55: The name plate as a member of the bridge.

8.2 – Paint Ideas

To paint the bridge, there were two realistic options: Spray paint the bridge ourselves or find a company willing to paint the bridge with their own equipment and labor. To have something painted, we estimated that most auto-body shops would charge nearly $750. This is completely unrealistic to fit within our budgets. The group decided to find an auto-body shop willing to donate the paint, facilities, and labor. This would be the only way for us to have it painted professionally. To paint the bridge ourselves, it would take several hours of work and several hours to let the paint dry. Based on past experience, the spray paint jobs that we have done in the past have looked poor at best.

8.2.1 – In-Home Painting

The group discussed in-home painting and didn’t want to do it if we didn’t have too. Spray painting looks tacky and doesn’t really show off the final product the group had been working on for the past 8 months. This was a last resort option if there was no other option. The group also discussed not painting the bridge at all. If the bridge could be degreased and polished enough, the silver color of the steel would serve as the desired color of the bridge. As learned from other schools that are very competitive, painting the bridge adds a significant amount of weight to the bridge which in turn hurts your final score. Most schools that are very competitive do not paint their bridges for this fact so this was considered more than spray painting.

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8.2.2 – Professional Painting

To have the bridge professionally painted would be ideal. It would look amazing and really show off the work we have put into the project. This option is only applicable if we could find a company to donate the shop and skills to paint the bridge for us.

A company in Fort Wayne was contacted in January and showed interest in helping; the group was hopeful that the bridge would finally look professional. Because the possibility to have the bridge painted, the group came up with three possible paint schemes as shown in Figures 56 – 58 below.

Figure 56: Paint scheme 1.



The final paint scheme chosen was to be paint scheme 3 due to its school spirit significance.

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8.3 – Final Product

As the project neared competition, the auto-body shop which volunteered to paint the bridge was contacted several times. After a week of calling them with no response or reply, the group decided they would have to do the finishing themselves. Not willing to spend money on paint, the group looked through the lab to find the paint used last year. There wasn’t very much left but the group decided to try and make it work.

Each member of the bridge was lightly grinded on all sides. It was then polished on all sided with 120 grit sandpaper to really make the steel shine. Then, round rods on the insides of the members we painted dark blue (mostly because they were very difficult to polish). To paint just the inside dark blue, the polished portion of the members must be taped completely. Figure 59 shows the members being taped before painting began.

Figure 59: The taped members before painting.

Once the members were painted and polished the final product looks as shown below in Figure 60.

Figure 60: The final product as shown at competition.

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Section 9: Competition

Competition took place on April 20th, 2013 at Trine University, Angola, IN. The competition had several parts to it and took from 6:30am to 7:00pm. There is also a meeting the night before to go over all final competition clarifications.

This year, there were 18 bridge teams competing in our conference; this is the most bridges that have ever competed in any regional conference across the United States to date. Among us were 3 schools that frequently qualify for national competition: The University of Wisconsin – Madison, Milwaukee School of Engineering, and Purdue University. We knew that the goal of making it to national competition this year would not be easy.

9.1 – Captains Meeting

At the captains meeting, generally only the captains of each group attend to go over any final questions or competition concerns. This year, most groups, including ours, brought the whole team. There were several confusing rules (mostly about faying surface connections) that people had questions about. Our group, along with Madison – Wisconsin, were the most versed groups on the rulebook there having an answer to every question asked when the judges struggled to answer. The display areas and competition order were decided at this meeting and our group was given the back corner display area and the third starting time.

9.2 – Display

The group arrived at the designated area at 6:45am and began unloading into our designated display area. The bridge was assembled and the poster was set upon an easel. Several groups that began putting their bridges together prior to us were still not close to finishing their relaxed build of their bridges; this inspired confidence in our team. The following Figures 61 – 62 show the display area before and after the group was ready for display judging.

Figure 61: The bridge, ready for display construction.

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Figure 62: The completed display area.

It can be noted that our bridge received a lot of attention from all schools attending and that during display judging, a judge walked into our area and turned to another judge saying but one word in excitement, “Aesthetics.”

9.3 – Construction

After display judging, as the group’s turn came to construct, the bridge was carried to the staging yard in the construction site as shown in Figure 63 below. At this point is where the competition truly starts.

Figure 63: Carrying the bridge to the construction site.

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9.3.1 – Preparation

Once the bridge was in the staging yard, it was disassembled and organized in compliance with the rulebook. After the group was fully prepared, the construction judges examined the members of the bridge ensuring each member fit into the designated box according to the rules. They also ensure each tool was acceptable and each fastener was set on the floor in accordance with the rulebook. The bridge passed all member dimensions and the staging preparation was set-up without penalty or question. In Figures 64 – 67 below, the staging yard preparation is shown.

Figure 64: Disassembly in the staging

yard.

Figure 65: Final preparations being

finished.

Figure 66: Judges asking question

about the construction team. Figure 67: Last group meeting

before construction. Once the judges gave us the permission to start, the group assumed the position and timed construction began.

9.3.2 – Construction

The construction begins when all three members, Dustin Lambert, Andrew Hilty, and Nicholas Fenton were in the position as the runner, cofferdam, and cantilever respectively. Ethan Hess, the team captain, stood on the sidelines with the judges and commenced competition by saying, “Start.”

Throughout competition, the runner is constantly sprinting back and forth to get members to the other builders as quickly as possible. The left span of the bridge was constructed first from the cantilever to the back span end of the bridge. Doing this

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allows each builder to be able to work on a portion of the bridge at once. Dustin, the runner, would work on the back portion of the bridge and whenever either builder was ready for the next member, they would yell the name of the member they needed. Dusting would then run to grab the member, pass it to the cofferdam and then continue constructing until the next member was needed.

Once the left span of the bridge reached the cofferdam, a temporary pier was set in place to support the bridge so each builder could continue to use both hands to construct. When the span reached the back portion and the back leg was near to be placed, the bridge began to wobble and nearly fell to the floor. This had never happened in practice and was caused mostly because of nerves. Each builder took a deep breath, stabilized the bridge and continued construction. At this point, focus was on constructing the right span of the bridge back to the back span so the fourth leg could be placed and the pier could be removed.

Once all legs were on the ground, the pier was removed and cross members became the focus. At this point, all builders are rushing as quickly as possible to tighten the fasteners and ensure all bolts also had nuts on them. This was a responsibility of the team captain. Throughout construction, Ethan was watching that each bolt also had a nut on it and that the nut was tight enough that while using impact wrenches on other connection, the nuts would not vibrate off.

When every member was connected to the bridge, the impact wrenches were used to tighten every connection as quickly as possible and when the team thought to be completely finished tightening, we raised our hand and Ethan told the judge that we were finished. At this point, construction time was stopped and neither builder could touch the bridge. The total construction time was 17.20 minutes resulting in a potential construction cost of $2,580,000 which was just over the goal construction cost. Figures 68 – 77 below show a summary of the construction process.

Figure 68: Running a member and the

pier to the construction site.

Figure 69: Passing members across the

river.

Figure 70: Construction the left span of the bridge starting at the cantilever.

Figure 71: Continuing to build the left

span to the back span leg.

Figure 72: Placing the first back span

leg.

Figure 73: Constructing the right span

of the bridge.

Figure 74: Placing the last leg on the

back span abutment.

Figure 75: Adding cross-members

throughout.

Figure 76: Tightening the fasteners

with impact wrenches.

Figure 77: The last finishing touches.

The team was excited to be finished constructing however several things

throughout construction went wrong resulting in several penalties as listed: There was a spare pile of bolts and nuts in the fastener zone in the staging

yard that was kicked at the beginning of construction causing 6 bolts to exit the construction site. This cause 1.5 minutes worth of penalty time.

5 more nuts/bolts and a socket were dropped throughout competition causing another 1.5 minutes of penalty time to be added.

A builder touched the river with their foot for a 0.5 minute penalty.

These were all noticed by judges throughout competition but there were more unexpected penalties soon to occur.

Once construction was completed, two builders may inspect the bridge for any mistakes, missing bolts, or things they would like to change. Through inspection the group noticed a connection missing a bolt entirely and at the last second during construction, a socket had stuck to a bolt while tightening. Repair time, unfortunately, had to be taken to fix the mistakes.

9.3.3 – Repair

Repair time adds two minutes of penalty time and then twice the amount of time taken during repair. However, because only two things needed to be fixed, the amount of repair time was .32 minutes. This was then doubled and two minutes were added for a total of 2.63 minutes of penalty time.

The total construction time after all penalties was then 23.33 resulting in a construction cost of $3,500,000. This was $1M over the construction cost goal and was mostly due to nerves of competition.

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9.4 – Loading

After the construction portion of the competition was over it was time to move onto the loading stage. During this part of the competition each school is required to weight their bridge followed by running it through a series of loading test. These loading tests included a lateral load test, back span load test, and a cantilever load test. Each team must provide the workers necessary to run these test safely while being monitored by a group of judges.

9.4.1 – Lateral Load

The first load test each team must pass is the lateral load test which is used to determine if a bridge is safe for construction. During this test each team uses a testing device, shown in Figure 78, which attaches to the side of the bridge at one end and has a hanging 50 pound weight hanging at the other end. The judges mark the testing location on the appropriate side of the bridge along the back span based on dice roll prior to construction portion (discussed in section 1.6), which happened to be the left side of the bridge for this year’s competition. After the testing location was marked a plumb bob was attached and centered over a1 inch diameter circle followed by attaching the testing apparatus. The team then lined up the testing device and slowly lowered the 50 pound weight until the bridge was fully supporting the weight. The judges then checked to see if plumb bob was still within the circumference of the 1 inch diameter circle. If the plumb bob was outside of the circle the bridge would be deemed unsafe for construction and the team would be disqualified from the competition. The IPFW Bridge Team experienced very little deflection and was able to move onto the next load test.

Figure 78: The lateral load test.

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9.4.2 – Back span Load

The second part of the load test was to load the back span of the bridge with 1500 pound using 25 pound weights. The judges once again measured the loading location based on a dice roll which had decided that the bridge would be loading 7 feet from the back of the bridge. A 50 pound piece of decking support was centered over this location and the deflection measurement equipment was attached. Once this was done the team then started loading the 25 pound weights one at a time which can be seen in Figure 79. During this process the judges had to observe the deflection measurement to insure the bridge wasn’t deflecting over 3 inches (automatic disqualification), that the plumb bob was still within the 1 diameter circle (automatic disqualification), along with determining if the bridge was safe to continue to add weights to (automatic disqualification is deemed unsafe). After the team reached the total weight of 1500 pounds the judges took a deflection reading of 0.633 inches at the back span and a 0.474 inch reading from the cantilever and the prepared for the next phase of loading.

Figure 79: The back span loading.

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9.4.3 – Cantilever Load

For the final stage of the load testing each team is required to attempt to place a total load of 1000 pounds onto the cantilever end of the bridge. Just like in the previous test the judges marked the testing location which was 1 foot from the end of the cantilever (decided by dice roll) and the decking support was centered over this location. Like the back span, the team quickly loaded the 25 pound weights to the top of the decking support (Figure 80) until they reached a total weight of 1000 pounds. During this process the judges once again observed the loading and the deflection to make sure the bridge was safe to continue. After the 1000 pound load was placed on the end of the cantilever the judges quickly measured the cantilever deflection (.0520 inch) and the back span deflection (0.542 inch) were taken again. At this point it was the first time that IPFW had taken a bridge to competition and successfully constructed and fully loaded a bridge. After a short celebration the team quickly unloaded the bridge (safely) and removed the bridge from the testing area so that the next team could move their bridge into it.

Figure 80: The cantilever loading.

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9.5 – Results

The results of the entire competition are kept track on a spreadsheet created by the AISC head judges but is too large to list in the paper. Also, an electronic copy of the spreadsheet with each school’s scores on them have yet to be sent to the participating schools. Because of this, a summary of this groups’ results is shown in Table 20 below.

Table 20: A summary of the conference results.

Conference Results Number of Builders 3 Bridge Weight (lbs) 235.6 Construction Time (min) 17.20 Dimension Violations 0 Weight Penalties (lbs) 0 Construction Penalties 13 Construction Penalty Time (min) 3.50 Total Bridge Weight 235.6 Repair Time Taken (min) 0.32 Max Back Span Deflection (in) 0.633 Total Repair Time Added (min) 2.63 Cantilever Deflection 1 (in) 0.474 Cantilever Deflection 2 (in) 0.520 Total Construction Time (min) 23.33 Aggregate Deflection (in) 1.627 Total Construction Cost $3,500,000 Total Structural Cost $3,983,000

Overall Project Cost $7,483,000

With these results, IPFW achieved the highest placement in school history with the overall project cost of $7,483,000: 4th place! That is, 4 out of 18 which places us within the top 25 percentile. Along with achieving 4th place, several other competition accomplishments were achieved as follows:

IPFW received second place in the display category. IPFW was the only school to construct the bridge with three builders. This year was the first year that IPFW completed every stage of competition

and was not disqualified. Many complements on the bridge were received from other students and

professors considering how young IPFW’s civil engineering program is.

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Section 10: Sponsors and Special Thanks

This year, many local Fort Wayne companies stepped in to help our project become successful. Throughout each semester, both group members diligently promoted their project to companies with potential to help it become successful and nearly every company asked to donate or volunteer materials, time, experience, and money agreed willingly. This project could not have succeeded in the way that it did without the help of the following companies and individuals:

Mike Pettit of National Recreation Systems for welding Best Buy at Appleglen for the $1000 cash donation Teresa Starnes of Metal Supermarkets for the 50% discount on materials IPFW’s Department of Engineering for purchasing a drill press and abrasive saw AISC for the $250 cash donation Tim at Spangle Fasteners for donating all Grade 8 bolts and nuts Berry’s Welding for the custom, plasma-cut name plate

Without the above mentioned help, this project would have been nearly impossible but there were also several individuals who volunteered their time and knowledge to help with the project. A special thanks to the following individuals:

Ethan Hess for coming to every practice, helping with fabrication and painting, and being the team captain

Dustin Lambert for coming to every practice and helping with fabrication and painting. Ryan Prince for coming to nearly every practice Levi Rednour for coming to the six person practices Dr. Suleiman Ashur for his financial advice and project guidance throughout each

semester Kaye Pitcher for advising the group activities and help with lab activities Dustin Lamberts’ parents for housing and feeding the bridge team during the

competition weekend Mike Pettit for his volunteering his time to fabricate after a full day’s work this year and

last Teresa Barnes for always having our material ready before deadlines Boyd Berry for his enthusiastic donation of the name plate

Finally, a very special thanks goes to Dr. Mohammad Alhassan for always guiding the group in the right direction with technical and personal advice. Without his help throughout the years of schooling the group has had with him, none of this project would have come to fruition. Thank you so much.

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Section 11: Future Project Recommendations

For the project to continue to succeed throughout the years to come in the ASCE program at IPFW, some recommendations can be made to help future projects improve in succession.

11.1 – Rulebook and Clarifications

Each member of the team should know the rulebook like the back of their hand. And should be read at the following times for clarification:

o Before the design process o After a final design has been chosen o During the fabrication process o During the construction process

Clarifications are posted weekly to the steel bridge website and can be emailed to each group member every time they are posted.

o Knowing these clarification help find the best ways to design and construct the bridge.

Ask the head judge any question you come up with; they nearly always reply within 1 business day and can clear up any confusion throughout the project.

11.2 – Bridge Design

Come up with several alternative design (hand drawn) and discuss possible benefits and detriments each design poses.

o Select several alternatives to draw in the analysis software. Make changes to successful alternatives until the best results are received.

Besides construction time, bridge weight generally has the highest influence on the total cost of the project.

o Minimize weight as much as possible.

11.3 – Connection Design

For each alternative bridge design attempt to develop a basic AutoCAD drawing of the main connection that be used for that bridge.

Depending on the rules, attempt to develop connections can support the bridge without using bolts or a minimum of only one bolt.

Design connections that don’t depend on the tightening of a fastener to form a sturdy connection.

o This will require very precise drilling. Try to avoid all bolted connections that are perpendicular to the surface of the ground to

help avoid bolts and nuts from being dropped. Either free hand draw or use AutoCAD to draw ALL connection ideas and save them for

future reference. o This is important in helping all team members understand how a connection idea

works. o All connection ideas have the potential to be revisited and altered to form better

connections. If possible attempt to fabricate one connection prior to bridge fabrication in order to

determine how easily it can be made and how ridged the final product actually is.

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11.4 – Fabrication

Look into getting a company to mill connections for the bridge. These connections will be identical and offer an incredibly small margin of error. Nearly every school that goes to nationals has their connections milled.

11.4.1 – Material

If possible in accordance with the rules, look into using circular HSS members. They are much lighter than the comparable HSS square or rectangular sections and offer comparable strength.

¼” plates are overkill. Ensure that all fastener holes are far enough from the edge or materials and at most only half of that thickness will be needed.

11.4.2 – Welding

Throughout the welding process ensure all materials are cut and/or drilled to spec; this allows the fabricator to be continuously welding which is something the students generally aren’t able to do.

If any parents are skilled welders and live close by, which can be a life saver when the group is coming close to deadlines and the professional fabricator cannot make time; parents can always make time to help.

11.5 – Load Testing

Load test as early as possible and load the full weight required in competition. o Load test the worst case scenario as noted by the analysis software.

11.5.1 – Materials Needed

Talk to an advisor early about getting the proper material to load test. o 25 pound angle steel bar is what is generally used at competition and is

much easier to load than concrete beams and cement bags. These angle bars could possibly be borrowed or donated by a local company.

11.6 – Practice

Practice all possible alternatives at least twice. o You can never be 100% sure a specific team set-up will be unsuccessful after only

one single practice. Practice the best alternative as much as possible before competition in front of a crowd if

possible. o Nerves will get the best of you at competition.

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11.7 – Competition

Eat breakfast on the day of competition. o Steady hands during construction is the difference between mistakes and

success. Despite how fast you’re putting the bridge together, spend ten seconds double

checking everything before calling time. o The last thing you want to do it take ‘repair’ time.

While transporting the constructed bridge to weighing and loading, be very careful not to bump into anything and lift as close to the supports as possible.

o This will keep the connections as rigid as possible before loading. During loading, use a single loader on the opposite side of the bridge as the

weights. o This allows the quickest loading to occur.

The longer you take, the more deflection occurs due to creep. During loading, have a team member ensure the weights are perfectly centered

on the bridge. o Stress distribution can cause brittle failure at the connection.

This is why you wear steel-toed boots.

11.8 – Sponsors and Donations

Contact all companies who have previously donated; they will be familiar with the project and have already expressed the desire to help. They include:

o Metal Supermarkets (Teresa Starnes) o National Recreation Systems (Mike Pettit) o Spangle Fasteners (Tim) o Berry Welding (Boyd Berry)

Contact other engineering firms in Fort Wayne about monetary donations although most companies are much less likely to donate money than they are materials.

Big companies such as Lowes or Home Depot are not even worth talking to. o They have far too long of a process before anything can be finalized and donated

to be a viable option.

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Section 12: Conclusions

Working through the process of developing alternative designs and comparing them to each other proved to be successful in helping select a bridge design for the 2013 Great Lakes Regional Conference Steel Bridge Competition. The selected bridge was Alternative 3 which was a refinement of the bridge used in the 2012 competition. Alternative 3 meets all the dimensioning requirements for both the bridge as a whole and for the individual members. The total length of the bridge is 16’ 6” with a total weight of 235.6 pounds and is composed of 39 members. Using SAP2000 to run an analysis on the bridge, it was determined that it would not fail under the 2500lbs load that it will be subjected to at competition. It also showed that bridge will pass lateral loading deflection which will keep it from being disqualified during the early parts of testing.

The bridge passed the load testing application and was put together more than thirty times throughout the second semester. With practice comes a faster construction time and a less likelihood to make mistakes during construction. The fastest bridge construction was 13.67 minutes and was built with three people during practice having a construction cost just over $2M which met the $2.5M goal.

At competition, the bridge was put together by three builders in 23.33 minutes after penalties and had a construction cost of $3,500,000 which was more than the goal construction cost by $1M. The aggregate deflection of the bridge was 1.627” and the bridge weight 235.6 pound leading to a structural cost of $3,983,000.

The total competition cost of the project was $7,483,000. IPFW place 4th in the bridge competition of 18 teams; this is the best finish in school history and the only bridge to not be disqualified or to fail under loading.

The actual project cost was $0 due to the amount of donations received from local companies. The project actually allowed ASCE to bank over $500 for next year’s bridge because of the contributions made.

The project was a success.

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Section 13: References

1. Steel Construction Manual. N.p.: American Institute of Steel Construction, 2011.

Print.

2. Segui, William T., and William T. Segui. Steel Design. Toronto, Ontario, Canada: Thomson, 2007. Print.

3. "ASCE - AISC Student Steel Bridge Competitions." ASCE - AISC Student Steel Bridge

Competitions. N.p., n.d. Web. 14 Dec. 2012

4. National Student Steel Bridge Competition. American Society of Civil Engineers, n.d. Web. 14 Dec. 2012. <http://www.nssbc.info/>.

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Section 14: Appendices

Appendix A: 2013 ASCE / AISC Steel Bridge Competition Rulebook

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STUDENT STEEL BRIDGE COMPETITION

2013 RULES

MISSION The mission of the Student Steel Bridge Competition (SSBC) is to supplement the education of civil engineering students with a comprehensive, student-driven project experience from conception and design through fabrication, erection, and testing, culminating in a steel structure that meets client specifications and optimizes performance and economy. The SSBC increases awareness of realworld engineering issues such as spatial constraints, material properties, strength, serviceability, fabrication and erection processes, safety, aesthetics, project management, and cost. Success in inter-collegiate competition requires application of engineering principles and theory, and effective teamwork. Future engineers are stimulated to innovate, practice professionalism, and use structural steel efficiently.

WELCOME

ASCE and AISC support and encourage the equitable opportunity for participation by all interested and eligible individuals in the Student Steel Bridge Competition without regard to race, ethnicity, religion, age, gender, sexual orientation, nationality, or physical challenges. Bridge teams should be inclusive and open and fair to all interested and eligible participants. Organizing sponsors of the Student Steel Bridge Competition are � American Institute of Steel Construction (AISC) � American Society of Civil Engineers (ASCE) Co-sponsors are � American Iron and Steel Institute (AISI) � Bentley Systems, Inc. � Canadian Institute of Steel Construction (CISC) � DS SolidWorks Corp. � James F. Lincoln Arc Welding Foundation � National Steel Bridge Alliance (NSBA) � Nelson Stud Welding � Nucor Corporation � Steel Structures Education Foundation (SSEF) Any revisions to the rules in this document are incorporated in clarifications that are published at the bridge competition web site, http://www.aisc.org/steelbridge. Revisions and clarifications do not appear in this document but are considered formal addenda to the Rules.

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Section 1 INTRODUCTION

Students design and erect a steel bridge by themselves but may seek advice from faculty and student organization advisers. Students gain maximum benefit if they fabricate the entire bridge themselves. However, because appropriate shop facilities and supervision are not available at all universities, students may use the services of a commercial fabricator provided that they develop the work orders and shop drawings, and observe the operations. Students are encouraged to maximize their involvement in fabrication. Safety is of primary importance. AISC and ASCE request that competitors, advisers, hosts, and judges take all necessary precautions to prevent injury to competitors, judges, host personnel, and spectators. This document describes the competition and states the rules for competitions conducted during 2013 at both conference and national levels. It is available at http://www.aisc.org/steelbridge, together with revisions, clarifications, other information, and the form for submitting requests for clarifications. Information at this site takes priority over any other source except as noted herein. The rules are changed every year to enhance the competition and ensure that competitors design and build new bridges. The rules are intended to be prescriptive but may require some interpretation. The procedure for requesting clarification of the rules is described in section 14, “Interpretation of Rules.” Competitors, judges, and host personnel are encouraged to read this Rules document thoroughly from beginning to end and then review the Competition Guide at http://www.nssbc.info. That site also is the source of the official scoring spreadsheet which generates forms for recording data. Judges should be familiar with these forms prior to the competition. Members of the Student Steel Bridge Rules Committee are � Michael F. Engestrom, Technical Marketing Director, Nucor-Yamato Steel � Nancy Gavlin, S.E., P.E., Director of Education, AISC � Jennifer Greer-Steele, ASCE Committee on Student Activities Corresponding Member � Frank J. Hatfield, P.E., Professor Emeritus, Michigan State University � John M. Parucki, Structural Steel Consultant � Brian Raff, Marketing Director, NSBA � Don Sepulveda, P.E., Executive Officer, Regional Rail, Los Angeles County Metropolitan Transportation Authority � Ping Wei, Director of Educational Activities, ASCE � James C. Williams, P.E., Professor, University of Texas at Arlington

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Section 2 EXECUTIVE SUMMARY

Civil Engineering students are challenged to an inter-collegiate competition that includes design, fabrication, and construction of a scaled steel bridge. Participating students apply engineering principles and theory, and gain practical experience in structural design, fabrication processes, construction planning, organization, project management, and teamwork. The rules of the competition simulate a request for proposal that requires a scaled model to demonstrate the efficacy of competing designs. Section 3, “Problem Statement,” relates the rules to realistic challenges encountered in bridge design and construction. Standards for strength, durability, constructability, usability, functionality, and safety reflect the volumes of requirements that govern the design and construction of full-scale bridges. Criteria for excellence are represented by the award categories of stiffness, lightness, construction speed, display, efficiency, and economy. Competition judges and the Rules Committee take the role of the owner and have the authority to accept and reject entries. The safety of competitors, judges, host personnel, and spectators is paramount. Risky procedures are prohibited. Load testing is stopped if sway or deflection exceeds specified limits, or if collapse is deemed imminent in the opinion of the judges. Bridges that cannot be constructed and loaded safely are withdrawn from competition. In addition, the rules identify and penalize construction errors that represent accidents in full-scale construction. The rules of the competition accommodate a variety of designs and allow innovation. Designers must consider carefully the comparative advantages of various alternatives. For example, a truss bridge may be stiffer than a girder bridge but slower to construct. Successful teams analyze and compare alternative designs prior to fabrication using value analysis based on scoring criteria. The Student Steel Bridge Competition provides design and construction planning experience, an opportunity to learn fabrication procedures, and the excitement of networking with and competing against students from other colleges and universities.

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Section 3 PROBLEM STATEMENT

The new Hill Music Hall and Marian Paroo Memorial Library sparked revitalization of the River City waterfront, with restaurants, theaters, and luxury condominiums scrambling for space in the old brick warehouses. The resulting vehicle traffic now exceeds the capacity of city streets. Therefore, the River City Development Corporation (RCDC) is requesting design/build proposals for a bridge to provide direct access from suburbs across the river. Accelerated Bridge Construction (ABC) is mandated in order to minimize travel delays and financial losses to waterfront businesses caused by disruption of traffic during construction. As an attractive signature structure for the redeveloped waterfront, the new bridge will provide clearance for tour boats, and will cantilever over the historically significant billiard parlor. RCDC specifies steel because fast erection is essential to ABC, and because steel’s durability and high level of recycled content contribute to exceptional sustainability. The high strength to weight ratio of steel assures an efficient structure, and prefabricated deck panels expedite ABC. The congested urban site restricts location and size of the staging area, and the dimensions and weight of equipment and transported material are limited by narrow, thinly paved streets. Navigation must not be restricted by construction barges or permanent abutments in the river. However, a permit has been obtained for a temporary cofferdam. The scope of the bridge contract does not include foundations, approaches, deck panels, or the cofferdam. Your company’s proposal is among those that the RCDC has deemed responsive, and winning the contract would be a step toward leadership in ABC. Each competing firm is requested to submit a 1:10 scale model to demonstrate its concept. Models will be erected under simulated field conditions and will be tested for stability, strength, and serviceability using standardized lateral and vertical loads. The RCDC has selected a panel of engineers to judge the models by multiple criteria including durability, constructability, usability, stiffness, construction speed, efficiency, economy, and attractiveness. The contract will be awarded to the company whose model satisfies specified requirements and best achieves project objectives. Any attempt to gain advantage by circumventing the intent of the competition as expressed by the Rules, including this Problem Statement, will be grounds for rejecting the model and terminating the company’s eligibility.

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Section 4 ELIGIBILITY

4.1 LEVELS OF COMPETITIONS There are two levels of competition: conference and national. Conference competitions are held in conjunction with ASCE annual student conferences. Outstanding performance in conference competitions qualifies eligible teams for the national competition. 4.2 CONFERENCE COMPETITIONS 4.2.1 Only one bridge per college or university may compete in an ASCE student conference, and a college or university may compete in only one ASCE student conference. 4.2.2 The ASCE student organization that is hosting a conference may invite guest teams, which are teams from colleges or universities that do not have ASCE student organizations, or from official ASCE student organizations that are assigned to different conferences. Conference assignments are listed in the ASCE Official Register. 4.2.3 A team shall consist only of undergraduate and graduate students in good standing with their ASCE student organization. This requirement is waived for guest teams. 4.2.4 The official scoring spreadsheet shall be used, and all teams (including guest teams) shall be listed on that spreadsheet. The official scoring spreadsheet may be downloaded from http://www.nssbc.info. 4.2.5 The host student organization shall promptly submit the completed official scoring spreadsheet for a conference competition to [email protected]. Teams from that conference will not be invited to the National Student Steel Bridge Competition (NSSBC) until the spreadsheet is received. 4.3. NATIONAL COMPETITION 4.3.1 A team is not eligible to be invited to compete in the NSSBC if it is (1) a guest team as defined in 4.2.2, or (2) from an organization that is not in good standing with ASCE, or (3) from an organization that has not satisfied ASCE requirements regarding participation in its conference, or (4) ruled to be ineligible to complete its conference competition. ASCE requirements for good standing and for conference participation are reprinted in 4.4 but are subject to change. 4.3.2 The maximum number of eligible teams from a conference that will be invited to compete in the NSSBC is based on the number of teams at that conference that competed (that is, presented bridges and staged them for timed construction) but not including guest teams as defined in 4.2.2. (1) Only the single best scoring eligible team will be invited from a conference in which two, three or four non-guest teams competed. (2) The two top scoring eligible teams will be invited from a conference in which five to ten non-guest teams competed. (3) The three top scoring eligible teams will be invited from a conference in which eleven or more non-guest teams competed. 4.3.3 Teams are not invited to compete in the NSSBC as guests. 4.3.4 Only one bridge per college or university may be entered in the NSSBC.

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4.3.5 A team must consist only of members who are or were students in good standing with their ASCE student organization during all or part of the academic year leading up to the NSSBC. 4.4 ASCE NATIONAL COMPETITION ELIGIBILITY REQUIREMENTS ASCE requirements for good standing and for conference participation, as they existed in July, 2012, are reprinted in this sub-section (4.4) but are subject to change. The current version is at http://www.asce.org/studentorgs/competition-eligibility/. ASCE has sole authority for determining and enforcing these requirements; questions should be sent by e-mail to [email protected]. “In order to facilitate broader participation by ASCE Student Organizations in Student Conference activities, the ASCE Committee on Student Activities (CSA) stresses the importance of the conference as an event that is much more than a qualifying round for national competitions and highlights the required events at a conference. As such, the following qualifications are required of all ASCE Student Organizations in order to participate in an ASCE-sponsored National Competition. An ASCE Student Organization must: � Be in good standing with ASCE (annual report and annual dues submitted and received by ASCE prior to the start of the Student Conference). � Attend and participate in their assigned Student Conference as shown through their school's: a) Good faith participation in the Student Conference Business Meeting (i.e. on time attendance by at least one student representative); b) Good faith participation in the Student Conference Paper Competition (i.e. submission and presentation by at least one member of the ASCE Student Organization); and c) Meeting any additional requirements of Student Conference participation set by the Student Conference at the previous year's business meeting or in their written and approved by-laws, standing rules, or constitution. Note: The concrete canoe design paper/oral presentation does not count as an entry into the Student Conference Paper Competition.”

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Section 5 RULE CHANGES

The following items in this section (5) identify some of the major changes from the 2012 rules. Not all changes are included. Contestants, hosts, and judges are cautioned to read this entire document carefully and disregard rules and clarifications from previous years. (1) Scoring and penalties have been revised. (2) Bridge and site dimensions are different. (3) Interlocking connections that were acceptable last year, such as typical dovetails, tees, and those that lock by twisting, will be penalized this year. (4) Responsibilities are assigned to team captains. (5) Bridges that collapse or deflect excessively will be withdrawn from competition.

Section 6 SAFETY

Safety has the highest priority – risk of personal injury will not be tolerated. Sub-sections 9.2, 10.1, 11.2, and 11.3 of these Rules identify hazardous conditions and actions that will result in withdrawing a bridge from competition if not corrected. Judges will document these safety violations by checking appropriate boxes on the data entry forms. Judges also must comply with and enforce the safety regulations for load testing in sub-sections 12.1, 12.2, and 12.3. Sub-sections 12.4, 12.5, and 12.6 specify penalties for bridges that exhibit unsafe characteristics during load testing. Judges are empowered to halt any activity that they deem to be hazardous. If a bridge cannot compete safely, it must be withdrawn from competition. If the problem is not anticipated by the sub-sections listed in the preceding paragraph, the judge should write a brief description of the problem on the data form.

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Section 7 SCORING

7.1 RECORDING DATA AND SUBMITTING SCORES Scoring data should be recorded for every team that competes, using judges’ data forms printed from the official scoring spreadsheet downloaded from http://www.nssbc.info. Data from those forms are then entered on the spreadsheet. After all scoring information has been collected for a team, the scoring official reviews data entry with the captain of that team. The team captain is given adequate time to verify the data before signing the form. The completed official scoring spreadsheet for a conference competition shall be submitted to [email protected] by the host student organization. Conference results are not final until the spreadsheet is submitted. Questions and comments regarding the spreadsheet should be sent to [email protected]. Judges’ data forms shall be retained by the host student organization for two weeks after the competition. 7.2 CATEGORIES OF COMPETITION 7.2.1 Categories of competition are display, construction speed, lightness, stiffness, construction economy, and structural efficiency. In addition, overall performance is rated. 7.2.2 Display 7.2.2.1 Display is the tie-breaker for all categories of competition. Judges shall not declare ties in display. The bridge is displayed exactly as it will be erected during timed construction. Display is judged by the following criteria 7.2.2.2 Appearance of bridge, including balance, proportion, elegance, and finish. Quality of fabrication, including welding, shall not be considered because some bridges may be fabricated professionally rather than by students. 7.2.2.3 Permanent identification of the bridge consisting of the name of the college or university exactly as shown on the ASCE student web site, http://www.asce.org/Content.aspx?id=14843. The name must appear on member(s) of the bridge in letters that are all, by measurement, at least one inch high, and must be formed from steel or applied to steel with paint or decals. A bridge that lacks appropriate identification will receive a very low display rating. 7.2.2.4 Poster describing design. The poster must (1) be flat with maximum dimensions of two by three feet and must present all information on one side without attached pages that must be lifted or turned, (2) identify the college or university with the same name that appears on the bridge, (3) be illustrated with a scaled, dimensioned side view of the bridge, (4) present a brief explanation of why the overall configuration of the bridge was selected, (5) include a brief computation demonstrating design for one limit state, (6) discuss provisions for sustainability, if any, for example, by listing or designating on the drawing those parts of the bridge that were salvaged from previous bridges or projects, or obtained from salvage yards, (7) acknowledge university technicians, faculty, and others who helped fabricate the bridge or provided advice, and (8) be in English.

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Additional information may be included. Names of financial sponsors may be shown on the poster or on an optional second poster that could accommodate their logos. Electronic displays, decorated supports, lights, and sound are not permitted and will result in the worst possible rating for the poster. A very low rating will be imposed if there is no poster or if it is grossly inadequate. The poster is not part of the bridge but must be in place whenever the bridge is on display. If English is not the dominant language where the competition is conducted, an optional additional poster may be displayed that is a translation into the local language of the required English language design poster. 7.2.3 Construction Speed The bridge with the lowest total time will win in the construction speed category. Total time is the time required for construction modified by construction penalties prescribed in 11.4 and 11.8.1, plus two minutes if repair time is commenced, plus double the repair time modified by construction penalties prescribed in 11.4 (see 11.10.1). There are upper limits on construction and repair time (see 11.8.2 and 11.10.2). 7.2.4 Lightness The bridge with the least total weight will win in the lightness category. Total weight is the weight of the bridge (determined by scales provided by the host student organization) plus weight penalties prescribed in 9.3, 9.4, and 10.2. Decking, tools, temporary pier, lateral restraint devices, and posters are not included in total weight. 7.2.5 Stiffness The bridge with the lowest aggregate deflection will win in the stiffness category. Aggregate deflection is determined from measurements as prescribed in 12.5. 7.2.6 Construction Economy The bridge with the lowest construction cost (Cc) will win in the construction economy category. Construction cost is computed as Cc = Total time (minutes) x number of builders x 50,000 ($/builder-minute) + load test penalties ($). Total time is defined in 7.2.3, and load test time penalties are prescribed in 12.2, 12.4, and 12.5. The number of builders includes all members and associates of the competing organization who physically assist the team at any time during timed construction or repair. A captain who is not a builder and does not physically assist with construction or repair is not included in number of builders. 7.2.7 Structural Efficiency The bridge with the lowest structural cost (Cs) will win in the structural efficiency category. Structural cost is computed as For a bridge that weighs 400 pounds or less, Cs = Total weight (pounds) x 10,000 ($/pound) + Aggregate deflection (inches) x 1,000,000 ($/inch) + Load test penalties ($) For a bridge that weighs more than 400 pounds, Cs = [Total weight (pounds)]2 x 25 ($/pound2) + Aggregate deflection (inches) x 1,000,000 ($/inch) + Load test penalties ($)

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Total weight is defined in 7.2.4, aggregate deflection is defined in 7.2.5, and load test weight penalties are prescribed in 12.4 and 12.5. 7.2.8 Overall Performance The overall performance rating of a bridge is the sum of construction cost and structural cost, (Cc + Cs). The bridge achieving the lowest value of this total wins the overall competition. 7.3 SPREADSHEET FOR SCORING The spreadsheet for scoring the competition is also useful for comparing alternatives when designing a bridge. Teams are encouraged to download, understand, and verify the spreadsheet before the competition. It is available in the Competition Guide at http://www.nssbc.info. Questions and comments regarding the spreadsheet should be sent to [email protected].

Section 8 SCHEDULE OF COMPETITION

In the months before the competition, students design their bridges, fabricate members, test load, practice construction, and select the captain and builders for timed construction. The following events occur during the competition (1) Bridges are erected for public viewing and are judged for display. After the start of display judging, bridges must not be altered, modified, or enhanced in any way except for disassembly, timed construction, and repair as described in 11.10. (2) Bridges are disassembled. (3) In a meeting at which all team captains are present, the head judge clarifies rules and conditions of the competition and answers questions. (4) The head judge selects the location of the load on the back span and the locations of two of the three vertical deflection targets. See 12.5.1, the Lateral Loading Diagram, and the Vertical Loading Diagram. Selection is done in the presence of the team captains by rolling a die twice. For each possible result S1 of the first roll, Table 8.1 gives the dimension M for positioning the load on the back span and the dimension TB for placing the vertical deflection target on the back span. TABLE 8.1 Determination of M and TB from first roll of die

S1 even odd M 3’0” 7’0” TB 4’6” 8’6”

For each possible result S2 of the second roll, Table 8.2 gives the dimension TC for placing a vertical deflection target on the cantilever. TABLE 8.2 Determination of TC from second roll of die

S2 1 2 3 4 5 6 - TC 1’0” 1’3” 1’6” 1’9” 2’0” 2’6”

The same locations will be used for all bridges in the competition. (5) Using a random process, the head judge determines the order in which teams will compete. (6) Bridge members, fasteners, tools, and the temporary pier are staged for construction and inspected by the judges. See section 10, “Material and Component Specifications,” 9.4.5, 9.4.6, 11.2, and 11.6 for details. (7) Timed construction and repair. See section 11, “Construction Regulations,” for details.

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(8) Judges inspect assembled bridges. For details, see section 9, “Dimension and Support Specifications,” (including 9.4.5 and 9.4.6 as they apply to installation of fasteners) and 10.1.3. (9) Bridges are weighed (if it is impractical to weigh the entire bridge, its parts may be weighed prior to construction). All bridges must be weighed, including those that are withdrawn from competition. (10) Load testing. See section 12, “Load Tests,” for details. (11) Scores and rankings are determined using the official scoring spreadsheet found at www.nssbc.info. (12) The host ASCE student organization submits the completed official scoring spreadsheet by e-mailing it to the address given on that spreadsheet. (13) Copies of the summary score sheets are distributed to all teams or posted on the conference host’s web site. (14) The host student organization retains judges’ data forms for two weeks. The order recommended above may be altered. However, it is essential that (1) Bridges are not modified after selection of the load location. (2) Bridges are not modified between display judging and timed construction. (3) No components or tools are added to or removed from the construction site after staging for inspection. (4) Modifications between timed construction and load testing are limited to repairs as described in 11.10 and 12.2. Between repairs and load testing, force shall not be applied to the bridge except as necessary to move it. For example, leaning or sitting on the bridge is not allowed.

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Section 9 DIMENSION AND SUPPORT SPECIFICATIONS

9.1 MEASUREMENT Dimensions and support will be checked with the bridge in its as-built condition after construction and repair are completed, and before the bridge is moved from the construction site or load tested. The bridge must not be modified or distorted from its as-built condition in order to satisfy dimension and support rules. Dimensions will be checked without decking or applied load on the bridge. 9.2 FUNCTIONALITY AND SAFETY 9.2.1 If any of the following rules in this sub-section (9.2) is violated, the bridge will not be approved for load testing and will not be eligible for awards in any category. 9.2.2 The back span is the part of the bridge that has supports at both ends. The back span must span the river completely without touching it. The river is twelve feet wide. See the Site Plan on the Site and Bridge Diagram. 9.2.3 The cantilever is the part of the bridge that has an unsupported end. The part of the bridge farthest from the staging yard must be a cantilever. 9.2.4 The bridge must have two surfaces on which the sides of the decking will bear. These decking support surfaces are continuous in the span direction of the bridge. See the Elevation and Section on the Site and Bridge Diagram. 9.2.5 The bridge must provide access for safely placing the decking and load. 9.2.6 The decking must not be attached or anchored to the bridge, and it must not be used to distort the bridge from its as-built condition. 9.2.7 The bridge must not be anchored or tied to the floor. 9.2.8 It must be possible to construct and load the bridge safely using the site, equipment, and floor surfaces provided by the host student organization. Bridges and participants must accommodate local conditions. 9.3 USABILITY 9.3.1 A weight penalty will be assessed for each rule in this sub-section (9.3) that is violated, rather than for every violation of that rule. If there are multiple violations of the same rule, the penalty will be based on the largest violation. The penalty for violation of each of the rules in this sub-section (9.3) will be an addition to the weight of the bridge determined as follows (1) 50 pounds for a dimensional violation of ½ inch or less, (2) 150 pounds for a dimensional violation greater than ½ inch but not exceeding 1.0 inch, (3) 300 pounds for a dimensional violation greater than 1.0 inch but not exceeding 2.0 inches, and (4) If a dimensional violation exceeds 2.0 inches, the bridge will not be approved for load testing and will not be eligible for awards in any category. 9.3.2 The bridge shall not extend more than 5’0” above the surface of the ground or river. See the Section on the Site and Bridge Diagram. 9.3.3 Parts of the bridge (including fasteners and parts that bear on the ground) must not extend beyond the vertical plane defined by the ends of the decking support surfaces at each end of the bridge. 9.3.4 The length of each decking support surface shall not exceed 17’0”. 9.3.5 At every section along the full length of the bridge, each decking support surface shall be flat, level, and at least ½ inch wide.

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9.3.6 The decking support surfaces shall be smooth and free of vertical protrusions except for the fastener bolt heads that are no higher than ¼ inch. 9.3.7 The outer edges of the two decking support surfaces shall be no less than 2’6” from one another, and the inner edges of the decking support surfaces shall be no more than 3’2” apart. These dimensions are measured perpendicularly to the span of the bridge. See the Section on the Site and Bridge Diagram. 9.3.8 A gap is a discontinuity or depression that extends laterally across the full width of a decking support surface. No gap shall exceed ¼ inch measured in the span direction of the bridge. 9.3.9 The decking support surfaces shall be no more than 3’0” above the surface of the river or ground at any point. See the Section on the Site and Bridge Diagram. 9.3.10 A vehicle passageway must completely traverse the bridge from end to end. It must be at least 1’6” high measured up from the decking support surfaces, and must be at least 3’8” wide measured perpendicularly to the span of the bridge. See the Section on the Site and Bridge Diagram. 9.3.11 Vertical clearance must be provided under the bridge at all points directly over the river. The clearance must be at least 1’7” high, measured from the surface of the river. See the Elevation on the Site and Bridge Diagram. 9.3.12 Vertical clearance must be provided under the bridge for a minimum of 3’6” from the unsupported cantilever end of the decking support surfaces. The clearance must be at least 1’7” high, measured from the ground. See the Elevation on the Site and Bridge Diagram. 9.4 MEMBER-TO-MEMBER CONNECTIONS 9.4.1 Violations of the rules in this sub-section (9.4) will result in penalties being added to the weight of the bridge. The penalty for each violation is 25 pounds. 9.4.2 There shall be a connection at every place where one member contacts another, and by the end of timed construction there must be at least one fastener in every connection so that it cannot be taken apart without first turning the nut or the bolt and removing the nut from the bolt. Definitions of “member” and “fastener” are given in 10.2.3 and 10.2.4, respectively. 9.4.3 A faying surface is either of a pair of surfaces that are, or will be, in contact at a connection. Every member must have one or more faying surfaces at each connection. Faying surfaces must be flat and smooth, and must not have protrusions, ridges, studs, teeth, threads, holes (other than those for fasteners), or sockets that would lock into connecting members. 9.4.4 Every faying surface must be penetrated by a fastener. 9.4.5 The bolt must penetrate completely through a hole in each of the members that it connects. Dimension(s) of the hole must be small enough so that neither the head of the bolt nor the nut can pass through the hole. 9.4.6 The hole for a fastener shall not be threaded. It must be possible to install and remove the bolt without turning it. A nut welded to a member constitutes a threaded hole. 9.4.7 The bolt must fully engage the threads of the nut. That is, the terminal threads on the bolt must extend beyond, or be flush with, the outer face of the nut.

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Section 10 MATERIAL AND COMPONENT SPECIFICATIONS

10.1 SAFETY 10.1.1 If any one of the rules in this sub-section (10.1) is violated, the bridge will not be approved for construction or load testing, and will not be eligible for awards in any category. 10.1.2 A member must not weigh more than twenty pounds. See 10.2.3 for definition of “member.” 10.1.3 A bridge must not incorporate an electric, electronic, fluidic, or other non-mechanical sensor or control system; a non-mechanical energy transmission device such as a wire, duct, or tube; an energy conversion or storage device such as an electromagnet, electric cell, motor, hydraulic or pneumatic piston, turbine, chemical reactor, pressure vessel, pre-loaded spring, or triggering device. 10.2 DURABILITY AND CONSTRUCTABILITY 10.2.1 Penalties Violation of the rules in this sub-section (10.2) will result in penalties being added to the weight of the bridge. The penalty is 25 pounds for each member or fastener that is in violation. 10.2.2 Bridge A bridge must be constructed only of steel members and steel fasteners. For the purposes of this competition, steel is defined as an iron alloy that is strongly attracted to the magnet provided by the host organization. Solder, brazing, and adhesives are not permitted. Exceptions: Purely decorative items such as coatings and decals are permitted, and bridge parts may be labeled. 10.2.3 Members 10.2.3.1 A member is a rigid component comprised of steel parts welded together. A member must retain its shape, dimensions, and rigidity during timed construction and load testing. Hinged, jointed, articulated, and telescoping members are prohibited, as are those with parts that move. This prohibition includes members with parts that are intended to slide, rotate, deflect, or bend relative to the member such as cams, latches, sliding pins, springs, and snaplock devices. Also prohibited are members incorporating hinges or other devices that do not restrain rigid-body rotation or translation of one part of the member relative to another part. Exception: Deformations caused by mechanical strain (e.g., bending, stretching) during construction and load testing are not violations. 10.2.3.2 A member must not exceed overall dimensions of 3'0” x 6” x 4”. That is, it must fit into a right rectangular prism (i.e., box) of those dimensions. 10.2.4 Fasteners 10.2.4.1 A fastener is a bolt that is not part of a member, with one nut that is not part of a member. Grade and diameter are not restricted. Custom fabricated bolts and nuts are prohibited. A bolt or nut that is welded to a member does not qualify as part of a fastener 10.2.4.2 The bolt in a fastener must be solid and no more than 1½-inch nominal length (bottom of head to end) with a head that is hexagonal in shape. Bolts must be commercially available and shall not be mechanically altered or modified in any way but may be painted. 10.2.4.3 The nut for a fastener must match the bolt. That is, the nominal size (inside diameter) must be the same as that of the bolt and permit the nut to be turned onto the

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bolt. Nuts must be solid and hexagonal in shape, and must be available commercially. Only one bolt and nothing else shall be threaded into a nut. Nuts must not be mechanically altered or modified in any way but may be painted.

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Section 11 CONSTRUCTION REGULATIONS

11.1 DEFINITIONS 11.1.1 “River, “staging yard,” “cofferdam,” and “construction site boundary” are delineated by the Site Plan on the Site and Bridge Diagram. 11.1.2 “Ground” is the floor inside the construction site boundary, except for the river. Ground includes the cofferdam. 11.1.3 “Builders” are undergraduate or graduate student members of a competing student organization. See section 4, “Eligibility.” 11.1.4 A “team” is all the builders from the competing organization who are within the construction site boundary during timed construction. 11.1.5 A “captain” is an undergraduate or graduate student member of a competing student organization. A team designates one person to serve as captain for the entire competition. The captain may or may not be a builder but will observe timed construction, repair, weighing, and load testing, and will sign data forms. 11.1.6 “Personal protective equipment” consists of a hardhat meeting ANSI standard Z89.1 and protective eyewear or safety goggles meeting ANSI standard Z87.1. A team provides its own personal protective equipment. 11.1.7 A “pouch” is an optional article of clothing that may be used to carry fasteners and tools. This definition encompasses tool belts and other accessories worn by builders and having the same function. 11.1.8 A “tool” is a device that is used to construct the bridge and is not part of the completed bridge. A team provides its own tools. Tools may be assembled during timed construction and may be powered by batteries. 11.1.9 A “temporary pier” is an optional device that bears on the cofferdam and is used to support the constructed portion of the bridge during timed construction. It has no other purpose, is not a tool, and is not part of the completed bridge. A team provides its own temporary pier, which may be made of any material. 11.1.10 “Member-to-member connection” is defined in 9.4. “Member” and “fastener” are defined in 10.2.3 and 10.2.4, respectively. 11.1.11 The “constructed portion” is comprised of members and fasteners, and is created during timed construction. The constructed portion is not required to be contiguous. 11.1.12 To “fasten” means making a member-to-member connection by installing a fastener (i.e., bolt and nut) to attach a member to the constructed portion or to attach two non-contiguous parts of the constructed portion. 11.2 GENERAL SAFETY CONDITIONS 11.2.1 Timed construction or repair will not commence or will be stopped if any provision of this sub-section (11.2) is violated. 11.2.2 Builders, captains, judges, host personnel, and spectators must not be exposed to risk of personal injury. 11.2.3 Only builders and judges are permitted within the construction site boundary during timed construction and repair. The captain, if not a builder, must observe construction and be accessible to the judges, but shall not interfere with them. Spectators, including coaches, faculty, advisers, and other associates of the team, must remain in designated areas at a distance from the construction site that assures they are not at risk and cannot interfere with the competition. 11.2.4 The team shall include no more than six builders.

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11.2.5 At all times during timed construction and repair every builder must wear personal protective equipment in the proper manner (e.g., hardhat with peak in front). 11.2.6 A tool or unassembled part of a tool must not weigh more than twenty pounds, and not exceed overall dimensions of 3'0” x 6” x 4”. That is, it must fit into a right rectangular prism (i.e., box) of those dimensions. Welding machines and tools requiring external power connections shall not be used during timed construction or repair. Tools must be rigid except for rotary tools such as ratchet wrenches and battery-powered drivers. 11.2.7 There shall be no more than one temporary pier. It must retain its original dimensions, not weigh more than twenty pounds, and not exceed 1’6” in any horizontal dimension. That is, it should fit inside a vertical cylinder with diameter of 1’6”. 11.2.8 Containers of lubricant shall not be in the construction site at any time. 11.3 SAFE CONSTRUCTION PRACTICES 11.3.1 If any rule in this sub-section (11.3) is violated during timed construction or repair, the judge will stop the clock and explain the violation. Before the clock is restarted, builders, tools, parts of tools, members, fasteners, and the temporary pier will be returned to the positions they occupied before the violation. Then the team will be asked to resume construction using safe procedures. A team will have the opportunity to construct its bridge safely. However, if the team is not able to construct its bridge completely using safe procedures, construction will cease and the bridge will not be approved for load testing and will not be eligible for awards in any category. 11.3.2 Construction of every non-contiguous part of the constructed portion shall commence by placing a member on the ground. That member becomes part of the constructed portion. When a member is in contact with the constructed portion it becomes part of the constructed portion. 11.3.3 Surfaces of the constructed portion that bear on the ground shall be the same surfaces that will bear on the ground in the completed bridge and, after being placed, must be in contact with the ground continuously for the remaining duration of timed construction and repair. 11.3.4 A temporary pier shall not support tools or fasteners. 11.3.5 A member that is not part of the constructed portion shall not be supported by a temporary pier unless it is simultaneously supported by a builder. 11.3.6 The temporary pier shall not be moved while it is supporting the constructed portion, nor shall a builder simultaneously touch (or touch with tools) the temporary pier and the constructed portion. 11.3.7 Throwing anything is prohibited. 11.3.8 A builder shall not cross from the ground on one side of the river to the ground on the other side or to the cofferdam. A builder shall not cross from the cofferdam to the ground adjacent to the river. 11.3.9 Outside the staging yard, a builder shall not simultaneously touch (or touch with tools) more than one member that is not part of the constructed portion. 11.3.10 A pouch or other article of clothing shall not be removed from a builder’s person nor held in a builder’s hand(s). 11.3.11 Nuts, bolts, and tools shall not be held in the mouths of builders. 11.3.12 A builder must not use the bridge, a constructed portion of the bridge, the temporary pier, or a tool to support the builder's body weight. For example, lying,

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standing, sitting, or kneeling on those objects is prohibited. However, a builder may lean on the constructed portion if the builder is kneeling on the floor on both knees, kneeling on the floor on one knee with the other foot on the floor, or standing with the heels and toes of both feet on the floor. 11.3.13 A builder must not depend on another builder or builders for support or balance. 11.4 ACCIDENTS 11.4.1 In general, the clock is not stopped when there is an “accident,” i.e., an infraction of one of the provisions of this sub-section (11.4). A time penalty is assessed for every accident. If an accident is continuous (for example, a builder stands in the river, or a dropped item is not retrieved promptly) it will be counted as multiple occurrences until corrected. Builders involved in accidents may continue to build. Items involved in accidents shall be recovered promptly and may be used. Construction cannot depend on deliberately committing an accident. Therefore, the clock will be stopped if any work is accomplished by committing an accident. Before timed construction is resumed, builders, tools, members, temporary pier, and fasteners will be returned to the positions they occupied before the accident. 11.4.2 A builder or a builder’s clothing touches the river or the floor outside the construction site boundary. Penalty is 1/2 minute (30 seconds) for every occurrence. Exception: There is no penalty for stepping out of bounds or entering the river to retrieve an object that has been dropped, such as a member, tool, nut, bolt, or personal protective equipment. 11.4.3 The temporary pier falls over or collapses while in use. Penalty is ½ minute (30 seconds) for every occurrence. 11.4.4 The temporary pier touches the river, the ground outside the cofferdam, or the floor outside the staging yard. Penalty is 1/4 minute (15 seconds) for every occurrence. 11.4.5 A member, constructed portion, tool, nut, bolt, or personal protective equipment touches the floor outside the staging yard, the river, or the ground (which includes the cofferdam). Penalty is 1/4 minute (15 seconds) for every item during every occurrence. Exception: The part of the constructed portion that is intended to bear on the ground may touch the ground outside the river without penalty. 11.4.6 Outside the staging yard, a member that is not part of the constructed portion touches another member that is not part of the constructed portion. Penalty is 1/4 minute (15 seconds) for every occurrence. 11.5 CONSTRUCTION SITE 11.5.1 See the Site Plan on the Site and Bridge Diagram for layout of the construction site. The host student organization lays out the site before the competition. The construction site shall be laid out so that tape that designates lines is wet or out of bounds. That is, the edges of tapes, not the centerlines, designate the lines shown on the Site Plan. 11.6 START 11.6.1 Before construction begins, only the following items are in the staging yard: the temporary pier, all members, fasteners, tools, and unassembled parts of tools. The temporary pier and every member, tool, and fastener must be in contact with the ground within assigned areas of the staging yard as designated on the Site Plan on the Site and Bridge Diagram. Builders are on the ground, which includes the cofferdam and both

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sides of the river. Builders start without tools and fasteners, which may be passed from one builder to another after timed construction begins. Similarly, the temporary pier is passed from builder to builder. Builders are wearing personal protective equipment as well as optional clothing such as pouches. 11.6.2 Judges inspect members, fasteners, tools, and the temporary pier as they are placed in the staging yard. Tools and temporary piers that do not conform to rules 11.2.6 and 11.2.7, respectively, shall not be used and shall be removed from the staging yard. After inspection and throughout timed construction and repair, additional members, tools, parts of tools, fasteners, temporary piers, or other items shall not be brought into the construction site nor shall anything be removed. Additional builders shall not enter the construction site after the beginning of timed construction. 11.6.3 Timing and construction begin when the captain signifies that the team is ready and the judge declares the start. 11.7 TIME 11.7.1 Time is kept from start to finish of construction. The clock will be stopped under the following conditions (1) if a builder, captain, or judge sees a condition that could cause injury, or (2) when a safety rule has been violated (see 11.2 and 11.3), or (3) when work has been accomplished by committing an “accident.” The clock is not stopped if the “accident” does not contribute to the construction process (see 11.4), or (4) if a builder, captain, or judge is injured. 11.7.2 Construction ceases while the clock is stopped. After the situation has been corrected, builders, tools, the temporary pier, and bridge components are returned to the positions they occupied before the interruption, and the clock is restarted. 11.8 TIME LIMIT 11.8.1 If construction time, not including penalties and repair time, exceeds thirty minutes, construction time will be counted as 180 minutes for scoring. “Accidents” (11.4) that occur after thirty minutes will not be penalized but safety rules (11.2 and 11.3) will still be enforced. Judges may inform the team when this time limit is approaching and must inform them when it is reached. 11.8.2 If construction time, not including penalties and repair time, exceeds 45 minutes, judges must halt construction. If local conditions allow and the head judge approves, the team may move its bridge off site for continued, untimed construction if it can be done safely. The bridge will not be eligible for awards in any category but may be load tested at the discretion of the head judge. 11.9 FINISH 11.9.1 Construction ends and the clock is stopped when (1) the bridge has been completed by connecting all the members that were in the staging yard at the start of timed construction, (2) the temporary pier is in the part of the staging yard designated on the Site and Bridge Diagram, (3) every tool and extra fastener is held in the hands of a builder, or is in clothing worn by a builder, or is on the ground in the part of the staging yard designated on the Site and Bridge Diagram, and (4) the captain informs the judge that construction is complete. 11.9.2 Installation of decking is not included in timed construction.

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11.9.3 After construction is finished the bridge must not be modified except for repair as permitted by 11.10. 11.10 REPAIR 11.10.1 Before the judges inspect and measure the bridge, and before the bridge is moved from the construction site, two builders, or one builder and the captain, will be given one opportunity to inspect the bridge and plan any needed repairs. They will be given five minutes to accomplish this. They shall not modify the bridge, and they shall not touch the bridge except as necessary to use measuring devices. Following this inspection, builders will be permitted, but not required, to repair construction mistakes found by their inspectors. Repairs are made with the clock restarted and begin with builders and necessary items arranged in the staging yard as prescribed by 11.6.1. Safety precautions (11.2 and 11.3) are enforced and accidents (11.4) are counted. The repair period ends when the conditions listed in 11.9.1 are fulfilled and shall not be resumed. Judges will not inspect the bridge prior to the end of the repair period. If builders commence repairs, the scoring spreadsheet will increase construction time by the sum of two minutes plus double the time required to make repairs, including any time penalties assessed during the repair period. It is not necessary to inspect, measure, or repair a bridge that exceeded the 45-minute time limit prescribed in 11.8.2. 11.10.2 If the repair time, not including penalties, exceeds five minutes, judges must halt construction. If local conditions allow, and the head judge approves, the team may move its bridge off site for continued, untimed construction if it can be done safely. The bridge will not be eligible for awards in any category but may be load tested at the discretion of the head judge.

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Section 12 LOAD TESTS

12.1 SAFETY PRECAUTIONS An activity will be halted if the judge considers it to be hazardous. A bridge could suddenly collapse or sway in any direction during load tests. Therefore, the number of people near the bridge while it is being tested shall be minimized. Usually, the load should be placed on the bridge by only two competitors. Competitors who are not participating in loading, faculty, advisers, and other spectators must observe from an area designated by the judges and host student organization. People should be kept clear of the unsupported end of the cantilever; load should be placed from the sides; While participating in load testing, competitors must wear hardhats meeting ANSI standard Z89.1, protective eyewear or safety goggles meeting ANSI standard Z87.1, gloves, and leather construction boots. This safety equipment is provided by the competitors. Judges will not permit load testing by competitors who are not wearing the specified safety equipment or are wearing it improperly. During testing, safety supports must be in place below the decking. The safety supports shall be of sufficient height, strength, number, and extent that none of the load will fall more than approximately five inches if the bridge collapses. All preparations for load testing, including placement of safety supports, must be completed before any load is on the bridge so that it will not be necessary for anyone to reach, crawl, or step under the loaded bridge. However, if safety supports must be adjusted during loading, the load must first be removed without disturbing the bridge, adjustments made, and the load replaced as it was before being removed. If team members cannot load their bridge safely, loading will cease and the bridge will not be eligible for awards in any category. Do not exceed 400 psf uniform load or 500 pounds concentrated load on the decking. 12.2 DAMAGE A bridge will not be tested in a condition that compromises its strength or stability. If a bolt or nut is missing or the threads of a nut are not fully engaged, the fastener will be reinstalled correctly, and a penalty of $1,000,000 will be added to the Construction Economy score for every bolt and every nut that was reinstalled. A bridge with damage that would reduce its strength or stability (such as a fractured weld, or missing or broken member) will not be approved for load testing and is not eligible for awards in any category. Repair and modifications are not permitted after the end of timed construction and repair except as provided by the preceding paragraph of this subsection (12.2). 12.3 PREPARATION The captain must observe the load tests. The temporary pier is not used during load tests. The judge designates the “A” side of the bridge by a random process. The “B” side is opposite to the “A” side. Teams must accept imperfect field conditions such as bent decking, sloping floors, and unfavorable floor surfaces. At their discretion, judges may impose a penalty for a bridge that incorporates parts having the primary function of interfering with placement of targets, decking, load, or measuring devices. If the bridge cannot be loaded safely, or sway or deflection cannot be

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measured in accordance with the provisions of this section (12), the bridge will not be load tested and will not be eligible for awards in any category. 12.4 LATERAL LOAD TESTS 12.4.1 The provisions of this sub-section (12.4) are illustrated by the Lateral Loading Diagram. “Sway” is translation in any horizontal direction. The lateral load tests are conducted with one unit of decking placed at the center of the back span and approximately 75 pounds of weight on the decking near the “B” side of the bridge. This load is intended to prevent the bearing surfaces of the bridge from lifting off the floor when lateral load is applied. Bearing surfaces are prevented from sliding by lateral restraint applied by team members or the captain. This lateral restraint does not restrain rotation or uplift. The restraint is applied as close to the ground as possible, at the locations shown on the Lateral Loading Diagram. Teams may provide and use optional devices to prevent sliding. A lateral load test is failed if the bridge is restrained in other than the lateral direction, or if the restraint is not applied close to the ground, or if the restraint is not effective. 12.4.2 Lateral Load Test of the Back Span A sway target is established for measurement on the “A” side of the bridge, 6’6” from the end of the decking support surface at the end of the bridge that is not cantilevered. The sway target is located as close as possible to the decking support surface, which is at the same level as the bottom of the decking. Apply a 50-pound lateral pull and measure the sway. The pulling force is located as close as possible to the decking support surface and not more than four inches from the sway target. To pass the lateral load test, the sway must not exceed 1/2 inch. If the bridge does not pass this lateral load test it is not approved for further testing. Do not conduct any other load test. Check the appropriate box on the judges’ data form. The spreadsheet will add penalties of $20,000,000 to the Construction Economy score and $40,000,000 to the Structural Efficiency score when the judging data is entered. If the bridge passes the lateral load test of the back span, proceed with the lateral load test of the cantilever. 12.4.3 Lateral Load Test of the Cantilever A sway target is established for measurement on the “A” side of the bridge, at the end of the decking support surface at the unsupported end of the cantilever. The sway target is located as close as possible to the decking support surface, which is at the same level as the bottom of the decking. Apply a 50-pound lateral pull and measure the sway. The pulling force is located as close as possible to the decking support surface and not more than four inches from the sway target. To pass the lateral load test, sway must not exceed 1/2 inch. If the bridge does not pass this lateral load test it is not approved for further testing. Do not conduct any other load test. Check the appropriate box on the judge’s data form. The spreadsheet will add penalties of $20,000,000 to the Construction Economy score and $40,000,000 to the Structural Efficiency score when the judging data is entered. If the bridge passes this lateral load test, remove the load and decking, and proceed with the vertical load test.

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12.5 VERTICAL LOAD TESTS 12.5.1 The provisions of this section are illustrated by the Vertical Loading Diagram. Safety supports are placed under the decking so that no portion of the load will drop more than approximately five inches if the bridge collapses. Decking units are three feet long in the longitudinal (span) direction of the bridge. Place one decking unit at a distance M from the end of the decking support surfaces at the end of the bridge that is not cantilevered. M is determined at the beginning of the competition as described by Table 8.1 in section 8, “Schedule of Competition.” Place the other decking unit at a distance of one inch measured from the end of the decking support surfaces at the unsupported end of the cantilever. Decking units are placed square with the bridge and centered laterally with the main bars spanning laterally over the decking support surfaces. Decking units must not be attached to the bridge and must not distort it (see 9.2.5 and 9.2.6). Three targets are established for measuring vertical deflections at locations determined by the following dimensions � TB from the end of the decking support surface at the end of the bridge that is not cantilevered, on the “B” side of the bridge � TC from the end of the decking support surface at the cantilevered end of the bridge, on the “A” side of the bridge � One inch from the end of the decking support surface at the cantilevered end of the bridge, on the “B” side of the bridge. TB and TC are determined at the beginning of the competition as described by Tables 8.1 and 8.2 in section 8, “Schedule of Competition.” Vertical deflection targets are located on the decking. Position measuring devices on the three vertical deflection targets. Uniformly distribute 100 pounds of preload on the decking unit on the back span. Then uniformly distribute 50 pounds of preload on the decking unit on the cantilever. Preloads are laterally centered on the decking units. Preloads are distributed and aligned identically for every bridge. If, after the preload is installed, decking does not contact the decking support surface at a vertical deflection target, the judge will clamp the decking to the decking support surface at that location and leave the clamp in place during vertical load testing. If a competitor disturbs a measuring device after it has been initialized and before loading is completed and all measurement have been recorded, the judge will require the team to disassemble the bridge and repeat timed construction beginning with the initial conditions prescribed in 11.6. Scoring will be based on the run that results in the larger construction cost, Cc (not including load test penalties), but will not exceed 125% of Cc (not including load test penalties) for the initial run. The two steps (increments) of vertical loading produce four measurements (1) DB1 = absolute value of vertical deflection at the target on the “B” side of the back span that occurs during step 1 (loading the back span). (2) DCA = absolute value of vertical deflection at the target on the “A” side of the cantilever that occurs during step 2 (loading the cantilever with the load from step 1 remaining in place).

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(3) DCB = absolute value of vertical deflection at the target on the “B” side of the cantilever that occurs during step 2 (loading the cantilever with the load from step 1 remaining in place). (4) DB2 = absolute value of vertical deflection at the target on the “B” side of the back span that occurs from the beginning of step 1 to the end of step 2. The scoring spreadsheet computes aggregate deflection as the sum of DCA, DCB, and the larger of DB1 and DB2. 12.5.2 Step 1 – Vertical Load Test of the Back Span Load the decking unit on the back span and measure the deflection, using the following procedure (1) The two preloads remain in place. (2) Initialize the sway measurement device on the back span. (3) Initialize the sway measurement device on the cantilever. (4) Initialize the vertical deflection measuring device on the back span or record the initial reading. (5) Team members place 1400 pounds of additional load on the decking unit on the back span. The load is laterally centered on the decking unit and is distributed over the length of the decking unit as uniformly as possible at all times during loading. Load is distributed and aligned identically for every bridge. Load shall be placed at a steady pace, without hesitation. (6) As the load is being placed, observe the deflection target on the back span and both sway targets. Stop loading if (a) sway at either sway target exceeds 0.5 inch from the beginning of step 1, or (b) deflection at the deflection target on the back span exceeds three inches downward from the beginning of step 1, or (c) decking or any part of the bridge, other than the intended bearing surfaces, comes to bear on a safety support or the floor, or (d) a decking unit or some of the load falls off the bridge, or (e) the bridge collapses or a dangerous collapse is imminent, in the opinion of the judge. If loading is stopped for any of the situations a, b, c, d, or e, the bridge is not approved for further load testing and is not eligible for awards in any category. Remove the load and do not continue load testing. Check the appropriate box on the judge’s data form. If the bridge passes step 1, record the measured value DB1. If DB1 exceeds 1.5 inches, the scoring spreadsheet will add penalties of $8,000,000 to the Construction Economy score and $20,000,000 to the Structural Efficiency score. 12.5.3 Step 2 – Vertical Load Test of the Cantilever Load the decking unit on the cantilever and measure the deflections, using the following procedure (1) The two preloads and the load from step 1 remain in place. (2) Do not initialize the vertical deflection measuring device on the back span. (3) Do not initialize the sway measurement devices on the back span and cantilever. (4) Initialize the vertical deflection measuring devices on the cantilever. (5) Team members place 950 pounds of additional load on the decking unit on the cantilever. The load is laterally centered on the decking unit and is distributed over the length of the decking unit as uniformly as possible at all times during loading. Load is

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distributed and aligned identically for every bridge. Load shall be placed at a steady pace, without hesitation. (6) As the load is being placed, observe the three deflection targets and both sway targets. Stop loading if (a) sway at either sway target exceeds 0.5 inch from the beginning of step 1, or (b.1) deflection at the deflection target on the back span exceeds three inches downward from the beginning of step 1, or (b.2) deflection at either deflection target on the cantilever exceeds two inches downward from the beginning of step 2, or (c) decking or any part of the bridge, other than the intended bearing surfaces, comes to bear on a safety support or the floor, or (d) a decking unit or some of the load falls off the bridge, or (e) the bridge collapses or a dangerous collapse is imminent, in the opinion of the judge. If loading is stopped for any of the situations a, b.1, b.2, c, d, or e, the bridge is not approved for further load testing and is not eligible for awards in any category. Remove the load and do not continue load testing. Check the appropriate box on the judge’s data form. If the bridge passes step 2, record the measured values of DB2, DCA, and DCB. If DB2 exceeds 1.5 inches but DB1 did not, or If DCA or DCB exceeds one inch, the scoring spreadsheet will add penalties of $6,000,000 to the Construction Economy score and $15,000,000 to the Structural Efficiency score. 12.6 Unloading Remove all load from the cantilever before removing any load from the back span. If the bridge collapses during unloading (situation c, d, or e), it will not be eligible for awards in any category.

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Section 13 EQUIPMENT PROVIDED BY HOST

13.1 SOURCES OF INFORMATION The Competition Guide at http://www.nssbc.info should be reviewed by judges, host personnel, and competitors. It has detailed descriptions and illustrations of contest procedures and hosting equipment. The following provisions of this section (13) describe some of the equipment that is needed for the competition and is intended to help competitors know what to expect. Competitors should acquire similar equipment for use in practice and testing before the competition. 13.2 FLOOR The floor in both the construction site and loading area shall be solid, stable and as nearly flat and level as possible. 13.3 LATERAL LOAD DEVICE The lateral load device should be capable of applying a force of 50 pounds in the horizontal direction. 13.4 SWAY MEASUREMENT Sway is horizontal translation and is measured at two points by any accurate method. A suggested method is to suspend a plumb bob from the sway target and measure sway from a point marked on the floor. 13.5 DEFLECTION MEASUREMENT Deflection is vertical translation and is measured at three points by any accurate method. 13.6 DECKING Preferred decking is steel bar grating identified as W-19-4 (1 x 1/8). The dimensions of a unit of grating are approximately 3'6” x 3'0” x 1” and the weight is approximately fifty pounds. However, the host may provide a different type of decking with approximately the same dimensions. Grating has significant bending strength only in the direction of the main bars, which are 3'6” long. The grating will be installed with the main bars perpendicular to the length of the bridge, creating a roadway that is 3'6” wide. Therefore, support for the grating is needed for the edges that are parallel to the length of the bridge but not for the edges that are perpendicular to the length. 13.7 CLAMPS AND SMALL STEEL PLATES Clamps may be needed to hold the decking in contact with the decking support surfaces of a bridge. Small steel plates may be needed as bearing surfaces for clamps and measuring devices. 13.8 SAFETY SUPPORTS The safety supports must be used during load tests and are intended to limit the consequences of a bridge collapsing. The safety supports shall be of sufficient height, strength, number, and extent so that none of the load will fall more than approximately five inches if the bridge collapses. Safety supports may be steel, nested stacks of plastic buckets, timbers, sand bags, or masonry units. 13.9 LOAD A total load of 2500 pounds should be supplied in uniform pieces of size and weight that can be handled safely. When in place, the load should not provide significant stiffness in the longitudinal direction of the bridge. The recommended load consists of 25-pound lengths of 5” x 5” x 5/16” steel angle placed perpendicular to the length of the bridge.

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Sacks of material, containers of liquid, concrete blocks, or jacking systems could be used. Decking is not included as part of the 2500 pound load. 13.10 OFFICIAL SCORING SPREADSHEET AND DATA FORMS Results will not be official until the completed official scoring spreadsheet is submitted to [email protected] to report outcomes. It may be downloaded at http://www.nssbc.info. Judges’ forms for recording data are accessed from the spreadsheet. The host student organization retains the judges’ data forms for two weeks after the competition.

Section 14 INTERPRETATION OF RULES

The web site http://www.aisc.org/steelbridge lists clarifications of the rules. Competitors, judges, and host personnel may submit questions via a form on that web site but should first read the previously posted clarifications, reread this Rules document carefully in its entirety, and review the Competition Guide at http://www.nssbc.info. Submitters’ names and affiliations must accompany clarification requests and will be posted with the questions and answers. Internet deliberation by the SSBC Rules Committee typically requires one to two weeks but possibly longer. Questions must be submitted before 5:00 PM Eastern Daylight Saving Time, May 13, 2013.

Section 15 JUDGING

The host student organization will recruit judges. Judges are empowered to halt any activity that they deem to be hazardous. Judges have full authority over conduct of the competition and interpretation of the rules. Decisions, scoring, and ranking are the sole responsibility of the judges and will be final. The host student organization will assure that the judges are fully informed of the Rules and procedures, and fully equipped for their tasks. More information for host organizations and judges is available at http://www.aisc.org/steelbridge and at http://www.nssbc.info, where the official scoring spreadsheet may be downloaded and the Competition Guide reviewed.

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Section 16 APPEALS

16.1 CONFERENCE COMPETITIONS 16.1.1 At the beginning of the competition each team will identify its captain. The host organization will identify the conference head judge (CHJ). 16.1.2 A penalty, decision, measurement, score, or condition of competition may be appealed only by the team captain and only to the CHJ. The CHJ will not hear the appeal if he or she is approached by students other than the team captain. The CHJ will refuse to hear protests regarding bridges other than the captain’s. The appeal must be made as soon as possible after the situation becomes apparent. The CHJ will hear the appeal as soon as possible and may interrupt the competition. If the captain does not consent to the decision of the CHJ, he or she shall write an explanation on the judge’s data sheet before signing it. Participants are reminded that civility and ethical behavior are expected during the competition and particularly concerning appeals. 16.1.3 After the conference competition, the team captain has the option to appeal the decision of the CHJ by e-mail to Ms. Maria Mnookin <[email protected]> or by letter to Ms. Mnookin (AISC, Suite 700, One E. Wacker Dr., Chicago, IL 60601-2001). The e-mail message or letter shall include (1) name of the college or university making the appeal, (2) captain’s name, e-mail address, postal address, and telephone number, (3) faculty adviser’s name, e-mail address, postal address, and telephone number, (4) brief description of the problem, including citation of pertinent rules, (5) action taken at the competition to deal with the problem, (6) action that the appealing team feels should have been taken, (7) data showing that the team should have qualified for national competition, and (8) captain’s signature (letter only). The SSBC Rules Committee may ask the host student organization to provide judges’ data forms documenting the problem. 16.1.4 Appeals must be made by e-mail or letter. An appeal will be considered only if the e-mail is received or the letter is postmarked by 5:00 PM Eastern Daylight Saving Time on the Wednesday immediately after the conference competition. Ms. Mnookin will forward the appeal to the SSBC Rules Committee for their evaluation. The Committee will not respond to an appeal until the official scoring spreadsheet for that conference has been submitted by the host organization to [email protected]. The only redress that may be made is an invitation to participate in the national competition if the Committee is convinced that the appeal is valid and that the appealing team should have qualified for the national competition. Decisions and rankings made by conference judges will not be overturned. 16.2 NATIONAL COMPETITION 16.2.1 Judges will refuse to hear protests from a team concerning any bridge other than their own. 16.2.2 A penalty, decision, measurement, score, or condition of competition may be appealed only by a team captain and only to the station head judge (SHJ). The SHJ will not hear the appeal if he or she is approached by students other than the team captain. The appeal must be made as soon as possible after the situation becomes apparent and before the conditions at issue are changed (e.g., by further construction,

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loading, or disassembly of the bridge). The SHJ will hear the appeal as soon as possible and will make a ruling. The conditions at issue will not be changed during deliberation. Participants are reminded that civility and ethical behavior are expected during the competition and particularly concerning appeals. 16.2.3 After hearing the SHJ’s ruling, the team captain may request a five-minute recess to discuss the issue with the team. During the recess, the conditions at issue will not be changed. Immediately after that recess, if the team has justification to contest the SHJ’s ruling, the captain has the option to appeal that decision to the national head judge (NHJ). The NHJ will hear the appeal as soon as possible and will make a ruling. The NHJ may consult with the SSBC Rules Committee. The conditions at issue will not be changed during deliberation. 16.2.4 If the team has justification to contest the NHJ’s ruling, the team captain has the option to appeal that decision directly to the SSBC Rules Committee within fifteen minutes after hearing the NHJ’s ruling. The Committee may request information from the NHJ and SHJ but those judges will not vote on the final ruling. 16.2.5 The decision of the SSBC Rules Committee is final; there are no further appeals. However, AISC and ASCE welcome written suggestions for improving future competitions.

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Section 17 INDEX OF DEFINITION

Accident 11.4 Aggregate deflection 12.5.1

Back span 9.2.2 Builder 11.1.3

Cantilever 9.2.3 Captain 11.1.5

Clearance 9.3.11, 9.3.12 Cofferdam 11.1.1

Conference participation 4.4 Constructed portion 11.1.11

Construction cost 7.2.6 Construction economy 7.2.6

Construction site boundary 11.1.1 Construction speed 7.2.3

Data form 7.1, 13.10 DB1, DB2, DCA, DCB 12.5.1

Decking 13.6 Decking support surface 9.2.4

Deflection 13.5 Display 7.2.2 Fasten 11.1.12

Fastener 10.2.4 Faying surface 9.4.3 Fully engaged 9.4.7

Gap 9.3.8 Good standing 4.4

Ground 11.1.2 Guest team 4.2.2

Judge 15 Judges’ data form 7.1, 13.10

Lateral load device 13.3 Lateral restraint device 12.4.1

Lightness 7.2.4 Load 13.9 M 8, 12.5.1

Member 10.2.3 Member-to-member connection 9.4

Official scoring spreadsheet 7.1, 7.3, 13.10

Overall performance 7.2.8 Passageway 9.3.10

Personal protective equipment 11.1.6

Pouch 11.1.7 Preload 12.5.1 Repair 11.10 River 11.1.1

S1, S2 8 Safety 6, 9.2, 10.1, 11.2, 11.3, 12.1

Safety supports 13.8 Staging yard 11.1.1

Steel 10.2.2 Stiffness 7.2.5

Structural cost 7.2.7 Structural efficiency 7.2.7

Sway 12.4.1, 13.4 TB, TC 8, 12.5.1

Team 4.2.3, 4.3.5, 11.1.4 Temporary pier 11.1.9

Tool 11.1.8

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Appendix B: The Current Rule Clarifications

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Problem statement

Q3.1. Does the last sentence in Section 3 empower judges to disqualify a bridge? If so, please define the connections that do and do not conform to the rules in sub-section 9.4. Jeffrey Dowgala, Purdue University West Lafayette

Yes, that subjective sentence in Section 3 can be invoked to disqualify a bridge or a team. For example, a judge can disqualify a structure that is unusable as a bridge or a team that disrupts the competition or sabotages another team's bridge. These examples are not inclusive. The Rules Committee does not endorse or condemn specific designs. The reference cited in Q9.1 may be helpful. [3]

Dimensions and Support Specifications

Q9.1. Would round faying surfaces, e.g., for a round tube sleeved into another round tube, violate the requirement that faying surfaces be flat? Douglas Whiting, University of Oklahoma A. Yes, that would be penalized. Examples of connections that violate and that conform to the 2013 rules on connections are found atwww.nssbc.info at the bottom of the “post construction” page. However, the Rules document and clarifications take precedence over that web site if there is a discrepancy. [9.4.3] Q9.2. In rule 9.3.5, does "flat" mean planar or just flat in one direction? Josh Weaver, University of Akron A. "Flat" and "level" in that rule apply to sections transverse to the span direction of the bridge. Rules 9.3.6 and 9.3.8 govern in the longitudinal direction. [9.3.5, 9.3.6, 9.3.8] Q9.3. Can more than two members be connected by a single fastener? Jorge L. Soto Lorenzo, University of Puerto Rico Mayaguez A. Yes. [9.4.2] Q9.4. Are the dimensions in rule 9.3.7 switched? Josh Weaver, University of Akron A. They are correct as stated. The intent of the 2'6" out-to-out minimum is to limit the distance the decking cantilevers over the decking support surfaces. The intent of the 3'2" clear maximum is to assure adequate bearing of the decking on the decking support surfaces. For example, decking support surfaces built to either limit would automatically satisfy the other limit, and there are intermediate spacings that would satisfy both limits. [9.3.7] Q9.5. May multiple fasteners penetrate a pair of faying surfaces? Brian Giffin, University of California Davis A. Yes. [9.4.4] Q9.6. Section A on the Site and Bridge Diagram shows the decking support surfaces elevated slightly above the outline of the bridge envelope. What is the required distance that the decking support surfaces must be elevated? Nick Moore, North Dakota State University A. There is no requirement. The decking support surfaces are drawn that way to define the dimensions for their 1/2" minimum width and the 1'6" minimum vehicle clearance. [9.3.5, 9.3.10] Q9.7. Does the word "socket" in rule 9.4.3 mean that a tube-in-tube connection would be penalized? Brian Giffin, University of California Davis A. As used in that rule, "socket" means a depression in a faying surface that would accommodate a matching protrusion on the faying surface of the other member. The term is not intended to apply to the insertion of the tubular end of one member into the tubular end of another member. [9.4.3] Q9.8. How many faying surfaces are there if a rectangular tube fits snugly into another rectangular tube? Michael Dohnalik, Texas A&M University A. There are at least four on each of the two tubes, thus four pairs, requiring a minimum of two fasteners. There would be an additional pair of faying surfaces and another required fastener if the butt of one tube contacts part of the other member. Rectangular tubes are manufactured with rounded corners, and this

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slight deviation from flatness will not be penalized, nor are these corners required to be penetrated by fasteners. [9.4.3, 9.4.4] Q9.9. Can a decking support surface be the top of a round tube? Can a decking support surface be the top of a 1/2 inch rectangular tube with rounded corners? Josh Weaver, University of Akron A. Rule 9.3.5 requires a decking support surface to be 1/2 inch wide, flat, and level in the direction transverse to the span of the bridge. The top of a round tube is not flat, so there would be a penalty. A nominal 1/2-inch rectangular tube usually will have a flat surface that is less than 1/2 inch wide, due to rounded corners, and would be penalized. [9.3.5] Q9.10. In rule 9.4.3, what is meant by “flat” and the various features that are specifically prohibited by that rule? Josh Weaver, University of Akron A. “Flat” in that rule means planar for the full extent of the contact between two members. The list of prohibited features reinforces and exemplifies the flatness requirement but is not inclusive. A characteristic of a connection conforming to rule 9.4.3 is that it can be pulled apart if the fasteners are removed, but this characteristic alone is not sufficient evidence of conformance to that rule. [9.4.3] Q9.11. May a connection of two members have more than one pair of faying surfaces? David Bancroft, University of Central Florida A. Yes. [9.4.3] Q9.12. Must a faying surface on a member extend over the entire area of contact with the connected member? Tom Woloszyn, New Jersey Institute of Technology A. Yes. [9.4.3] Q9.13. Can a pin be used in a connection? Tom Woloszyn, New Jersey Institute of Technology A. A pin that is not welded to a member is considered to be a member because it does not conform to the definition of fastener. That pin must satisfy all requirements governing members. A pin welded to a member violates rule 9.4.3. [9.4.2, 9.4.3, 10.2.2, 10.2.3.1, 10.2.4.1] Q9.14. Does a bridge with no structure above the decking support surfaces provide the required vehicle passageway? Andrew Hilty, Indiana-Purdue University Fort Wayne A. Yes. [9.3.10] Q9.15. How will judges determine if a faying surface meets the smoothness requirement of rule 9.4.3? Jeffrey Dowgala, Purdue University West Lafayette A. Faying surfaces that are deliberately textured or roughened to resist slip will be penalized, as will surfaces with adhesive or sticky coatings. Mill scale typical of rolled steel and untextured paint will be acceptable. Judges will make the subjective determination, and, in marginal cases, determinations made by conference judges and national judges may differ. [9.4.3] Q9.16. What is the meaning of "faying surface... penetrated by a fastener" in rule 9.4.4? Hiep Nguyen, University of Texas San Antonio A. "Faying surface" is defined in rule 9.4.3; it is a surface of a member at a connection. "Fastener" is defined in rule 10.2.4.1. "Penetrate" means that at a member-to-member connection, there must be a hole located entirely within every faying surface of every member at that connection, and a fastener must pass through those holes. [9.4.2, 9.4.3, 9.4.4, 9.4.5, 10.2.3.1, 10.2.4.1] Q9.17. Section 5 states that interlocking connections will be penalized. Does this include all interlocking connections or just those that violate rules 9.4.3 and 9.4.4? Shelby Brothers, University of Florida A. The rules in section 9 govern. Item 3 of section 5 is just a warning that some connections used in prior years are no longer acceptable. [5, 9.4.3, 9.4.4] Q9.18. Will there be a penalty if a fastener is not perpendicular to a faying surface that it penetrates? Greg Zirkel, San Jose State University A. No. There is no restriction on the angle at which a fastener intersects a faying surface. [9.4.4]

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Q9.19. Will there be a penalty for a fastener that does not transmit force from one member to another? Jeffrey Dowgala, Purdue University West Lafayette A. No. [9.4.2, 10.2.4.1] Q9.20. Would a gap less than 1/4 inch, as permitted by rule 9.3.8, violate rules 9.3.5 and 9.3.6 which specify a minimum width of the decking support surface and require it to be smooth? Phillip Gutierrez, University of Texas San Antonio A. Not a violation. Rule 9.3.8 states a limited exception to rules 9.2.4, 9.3.5 and 9.3.6. [9.2.4, 9.3.5, 9.3.6, 9.3.8] Q9.21. If the surfaces of members are not in contact when the bridge is constructed, but then come into contact during load testing, are they faying surfaces that require penetration by a fastener? Phillip Gutierrez, University of Texas San Antonio A. Compliance with the specifications in section 9 will be checked before load testing. However, the bridge will be disqualified under the provision of section 3 if judges determine that the bridge was deliberately designed to have surfaces that come into contact during loading but do not comply with the specifications in sub-section 9.4. [3, 9.1, 9.4.2, 9.4.3, 9.4.4, 9.4.5, 9.4.6, 9.4.7] Q9.22. Can some of the fasteners in a connection be in slots rather than holes? Courtney Judish, Colorado School of Mines A. An open slot, i.e., one that is not completely enclosed by the same piece of steel, violates rules 9.4.2 and 9.4.5. However, an elongated hole, i.e., with a continuous perimeter and enclosed by the same piece of steel, is acceptable if it complies with the provisions of section 9 of the Rules. [9.4.2, 9.4.4, 9.4.5] Q9.23. Rule 9.3.8 permits a small gap in a decking support surface, but section 9.4 requires adjoining members to be in contact and connected. Which rules govern? Will Johnson, Boise State University A. These rules are not contradictory. A decking support surface is comprised of top surfaces of members. The members can be in contact even though the top surfaces are discontinuous. That is, the permitted gap in the top surface does not extend though the full depth of the members. [9.3.8, 9.4.2, 9.4.3] Q9.24. Is there a violation if a fastener passes through a faying surface so that the longitudinal axis of the bolt is parallel to, or forms a small angle with, the faying surface? Lawson Ho, California Polytechnic Institute Pomona A. Rule 9.4.5 is violated if the "hole" through which the bolt passes is not completely enclosed by the same continuous faying surface. [9.4.3, 9.4.4, 9.4.5] Q9.25. REVISED. How many fasteners are required when a member has two planar faying surfaces that are not co-planar but that meet, forming a corner of any angle? Brian Giffin, University of California Davis A. REVISED. Every faying surface must be penetrated by at least one fastener, but there is no limit on the number of faying surfaces that a single fastener may penetrate. Holes for fasteners must comply with specifications 9.4.5 and 9.4.6, and every hole must be completely within the faying surface. Corners are not faying surfaces because they are not surfaces. However, a corner of one member that contacts another member would violate specification 9.4.3 if it is not smooth or contributes to the resistance or stability of the connection. A corner cannot be the only contact at a connection – there must be faying surfaces. [9.4.3, 9.4.4, 9.4.5, 9.4.6] Q9.26. Can a third set of abutments bear on the cofferdam? Jonathon Hrehor, Cornell University A. No. That would violate specification 9.2.2, which is illustrated by the Elevation on the Site and Bridge Diagram. [9.2.2] Q9.27. Can a bolt head that is 5/16 inch high protrude above the decking support surface? Benjamin Frieling, Columbia University A. That would violate specification 9.3.6. [9.3.6] Q9.28. Is there a required width between the legs of the bridge? Giorgi Naoom, San Diego State University

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A. There is no specification that limits the lateral spacing of abutments. Longitudinal spacing must be sufficient for abutments to bear on the banks of the river. [9.2.2] Q9.29. Do the bridge legs need to fit in the box mentioned in specification 10.2.3.2? Giorgi Naoom, San Diego State University A. A bridge must be made of members and fasteners only. Every member, including those that are part of an abutment, must comply with the all specifications governing members. [10.2.2, 10.2.3.2] Q9.30. If there are multiple separate areas of contact between two members, are there multiple pairs of faying surfaces or just one?Matt Fields, University of Kansas A. Multiple. Each separate contact area is a faying surface. [9.4.2] Q9.31. May the outside of one rectangular tube contact the inside of another rectangular tube? Matt Fields, University of Kansas A. Yes. [9.4.3] Q9.32. Clarification Q9.14, as it is written, could apply only to members positioned directly above the decking support surfaces. Is this the intent? Matthew Michnewich, Rensselaer Polytechnic Institute A. No. A bridge with no structure above the level of the decking support surfaces will provide the required vehicle passageway. [9.3.10] Q9.33. Is there minimum clearance between two members that determines whether or not they are in contact? How will this be checked? Aaron Thompson, University at Buffalo A. "Contact" is an absolute term; there is no specified minimum clearance. Members connected to one another by one or more fasteners must meet the specifications for member-to-member connections even if they are not in contact. [9.4] Q9.34. What is the required clearance over the cofferdam? SSBC Rules Committee A. The minimum clearance over the cofferdam is the same as over the river. [9.3.11] Q9.35. At the cantilever end, a bridge has base plates that extend away from the river and beyond the abutments. Is the 3'6" length of the clearance under the cantilever measured from the abutments or from the edge of the base plates? Mike Shustack, University of Massachusetts Lowell A. The 1'7" height of the clearance is measured from the ground. Therefore, there will be a penalty if any part of the bridge, including base plates, extends into the 3'6" clearance, which is measured from the ends of the decking support surfaces. [ 9.2.3, 9.3.12] Q9.36. Two tubes of the same size are parts of different members and meet end-to-end. Are the end surfaces of the tubes acceptable as parts of faying surfaces? Kenneth Shulz, Oregon Tech A. No, because the open ends of the tubes would be holes in the faying surfaces. [9.4.3] ATTENTION: Q9.25 and the answer have been revised. Q9.37. Can there be more than two decking support surfaces? Can decking bear on other parts of the bridge? Brian Giffin, University of California Davis A. There must be two designated decking support surfaces that comply with specifications 9.2.4, 9.3.4, 9.3.5, 9.3.7, and 9.3.8, but the decking also may bear on other parts of the bridge. All parts of the bridge that contact the decking, including the two designated decking support surfaces, must comply with specification 9.3.6 and 9.3.9. If, after preloads are placed, the two designated decking support surfaces are not in contact with the decking at the vertical deflection targets, judges will clamp the decking to the designated decking support surfaces. If this is not possible, vertical load testing will not be conducted, and the bridge will not be eligible for awards in any category. [9.2.4, 9.2.8, 9.3.4, 9.3.5, 9.3.6, 9.3.7, 9.3.8, 9.3.9, 12.5.1]

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Q9.38. Can the width of a decking support surface vary along the span of the bridge? Brian Giffin, University of California Davis A. Yes, provided that the specified limits on spacing and width are satisfied at every location along the span. [9.3.5, 9.3.7] Q9.39. Is the prohibition of interlocking connections in specification 9.4.3 violated by a connection with multiple pairs of faying surfaces that intersect at various angles? Brian Giffin, University of California Davis A. There is no prohibition of interlocking connections. There is no limit on the number of faying surfaces or their alignment, but penalties will be imposed for violations of the specifications in section 9.4. The number of components penetrated by a fastener may be restricted by the limitation on bolt length. [9.4.3, 9.4.4, 9.4.5, 9.4.7, 10.2.4.2] Q9.40. In what direction must members be pulled apart to comply with specification 9.4.2? Brian Giffin, University of California Davis A. No direction is specified, and the word "pulled" is not used in specification 9.4.2. The specification is violated if there is a combination of pulls, pushes, and twists that will separate a connection without first removing the nuts from all the fasteners. [9.4.2] Q9.41. Would a fastener that penetrates a corner be considered to penetrate the two faying surfaces that form the corner? Phillip Sutter, Rochester Institute of Technology A. No. A hole for a fastener must be completely within the faying surface. [9.4.4] Q9.42. Can an abutment be made of two separate members? What is the minimum vertical clearance at the abutments? Tom Woloszyn, New Jersey Institute of Technology A. There is no limit on the number of members in an abutment. There is no specified vertical clearance under the bridge at the abutments. However, the abutments must facilitate application of restraint during lateral load testing as required by rule 12.4.1. The specified vertical clearance above the decking applies for the full length of the bridge including over the abutments. [9.2.8, 9.3.10, 9.3.11, 9.3.12, 12.4.1] Q9.43. Can a fastener that connects members be in contact with another member that is not in contact with any of the connected members? Tripp Collier, University of Alaska Fairbanks A. No. That detail could function as a connection while circumventing specifications that govern connections, resulting in disqualification. [3, 9.4.2] Q9.44. Are there specific areas where the bridge bears on the ground? Brent Ashmore, Mississippi State University A. No part of the finished bridge can bear in the river. The specified maximum bridge length and clearance under the cantilever impose another limitation. During construction and repair, an accident penalty will be assessed if any part of the bridge, including a bearing surface, touches the river. [9.2.2, 9.3.3. 9.3.4, 9.3.12, 11.4.5] Q9.45. Must a decking support surface be continuous side to side? For example, is specification 9.3.5 violated if on one side of the bridge there are two decking support surfaces each less than 1/2 inch wide but totaling 1/2 inch or more in width? Tristan Donovan, University of New Hampshire A. This would be a violation. On each side of the bridge the decking support surface must be continuous across its width, except as provided by specification 9.3.8. [9.3.5, 9.3.8] Q9.46. Does the discussion of corners in the answer to clarification Q9.25 apply to a corner formed by the intersection of a planar faying surface with a surface that is not a faying surface? Suong Chong, California State Polytechnic University Pomona A. Specification 9.4.3 is violated by a member that has a corner formed by the intersection of two surfaces, one or both of which are not faying surfaces, if that corner is in contact with a surface of another member that is not a faying surface that complies with the specifications in sub-section 9.4. [9.4.2, 9.4.3, 9.4.4, 9.4.5]

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Q9.47. Is there a violation of specification 9.3.8 if a gap in a decking support surface is less than 1/4 inch wide in the span direction but does not extend completely across the decking support surface? Vince DePianta, University of South Florida A. Not a violation. [9.3.8] Q9.48. What are the limits on the width of the bridge? David Tran, University of California San Diego A. There are no specifications that specifically limit width. However, lower limits are imposed indirectly by specifications 9.3.7 and 9.3.10. The latter applies only to bridges with structure above the level of the decking support surfaces. [9.2.8, 9.3.7, 9.3.10] Q9.49. Does clarification Q9.8 apply to rectangular connection fittings that are rectangular but have larger corner radii than manufactured rectangular tubes? Brent Clavin, California Polytechnic Institute San Luis Obispo A. A corner cannot comply with specification 9.4.3, and clarification Q9.46 applies regardless of radius. [9.4.3, 9.4.4] Q9.50. Can a nut protrude from the decking support surface if the height of the nut is less than 1/4 inch? Kristin Rivard, Colorado School of Mines A. That would be penalized as a violation of specification 9.3.6. The shank end of a bolt protruding from the decking support surface also would be penalized. [9.3.6] Q9.51. Can a single plate that spans across two parts of the same member also serve as a faying surface for connecting to another member? Can several separate plates on a member serve as a faying surface for connecting to another member? Bert Yee, University of California San Diego A. Both the single and multiple plate options are acceptable if they comply with all specifications governing faying surfaces. Each of the multiple plates serves as a separate faying surface. [9.4.3, 9.4.4] Q9.52. May gaps or depressions be incorporated intentionally in the decking support surfaces? Brian Watkins, Colorado School of Mines A. Specification 9.3.8 makes no distinction regarding intent. However, the bridge will be judged ineligible for competition if the gaps or depressions are an attempt to circumvent the Rules. [3, 9.3.8] Q9.53. Part of a member is cut short so that it will not contact another member. This is done deliberately to avoid creating a faying surface. Would this violate section 3 of the Rules by "circumventing the intent of the competition?" David Tran, University of California San Diego A. This would not violate section 3 unless the bridge is designed intentionally so that the part makes contact with another member during loading, or there is interference with measurement of the bridge or its deflections. It is advisable for non-contacting parts of different members to be spaced far enough apart so that the lack of contact is readily apparent to judges. Clarifications Q9.21, Q9.25, and Q9.33 are pertinent. [3, 9.4.3]

Materials and Component Specifications

Q10.1. Are Nylock nuts permitted? Courtney Judish, Colorado School of Mines

A. Nylon insert nuts would be penalized because they are not solid steel. [10.2.2, 10.2.4.3]

Q10.2. Can part of the bridge be a chain composed of rigid members connected by fasteners? Diego Garcia, University of Arkansas A. Yes. Every “link” must comply with specifications for members, and the connections between “links” must comply with specifications for member-to-member connections. The “chain” must be assembled during timed construction in compliance with construction regulations. [9.4, 10.2.3.1, 10.2.4.1, 11.3.2, 11.4.6]

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Q10.3. Can cables be used? David Van Atta, California State University Chico

A. Cables are not rigid and would violate specification 10.2.3.1. [10.2.3.1]

Q10.4. Are hex washer head bolts and hex washer nuts acceptable as fastener components? Anthony Campana, University of California Berkeley

A. Both would be penalized. [10.2.4.2, 10.2.4.3]

Q10.5. Is specification 10.2.3.2 fulfilled by a bridge member that fits in the box diagonally? Mike Shustack, University of Massachusetts Lowell

A. Yes. A team member or a judge directed by a team member can place a bridge member in the box in any orientation. The specification is fulfilled if no force other than gravity is needed to fit the member into the box. [10.2.3.2]

10.6. What is the definition of "rigid" as used in specification 10.2.3.1? Tristan Donovan, University of New Hampshire

A. That specification lists attributes of a rigid member. In addition, a member is not rigid if it displays no permanent distortion, such as a kink or buckle, if a judge bends it and then straightens it. For example, a cable is not rigid. [10.2.3.1]

Construction Regulations

Q11.1. Can a member be supported by a tool that is supported by a builder or by a tool that is supported by the constructed portion?Tom Woloszyn, New Jersey Institute of Technology

A. Yes to both questions. [11.1.8, 11.3.6, 11.3.9]

Q11.2. Must a member be fastened to the constructed portion before being released by a builder? Brian Watkins, Colorado School of Mines

A. No. [9.4.2, 11.1.11, 11.1.12, 11.3.2]

Q11.3. Can a member be placed on the constructed portion temporarily? Tom Woloszyn, New Jersey Institute of Technology

A. Yes. While it is in contact with the constructed portion it is considered to be part of the constructed portion. [11.1.11, 11.3.2]

Q11.4. Can a tool support another tool? Can a member be supported by a tool that is supported by another tool? Can a tool support more than one member? Kenneth M. Lemens, University of Wisconsin Platteville

A. Yes to all three questions but only if the assembly can be used safely, as determined by judges at the competition. [11.1.8, 11.2.6, 11.3.9]

Q11.5. Is a boombox a tool? Kenneth M. Lemens, University of Wisconsin Platteville

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A. A boombox is not a tool unless it is used to construct the bridge rather than just playing music. A boombox cannot be within the construction site and must not interfere with judges' movement or communication. Judges at the competition will decide whether to allow boomboxes and how loud they can be. [11.1.8, 11.6.1, 11.6.2]

Q11.6. Can spectators talk to or give advice to builders? Alex Armstrong, Florida Institute of Technology

A. Spectators are confined to areas distant from construction where they are safe and cannot interfere. These areas may be too far away for effective communication with builders. Spectators will be asked to refrain from yelling if it interferes with judges' communication. Teams cannot request a specific construction site. [11.2.3]

Q11.7. Can a builder simultaneously hold a member and the temporary pier, or a member and the constructed portion? Alex Armstrong, Florida Institute of Technology

A. There would be no violation if the judge determines that these actions are safe. [6, 11.2.2]

Q11.8. Can the surfaces of members that will be on the ground in the completed bridge be moved or rotated during timed construction?Brian Giffin, University of California Davis

A. Yes, but they must continuously remain in contact with the ground. However, there is risk that local conditions or a judge’s decision may not permit relocation of the constructed portion as a deliberate construction procedure. For example, it will not be permitted if it cannot be done safely and without damaging the floor. Also, it may not be possible due to local floor conditions or a construction site that is too short due to limited available space. [6, 9.2.8, 11.2.2, 11.3.2, 11.3.3]

Q11.9. Can a portion of the bridge be assembled in the staging yard and then transferred to the river? Christopher Gochnauer, Polytechnic Institute of New York University

A. That would violate regulations 11.3.2, 11.3.3 and 11.4.6, as well as circumventing the intent of the construction regulations, resulting in disqualification. [3, 11.3.2, 11.3.3, 11.4.6]

Q11.10. Does a member become part of the constructed portion simply by being in contact, or must a connection be made? Brian Giffin, University of California Davis

A. A member that is in contact with the constructed portion is part of the constructed portion. Compliance with specifications in sub-section 9.4 of the Rules is checked at the end of timed construction and repair. [9.4.2, 11.3.2]

Q11.11. Can a part of the constructed portion comprised of several members be moved or rotated relative to another part? Jason Douglas, Clemson University

A. Yes, but with the following qualifications. A judge must determine that there is no risk of injury. Regulation 11.3.3 would be violated if both parts are initially in contact with the ground but those contacts are not maintained continuously. If only one of the parts is initially in contact with the ground, regulation 11.4.6 would be violated if the two parts are initially in contact with one another but those contacts are not maintained continuously. Clarifications 11.3, 11.8, 11.9, and 11.10 are pertinent. [6, 11.2.2, 11.3.2, 11.3.3, 11.3.9, 11.4.6]

Q11.12. Can a member incorporate a fastener? For example, a bolt is tack welded to a member, the nut is

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installed during construction, and the weld is broken. Is that bolt and nut an acceptable fastener? JG McCall, Saint Martin's University

No, that would violate specification 10.2.4.1 and regulation 11.6.1. The same violations would apply to a nut welded to a member. [10.2.4.1, 11.6.1]

Load Test

Q12.1. If a bridge fails a lateral load test, is it eligible for any awards? Rules Committee

A. A bridge that fails a lateral load test is eligible for awards in all categories except stiffness. However, very large cost penalties will be assessed. The following values will be substituted for vertical deflections, with penalties as prescribed by rules 12.5.2 and 12.5.3: DB1 = three inches, DCA = two inches, and DCB = two inches. Penalties for these vertical deflection values are in addition to penalties prescribed by rules 12.4.2 and 12.4.3 for failing a lateral load test. [12.4.2, 12.4.3, 12.5.2, 12.5.3]

Q12.2. What if there are holes in the bridge that do not have fasteners? Alex Armstrong, Florida Institute of Technology

A. Unfilled holes in faying surfaces violate rule 9.4.3. Rule 12.2 prescribes a penalty if a judge determines that an unfilled hole was intended to accommodate a fastener. Holes not associated with connections are not violations. [9.4.3, 9.4.4, 12.2]

Q12.3. Can team members or the captain use their feet to restrain the bridge from sliding during lateral load tests? Alex Armstrong, Florida Institute of Technology

A. Yes. [12.4.1]

Q12.4. What is the distance from the B side of the bridge to the centroid of the 75-pound load that is used during lateral load testing? What will judges do if bearing surfaces of the bridge lift off the floor when lateral load is applied? Will additional load be applied? Phillip Bellis, Lafayette College

A. Judges should position the 75-pound load as close as practical to the edge of the decking. Since the decking is 3'6" wide and no more than 3'0" above the floor, the 75-pound load is sufficient to prevent tipping of the bridge, considered as a weightless rigid body. Bearing surfaces may lift off the floor if the bridge is very weak in torsion. The 75-pound load will not be increased, and the lateral load test will be conducted as usual. [9.3.9, 12.4.1, 12.4.2, 12.4.3, 13.6]

Q12.5. Will the initial reading of the vertical deflection measuring device on the back span be subtracted from the reading taken at the end of step one of the vertical load test? Gaurav Bali, California State University Sacramento

A. Yes. The initial reading is taken with both preloads in place and is subtracted from subsequent readings so that DB1 is the deflection of the back span caused by the 1400-pound test load. [12.5.1, 12.5.2]

MANY MORE CLARIFICATIONS TO BE FOUND AT THE FOLLOWING WEBSITE:

http://www.aisc.org/content.aspx?id=3232

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Appendix C: The SAP2000 Analysis Tables

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Base Reactions

Frame Section Assignments

TABLE: Frame Section Assignments

Frame SectionType AnalSect DesignSect MatProp

Text Text Text Text Text

1 Box/Tube HSS 1X1X1/8 HSS 1X1X1/8 Default














15 Angle L1-1/2x1-1/2-1/8 L1-1/4x1-1/4x1/8 Default








48 SD Section Rod 3/8 Correct Rod 3/8 Correct Default





127








































191 Angle L1-1/4x1-1/4x1/8 L1-1/4x1-1/4x1/8 Default



198 Box/Tube HSS 1/2X1/2X1/16 HSS Default

128

1/2X1/2X1/16






223 Box/Tube HSS 1/2X1/2X1/16 HSS 1/2X1/2X1/16 Default



































129











































130

Steel Design Summary – Strength Ratio

TABLE: Steel Design 1 ‐ Summary Data ‐ AISC360‐05‐IBC2006

Frame DesignSect DesignType Ratio Combo

Text Text Text Unitless Text

1 HSS 1X1X1/8 Column 0.175869 Backspan Combo

2 HSS 1X1X1/12 Beam 0.116406 Backspan Combo




6 HSS 1X1X1/12 Beam 0.249 Cantilever Combo






12 HSS 1X1X1/12 Column 0.033426 Cantilever Combo



25 HSS 1X1X1/12 Brace 0.067738 Cantilever Combo















130 HSS 1X1X1/12 Brace 0.067738 Cantilever Combo








131


191 L1‐1/4x1‐1/4x1/8 Beam 0.004342 Backspan Combo


197 Rod 3/8 Correct Beam 0.000119 Backspan Combo

198 HSS 1/2X1/2X1/16 Beam 0.001094 Backspan Combo

200 Rod 3/8 Correct Brace 0.000018 Backspan Combo














244 L1‐1/4x1‐1/4x1/8 Beam 0.003437 Cantilever Combo


246 Rod 3/8 Correct Beam 0.000233 Cantilever Combo

247 HSS 1/2X1/2X1/16 Beam 0.000976 Cantilever Combo

248 Rod 3/8 Correct Brace 0.000006674 Cantilever Combo




258 Rod 3/8 Correct Beam 0.000195 Cantilever Combo

259 HSS 1/2X1/2X1/16 Beam 0.000959 Cantilever Combo




267 HSS 1/2X1/2X1/16 Beam 0

48 Rod 3/8 Correct Column 0.000475 Cantilever Combo










132


151 Rod 3/8 Correct Column 0.002062 Backspan Combo










































133























15 L1‐1/4x1‐1/4x1/8 Brace 0

16 L1‐1/4x1‐1/4x1/8 Brace 0.000211 Cantilever Combo

17 L1‐1/4x1‐1/4x1/8 Brace 0.000391 Cantilever Combo




21 L1‐1/4x1‐1/4x1/8 Brace 0.000037 Backspan Combo

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Appendix D: Hand Calculations

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136

137

138

Appendix E: Shop Drawings

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140

141

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Documents

Design and Build Paper - Final Paper