Railings - WSPondemandweb.pbworld.net/pbucontent/aicc/LRFD_Railings/data... · a new section that specifically addresses railings. ... • Steel Structures ... conditions beneath

AASHTO- Load and Resistance Factor Design (LRFD)

Railings

V 1.2 – Rev. 1.17.08

Credits

The content for this class has been provided by the following PB employees:

Paul Pilarski, P.E., S.E.

Emily Elwood, E.I.T.

Ali Askari, E.I.T.

If you have any questions about the content of this course please contact Paul Pilarski. If you have any technical difficulties, please contact your IT Help Desk.

Download Information

• As with all of our LRFD courses, you may download a PDF version of this course for your future reference.

• Click on the ATTACHMENTS link located in the upper right corner of this course window to access the document and save the file to your desktop.

Successful Completion

• After completing the content within the class you will be asked to take a final test to ensure that you mastered the key training objectives.

• You will need to make a minimum scoreof 80% to receive credit for passing the class.

• Successful completion of the class will earn 0.1 IACET CEU.

• Please refer to your state’s specific continuing education requirements regarding applicability.

Curriculum

This class is the final class in the Structures TRC curriculum for LRFD Design, developed internally at PB. The LRFD Specifications introduce a new section that specifically addresses railings.

• Foundations

• Deck & Deck Systems

• Joints and Bearings

• Abutments, Piers, and Walls

• Railings

• Introduction to LRFD

• Loads and Load Factors

• Concrete Structures

• Steel Structures

• Buried Structures

Objectives

At the end of this course you should be able to identify:

1. The variety of railing types that exist2. Common design issues with railings3. The LRFD Test Level railing categories and applications4. Applications of yield line theory to concrete railing design

5. Examples of LRFD loading applications to common pedestrian and traffic railing designs

This course will take you approximately one hour to complete.

Course Outline – LRFD Railings

Course Outline

1. Railing Types and Considerations

2. Traffic Railings

3. Railing Design Example

4. Pedestrian/Bicycle Railings

5. Combination Railings

Topic 1

Topic 1Railing Types and Considerations

Topic 1- Railing Types and Considerations

Railing Selection

• Applicable railing design/retrofit:• All new bridges

• Bridge Widening Projects

• Deck Replacements

• Railing reconstruction with design speeds in excess of 45 mph

• General factors/considerations:• Variations in traffic volume, speed, vehicle mix, roadway alignment, activities and

conditions beneath the structure (C13.7.1.1)

• Traffic on structure, vehicular (highway), pedestrian

• Ultimate strength, durability, ductility, maintenance, ease of replacement, and long term behavior (C13.5)

• Average Daily Traffic (ADT), Average Daily Truck Traffic (ADTT), Design Hourly Volume (DHV)


LRFD Railing Types (Chapter 13)

• Traffic Railing (Art. 13.7)

• Pedestrian Railing (Art. 13.8)

• Bicycle Railings (Art. 13.9)

• Combination Railings (Art 13.10)


Rail Application Guidelines C13.4

• Highway traffic only – Traffic Railing

• Highway traffic and pedestrians: low-speed highways (≤ 45mph) – Combination Railing, Barrier Curb Application

• Highway traffic and pedestrians: high-speed highways (> 45mph) – Combination Railing, Outboard & Inboard Application

• Pedestrians only – Pedestrian/Bicycle Rail


Common Materials

• Steel

• Aluminum

• Concrete

• Timber

See Commentary Section C13.5


Railing Selection

• Standard• Availability

• Cost

• Non-Standard• Increased Fabrication

• Increased Design Review

• Possible crash testing required

• Funding• TH Projects

• SA Projects


Maintenance Issues

• Snow plow

• Galvanizing and painting• Galvanize for protection

• Paint for aesthetics

Rub Rail

Topic 1 – Railing Types and Considerations

LRFD Limit States and Resistance Factors

• Applicable load combinations: Table 3.4.1-1

• Resistance factors specified in Articles 5.5.4, 6.5.4, 7.5.4, and 8.5.2

• Strength Limit State – Pedestrian and Bicycle Railings

• Loads (LL) given in Section 13

• Extreme Event Limit State – Traffic Railings

• Impact forces (CT), as described in 3.6.5

• Section 3.6.5 outlines need for impact protection

• Loads given in Section 13 Appendix A


Course Outline


2. Traffic Railings




Topic 2

Topic 2

Traffic Railings

Topic 2 - Traffic Railings

Traffic Railing (Art. 13.7.1.1)

Consideration should be given to:

• Protection of the occupants of a vehicle in collision with the railing

• Protection of other vehicles near the collision

• Protection of persons and property on roadways and other areas underneath the structure

• Possible future rail upgrading

• Railing cost-effectiveness

• Appearance and freedom of view from passing vehicles

Topic 2 – Traffic Railings

Traffic Railing (13.7.2)

Test Level Index

Test Level

Application Test Speed

Vehicle Characteristics

TL-1 •Work zones, low posted speeds, low volume

•Low speed local streets

30 mph30 mph

Small Auto (1550 lbs, 1800 lbs)Pickup Truck (4500 lbs)

TL-2 •Work zones

•Local and collector roads, small number of heavy vehicles, reduced posted speeds

45 mph45 mph


TL-3 •Wide range of high-speed arterial highways, low mixtures of heavy vehicles

•Favorable site conditions

60 mph60 mph



Traffic Railing (13.7.2)

Test Level Index (Cont.)

Test Level

Application Test Speed

Vehicle Characteristics

TL-4 •High speed highways, freeways, expressways and Interstate highways

•Mixture of trucks and heavy vehicles

60 mph60 mph50 mph

Small Auto (1550 lbs, 1800 lbs)Pickup Truck (4500 lbs)Single-Unit Truck (18,000 lbs)

TL-5 •Same applications as TL-4, large average daily truck traffic, unfavorable site conditions

60 mph60 mph50 mph

Small Auto (1550 lbs, 1800 lbs)Pickup Truck (4500 lbs)Tractor Trailer (80,000 lbs)

TL-6 •Tanker-type trucks or similar high center of gravity vehicles

•Unfavorable site conditions

60 mph60 mph50 mph

Small Auto (1550 lbs, 1800 lbs)Pickup Truck (4500 lbs)Tractor-Tanker Trailer (80,000 lbs)


Common Traffic Railings:

• W-Beam Bridge Rail

• Thrie-Beam Bridge Rail

• Metal Tube Bridge Rail

• Vertical Concrete Parapet

• F-Shape Concrete Barrier/Single Slope

• Timber Bridge Rail

W-Beam Bridge Rail

Texas T101 Transition Rail• Height: 32”

• Test Level: TL-2

• Utilized in: Federal Lands

Box Beam Rail (W-Beam Backed with Steel Beam)• Height: 27”


• Utilized in: Ohio

Thrie-Beam Bridge Rail

Oregon Thrie-Beam Side Mount• Height: 29”


• Utilized in: Oregon

Michigan Bridge Railing, Thrie-Beam Retrofit (R4 Type)• Height: 34”


• Utilized in: Michigan

Metal Tube Bridge Rail

Illinois 2399 – Type Side Mount (Steel Tube Bridge Rail Attached to Side of Deck)

• Height: 32”


• Utilized in: Illinois

Minnesota Combination Bridge Rail, Design #3 (Steel Tube Bridge Rail Attached to Parapet)• Height: 36”


• Utilized in: Minnesota

Oregon 2 – Tube Curb Mount (Steel Tube Bridge Rail Attached to Curb)• Height: 32”


• Utilized in: Oregon

Metal Tube Bridge Rail

Foothills Parkway Aluminum Bridge Rail (Aluminum Tube Bridge Rail)• Height: 33”


• Utilized in: Federal Lands

California Type 18 (Steel Tube Bridge Rail Attached to Side of Deck)• Height: 36”


• Utilized in: California

Vertical Concrete Parapet

New Jersey Barrier• Height: 32”


• Utilized in: Georgia

Type 732 Concrete Barrier• Height: 32”


• Utilized in: California

32”/42” F-Shape• Height: 32”/42”


• Utilized in: Florida

F-Shape concrete Barrier/Single Slope & Timber Bridge Rail

Timber Rail 3 Bridge Rail

• Height: 27”



Custom or New Traffic Railings:

• Testing required for new systems per LRFD 13.7.3.1.2

• Previously tested railings may be used provided no changes made to the features tested (LRFD 13.7.3.1.1)

• Geometry must meet geometric constraints previously mentioned

• Design according to LRFD 13.7.3 and Appendix A


Minimum Height of Traffic Parapet or Railing (Art 13.7.3.2)

Ref. Table A13.2-1

Test Level Minimum Railing Height, H

TL-1 27.0 in

TL-2 27.0 in

TL-3 27.0 in

TL-4 32.0 in

TL-5 42.0 in

TL-6 90.0 in


Traffic Railing Geometry (A13.1.1)

Figure 1: Typical Traffic Railings

• Distance below bottom rail, cb• Setback distance, S• Maximum opening, c• Minimum Height, H• Rail Height, A• ΣAi > 25% of H


Traffic Railing Geometry (A13.1.1)

Figure 2: Potential for Wheel, Bumper, or Hood Impact with Post

• Vertical clear opening, c

• Post setback, S


Traffic Railing Geometry

Figure 3: Post setback and rail configuration limits


Traffic Rail – Traffic Railing Design Forces (Ref. Article A13.2)

The effective height of the vehicle rollover force, He is:

12.13A.EqnF2WB12GH

te −−=

where:

G = height of vehicle center of gravity above bridge deck, as specified in Table 13.7.2-1 (in)

W = weight of vehicle corresponding to the required test level, as specified in Table 13.7.2-1 (kips)

B = out-to-out wheel spacing on an axle, as specified in Table 13.7.2-1 (ft)

Ft = transverse force corresponding to the required test level as specified in Table A13.2-1 H

e


Traffic Rail – Traffic Railing Design Forces (Ref. Article A13.2)

The effective height of the vehicle rollover force, He is:

12.13A.EqnF2WB12GH

te −−=

LRFD Table 13.7.2-1


Traffic Railing Design Forces


Traffic Railing Design Forces

12H

R)YR(Y

FRR

eii

ti

≥=

≥=

∑

∑


(ft.) rail of heightH(ft.) wallof heightH

(kips) A13.3.1 Articlein specified as wallofcapacity ultimateR(kips) span one over rail ofcapacity ultimateR

:where

)23.3.13A( R

HRHRY

)13.3.13A(RRR

R

W

W

R

WWRR

WR

=

==

=

−+

=

−+=

Traffic Railing Impact Resistance


Course Outline


2. Traffic Railings




Topic 3Railing Design Example

Topic 3 – Railing Design Example

Design Example: Type F Barrier, TL-4 Barrier

Type F Barrier Design Outline:

Barrier Flexural Resistance

Interior Region

Exterior Region

Shear Capacity Check


LRFD Design Example – Type F Barrier Design

Method described in LRFD Article A13.3.1

Yield Line Theory• Under loading cracks develop

• Increase loads reinforcement begins to yield in area of crack (yield line develops)

• Load resistance shifts to non-yielded sections Cracks migrate and divides element into rigid

regions

• Regions rotate about yield lines and pivot about their axis of rotation

• Work dissipated by hinges in lines = work expended by loads causing displacements

Before Impact

First yield and hinge formation

Additional hinge formation/Yield lines



Typical reinforcement and geometry:• Horizontal reinforcement: eight #4

bars

• Vertical reinforcement: two #5 bars

• anchored in the deck and projects 10” into the rail

• closed stirrup that laps the other #5 bar

• TL-4 minimum height, 32”


Moment resistance components:

• Mb = the flexural capacity of the cap beam (if present)

• Mw = the flexural capacity of the railing about its vertical axis

• Mc = the flexural capacity of the railing about a horizontal axis


Lce = length of the end regions

Lci = length of interior yield line mechanisms


Determine Mb: Type F barrier has no additional beam section at its top.

Mb = 0

Determine Mw:

1,3,5, and 7: yield lines that produce tension on the inside face of the rail

2, 4, 6, and 8: yield line has tension on the outside face of the rail


Mw Interior Region:

in21.0242.0

2a

in42.0340.485.060.020.04

b'f85.0fA

ca

,where

ksi60f)bar4#for(in20.0A

.Art.fRe),StateLimitEventExtremefor(0.1

12.2.3.7.5.Eqn2adfAM

c

ystotal1

y

2s

ysn

==

=∗∗

∗∗==β=

=

=

=ϕ

−⎟⎠⎞

⎜⎝⎛ −ϕ=ϕ

b = height of rail = 34 in.


Mw Interior Region (cont.):

Bar d (in) Lever Arm

d-a/2 (in)

φMni forInside Face

Tension (k-in)

φMno forOutside FaceTension (k-in)

1 7.72 7.51 90.1

2 7.94 7.73 92.8

3 8.88 8.67 104.0

4 9.07 8.86 106.3

5 10.04 9.83 118.0

6 11.93 11.72 140.6

7 10.77 10.56 126.7

8 14.87 14.66 175.9

Totals 438.8 515.6


ft/ftkip18.1583.2

12/6.515HMM

ft/ftkip92.1283.2

12/8.438HMM

nowo

niwi

−=⎟⎠⎞

⎜⎝⎛=⎟

⎠⎞

⎜⎝⎛ ϕ=

−=⎟⎠⎞

⎜⎝⎛=⎟

⎠⎞

⎜⎝⎛ ϕ=

Mw Interior Region (cont.):

For interior rail regions there is one outside tension yield line and two inside tension yield lines. Compute the average Mw:

ft/ftkip7.13 3

18.15192.122

3M1M2M wowi

intw

−=

∗+∗=

∗+∗=


Mw End Region:

BAR Embedded Length (in)

Bar Fraction

Developed

Developed Bar Area As (in2)

1 36 1.00 0.20

3 24.9 1.00 0.20

5 10.9 0.91 0.18

7 2.1 0.18 0.04

Total 0.62


Mw End Region:


Bar Fraction

Developed


1 36 1.00 0.20

3 24.9 1.00 0.20

5 10.9 0.91 0.18

7 2.1 0.18 0.04

Total 0.62in16.0

232.0

2a

in32.0340.485.0

60.062.0b'f85.0

fAca

ksi60fin20.0A

0.12adfAM

c

ystotal1

y

2s

ysn

==

=∗∗

∗==β=

=

=

=ϕ

⎟⎠⎞

⎜⎝⎛ −ϕ=ϕ



Bar Fraction

Developed


d (in) Lever Arm d-a/2 (in)

φMn for Inside Face Tension

(k-in)

1 36 1.00 0.20 7.72 7.56 90.7

3 24.9 1.00 0.20 8.88 8.72 104.6

5 10.9 0.91 0.18 10.04 9.88 106.7

7 2.1 0.18 0.04 10.77 10.61 25.5

Total 0.62 Total 327.5

Capacities φMn for End Region:

Mw is found by averaging the capacity of the rail over the height of the rail:

ft/ftkip6.983.2

12/5.327HMM n

wend −=⎟⎠⎞

⎜⎝⎛=⎟

⎠⎞

⎜⎝⎛ ϕ=


Section for Mc (flexural capacity about horizontal axis) and shear:

Location d (in) Average d (in)

Top 7.97

Mid Top 10.50

Mid Bottom 11.02

Bottom 14.25

12.64

9.24


Mc Interior Region – Bottom Portion :

#5 bar basic hook development length

( )( ) in98.988.117.02.1db ==l

( ) in88.114625.00.38

'fd0.38

c

bhb ==

∗=l

Modification factors

5.2”

4.5”

%97 in98.9

in5.4in2.5developed %

=

+=

Avg. “d” = 12.64”

MnDOT chose to assume 75%


Determine Mc (Bottom Portion):

Bottom Portion

Compression block depth and

moment per foot:


Top 7.97

Mid Top 10.50

Mid Bottom 11.02

Bottom 14.25

12.64

9.24

Astop = 0.31in2/ft x 75% = 0.23 in2/ft

( )( ) ft/ftkip3.14121

234.064.126023.00.1

2adfAMM

in34.012485.0

6023.0b'f85.0

fAca

botbotysbotncbot

c

ysbot1bot

−=⎟⎠⎞

⎜⎝⎛⎟⎠⎞

⎜⎝⎛ −=

⎟⎠⎞

⎜⎝⎛ −ϕ=ϕ=

=∗∗

∗=

∗∗

∗=β=



Top 7.97

Mid Top 10.50

Mid Bottom 11.02

Bottom 14.25

12.64

9.24

Determine Mc (Top Portion):

Top Portion

Compression block depth and

moment per foot:

Astop = 0.31in2/ft

( )( )

ft/ftkip0.14 121

246.024.96031.00.1

2a

dfAMM

in46.0120.485.0

60.031.0b'f85.0

fAca

toptopystopnctop

c

ystop1top

−=

⎟⎠⎞

⎜⎝⎛∗⎟

⎠⎞

⎜⎝⎛ −∗=

⎟⎟⎠

⎞⎜⎜⎝

⎛−ϕ=ϕ=

=∗∗

∗==β=


Determine Mc (Average):

( ) ( )

ft/ftkip1.14 ft83.2

ft00.1ft/ftkip3.14ft83.1ft/ftkip0.14M intc

−=

−+−=


Mc End Region:

For the top portion, Astop = 0.62in2/ft

( )( ) ft/ftkip2.27121

291.024.96062.00.1

2a

dfAMM

in91.012485.0

6062.0b'f85.0

fAca

toptopystopnctop

c

ystop1top

−=⎟⎠⎞

⎜⎝⎛⎟⎠⎞

⎜⎝⎛ −=

⎟⎟⎠

⎞⎜⎜⎝

⎛−ϕ=ϕ=

=∗∗

∗=

∗∗

∗=β=

For the bottom portion, Asbot = 0.75(0.62) = 0.47 in2/ft

( )( ) ft/ftkip9.28121

269.064.126047.00.1

2adfAMM

in69.012485.0

6047.0b'f85.0

fAca

botbotysbotncbot

c

ysbot1bot

−=⎟⎠⎞

⎜⎝⎛⎟⎠⎞

⎜⎝⎛ −=

⎟⎠⎞

⎜⎝⎛ −ϕ=ϕ=

=∗∗

∗=

∗∗∗

=β=

( ) ( ) ft/ftkip8.2783.2

00.19.2883.12.27Mcend −=+

=


Summary of Flexural Capacities

Axis Interior Region End RegionMw (Bending about vertical axis)

(Average k-ft/ft)

13.7

14.1

9.6

Mc (Bending about horizontal axis)

(Average k-ft/ft)

27.8


Flexural Capacity Check – Interior Region (Article A13.3.1):

Mbint = 0 Lt = 3.5 ft per Table A13.2-1

Mwint = 13.7 kip-ft/ft

Mcint = 14.1 kip-ft/ft

( )

11.3.13A.Eqnkips0.98HLMM8M8

LL22R

21.3.13A.Eqnft8.9M

HMMH82L

2LL

2ciintc

intwintbtci

wi

intc

intwintb2

ttci

−=⎟⎟⎠

⎞⎜⎜⎝

⎛++⎟⎟

⎠

⎞⎜⎜⎝

⎛−

=

−=⎥⎦

⎤⎢⎣

⎡ ++⎟

⎠⎞

⎜⎝⎛+=

• H = height of wall (ft)

• Lc = critical length of yield line failure pattern (ft)

• Lt = longitudinal length of distribution of impact force Ft (ft)

• Rw = total transverse resistance of the railing


Type F Barrier, TL-4 Barrier• Ft Transverse (kip) = 54

• FL Longitudinal (kip) = 18

• FV Vertical/Down (kip) = 18

• Lt and LL (ft) = 3.5

• He Minimum Height of Horizontal Loads (in) = 32

• H Minimum Height of Rail (in) =32


Flexural Capacity Check – Exterior Region (Article A13.3.1):

Mbend = 0 Lt = 3.5 ft per Table A13.2-1

Mwend = 9.6 kip-ft/ft

Mcend = 27.8 kip-ft/ft

( )

31.3.13A.Eqnkips8.81HLMHMM

LL22R

41.3.13A.Eqnft2.4M

H*MMH2L

2LL

2cecend

wendbendtce

we

cend

wendbend2

ttce

−=⎟⎟⎠

⎞⎜⎜⎝

⎛+∗+⎟⎟

⎠

⎞⎜⎜⎝

⎛−

=

−=⎥⎦

⎤⎢⎣

⎡ ++⎟

⎠⎞

⎜⎝⎛+=


Shear Capacity Check – Exterior Region (Article A13.3.1):

Ft = 54 kips Ref. Table A13.2-1

FL = 18 kips Ref. Table A13.2-1

Shear friction formula:

Use µ = 0.60 and substitute Vres for φVn:

( )[ ]cyvfcvn PfAcAV +µϕ=ϕ

legs7.531.076.1

AA

in76.1ksi6060.090.0

kips9.56f

vA

b

vfreq

2

yv

resvfreq

=⎟⎠⎞

⎜⎝⎛⎟⎟⎠

⎞⎜⎜⎝

⎛

=⎟⎠⎞

⎜⎝⎛

∗∗=⎟

⎟⎠

⎞⎜⎜⎝

⎛

µϕ=

4.8.5f.Rekips9.561854FFV 222L

2tres =+=+=


Shear Capacity Check (continued):

5.7 legs of #5 reinforcement required

Interior Region:

Lci = 9.9 ft

10 provided

Exterior Region:

Lci = 4.2 ft

9 provided


Course Outline


2. Traffic Railings




Topic 4

Topic 4Pedestrian/Bicycle Railing

Topic 4 – Pedestrian/Bicycle Railing

Pedestrian Railing (Art. 13.8)

Design:

• Minimum height 42.0 in. measured from the top of the walkway

• Max openings – horizontal rails only: • 6” sphere cannot pass through

• Max openings – horizontal and vertical elements (grid):

• 6” sphere cannot pass through lower 27”

• 8” sphere cannot pass through openings above 27”

• Max openings – Rails with fencing• Fence openings < 2.0”

• Suggested that rails should project beyond posts and that a curb should be provided



Design 13.8.2

Railings

• PLL = 0.05 kips/ft

• Horizontally and vertically

Posts

• PLL = 0.20 + 0.050Lwhere L = post spacing (feet)

Chain link fence

• PLL = 0.015 ksf on fence area assuming enclosed


Bicycle Railing (Art. 13.9)

Same as pedestrian bridge except:

Geometry

• Railing at 27” spacing or less

• Railing outside of posts to prevent catch hazard

• Rubrails are optional

Design

• Design of rails 54” above surface are left up to the owner/designer

• Railing design load identical to pedestrian railing



Pedestrian railing examples:


Bicycle Railing (Art. 13.9)

Bicycle railing examples:


Course Outline


2. Traffic Railings




Topic 5Combination Railings

Topic 5 – Combination Railings

Combination Railings (Art. 13.10)

High Speed Combination Railing

Low Speed Combination Railing



High-Speed Highways:

• Applicable for design speeds in excess of 45 mph

• Shall conform to pedestrian or bicycle railing requirements (whichever is applicable) Arts. 13.8 and 13.9

• Traffic railing portion: Art. 13.7

• Design loads for pedestrians/bicycles shall not be applied simultaneously with the vehicular impact loads (Ref. Art. 13.10.3)



Low-Speed Highways

• Applicable for design speeds less than 45 mph

• Minimum curb height adjacent to sidewalk is 6 in.

• Shall conform to pedestrian or bicycle railing requirements (whichever is applicable) Arts. 13.8 and 13.9

• Traffic railing portion: Art. 13.7

• Design loads for pedestrians/bicycles shall not be applied simultaneously with the vehicular impact loads (Ref. Art. 13.10.3)


Course Outline


2. Traffic Railings




Objective Review

You should now be able to identify:

1. The variety of railing types that exist

2. Common design issues with railings

3. The LRFD Test Level railing categories and applications

4. Applications of yield line theory to concrete railing design

5. Examples of LRFD loading applications to common pedestrian and traffic railing designs

References

• American Association of State and Highway Transportation Officials, "AASHTO LRFD Bridge Design Specifications" 4th Edition 2007, Section 13 Railings, Appendix A13 Railings.

• Federal Highway Administration, FHWA California Division, "Bridge Rail Guide 2005". http://www.fhwa.dot.gov/bridge/bridgerail/bridgerail.pdf

• Goodchild, Charles and Kennedy, Gerald, "Practical Yield Line Design". Reinforced Concrete Council, British Cement Association 2003. http://www.concretecentre.com/PDF/PYLD240603a.pdf

• Kettleson, Paul, Railings, Presented at LRFD Bridge Design Workshop, June 12, 2007. Minnesota Department of Transportation Bridge Office. http://dot.state.mn.us/bridge/Manuals/LRFD/June2007Workshop/11a%20Railings.pdf

• Minnesota Department of Transportation, "Mn/DOT Bridge Office LRFD Bridge Design Manual". Minnesota Department of Transportation Manual 5-392, Oakdale, MN, July 2007. Section 13 Railings. http://ihub.dot.state.mn.us/bridge/Manuals/LRFD/LRFD-Manual.pdf

• Western, Kevin, LRFD Railing Design, Presented at LRFD Bridge Design Workshop, 2004. Minnesota Department of Transportation Bridge Office.

Final Assessment

Instructions

You are now ready to begin the final assessment.

• The assessment consists of 10 multiple choice questions.

• You will need to achieve a minimum score of 80% to receive credit for passing the course.

• If you score below 80%, please go back and review the content of this course, and then retake the assessment to achieve a passing score.

When ready, click the Right arrow below to advance to the assessment.

Conclusion

Thank you for completing this course. If you received a passing score on the assessment, simply close this window to exit the course. Your score will be recorded on your transcript. If you did not achieve a passing score, please review the content of this course and thenretake the assessment to achieve a passing score.

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If you need a certificate that specifically states the IACET certification and credit hours, please email a request to us at [email protected].

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Documents

Railings - WSPondemandweb.pbworld.net/pbucontent/aicc/LRFD_Railings/data... · a new section that specifically addresses railings. ... • Steel Structures ... conditions beneath