Michael J. Szott Structural Option Duquesne University Multipurpose Facility Duquesne University Forbes Expansion Michael Szott Structural Option Senior

Michael J. SzottStructural OptionDuquesne University Multipurpose Facility

Duquesne University Forbes ExpansionDuquesne University Forbes Expansion

Michael SzottMichael SzottStructural OptionStructural Option

Senior Thesis Senior Thesis PresentationPresentation

The Pennsylvania State University Spring Semester 2007


PresentationPresentation OutlineOutline

IntroductionIntroduction

Proposed AnalysisProposed Analysis

Structural Depth StudyStructural Depth Studyo Lateral system redesignLateral system redesigno Gravity system redesignGravity system redesign

Breadth StudiesBreadth Studieso AcousticsAcousticso Construction cost comparisonConstruction cost comparison

Conclusions and RecommendationsConclusions and Recommendations


LocationLocation


LocationLocation


Project OverviewProject Overview

Project TeamProject Teamo Duquesne UniversityDuquesne Universityo DRS ArchitectsDRS Architectso Jendoco ConstructionJendoco Constructiono Atlantic Engineering ServicesAtlantic Engineering Serviceso Dodson EngineeringDodson Engineeringo Hornfeck ElectricalHornfeck Electrical



Building StatisticsBuilding Statisticso Construction datesConstruction dates

o March 2006 – December 2007/January2008March 2006 – December 2007/January2008

o Building occupancyBuilding occupancyo Mixed Use – retail, student fitness, office, entertainmentMixed Use – retail, student fitness, office, entertainment

o Building sizeBuilding sizeo 7 stories – 125,000 sq. ft.7 stories – 125,000 sq. ft.

o Project costProject costo $24 million $24 million



Existing Structural SystemExisting Structural Systemo Gravity systemGravity system

o Composite steel constructionComposite steel construction

o Lateral systemLateral systemo Concentrically braced framesConcentrically braced frames

o FoundationsFoundationso Auger cast pilesAuger cast pileso Grade BeamsGrade Beams



Typical – Floors 1-3



Long Span Framing, Floors 4-5


Proposed AnalysisProposed Analysis

Lateral Resisting SystemLateral Resisting Systemo More efficient bracing scheme?More efficient bracing scheme?

Gravity System – Vibration AnalysisGravity System – Vibration Analysiso Intermixed activity spacesIntermixed activity spaceso Long span conditionsLong span conditions

Interior Acoustical PerformanceInterior Acoustical Performance

Impact on Construction Cost Impact on Construction Cost


Structural Depth: Lateral Structural Depth: Lateral RedesignRedesign

Lateral Bracing Lateral Bracing LocationsLocationsTypical FrameTypical Frame



Three Alternate Bracing Three Alternate Bracing SchemesSchemes

o Modified concentric bracingModified concentric bracing

o Chevron bracingChevron bracing

o Alternating diagonals (K-Alternating diagonals (K-bracing)bracing)



Design CriteriaDesign Criteriao IBC 2003IBC 2003o ASCE 7-02ASCE 7-02

Applied LoadsApplied Loadso DeadDeado LiveLiveo SnowSnowo WindWindo Seismic Seismic

IBC2003 section 1616.6 :

“analysis must be performed except when structures are assigned to Seismic Design Category A”



Individual Frames: RAM AdvanseIndividual Frames: RAM Advanseo OptimizationOptimization

o Minimal WeightMinimal Weight

o Member checkMember checko Local BucklingLocal Buckling

Overall System: RAM FrameOverall System: RAM Frameo Drift checkDrift check



Existing - Tension Existing - Tension OnlyOnly

Modified – Modified – Tension/CompresTension/Compres

sionsion

Chevron Chevron BracingBracing

““K” K” BracingBracing

LC: LC: DL+0.75LL+0.75WDL+0.75LL+0.75W



Existing Frame DesignExisting Frame Designo HSS 6x4x1/4 – 8x4x5/8HSS 6x4x1/4 – 8x4x5/8o Columns: Columns: W14x53 – W14x53 –

132132o Beams: Beams: W33x118W33x118

Modified Ten. – CompModified Ten. – Comp..o HSS 4x3x1/4 – 9x7x1/4HSS 4x3x1/4 – 9x7x1/4o Columns: Columns: W14x53 – W14x53 –

211211o Beams:Beams: W33x118W33x118

Chevron BracingChevron Bracingo HSS 4x3x1/4 – 10x8x3/8HSS 4x3x1/4 – 10x8x3/8o Columns: Columns: W14x53 – W14x53 –

211211o Beams:Beams: W24x76W24x76

““K” BracingK” Bracingo HSS 4x3x1/4 – 12x10x1/2HSS 4x3x1/4 – 12x10x1/2o Columns: Columns: W10x45 – W10x45 –

W24x131W24x131o Beams:Beams: W33x118W33x118



Chevron Bracing Chevron Bracing o Least weight of all systemsLeast weight of all systems

o Smallest frame beamsSmallest frame beamso Controlling deflection limits – L/600 or 0.3”Controlling deflection limits – L/600 or 0.3”

Bracing Layout HSS Braces Beams/Columns TotalsX-Bracing (T only) 46.5 198.7 245.2X-Bracing (T-C) 38.4 202.5 240.9Chevron Bracing 37.9 178.2 216.1

K-Bracing 37.4 192.4 229.8

Component weights

Lateral System Weight Comparison


Bracing Layout Drift @ HR Drift @ IR Drift @ 5th H/400 Existing 5.6 3.3 2.1 3.96

X-Bracing (T/C) 4.6 2.6 1.5 3.96Chevron Bracing 4.8 2.7 1.5 3.96

K-Bracing 5 2.9 1.6 3.96

Overall Building Drift (in.)


Drift at High Roof LevelDrift at High Roof Level

Drift at Intermediate Roof LevelDrift at Intermediate Roof Level

Drift at 5Drift at 5thth Floor Level Floor Levelo Pedestrian bridgePedestrian bridge


Structural Depth: Gravity Structural Depth: Gravity RedesignRedesign

VibrationVibration Design: AISC Design Guide Design: AISC Design Guide 1111o Floor vibrations due to human activityFloor vibrations due to human activityo Criteria based on rhythmic activityCriteria based on rhythmic activity

o AerobicsAerobicso Dining and DancingDining and Dancing

o Serviceability issue – Serviceability issue – not strengthnot strengtho Design to avoid personal discomfortDesign to avoid personal discomfort



Four Critical Spaces AnalyzedFour Critical Spaces Analyzedo 22ndnd floor Aerobic/Fitness areas floor Aerobic/Fitness areaso 33rdrd floor gymnasium (typical bays) floor gymnasium (typical bays)o 44thth floor gymnasium (long spans) floor gymnasium (long spans)o 55thth floor ballroom (long spans) floor ballroom (long spans)

o Designed for partially loaded baysDesigned for partially loaded bayso Modified constant “k” usedModified constant “k” used



Acceleration LimitsAcceleration Limits

Dancing/Dining Dancing/Dining 0.02g0.02g

Aerobics only Aerobics only 0.06g0.06g

Gymnasium 0.10g-Gymnasium 0.10g-0.15g0.15g

(i.e. basketball, etc…)(i.e. basketball, etc…)





Existing Fitness FramingExisting Fitness Framingo 20’8” span20’8” span

o Beams: W12x16 @ 7’ o.c.Beams: W12x16 @ 7’ o.c.o Girders: W16x31 (21’0”)Girders: W16x31 (21’0”)

o 31’4” span31’4” spano Beams: W18x40 @ 7’ o.c.Beams: W18x40 @ 7’ o.c.o Girders: W18x35 (21’0”)Girders: W18x35 (21’0”)

Span fn(act) 1st Harmonic 2nd Harmonic ap/g (%g) ao/g (%g)

20' 8" 8.48 5.38 8.03 0.051 0.0631' 4" 5.18 5.38 8.03 0.45 0.06

fn(reqd) (Hz)



New Fitness FramingNew Fitness Framingo 31’4” span31’4” span


Span fn(act) 1st Harmonic 2nd Harmonic ap/g (%g) ao/g (%g)

20' 8" 8.48 5.38 8.03 0.051 0.06

fn(reqd) (Hz)





Existing Ballroom Existing Ballroom FramingFramingo 79’6” span79’6” span


o Criteria not metCriteria not met

fn(act) fn(reqd) ap/g (%g) ao/g (%g)

3.89 5.4 0.105 0.02



Ballroom RedesignBallroom Redesigno Departure from Design Guide 11Departure from Design Guide 11

o Partial loading vs. Fully loaded baysPartial loading vs. Fully loaded bays



New Ballroom FramingNew Ballroom Framingo ConventionalConventional


o Castellated BeamsCastellated Beamso Modified wide flange sectionsModified wide flange sectionso Lighter and more stiffLighter and more stiffo EconomicalEconomical



Castellated Ballroom Castellated Ballroom FramingFramingo 79’6” span79’6” span

o Beams: CB50x221 @ 7’ o.c.Beams: CB50x221 @ 7’ o.c.o Girders: W27x84 (21’0”)Girders: W27x84 (21’0”)

fn(act) fn(reqd) ap/g (%g) ao/g (%g)

5.4 5.4 0.019 0.02



Overall Effects of New FramingOverall Effects of New Framingo Lighter gravity systemLighter gravity systemo Reduced clear height in both gym spacesReduced clear height in both gym spaceso Improved vibrational performanceImproved vibrational performanceo Cost?Cost?

Floor Use (Floor #) Existing AlternateBallroom (5th) 428.9 406.2Gym (4th) 377.5 321.9Gym (3rd) 127.4 162.8Aerobic (2nd) 132.2 153.8Totals 1066 1044.7

Framing Weight (kips)


Breadth Study: Breadth Study: Construction CostConstruction Cost

Castellated SectionsCastellated Sectionso Less material, reduced material costLess material, reduced material costo 2 man hours to convert from wide flange to castellated2 man hours to convert from wide flange to castellated

o “…“…in general, spans longer than 40’ can recoup these in general, spans longer than 40’ can recoup these costs.”costs.”

- Billy Milligan, VP of CMC Steel Products- Billy Milligan, VP of CMC Steel Products

DeliveryDeliveryo From Hope, ARFrom Hope, AR

o Distance: Distance: 1015 miles1015 mileso Cost: Cost: $65,500$65,500



Floor No. Material/Fabrication Labor/Delivery Totals2 $148,817.05 $10,943.67 $159,760.723 $143,289.60 $11,070.40 $154,360.004 $453,475.10 $10,612.77 $464,087.875 $452,528.50 $9,665.95 $462,194.45

$1,240,403.04

Floor No. Material/Fabrication Labor/Delivery Totals2 $173,202.95 $11,216.79 $184,419.743 $183,722.60 $11,112.59 $194,835.194 $357,415.10 $28,596.20 $386,011.305 $458,540.10 $36,454.99 $494,995.09

$1,260,261.32

Existing Gravity Framing per Floor (not including O+P)

Alternate Gravity Framing per Floor (not including O+P)

Material savings, Material savings, greater than fabrication greater than fabrication costscosts

Delivery costs drive Delivery costs drive more expensive systemmore expensive system



Lateral FramesLateral Frameso Structural tubing more expensive than wide flange Structural tubing more expensive than wide flange

sectionssectionso Fabrication and connection costsFabrication and connection costs

o Chevrons bracing: least material = least costChevrons bracing: least material = least costo Frame beams considerably smallerFrame beams considerably smaller

Lateral System Material/Fabrication Labor TotalsExisting Frames $313,054.75 $13,660.18 $326,714.93Alt.#1: Concentric $324,612.25 $13,710.44 $338,322.69Alt #2: Chevron $282,774.40 $12,160.28 $294,934.68Alt #3: "K" Bracing $347,034.25 $10,364.08 $357,398.33

Lateral System Cost Comparison (not including O+P)


Conclusions and Conclusions and RecommendationsRecommendations

A chevron bracing scheme offers a A chevron bracing scheme offers a reduction in weight and materialreduction in weight and material

Redesigning the lateral system will save Redesigning the lateral system will save on material costson material costs

Castellated beams improve floor vibrations Castellated beams improve floor vibrations and decrease floor weight over long spansand decrease floor weight over long spans

Gravity system costs increase slightlyGravity system costs increase slightly

Suggested improvements are cost feasible Suggested improvements are cost feasible


Questions??Questions??

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Michael J. Szott Structural Option Duquesne University Multipurpose Facility Duquesne University Forbes Expansion Michael Szott Structural Option Senior