final thesis presentation - penn state engineering · pdf filefinal thesis presentation. hali...

Schenley PlacePittsburgh, PA

Final Thesis Presentation

Hali Voycik I Structural OptionM. Kevin Parfitt, P.E., Thesis Advisor

BUILDING LOCATION4420 Bayard Street

Pittsburgh, PA 15213

OCCUPANCY TYPETypical office

PROJECTED COST$17.5 Million

SIZE165,000 SF

PROGRAM7 levels of unfinished tenant space

3.5 levels of parking garage

KEY PLAYERSElmhurst Group, owner

Burt Hill, architectAtlantic Engineering Services, structural

Image courtesy of Google Map

PROJECT OVERVIEW PRESENTATION OUTLINE

IntroductionProject OverviewScope of Work

Structural Depth StudyBuilding Site RelocationExisting StructureGravity Framing for 3-story AdditionRedesign of Supporting Gravity SystemsDesign of Lateral Force Resisting SystemsDetermination of Effective LFRS

Architectural BreadthEvaluation of LFRS Relocation

Construction Management BreadthEvaluation of Cost due to 3-story AdditionEvaluation of Benefits to Owner

ConclusionsAcknowledgementsQuestions

SCOPE OF WORK

STRUCTURAL DEPTH STUDY1. Relocate Schenley Place Office Building to a site free of zoning and design constraints2. Design the gravity framing for a 3-story addition of rentable office space3. Redesign the supporting above and below grade gravity systems of the existing structure4. Design a lateral force resisting system that effectively reduces torsional effects

ARCHITECTURAL BREADTH STUDY1. Evaluate the effect relocating the LFRS core has on the existing floor plans

CONSTRUCTION MANAGEMENT BREADTH STUDY1. Evaluate the effect a 3-story addition has on the final cost of the existing structural system2. Determine if the owner benefits from a 3-story addition

PRESENTATION OUTLINE






Originally designed as a 10-story building

Final 7-story design and existing geometry dictated by historic zoning constraints governing the building’s site due proximity to:

1. Schenley Farms—a historic residential district

2. The First Baptist Church of Pittsburgh—a designated historic structure


BUILDING DESIGN PRESENTATION OUTLINE






Image courtesy ofGoogle Map

Image courtesy of The Elmhurst Group

HISTORIC PROTECTION ZONING ORDINANCES PRESENTATION OUTLINE






BUILDING SITE RELOCATION

PROPOSED SITE

EXISTING SITE








EXISTING STRUCTURE

FOUNDATION SYSTEMConcrete perimeter caisson wall

Concrete drilled caissonsConcrete grade beams

PARKING GARAGEFLOOR SYSTEM

11” two-way flat slab with drop panelsGRAVITY SYSTEM

30”X18” concrete columns8” to 12” concrete walls

TYPICAL OFFICESFLOOR SYSTEM

3 ½” n.w.c. slab3”-20 G composite metal floor deck

GRAVITY SYSTEMComposite steel W-shape beams

Steel W-shape columns

LATERAL SYSTEMEccentrically braced frames

Concentrically braced frames







GRAVITY FRAMING FOR 3-STORY ADDITION PRESENTATION OUTLINE






REDESIGN OF SUPPORTING GRAVITY SYSTEM

ABOVE GRADE GRAVITY SYSTEMRAM Steel Column used to optimize designWherever possible, original column depths maintained

BELOW GRADE GRAVITY SYSTEMExisting designs analyzed in PCA ColumnRAM Concrete Column Load Summary output used to verify designs

DRILLED CAISSION FOUNDATION SYSTEMDesigned with an end-bearing capacity of 25 tons per square foot







ETABS MODELS

GENERAL ASSUMPTIONS AND CONSIDERATIONSOnly lateral members were modeledFloor diaphragms were modeled as rigid area elementsGravity loads were applied as additional area masses

BRACED FRAME ASSUMPTIONS AND CONSIDERATIONSColumn splices and beam-to-column connections were assumed rigidBraces were released of end fixity

SHEAR WALL ASSUMPTIONS AND CONSIDERATIONSWalls were modeled as area objects, meshed with maximum 48”X48” dimensionsWalls were modeled to only resist in-plane shear







CONTROLLING LOAD CASES

DESIGN WIND LOADSDesign wind load cases were calculated by hand and applied manually

DESIGN SEISMIC LOADSDesign seismic load cases were calculated by hand and applied manuallySeismic accidental torsion was calculated by hand applied manuallyAssumed inherent torsion was accounted for by ETABS







DESIGN OF BRACED FRAME LFRS

DESIGN CONSIDERATIONSMaintained design of a LFRS core as well as its existing location for practical reasonsSpecial attention paid to torsional effects







FINAL DESIGN OF BRACED FRAME LFRS

FINAL DESIGNControlling wind design base shear: 448 kipsDesign values determined via ETABS model and hand calculationsDesigns of steel members verified through hand checks based on Specification for Structural Steel Buildings, 2005 (AISC 360-05)

COLUMN LINE 4 COLUMN LINE C COLUMN LINE DCOLUMN LINE 5.1







DESIGN OF SHEAR WALL LFRS

DESIGN CONSIDERATIONSMaintained design of a LFRS core as well as its existing location for practical reasonsAccommodated existing architectural floor plansSpecial attention paid to torsional effects







FINAL DESIGN OF SHEAR WALL LFRS

FINAL DESIGNControlling wind design base shear: 448 kipsDesign values determined via ETABS model and hand calculationsSteel reinforcement designed according to Building Code Requirements for Structural Concrete, 2008 (ACI 318-08)








FINAL SHEAR WALL DESIGN18” thick wallsDesigned both shear and flexural reinforcement

Uplift was accounted for in design of flexural reinforcementFlexural reinforcement design was verified in PCA Column








FINAL COUPLING BEAM DESIGN18” in width, 24” in depth (typical)Designed both shear and flexural reinforcementNot specially detailed for seismic







DETERMINATION OF EFFECTIVE LFRS

DESIGN CONSIDERATIONSSystem that adequately resists lateral loads System that reduces the direct effects of torsion

Ftotal = Fdirect + Ftorsional

Where, Fdirect = Viki and Ftorsional = kixi(Viey/Ji)







ARCHITECTURAL BREADTH

EVALUATION OF LFRS RELOCATIONFeasibility initially assumedPractical relocations of LFRS create greater eccentricities or interrupt exterior façadeElimination of core and scattered lateral system interrupts open office floor plans







CONSTRUCTION MANAGEMENT BREADTH

ASSUMPTIONS AND CONSIDERATIONSExisting schedule and cost information was not attainableCost Works, a program created by RS Means used in analysisSteel and area take-offs as computed by RAM








IMPACT OF 3-STORY ADDITION ON COST OF STRUCTURAL SYSTEM







TOTAL ADDITIONAL COST: $1,120,000


BENEFIT OF 3-STORY ADDITION TO OWNER







CONCLUSIONS

A 3-story addition forces the redesign of the supporting above and below grade gravity systems

Redesign of drilled caisson foundation system is necessary

Braced frame lateral system determined most effective in reducing direct affects of torsion after comparative analysis of calculated torsional shears

The relocation of the LFRS core not structurally feasible

The design of a scattered LFRS is not architecturally feasible

Although the 3-story addition adversely impacts the final building cost, the owner benefits from the increased cost through increased profits allowing for a shorter pay-back period







ACKNOWLEDGEMENTS PRESENTATION OUTLINE






I would like to thank the following individuals and companies for the steadfast support they offered throughout the duration of the thesis process:

The Elmhurst Group Andy GildersleeveAtlantic Engineering Services Andy VerrengiaThe Pennsylvania State University The entire AE Faculty

Professor Parfitt

And lastly, my family and friends for their unconditional support and encouragement.

QUESTIONS? PRESENTATION OUTLINE






final thesis presentation - penn state engineering · pdf filefinal thesis presentation. hali...

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