koshland integrated natural science center

Koshland Integrated Natural Science Center

Haverford CollegeHaverford, Pennsylvania

Christopher J. Shelow Structural Option

Senior Thesis Spring ‘06


Thesis Presentation Outline

•Introduction & Building Background

•Design Professionals

•Existing Conditions

•Proposal

•Structural Study

•Construction Management Study

•Conclusions


Introduction & Building Background

• Located on the Haverford College campus

•4-story laboratory facility w/basement

•Also contains classrooms, offices, & communal spaces

•185,423 ft2

•Directly connected to existing Hilles & Sharpless Halls

•Total project cost of $42.6 Million



• Constructed in multiple phases

• Completed in 2003

• State-of-the-art laboratories

• Undergraduate & graduate research facility

• Houses seven natural science departments




•Design Professionals


•Proposal

•Structural Study


•Conclusions


Design Professionals

• Owner – Haverford College (Physical Plant) Haverford, PA

•Architect – Ayers/Saint/Gross (ASG) Architects & Planners Baltimore, MD

•Engineer – CUH2A Princeton, NJ

•General Contractor/CM – Skanska USA Building, Inc. Blue Bell, PA

•Laboratory Planner – Earl Walls Associates San Diego, CA






•Proposal

•Structural Study


•Conclusions


Existing Conditions - Overview

•Superstructure – Precast concrete framing

•Foundation – CMU foundation/retaining walls, precast piers

•Floor System – 10” precast plank w/ 2” topping

•Façade – Stone & precast panels

•Roof System – Steel framing w/ metal deck; precast plank


Existing Conditions – Floor System

•10” precast concrete hollow core plank by Strescon

•2” cast-in-place concrete topping slab

•Prestressed steel reinforcing tendons

•Typical span of 31’-6”

10”

2” Topping Slab


Existing Conditions – Floor Framing

• Typical bay: 31’-6” X 21’-0”

• Precast beams : 24”x12” spanning 21’-0”

• Precast columns : 16”x16” & 20”x20”

• Typical story height of 13’


Existing Conditions – Expansion Joints

• Separated by expansion joints into three independent structures

– East Wing– West Wing– Link


Existing Conditions – Typical Floor Plan

WEST WING

LINK

EAST WING

Expansion Jts. -


Existing Conditions – East Wing Plan

EAST WING

Typ. P.C. Beam

Typ. P.C. Column

Typ. P.C. Shear Wall

31’-5”31’-5”

13’-8”

21’


Existing Conditions – West Wing Plan

WEST WING

Typ. P.C. Column

Typ. P.C. Shear Wall

Typ. P.C. Beam

31’-6” 31’-6”13’-8”

21’


Existing Conditions – Link Plan

LINK

Typ. CMU Shear Wall Typ. CMU

Brg. Wall

104’

23’

25’-1

1”


Existing Conditions – Roof System

• East & West Wings – typical steel bent frames; W-shapes

• Link – precast plank w/ topping slab


Existing Conditions – Lateral System

• East & West Wings – 8” precast concrete shear walls

• Link – 10” CMU shear wall

WEST WING

LINK

EAST WING





Existing Conditions

•Proposal

•Structural Study


•Conclusions


Proposal – Problem Statement

Investigate an alternate system that could prove to be a more efficient system based on certain criteria

•Investigation Criteria:

– Cost of structural system

– Construction schedule duration

– Reduce loads – gravity & seismic

–Maintain existing floor layout & architecture


Proposal – Solution Process•Gravity system designs:

– Composite slab on deck floor system– Structural steel floor framing – beams, girders, & columns– Maintain typical bay size & story height

•Lateral system designs:– Reduced seismic loads– Concentric steel braced frame system– Check drift limitations

•Construction Management comparisons:– Structural system cost– Construction schedule of structural system


Proposal•Additional design considerations:

– All expansion joints will remain

– Existing foundation remains; lighter overall building weight

– Existing roof systems for East & West Wings remain; coincides steel framed system

– Central stair case design to remain, preserving innovative design of spiraled cantilevered stairs





Existing Conditions

Proposal

•Structural Study


•Conclusions


Structural Study – Design Codes

• 2003 International Building Code (IBC)

• AISC Load and Resistance Factor Design (LRFD), 3rd Edition

• ASCE 7-02 Minimum Design Loads for Buildings and Other Structures


Structural Study – Procedure

• Recalculation of gravity loads

• Create building model in RAM

• Perform RAM design of gravity members

• Recalculation of lateral loads

• Create several models of steel braced frames in STAAD Pro.

• Check drift limitations

• Calculate approximate cost of both structural systems & compare

• Create construction schedules for systems & compare


Structural Study – Slab Design

• Slab:

4” normal weight concrete, C.I.P.

• Deck:

1.5SB Normal Wt. Composite Metal Deck – Wheeling Catalog

1 ½” depth; 20 gage

Span – 7’-0”


Structural Study – Gravity Loads


Structural Study – RAM Design – East Wing• Typical beam size for typical bay: W10X12

• Typical girder size for typical bay: W21X44

• Typical column sizes: W10X33 & W10X39


Structural Study – RAM Design – West Wing• Typical beam size for typical bay: W8X10, W10X12


• Typical column sizes: W10X33 & W10X39


Structural Study – RAM Design – Link

• Typical beam size for typical bay: W10X12


• Typical column size: W10X33


Structural Study – Lateral Loads• Despite a lighter system, seismic still controlled

• Reduced shear on the building:

Precast Steel Precast Steel Precast SteelRoof - - - - 4th 71 73 - - 49 50 3rd 253 173 89 37 171 119 2nd 377 242 270 85 254 167

Base Shear 441 277 366 354 297 191

EAST WING WEST WINGLINK

34

7 8

9

10

1114 15

12 13

2

1

56


Structural Study – Braced Frames Layout

N


Structural Study – Lateral System

• Torsional components calculated for each frame

• In most, torsional forces negligible but still included

• Columns may be biaxially loaded; accounted for in STAAD design

• Strong and weak axis bending in braced frame columns


Structural Study – Lateral System

• Frames design - concentric K-braces or X-braces

• Drift limitations - L/600

• E-W direction: typ. K-braced frames

• N-S direction: typ. X-braced frames


Structural Study – Typical K-braced Frame

• L/600 = 1.04”

• Typ. column

W12X40

• Typ. girder

W21X44

• Typ. brace

W12X40

= 0.908”


Structural Study – Typical X-braced Frame

• L/600 = 1.04”

• Typ. column

W12X40

• Typ. beam

W12X14

• Typ. brace

W10X49

= 0.982”


Structural Study – 3D Models of Each Wing

West Wing Link East Wing





Existing Conditions

Proposal

Structural Study


•Conclusions


C. M. Study - Procedure

• Cost breakdown of both structural systems

• System cost comparison

• Task duration estimates for both systems

• Construction schedule comparison


C. M. Study – Cost Comparison

Precast Concrete System Structural Steel System

VS.

Summary

Proposed Steel system saves approx. 14% of total structural cost

Structure component System CostP.C. Columns 332,267.00P.C. Beams 245,600.00Precast Planks 670,311.00Concrete Topping 181,561.66CMU Bearing Walls 37,742.30P.C. Shear Walls 119,889.00

Total Cost: $1,587,370.96

Building Cost BreakdownStructure component System CostStructural Beams 469,665.36Structural Columns 162,370.26Lateral Braces 95,035.55Metal Deck 130,210.89WWF Slab Reinforcing 27,555.19Concrete Slab 193,482.38Fireproofing 229,301.51Connections 30,529.68Shear Studs 23,828.09

Total Cost: $1,361,978.90

Building Cost Breakdown

Building System System Cost Cost/sq. ft.Steel System 1,361,978.90 14.85Precast System 1,587,370.96 17.31

Total Savings: $225,392.06% Savings: 14%

Building Cost Breakdown


C. M. Study – Schedule Comparison

• Existing Precast Concrete System

Duration: 21 weeks

• Proposed Steel System

Duration: 27 weeks

• Existing precast system saves 6 weeks of construction time





Existing Conditions

Proposal

Structural Study

Construction Management Study

•Conclusions


Conclusions

• Proposed steel system to save 14% structural cost

• Precast system cuts erection time by 6 weeks

• Material availability – systems similar

• Floor layout & architecture remained unchanged

• Findings:

–Both systems viable options

–14% savings outweighs 6 wk. prolonged schedule

–Proposed steel system is slightly more efficient


Acknowledgements

• John Diaz & Ron Tola – Haverford College

• Sam Rozycki – CUH2A

• Valerie Gillespie – Gillespie Engineering

• AE Department Faculty & Staff

• Professor Parfitt – Thesis Advisor

• Chris Glinski, Dave Melfi, Justin Mulhollan, and many other 5 th year AE students

• Family & Friends

Thank you


Questions

koshland integrated natural science center

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