Computer Associates International, Regional Office Herndon, VA Seth R. Takoch AE Senior Thesis Structural Option April 15, 2003
Presentation Outline Background Information Existing Structural Conditions Design Criteria Redesign Construction Management Lighting Design Conclusions and Recommendation Acknowledgements SETH R. TAKOCH STRUCTURAL OPTION
Location 15min. Off Beltway 35mins. Outside D.C Wood Oak Dr. Baseball Field
Background Information Function: Computer Associates Int. Regional Headquarters Size: 233,000 sq. ft. – 6 floors Rentable Office Space: 207,000 sq. ft. Architectural Features: Precast Concrete Façade with Glass Curtain Wall Six Story Glass Enclosed Atrium Adjacent Day Care Facility
Project Team Owner – Computer Associates International Arcitect – Davis, Carter, Scott Structural Engineer – Smislova, Kehnemui, & Associates. General Contractor – Clark Construction Developer – Tishman Speyer Properties Mechanical – GHT Limited Plumbing – GHT Limited
Existing Structure Flat Slab Construction Concrete Structure 30’ x 30’ Bays 9” Thick Slab Thickness 10’ x 10’ x 5-1/2” Drop Panels 24” x 24” Conc. Columns
Existing Structure Wind Loads are Transferred by Diaphragm Action of Façade Transferred to Framing by Tributary Area 8 Frames N-S and 9 Frames E-W Concrete Frames Resist Lateral Forces Short and Long Frames Floor Slab Adds Resistance due to Diaphragm Action
Design Limitations 50 psf 22 psf 30 psf Old Code – BOCA 96 New Code – IBC 2000 Local Zoning Ordinances Similar Square Footage Minimal Architectural Changes Floor-to-Floor Heights LIVE LOADS PER IBC 2000 LOAD TYPE LOAD ROOF ( RAIN ) 50 psf ROOF ( SNOW ) HIGH ROOF 22 psf ROOF (SNOW) LOW ROOF 30 psf OFFICES, CUBICLES ASSEMBLY, STAIRS 100 psf MECHANICAL 150 psf CORRIDORS 80 psf
Proposal To Redesign a Feasible and Desirable Alternative Structural System and to Incorporate Construction Costs and Schedule Length Into My Solution Time = Money … Money = Time $$$$
Possible Faming Alternatives Composite Steel Construction Non-Composite Steel Construction
Steel Construction Code – IBC2000 LRFD Analysis Parameters 30’ x30’ Typical Bays Fy = 50ksi ASTM A992 Steel F’c = 3ksi Normal Weight Concrete Shear Studs - 3-1/2”high, ¾” diameter (composite) 22 gage Metal Deck
Composite Steel Construction Gravity Analysis – RAM Determined Beam Sizes Determined Column Sizes 2 Story Column Lengths 26’ – 28’ Tall Ranging from W10’s to W12’s Beam Sizes W12x14 Spaced at 6’ o.c. Girders as Deep as a W21’s
Non-Composite Construction Gravity Analysis – RAM Determined Beam Sizes Determined Column Sizes 2 Story Column Lengths 26’ – 28’ Tall Using W12’s Beam Sizes W12x14 Spaced at 6’ o.c. Girders as Deep as a W24’s
Depth Comparison Composite Steel Average – W12’s Critical Depth – W21 Composite Saves 20 Tons of Steel Non-Composite Steel Average – W12’s Critical Depth – W24 Advantage – Composite Steel Construction
Lateral System Shear Wall to Resist Lateral Loading Based on Critical Wind Loading and Torsion 2 – 60’ Long Shear Walls Reinforced to Resist Forces Deflection of h/400
Design Reinforcement Based on the Following Wall Floor Shear Bending 1 #4 @ 12" 8 - #11 2 6 - #11 3 6 - #9 4 #6 @ 12" 4 - #9 5 #7 @ 12" 2 - #9 6 #9 @ 12" 1 - #9 #5 @ 12" #8 @ 12" #10 @ 12" Reinforcement Based on the Following Vn = (2f’c bd + Avfyvd/s) Mn = Asfy (d-a/2)
Construction Management ` Address Two Main Issues Cost Comparison Project Duration
Construction Management ` Total Building Cost D4 Cost Total = $27,678,667 20-25% Accurate Range of $34.6 million to $20.8 million Not Very Accurate $115.33 / sq. ft.
Construction Management ` Total Building Cost Means Building Construction Cost Data Separate Estimates for Steel and Concrete 10 -15% Accurate More Precise Than D4 Steel Framing = $96.74 / sq.ft. Concrete Frame = $98.45 / sq.ft. Difference = $1.71 / sq.ft. = $410,400
Construction Management ` Cost Comparison D4 Cost = $115.33/sq.ft. = $27,678,667 Means Steel = $96.74/sq.ft. = $23,217,600 Means Concrete = $98.45/sq.ft. = $23,628,000 Percentage Savings Using Steel = 1.7% Savings
Construction Management ` Scheduling Means Data to Calculate Duration Primavera Utilized to Schedule Sequences Total Duration Steel Erection = 376days Total Duration Concrete Placement = 847 days
Construction Management ` After Scheduling Concrete – 260 Days
Construction Management ` After Scheduling – 150 Days
Construction Management ` Savings Advantage Composite Steel Construction Time Advantage Composite Steel Construction Composite Design is Considered One of the Most Economical Methods of Floor Construction for an Office Building
Construction Management ` Crane Sizing On Site 3-1/2 Months Tower Crane Placed Through Atrium Liebherr 200HC Hook Radius – 197ft. Capacity – 5,070# Satisfies Critical Lift of 3,000# @160ft.
Lighting Design Design of Lighting of Daycare Facility Minimum Footcandles of 30fc Fluorescent Luminaries 120’ x 56’ Space to Illuminate 2’ x 4’ Fixtures with 3” Louvers Spaced on a 16’ x 8’ grid Specification From Lithonia Workplane of 2-1/2 ft.
Lighting Design Designed Using Luxicon Renderings on April 15, 2003 At 9:00 am with Daylighting At 1:30 pm with Daylighting At 5:00 pm with Daylighting Without Daylighting
Lighting Design 9:00 am
Lighting Design At 1:30 pm
Lighting Design At 5:00 pm
Lighting Design Without Daylighting
Lighting Design The Lighting Design Meets Required Parameters of 30fc
Conclusion In Conclusion, Composite Steel Construction is a Better Alternative to Non-Composite Construction. Composite Steel is a Viable Alternative to a Two-Way Flat Slab System
Shout Outs’ My Family My Friends The AE Student Body The Entire AE Faculity Smislova, Kehnemui, & Associates, P.A. Computer Associates The ‘U’ And All Of Those Out There That Stuck With Me
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