1. Welcome to Daniel Painter’s Architectural Engineering Senior Thesis Presentation of Two Freedom Square April 16, 2003 Pennsylvania State University

2. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

3. Background Information Located in Reston, Virginia Part of Reston Town Center Seven Miles from Dulles Airport 16-story Office Building 450,000 Square Feet 2 nd building of a two building complex Total Cost: $42 million Start and Finish Dates October 24, 2000 June 15, 2002 Building Code: BOCA 1996

4. Important People Owner: Boston Properties Architect: SmithGroup, Inc. Structural Engineer: Tadjer Cohen Edelson General Contractor: Centex Construction

5. Picture of Two Freedom Square

6. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

7. Existing Structure – Floor System Two-way Flat Slab with Drop Panels 8” Slab 10” to 12” Drop Panels Floor to Floor Height 11’-11” Bay Sizes –N-S direction 31’-6” 28’-0” 25’-0” –E-W direction 30’-6” 29’-0”

8. Bay Sizes 31.5’ 28’ 25’ 28’ 31.5’ 29’ 30.5’

9. Existing Structure – Lateral System Eccentrically Braced Frames Columns – vary in sizes Largest - 32” x 32” Smallest - 12” x 24” Column Strength 4,000 psi (13 th to roof) 6,000 psi (9 th to 12 th ) 8,000 psi (4 th to 8 th ) 10,000 psi (cellar 2 to 3 rd ) Wind vs. Seismic Wind Controlled System Overall Drift was 2:1 Allowable Drift –h/400 = 6.6 inches –Actual drift Wind = 3.38 inches Seismic = 1.68 inches

10. Pros and Cons Efficient Core Design Low Floor to Floor Heights Cost Effective No Addition Fireproofing Required Excess Number of Columns

11. Proposed Problems Rearrange the Column Layout by placing the Columns on the Column Lines Investigate a Concrete and Steel Design of the building Redesign the Core of the Building Resize Crane Investigate Fireproofing Use the IBC 2000 code

12. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

13. Structural Design Option: Concrete Floor System Two-way Flat Slab with Drop Panels 10” Slab 12” Drop Panels Floor to Floor Height 11’-11” Bay Sizes –N-S direction 30’-0” 28’-0” 25’-0” –E-W direction 30’-6” 29’-0”

14. Bay Sizes 30’ 28’ 25’ 28’ 30’ 29’ 30.5’

15. Structural Design Option: Concrete Lateral System Eccentrically Braced Frames Columns – vary in sizes Largest - 30” x 30” Smallest - 18” x 18” Column Strength 5,000 psi was used for all floors Wind vs. Seismic Wind Controlled System Overall Drift was 2:1 Allowable Drift –h/400 = 6.6 inches h = 220 ft –Actual drift Wind = 5.99 inches

16. Pros and Cons Simpler Column Layout Smaller Columns Faster Schedule than Steel Same Floor to Floor Height of Existing Structure Increased Slab Depth Increased Drop Panel Depth Redesign of the Core

17. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

18. Structural Design Option: Steel Floor System Slab on Deck 2” LOK Deck 4½” Concrete Cover Maximum Span = 10 ft Floor to Floor Height 14’-0” Non-Composite Composite

19. Bay Sizes 30’ 28’ 25’ 28’ 30’ 29’ 30.5’

20. Structural Design Option: Steel Lateral System Moment Frames In both directions Not symmetric Comprised of W- Shapes Shear Walls –4 in the N-S direction 10 feet long each –2 in the E-W direction 20 feet long each Overall Height Increased to 250 feet Wind vs. Seismic Wind Controlled System Torsion Allowable Drift –h/400 = 7.5 inches –Actual Drift Wind = 7.34 inches

21. Pros and Cons Simpler Column Layout Increased Floor to Floor Height Need for a Crane for Erection Longer Schedule than Concrete Need of Additional Fireproofing Higher Cost than Concrete

22. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

23. Construction Management Design Option Estimates (RS Means) Steel BuildingConcrete Building Adjusted Cost per Sq. Ft. $69.41 Contractor Fee (25%) $17.35 Architect Fee (6%) $4.16 Final Cost per Sq. Ft. $90.92 Final Cost$40,934,911.60 Adjusted Cost per Sq. Ft. $74.19 Contractor Fee (25%) $18.55 Architect Fee (6%) $4.45 Final Cost per Sq. Ft. $97.19 Final Cost$43,757,853.70

24. Construction Management Design Option Time Estimates (RS Means) Daily OutputAmountDaysCrews Steel Erection13.9 ton/day3,466.479 tons249.39E-6 Non-Composite Deck4,000 sq. ft./day450,230 sq. ft.112.56E-4 Composite Deck3,600 sq. ft./day450,230 sq. ft.125.06E-4 Slab – pumped140 cy/day18,759.58 cy134C-20 Slab – crane & bucket100 cy/day18,759.58 cy187.6C-7 Steel Construction Concrete Construction Existing Structure 2 weeks per floor 200 days

25. Construction Management Design Option Crane Sizing Liebherr –290 HC Crane –Tower Crane –Cost = $11,500 per month –Capacity = 9,070 pounds at 197 foot radius Example of Crane Capacity at 197 ft

26. Crane Location

27. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

28. Architecture Design Option New Column Layout –Adjusted Core Layout –Adjusted some Floor Layout Switched the bathrooms Separated the Elevators Mens Womens

29. Pictures of Ground Floor Plan

30. Pictures of 9 th Floor Plan

31. Pictures of 12 th Floor Plan

32. Pictures of 15 th Floor Plan

33. Pros and Cons Changed Core Column by the Elevators

34. Order of Presentation Introduction/Background Existing Structure Structural Design Options –Concrete Design –Steel Design Breadth Design Option –Construction Management –Architecture Conclusion Questions

35. Conclusion Steel vs. Concrete Concrete has a lower Floor to Floor Height Steel Requires Additional Fireproofing Concrete is Cheaper New Column Layout Requires a redesign of the Core of the Building Reduces the number of Columns in the building Schedule Concrete Building is faster to Construct Crane Necessary for Steel Construction So which Design should be Chosen??

36. The Existing Structure is the Logical Choice due to the Cost, Schedule, and better Core Design The Steel Redesign Adds Height, a Crane and Cost The Concrete Redesign could work with some Refining

37. Special Thanks William Hendrix and Joel Kelty from SmithGroup The AE Faculty Friends in the Lab

38. Questions