1. URS – ARENA DISTRICT OFFICE BUILDING DAVID LEE STRUCTURAL OPTION

2. PRESENTATION OUTLINE 1. EXISTING CONDITIONS 2. DEPTH STUDY 3. BREADTH STUDY 4. CONCLUSION & RECOMMENDATION David Lee Structural Option URS – Arena District Office Building

3. PRESENTATION OUTLINE 1. EXISTING CONDITIONS 2. DEPTH STUDY 3. BREADTH STUDY 4. CONCLUSION & RECOMMENDATION David Lee Structural Option URS – Arena District Office Building

4. EXISTING CONDITIONS 1 Located in Columbus, Ohio 5 story – 100,000 SF building March 2000 – January 2001 construction duration Total project cost $7 million David Lee Structural Option URS – Arena District Office Building Building Statistics

5. EXISTING CONDITIONS 2 David Lee Structural Option URS – Arena District Office Building OHIO BASIC BUILDING CODE 1998 STRUCTURAL STEEL  AISC Manual of Steel Construction CAST IN PLACE CONCRETE  ACI 318 – “Building Code Requirement for Reinforced Concrete”  ACI 301-89 – “Specification for Structural Concrete for Buildings” PRECAST CONCRETE  ACI 318 – “Building Code Requirement for Reinforced Concrete”  PCI MNL 120 – “PCI Design Handbook Pre-cast and Pre-stressed Concrete” METAL DECK  AISI – “Specification for the Design of Cold-formed Steel Structural Members”  SDI – “Design Manual for Composite Decks, Form Deck, and Roof Decks” MASONRY  ACI 530.1/ASCE 6/TMS 602 Table 1 Building Code

6. EXISTING CONDITIONS 3 David Lee Structural Option URS – Arena District Office Building Typical Floor Framing

7. EXISTING CONDITIONS 4 David Lee Structural Option URS – Arena District Office Building Lateral Load Direction Factored Base Shear Due to WIND Factored Base Shear Due to SEISMIC North-South Loading Considered Y 281.38 kip169.30 kips East-West Loading Considered X 142.8 kips169.30 kips Existing Lateral System Y X

8. EXISTING CONDITIONS 5 David Lee Structural Option URS – Arena District Office Building Center of Mass Center of Rigidity Floor Height (feet) Floor to Floor Height Max Displacement X (inch)Y (inch) R72141.4561.019 558141.2320.855 444140.9570.67 330140.6410.438 216 0.3040.209 Story Drift Seismic Story Drift Limit X (inch)Y (inch) 0.6720.1643.36 0.8250.1853.36 0.9480.2323.36 1.0110.2293.36 0.9120.2093.84 Drift and Torsion

9. PRESENTATION OUTLINE 1. EXISTING CONDITIONS 2. DEPTH STUDY 3. BREADTH STUDY 4. CONCLUSION & RECOMMENDATION David Lee Structural Option URS – Arena District Office Building

10. DEPTH STUDY 1 OBJECTIVES Eliminate Moment Frames Reduce Floor Depth David Lee Structural Option URS – Arena District Office Building CONSTRAINTS North and West façade must be free of obstruction Large open floor space must be maintained Objectives and Constraints

11. Design: Removed both moment frames Added a braced frame Result: Reduced eccentricity David Lee Structural Option URS – Arena District Office Building Steel Alternative DEPTH STUDY 2

12. Steel Member Size New steel frame identical to braced frame 1 David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 3 Steel Alternative

13. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 4 Steel Alternative Constraint Met & Design Goal Achieved

14. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 5 Steel Alternative Drift and Story Drift Calculated Maximum Drift L/780 *due to wind

15. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 6 Concrete Alternative Concrete Design Flat plate 2 way PT slab CIP columns Shearwalls

16. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 7 Concrete Alternative Recalculate Loads Self weight of building increase from 52 PSF to 106 PSF Seismic lateral load controls in both X and Y direction 8.5” concrete slab with density of 150PCF = 106PSF

17. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 8 Concrete Alternative PT Slab Design Feasibility domain created to obtain possible force, eccentricity combination Steel envelop developed after tendon force is determined Y X

18. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 9 Concrete Alternative  Max initial deflection = 0.1” Max sustained  deflection = 0.46” Max long term deflection = 1.58”  Limit Floor Deflection L = l /360 D+L = l /240

19. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 10 Concrete Alternative CIP Column Perform gravity design Consider slenderness effects Check punching shear

20. David Lee Structural Option URS – Arena District Office Building DEPTH STUDY 11 Concrete Alternative Shearwalls Coincide with elevator shaft and stairwell Max Drift = l /1000 Foundation Larger footings needed Existing foundations require 350CY of concrete Concrete design require 1000CY of concrete for foundation

21. PRESENTATION OUTLINE 1. EXISTING CONDITIONS 2. DEPTH STUDY 3. BREADTH STUDY 4. CONCLUSION & RECOMMENDATION David Lee Structural Option URS – Arena District Office Building

22. BREADTH STUDY 1 Cost and Schedule Considerations Cost Construction Duration Constructability RS MEANS SteelConcrete Cost ($/SF)15.5816.80 Duration (days)2753

23. PRESENTATION OUTLINE 1. EXISTING CONDITIONS 2. DEPTH STUDY 3. BREADTH STUDY 4. CONCLUSION & RECOMMENDATION David Lee Structural Option URS – Arena District Office Building

24. CONCLUSION & RECOMMENDATION Recommendation Steel Construction cost savings of $122,000 Shorter construction duration Majority of office building in Columbus use steel frame Concrete Cost savings due to reduced floor depth Flexibility in on-site alterations No lead time

25. ACKNOWLEDGEMENTS URS Corporation Bill Huckleberry, Structural Engineer ONCORE Construction Raymond E. Sowers AE Faculty Professor Andres Lepage Professor M. Kevin Parfitt Professor Jelena Srebric Professor John Messner Rest of the AE Faculty AE Students Sean Flynn Brian Ault AND All my family and friends David Lee Structural Option URS – Arena District Office Building

26. QUESTIONS ?