1. Structural Engineering: Skyscrapers
Sergio F. Breña
STEM Education Institute
Saturday Workshop
September 30, 2006
University of Massachusetts Amherst

2. Skyscraper Design Process
The challenge: provide increased office space in urban environments
Research/brainstorm
Constraint: expensive real estate (limited floor plan)
Other successful applications?
Materials available locally?
What are known structural solutions that have worked well before?
Design alternative(s)
Testing/validation of design (particularly for cases where experience is limited)
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3. Evolution of Skyscrapers
Skyscraper construction was largely due to:
Need for large office space in crowded downtown areas
Creation of an Icon for companies or individuals
The name of numerous skyscrapers comes from the company occupying the building
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4. Evolution of Skyscrapers
Skyscraper development was possible because of:
Development of Stronger Materials
Steel and concrete replaced stone and masonry
Invention of Elevator
Development of more efficient structural systems
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5. Stability of Buildings
Sinking
(Settlement)
Sliding
Overturning
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6. Lateral Deformation of Tall Buildings
Lateral loads drive design of tall buildings
Even if stable, buildings still deform
Wind Pressure
Top Displacement (Drift) H
Wind Drift < H/500
Example:
H = 1,400 ft (WTC)
Wind Drift = 2.8 ft
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7. Structural Systems for Skyscrapers
1st National Bank - Chicago
Structure: Exterior Frame, Exterior Shear Walls
Height: 850 ft (60 stories)
Year: 1969
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8. Structural Steel Frame
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9. Reinforced Concrete Frame
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10. Early Steel Skyscrapers
Flatiron Building
Structure: Steel Frame
Height: 285 ft
Year: 1903
Façade: Non-structural limestone
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11. Early Steel Skyscrapers
Woolworth Building
Structure: Steel Frame, Vertical Truss
Height: 792 ft
Year: 1913
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12. University of Massachusetts Amherst
International Style
Lever House
Structure: Steel Frame
Façade: Glass Curtain Wall
Height: 24 stories
Year: 1952
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13. Structural Systems for Skyscrapers
Chicago Civic Center
Structure: Steel Frame, Vertical Truss
Height: 285 ft
Façade: Glass
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14. Example of Braced Frame
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15. Early Steel Skyscrapers
Chrysler Building
Structure: Steel Frame, Vertical Truss
Height: 1,046 ft (77 floors)
Year: 1930
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16. Early Steel Skyscrapers
Empire State Building
Structure: Steel Frame, Vertical Truss
Height: 1,250 ft (1453 ft to top of spire)
Year: 1931
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17. University of Massachusetts Amherst
International Style
Seagram Building
Structure: Steel Frame
Height: 38 stories
Year: 1958
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18. University of Massachusetts Amherst
Modern Steel Frames
MetLife (PanAm) Building
Structure: Steel Frame
Façade: Glass Curtain Wall
Height: 808 ft
Year: 1963
2.8 M SqFt office space
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19. Structural Systems for Skyscrapers
Alcoa Building - Chicago
Structure: Exterior Braced Frame
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20. Structural Systems for Skyscrapers
First Wisconsin Center
Structure: Steel Frame, Vertical Truss, Steel Belts
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21. Structural Systems for Skyscrapers
Structure: Exterior Tube and Central Concrete Core
“Tube in Tube”
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22. Structural Systems for Skyscrapers
World Trade Center
Structure: Steel Tube
Height: 1,368 ft
Year: 1972
Collapsed: 2001
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23. University of Massachusetts Amherst
Modern Skyscrapers
Water Tower Place
Structure: Concrete Tube
Façade: Glass and Granite
Height: 859 ft (74 stories)
Year: 1976
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24. Structural Systems for Skyscrapers
John Hancock Center
Structure: Exterior Braced Frame Tube
Height: 1,127 ft
Year: 1969
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25. Structural Systems for Skyscrapers
Sears Tower
Structure: Bundled Tube
Height: 1,454 ft
Year: 1974
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26. Structural Systems for Skyscrapers
Landmark Tower
Structure: Superframe
Height: 971 ft
Year: 1993
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27. University of Massachusetts Amherst
Modern Skyscrapers
Petronas Towers
Structure: Stiff concrete core and perimeter supercolumns
Height: 1,483 ft
Year: 1999
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28. University of Massachusetts Amherst
Modern Skyscrapers
Taipei 101
Structure: Outrigger frames on supercolumns; tuned mass damper
Height: 1,667 ft (101 stories)
Year: 2003
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29. Taipei 101 – Structural System
Source: Poon, D.C.K., Shieh, S., Joseph, L.M., Chang, C.C., “Reaching for the Sky”, Civil Engineering, V. 74, No. 1, pp
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30. University of Massachusetts Amherst
It’s all About Height
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31. University of Massachusetts Amherst
Future
Shanghai World Financial Center
Height: 1,614 ft
Projected Completion: 2007
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32. University of Massachusetts Amherst
Future
Burj Dubai
Height: 2,314 ft (?) – “well guarded secret but will surpass Taipei 101
Structural Design: Skidmore, Owings, Merrill LLP (SOM)
Projected Completion: 2009
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33. Construction of Burj Dubai Tower
Source: Irwin, P.A. and Baker, W.F. “The Burj Dubai Tower Wind Engineering, Structure magazine, NCSEA/CASE/SEI, June 2006, pp
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34. Burj Dubai Tower Models
Source: Irwin, P.A. and Baker, W.F. “The Burj Dubai Tower Wind Engineering, Structure magazine, NCSEA/CASE/SEI, June 2006, pp
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35. University of Massachusetts Amherst
Future
Freedom Tower
Height: 1,776 ft (to tip of spire)
Projected Completion: 2010
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36. University of Massachusetts Amherst
Building Big Website
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37. PEER Undergraduate Competition – Seismic Design
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