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

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) University of Massachusetts Amherst

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 University of Massachusetts Amherst

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 University of Massachusetts Amherst

Stability of Buildings Sinking (Settlement) Sliding Overturning University of Massachusetts Amherst

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 University of Massachusetts Amherst

Structural Systems for Skyscrapers 1st National Bank - Chicago Structure: Exterior Frame, Exterior Shear Walls Height: 850 ft (60 stories) Year: 1969 University of Massachusetts Amherst

Structural Steel Frame University of Massachusetts Amherst

Reinforced Concrete Frame University of Massachusetts Amherst

Early Steel Skyscrapers Flatiron Building Structure: Steel Frame Height: 285 ft Year: 1903 Façade: Non-structural limestone University of Massachusetts Amherst

Early Steel Skyscrapers Woolworth Building Structure: Steel Frame, Vertical Truss Height: 792 ft Year: 1913 University of Massachusetts Amherst

University of Massachusetts Amherst International Style Lever House Structure: Steel Frame Façade: Glass Curtain Wall Height: 24 stories Year: 1952 University of Massachusetts Amherst

Structural Systems for Skyscrapers Chicago Civic Center Structure: Steel Frame, Vertical Truss Height: 285 ft Façade: Glass University of Massachusetts Amherst

Example of Braced Frame University of Massachusetts Amherst

Early Steel Skyscrapers Chrysler Building Structure: Steel Frame, Vertical Truss Height: 1,046 ft (77 floors) Year: 1930 University of Massachusetts Amherst

Early Steel Skyscrapers Empire State Building Structure: Steel Frame, Vertical Truss Height: 1,250 ft (1453 ft to top of spire) Year: 1931 University of Massachusetts Amherst

University of Massachusetts Amherst International Style Seagram Building Structure: Steel Frame Height: 38 stories Year: 1958 University of Massachusetts Amherst

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 University of Massachusetts Amherst

Structural Systems for Skyscrapers Alcoa Building - Chicago Structure: Exterior Braced Frame University of Massachusetts Amherst

Structural Systems for Skyscrapers First Wisconsin Center Structure: Steel Frame, Vertical Truss, Steel Belts University of Massachusetts Amherst

Structural Systems for Skyscrapers Structure: Exterior Tube and Central Concrete Core “Tube in Tube” University of Massachusetts Amherst

Structural Systems for Skyscrapers World Trade Center Structure: Steel Tube Height: 1,368 ft Year: 1972 Collapsed: 2001 University of Massachusetts Amherst

University of Massachusetts Amherst Modern Skyscrapers Water Tower Place Structure: Concrete Tube Façade: Glass and Granite Height: 859 ft (74 stories) Year: 1976 University of Massachusetts Amherst

Structural Systems for Skyscrapers John Hancock Center Structure: Exterior Braced Frame Tube Height: 1,127 ft Year: 1969 University of Massachusetts Amherst

Structural Systems for Skyscrapers Sears Tower Structure: Bundled Tube Height: 1,454 ft Year: 1974 University of Massachusetts Amherst

Structural Systems for Skyscrapers Landmark Tower Structure: Superframe Height: 971 ft Year: 1993 University of Massachusetts Amherst

University of Massachusetts Amherst Modern Skyscrapers Petronas Towers Structure: Stiff concrete core and perimeter supercolumns Height: 1,483 ft Year: 1999 University of Massachusetts Amherst

University of Massachusetts Amherst Modern Skyscrapers Taipei 101 Structure: Outrigger frames on supercolumns; tuned mass damper Height: 1,667 ft (101 stories) Year: 2003 University of Massachusetts Amherst

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. 54-61. University of Massachusetts Amherst

University of Massachusetts Amherst It’s all About Height University of Massachusetts Amherst

University of Massachusetts Amherst Future Shanghai World Financial Center Height: 1,614 ft Projected Completion: 2007 University of Massachusetts Amherst

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 University of Massachusetts Amherst

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. 28-31. University of Massachusetts Amherst

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. 28-31. University of Massachusetts Amherst

University of Massachusetts Amherst Future Freedom Tower Height: 1,776 ft (to tip of spire) Projected Completion: 2010 University of Massachusetts Amherst

University of Massachusetts Amherst Building Big Website http://www.pbs.org/wgbh/buildingbig/skyscraper/index.html University of Massachusetts Amherst

PEER Undergraduate Competition – Seismic Design University of Massachusetts Amherst