Chicago School (architecture) - Second Chicago School

Second Chicago School

In the 1940s, a "Second Chicago School" emerged from the work of Ludwig Mies van der Rohe and his efforts of education at the Illinois Institute of Technology in Chicago. Its first and purest expression was the 860-880 Lake Shore Drive Apartments (1951) and their technological achievements. This was supported and enlarged in the 1960s due to the ideas of structural engineer Fazlur Khan. He introduced a new structural system of framed tubes in skyscraper design and construction. The Bangladeshi engineer Fazlur Khan defined the framed tube structure as "a three dimensional space structure composed of three, four, or possibly more frames, braced frames, or shear walls, joined at or near their edges to form a vertical tube-like structural system capable of resisting lateral forces in any direction by cantilevering from the foundation." Closely spaced interconnected exterior columns form the tube. Horizontal loads, for example wind, are supported by the structure as a whole. About half the exterior surface is available for windows. Framed tubes allow fewer interior columns, and so create more usable floor space. Where larger openings like garage doors are required, the tube frame must be interrupted, with transfer girders used to maintain structural integrity.

The first building to apply the tube-frame construction was the DeWitt-Chestnut Apartment Building which Khan designed and was completed in Chicago by 1963. This laid the foundations for the tube structures of many other later skyscrapers, including his own John Hancock Center and Willis Tower, and can been seen in the construction of the World Trade Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s.

Today, there are different styles of architecture all throughout the city, such as the Chicago School, neo-classical, art deco, modern, and postmodern.