Skyscraper design and construction
The design and construction of skyscrapers involves creating safe, habitable spaces in very high buildings.
The problems posed in skyscraper design are considered among the most complex encountered given the balances required between economics, engineering, and construction management.
Good structural design is important in most building designs, but particularly for skyscrapers since even a small chance of catastrophic failure is unacceptable given the high prices of construction and potential risk to human life on a massive scale, as seen in the Surfside condominium collapse of 2021.
On the other hand, John Hancock Center's shape is uniquely the result of how it supports loads.
Due to the features of a shear wall, it is acceptable for small constructions, such as suburban housing or an urban brownstone, to require low material costs and little maintenance.
This becomes inefficient and uneconomic for buildings above 40 stories tall as usable floor spaces are reduced for supporting column and due to more usage of steel.
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.
Tube structures cut down costs, at the same time allow buildings to reach greater heights.
The Willis Tower in Chicago used this design, employing nine tubes of varying height to achieve its distinct appearance.
The bundle tube design was not only highly efficient in economic terms, but it was also "innovative in its potential for versatile formulation of architectural space.
Efficient towers no longer had to be box-like; the tube-units could take on various shapes and could be bundled together in different sorts of groupings.
Most buildings over 40-stories constructed since the 1960s now use a tube design derived from Khan's structural engineering principles,[2][8] examples including the construction of the World Trade Center, Aon Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s.
[9] The strong influence of tube structure design is also evident in the construction of the current tallest skyscraper, the Burj Khalifa.
The elevators in a skyscraper are not simply a necessary utility like running water and electricity, but are in fact closely related to the design of the whole structure.
