Fazlur Khan - Innovations - Tube Structural Systems

Tube Structural Systems

See also: Tube (structure)

Khan's central innovation in skyscraper design and construction was the idea of the "tube" structural system for tall buildings, including the "framed tube", "trussed tube" and "bundled tube" variations. His "tube concept," using all the exterior wall perimeter structure of a building to simulate a thin-walled tube, revolutionized tall building design. Most buildings over 40-storeys constructed since the 1960s now use a tube design derived from Khan’s structural engineering principles.

The tubular designs are for resisting lateral loads (horizontal forces) such as wind forces, seismic forces, and etc. The primary important role of structural system for tall Buildings is to resist lateral loads. The lateral loads begin to dominate the structural system and take on increasing importance in the overall building system when the building height increases. Forces of winds become very substantial and forces of earthquake etc. are very important as well. It is the tubular designs that are used for tall buildings to resist such forces. Tube structures are very stiff and have numerous significant advantages over other framing systems. They not only make the buildings structurally stronger and more efficient, they significantly reduce the usage of materials while simultaneously allowing buildings to reach even greater heights. The reduction of material makes the buildings economically much more efficient and reduces environmental issues as it results in the least carbon emission impact on the environment. Tubular systems allow greater interior space and further enable buildings to take on various shapes, offering unprecedented freedom to architects. These new designs opened an economic door for contractors, engineers, architects, and investors, providing vast amounts of real estate space on minimal plots of land. Khan more than any other individual brought in a rebirth in skyscrapers construction after a hiatus for over thirty years.

Khan's tubular designs have dominated skyscraper construction design since the 1960s. The tubular systems have yet to reach their limit when it comes to height. The beauty of Khan’s tubular systems is that buildings can be constructed using steel or concrete, or a composite of the two to reach lofty heights. His clear approaches to structural systems have often led to expressive structures.

The population explosion, beginning with the baby boom of the 1950s, created widespread concern about the amount of available living space. Khan had the solution — building up. More than any other 20th-century engineer, Fazlur Rahman Khan made it possible for people to live, and work in “cities in the sky.” Mark Sarkisian (Director of Structural and Seismic Engineering at Skidmore, Owings & Merrill) said, "Khan was a visionary who transformed skyscrapers into sky cities while staying firmly grounded in the fundamentals of engineering."

Khan's initial projects were the 43 stories DeWitt-Chestnut (1964) and 35 stories Brunswick Building (1965). He then did the John Hancock Center (1969), a 100 stories tall building and would later go on to America's tallest building the iconic Willis Tower (formerly called Sears Tower).

Read more about this topic:  Fazlur Khan, Innovations

Other articles related to "tube structural systems, tube":

Skyskraper - Design and Construction - Tube Structural Systems - Concrete Tube Structures
... in Chicago, which employed his bundled tube and trussed tube system designs respectively ... in 1963 in Chicago, was also a concrete building with a tube structure ... The influence of Khan's tube structure design can be seen in numerous buildings built since the 1960s ...

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