Fazlur Rahman Khan

Fazlur Rahman Khan
Fazlur Rahman Khan
Born	April 3, 1929 Dhaka, Bangladesh
Died	March 27, 1982(1982-03-27) (aged 52)
Nationality	Bangladeshi
Education	Bangladesh University of Engineering and Technology, University of Illinois at Urbana-Champaign
Occupation	Engineer
Engineering career
Discipline	Architectural, Civil, Structural
Significant design	John Hancock Center, Willis Tower, Hajj Terminal, King Abdulaziz University, One Magnificent Mile, Onterie Center

For other people named Fazl ur Rahman, see Fazl ur Rahman (disambiguation).

Fazlur Rahman Khan (Bengali: ফজলুর রহমান খান Fozlur Rôhman Khan) (April 3, 1929 - March 27, 1982), born in Dhaka, Bangladesh, was a Bangladeshi-American architect and structural engineer. He is a central figure behind the "Second Chicago School" of architecture, and is regarded as the "father of tubular design for high-rises". Khan, "more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the twentieth century." He is also considered to be the "Einstein of structural engineering" and "the greatest structural engineer of the second half of the 20th century" for his constructions of structural systems that remain fundamental to modern skyscraper construction. His most famous buildings are the John Hancock Center and the Willis Tower (formerly Sears Tower), which was the world's tallest building for several decades.

Biography

Fazlur Rahman Khan is from the village of Bhandarikandi in Shibchar Upazila, Madaripur District, Dhaka Division. He was born on 3 April 1929, in Dhaka. His father, Khan Bahadur Abdur Rahman Khan, BES was ADPI of Bengal and after retirement served as Principal of Jagannath College, Dhaka.

Education

Khan completed his undergraduate coursework at the Presidency College, Bengal Engineering College, University of Calcutta (Now Bengal Engineering & Science University, Shibpur). He received his bachelor’s degree from the Engineering Faculty of University of Dhaka (Now BUET) in 1951 while placing first in his class. A Fulbright Scholarship and a Pakistani government scholarship (as Bangladesh was East Pakistan then) enabled him to travel to the United States in 1952 where he pursued advanced studies at the University of Illinois at Urbana-Champaign. In three years Khan earned two Master's degrees — one in structural engineering and one in theoretical and applied mechanics — and a PhD in structural engineering.

Career

In 1955, employed by Skidmore, Owings and Merrill, he began working in Chicago, Illinois. During the 1960s and 1970s, he became noted for his designs for Chicago’s 100-story John Hancock Center and 110-story Sears Tower, the tallest building in the world in its time and still the tallest in the United States since its completion in 1974. He is also responsible for designing notable buildings in Bangladesh and Saudi Arabia.

Fazlur Khan's personal papers, the majority of which were found in his office at the time of his death, are held by the Ryerson & Burnham Libraries at the Art Institute of Chicago. The Fazlur Kahn Collection includes manuscripts, sketches, audio cassette tapes, slides and other materials regarding his work.

Personal interests

Outside of work, Khan enjoyed spending time with his family (wife Liselotte and daughter Yasmin). He enjoyed singing, poetry, and table tennis. He was also heavily involved with creating public opinion and garnering emergency funding for Bengali people during the 1971 Bangladesh Liberation War. He created the Chicago-based organization known as Bangladesh Emergency Welfare Appeal.

Innovations

Dr. Fazlur Khan realized that the rigid steel frame structure that had "dominated tall building design and construction so long was not the only system fitting for tall buildings", marking "the beginning of a new era of skyscraper revolution in terms of multiple structural systems." Dr. Fazlur Khan's design innovations significantly improved the construction of high-rise buildings, enabling them to withstand enormous forces generated on these super structures. 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.

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." The constructions of most supertall skyscrapers since the 1960s, including the construction of the World Trade Center, Petronas Towers and Jin Mao Building, employ a tube structural system.

Framed tube

Since 1963, the new structural system of framed tubes became highly influential in skyscraper design and construction. 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 from wind and earthquake, 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. The bundled tube structure is more efficient for tall buildings, lessening the penalty for height. The structural system also allows the interior columns to be smaller and the core of the building to be free of braced frames or shear walls which use up valuable 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 Apartments building which Khan designed and was completed in Chicago in 1963. This laid the foundations for the framed tube structure used in the construction of the World Trade Center.

The John Hancock Center, designed by Fazlur Khan in 1965 and completed in 1969.

Trussed tube and X-bracing

Khan pioneered several other variations of the tube structure design. One of these was the concept of X-bracing, or the "trussed tube", first employed for the John Hancock Center. This concept reduced the lateral load on the building by transferring the load into the exterior columns. This allows for a reduced need for interior columns thus creating more floor space. This concept can be seen in the John Hancock Center, designed in 1965 and completed in 1969. One of the most famous buildings of the structural expressionist style, the skyscraper's distinctive X-bracing exterior is actually a hint that the structure's skin is indeed part of its 'tubular system'. This idea is one of the architectural techniques the building used to climb to record heights (the tubular system is essentially the spine that helps the building stand upright during wind and earthquake loads). This X-bracing allows for both higher performance from tall structures and the ability to open up the inside floorplan (and usable floor space) if the architect desires. Original features such as the skin, pioneered by Fazlur Khan, have made the John Hancock Center an architectural icon.

In contrast to earlier steel-frame structures, such as the Empire State Building (1931) which required about 206 kilograms of steel per square metre and Chase Manhattan Bank Building (1961) which required around 275 kilograms of steel per square metre, the John Hancock Center was far more efficient, requiring only 145 kilograms of steel per square metre. The trussed tube concept was applied to many later skyscrapers, including the Onterie Center, Citigroup Center and Bank of China Tower.

Sears Tower, designed by Fazlur Khan and completed in 1974, was the tallest building in the world at the time of its construction

Bundle tube

One of Khan's most important variations of the tube structure concept was the "bundled tube", which he used for the Sears Tower and One Magnificent Mile. The bundle tube design was not only the most 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."

Concrete tube structures

The last major buildings constructed by Khan were the One Magnificent Mile and Onterie Center in Chicago, which employed his bundled tube and trussed tube system designs respectively. In contrast to his earlier buildings which were mainly steel, his last two buildings were concrete. His earlier DeWitt-Chestnut Apartments building, built in 1963 in Chicago, was also a concrete building with a tube structure.

Influence

The influence of Khan's tube structure design can be seen in numerous buildings built since the 1960s. Tube structures have since been used in many skyscrapers, including the construction of the World Trade Center, Petronas Towers, Jin Mao Building, and most other supertall skyscrapers since the 1960s. The strong influence of tube structure design is also evident in the world's current tallest skyscraper, the Burj Khalifa in Dubai. According to Stephen Bayley of The Daily Telegraph:

Khan invented a new way of building tall. [...] So Fazlur Khan created the unconventional skyscraper. Reversing the logic of the steel frame, he decided that the building's external envelope could – given enough trussing, framing and bracing – be the structure itself. This made buildings even lighter. The "bundled tube" meant buildings no longer need be boxlike in appearance: they could become sculpture. Khan's amazing insight – he was name-checked by Obama in his Cairo University speech last year – changed both the economics and the morphology of supertall buildings. And it made Burj Khalifa possible: proportionately, Burj employs perhaps half the steel that conservatively supports the Empire State Building. [...] Burj Khalifa is the ultimate expression of his audacious, lightweight design philosophy.

Sky lobby

The first sky lobby was also designed by Khan for the John Hancock Center. Later buildings with sky lobbies include the World Trade Center, Petronas Twin Towers and Taipei 101. The 44th-floor sky lobby of the John Hancock Center also features the first high-rise indoor swimming pool, which remains the highest in America. This was the first time that people could have the opportunity to work and live 'in the sky'.

Professional milestones

• In 1961, was made a Participating Associate in Skidmore, Owings & Merrill; in 1966 he became an Associate Partner and in 1970 a General Partner - the only engineer partner at the time.
• Received an Alumni Honor Dada from the University of Illinois, Urbana-Champaign (1972), an Honorary Doctor of Science from Northwestern University (1973), and an Honorary Doctor of Engineering from Lehigh University (1980).
• In 1973, elected to the National Academy of Engineering.
• He was cited five times among 'Men Who Served the Best Interests of the Construction Industry' by Engineering News-Record (for 1965, 1968, 1970, 1971, and 1979); and in 1972 he was named 'Construction's Man of the Year'. He was posthumously honored with the International Award of Merit in Structural Engineering from the International Association for Bridge and Structural Engineering and a Distinguished Service Award from the AIA Chicago Chapter (both in 1982).
• In 1983 the American Institute of Architects recognized Fazlur Khan's contributions with an AIA Institute Honor for Distinguished Achievement. The same year he was honored with the Aga Khan Award for Architecture "for the Structure of the Hajj Terminal, An Outstanding Contribution to Architecture for Muslims," which was completed over the last years of his life.
• He was honored posthumously by the Structural Engineers Association of Illinois with the John Parmer Award in 1987 and with the commissioning of a sculpture by the Spanish artist Carlos Marinas, which is located in the lobby of the Sears Tower.
• In 1998 the city of Chicago named the intersection of Jackson and Franklin Streets (at the foot of the Sears Tower) “Fazlur R. Khan Way.”
• Made contributions in creating public opinion and amassing emergency fund for the people of Bangladesh during its War of Liberation. The Government of Bangladesh posthumously awarded him the Independence Day Medal, the country's highest state honour, in 1999 in recognition of his contributions, and a commemorative postal stamp was published in his memory.
• He was honored posthumously by The Bangladeshi-American Foundation, Inc. (BAFI) in May 2005 as the most famous Bangladeshi-American of the 20th Century.

List of buildings

Some the most famous buildings which Khan was responsible for performing as structural engineer include the following:

• DeWitt-Chestnut Apartments, Chicago, 1963
• John Hancock Center, Chicago, 1965-1969
• Sears Tower, Chicago, 1970-1973
• Hajj Terminal, King Abdulaziz International Airport, Jeddah, 1974-1980
• King Abdulaziz University, Jeddah, 1977–1978
• One Magnificent Mile, Chicago, completed 1983
• Onterie Center, Chicago, completed 1986

Other honors

Among Khan's other accomplishments, he received the Wason Medal (1971) and Alfred Lindau Award (1973) from the American Concrete Institute (ACI); the Thomas Middlebrooks Award (1972) and the Ernest Howard Award (1977) from ASCE; the Kimbrough Medal (1973) from the American Institute of Steel Construction; the Oscar Faber medal (1973) from the Institution of Structural Engineers, London; the International Award of Merit in Structural Engineering (1983) from the International Association for Bridge and Structural Engineering IABSE; the AIA Institute Honor for Distinguished Achievement (1983) from the American Institute of Architects; and the John Parmer Award (1987) from Structural Engineers Association of Illinois (Engineering Legends, Richard Weingardt).

Quotes

• "The technical man must not be lost in his own technology; he must be able to appreciate life, and life is art, drama, music, and most importantly, people." Fazlur Khan (Engineering Legends, Richard Weingardt)

• Khan was honoured by President Barack Obama during his speech at Cairo University in 2009, referring to how he "built our tallest building," the Sears Tower.

Further reading

• Weingardt, Richard G. "Engineering Legends: Great American Civil Engineers." ASCE Press, 2005.
• Khan, Y. S. "Engineering Architecture: the vision of Fazlur R. Khan." New York: W. W. Norton & Company, 2004.

External links

• Website dedicated to Fazlur Rahman Khan
• "Evolution of Concrete Skyscrapers". Retrieved 2007-05-14.
• Fazlur Rahman Khan at Structurae