A skyscraper is a tall continuously habitable building having multiple floors. Modern sources define skyscrapers as being at least 100 meters (330 ft) or 150 meters (490 ft) in height, though there is no universally accepted definition, other than being very tall high-rise buildings. Historically, the term first referred to buildings with between 10 and 20 stories when these types of buildings began to be constructed in the 1880s. Skyscrapers may host offices, hotels, residential spaces, and retail spaces.
Reinforced concrete, also called ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel bars (rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials. In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion.
The World Trade Center in New York City collapsed on September 11, 2001, as result of the al-Qaeda attacks. Two commercial airliners hijacked by al-Qaeda terrorists were deliberately flown into the Twin Towers of the complex, resulting in a total progressive collapse that killed almost 3,000 people. It is the deadliest and costliest building collapse in history.
Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries and late 1970s for many other parts of the world, many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. State-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world – such as the ASCE-SEI 41 and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines. These codes must be regularly updated; the 1994 Northridge earthquake brought to light the brittleness of welded steel frames, for example.
Steel frame is a building technique with a "skeleton frame" of vertical steel columns and horizontal I-beams, constructed in a rectangular grid to support the floors, roof and walls of a building which are all attached to the frame. The development of this technique made the construction of the skyscraper possible. Steel frame has displaced its predecessor, the iron frame, in the early 20th century.
The design and construction of skyscrapers involves creating safe, habitable spaces in very high buildings. The buildings must support their weight, resist wind and earthquakes, and protect occupants from fire. Yet they must also be conveniently accessible, even on the upper floors, and provide utilities and a comfortable climate for the occupants. The problems posed in skyscraper design are considered among the most complex encountered given the balances required between economics, engineering, and construction management.
Fireproofing is rendering something resistant to fire, or incombustible; or material for use in making anything fire-proof. It is a passive fire protection measure. "Fireproof" or "fireproofing" can be used as a noun, verb or adjective; it may be hyphenated ("fire-proof").
Structural steel is a category of steel used for making construction materials in a variety of shapes. Many structural steel shapes take the form of an elongated beam having a profile of a specific cross section. Structural steel shapes, sizes, chemical composition, mechanical properties such as strengths, storage practices, etc., are regulated by standards in most industrialized countries.
This is an alphabetical list of articles pertaining specifically to structural engineering. For a broad overview of engineering, please see List of engineering topics. For biographies please see List of engineers.
The construction of the first World Trade Center complex in New York City was conceived as an urban renewal project to help revitalize Lower Manhattan spearheaded by David Rockefeller. The project was developed by the Port Authority of New York and New Jersey. The idea for the World Trade Center arose after World War II as a way to supplement existing avenues of international commerce in the United States.
Dr. W. Gene Corley, P.E. was an American structural engineer and "preeminent expert on building collapse investigations and building codes." Corley was the Senior Vice President of CTLGroup from 1987 to 2013, where he led structural engineering projects, including numerous evaluations of buildings and structures damaged by earthquake, explosions, and from terrorist attacks. He led the investigation of structural performance of the Murrah Building following the Oklahoma City bombing in 1995, and the World Trade Center Building Performance Study in 2001–2002 following the September 11, 2001 attacks. He died on March 1, 2013. He was 77.
In structural engineering, the tube is a system where, to resist lateral loads, a building is designed to act like a hollow cylinder, cantilevered perpendicular to the ground. This system was introduced by Fazlur Rahman Khan while at the architectural firm Skidmore, Owings & Merrill (SOM), in their Chicago office. The first example of the tube's use is the 43-story Khan-designed DeWitt-Chestnut Apartment Building, since renamed Plaza on DeWitt, in Chicago, Illinois, finished in 1966.
A steel plate shear wall (SPSW) consists of steel infill plates bounded by boundary elements.
The history of structural engineering dates back to at least 2700 BC when the step pyramid for Pharaoh Djoser was built by Imhotep, the first architect in history known by name. Pyramids were the most common major structures built by ancient civilizations because it is a structural form which is inherently stable and can be almost infinitely scaled.
Architects & Engineers for 9/11 Truth, Inc. (AE911Truth) is an American non-profit organization promoting the conspiracy theory that the World Trade Center was destroyed in a controlled demolition, disputing accepted conclusions around the September 11 attacks, including the 9/11 Commission Report, as well as FEMA's "WTC Building Performance Study" (2002). Their claims and theories lack support among the relevant professional communities.
On June 29, 1995, the Sampoong Department Store in Seoul, South Korea, collapsed due to a structural failure. The collapse killed 502 people and injured 937, making it the largest peacetime disaster in South Korean history. It was the deadliest non-deliberate modern building collapse until the 2013 Rana Plaza factory collapse in Bangladesh.
Structural integrity and failure is an aspect of engineering that deals with the ability of a structure to support a designed structural load without breaking and includes the study of past structural failures in order to prevent failures in future designs.
Robustness is the ability of a structure to withstand events like fire, explosions, impact or the consequences of human error, without being damaged to an extent disproportionate to the original cause – as defined in EN 1991-1-7 of the Accidental Actions Eurocode.
The NIST World Trade Center Disaster Investigation was a report that the National Institute of Standards and Technology (NIST) conducted to establish the likely technical causes of the three building failures that occurred at the World Trade Center following the September 11, 2001 terrorist attacks. The report was mandated as part of the National Construction Safety Team Act, which was signed into law on October 1, 2002 by President George W. Bush. NIST issued its final report on the collapse of the World Trade Center's twin towers in September 2005, and the agency issued its final report on 7 World Trade Center in November 2008.
7 World Trade Center, colloquially known as Building 7 or the Salomon Brothers Building, was an office building constructed as part of the original World Trade Center Complex in Lower Manhattan, New York City. The tower was located on a city block bounded by West Broadway, Vesey Street, Washington Street, and Barclay Street on the east, south, west, and north, respectively. It was developed by Larry Silverstein, who held a ground lease for the site from the Port Authority of New York and New Jersey, and designed by Emery Roth & Sons. It was destroyed during the September 11 attacks.
