Case Study on "World Trade Center TowerCollapse"
Overview Location - New York, USA Date - 11th September 2001 Damage :North Tower (WTC 1) - A Boeing 767-200ER series aircrafthit between the 94th and 98th floors roughly at the centreof the north face at 08:46.South Tower (WTC 2) - A Boeing 767-200ER series aircrafthit between the 78th and 84th floors toward the east sideof the south face at 09:03.
Construction type - Steel perimeter frame-tube systemcomprising external perimeter columns, central corecolumns and concrete slabs on steel bar trusses. Fire resistance - Passive fire protection. Automaticsprinklers system. Building type - Commercial.North Tower: 417 m (101 storeys)South Tower: 415 m (101 storeys) WTC 1 collapsed at 10:29, 102 minutes after thecrash. WTC 2 collapsed at 09:59, 56 minutes after thecrash.
The Building The twin towers of the World Trade Center (WTC)were among the first skyscrapers built using theframed-tube concept to provide lateral resistance towind loads. The steel framed-tube system comprised four majorstructural components -External wallCentral service coreComposite floor systemHat truss system
Plane Crash and Damage On 11 September 2001, two passenger planes werehijacked by terrorists and crashed into the WorldTrade Center Towers in New York. When the two aircrafts crashed into the towers,fireballs erupted and jet fuel spread across the impactfloors and down internal shafts, igniting multiplefloor fires immediately. The resulting fires spread throughout the upper floorsabove the impact floors of the two towers. The twin towers collapsed shortly afterwards.
Sources of Information BBC News Online / World / America / Americas day ofterror - UK Edition (2001) Federal Emergency Management Agency. (2002). WorldTrade Center Building Performance Study: Data Collection,Preliminary Observations, and Recommendations,Washington, DC. National Institute of Standards and Technology. (2005).Federal Building and Fire Safety Investigation of the WorldTrade Center Disaster: Final Reports of the NationalConstruction Safety Team on the Collapses of the WorldTrade Center Towers (Draft), U.S. Government PrintingOffice, Washington.