Investigation of Progessive collapse in Seismically Designed Steel Structures

Abstract:

A progressive collapse is a situation where local failure of a primary structural component leads to the collapse of adjoining members which, in turn, leads to additional collapse. Global system collapse will occur if the damaged system is unable to reach a new static equilibrium configuration. During their lifetime, civil engineering structures could be subjected to natural hazards like earthquakes, hurricanes, tornadoes and fires, and man-made hazards such as blast and impact. Structures are usually designed for credible events that can happen during their lifespan, but extreme events for which they were not adequately designed for can result in catastrophic failure. Potential abnormal load hazards that can trigger progressive collapse are categorized as: aircraft impact, design/construction error, fire, gas explosions, accidental overload, hazardous materials, vehicular collision, explosions, etc. As these hazards have low probability of occurrence, they are either not considered in structural design or addressed indirectly by passive protective measures. Nowadays, extreme events are considered to be credible events, with a finite probability of occurrence. Most of them have characteristics of acting over a relatively short period of time and result in dynamic responses. Lack of knowledge about structural behavior under collapse conditions reveals the importance of this topic. The objective of this research is to investigate important issues related to progressive collapse of seismically designed steel structures using numerical and analytical methods.