Collapse Modelling of Soft-Storey Buildings

Abstract

This paper presents results from an extensive study investigating the seismic performance of soft-storey buildings. Such buildings rely on the moment and axial action of slender columns to resist horizontal and gravity forces at the ground floor level, and are banned in high seismic regions due to their poor performance in past earthquakes, but are a common feature of buildings in lower seismicity regions such as Australia and many countries in southeast Asia. A summary of the analytical studies and laboratory testing undertaken on limited ductile columns is presented and demonstrates that the displacement limits specified in existing international design guidelines are very conservative. Seismic studies undertaken using displacement principles, as opposed to the conventional force-based principles, indicated that the seismic performance of many of these buildings was satisfactory for the 500 and 1500 year return period events under typical Australian conditions.