This is a post-event investigation project to learn engineering lessons from the Loma Prieta earthquake (October 1989). The Loma Prieta earthquake has produced important information on performance of engineered structures subjected to strong ground shaking. The strong-motion data generated from the instrumented buildings provide a unique opportunity to further advance the knowledge about the seismic behavior and resistance of buildings and to develop improved methodologies for their design. Three steel and composite building structures have been selected for detailed studies in this project. One suffered serious structural damage, another experienced excessive sway motion, and the third showed excellent performance. Two main research tasks will be conducted. The first is to perform analytical calculations to study the seismic response of these buildings using the recorded motions at their basement and to correlate the analytical results with the recorded responses at the upper levels. For the seriously damaged building inelastic time- history analyses will also be carried out. The second task is to develop retrofit or strengthening schemes to improve the seismic performance of the damaged building and the building experiencing excessive dynamic motion. The study will improve the understanding of seismic behavior of steel structures based on the performance data during a major earthquake.
