This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)
The recently released Uniform California Earthquake Rupture Forecast by the Working Group on California Earthquake Probabilities concludes that there is a high probability that an earthquake of magnitude 6 or larger will occur on the southern section of the San Andreas fault in the next 30 years. The research objective of this award is to do a region-wide quantitative risk analysis of six steel buildings in the 20-story class for the hazard posed by the San Andreas fault. For this, end-to-end computer simulations of ground motion from 36 earthquakes and damage to the six buildings will be carried out. The earthquakes vary in magnitudes from 6.0 to 8.0 and originate at three hypocenter locations on the fault. Two rupture propagation directions will be considered. The Los Angeles metropolitan region will be divided into 636 analysis sites on a uniform grid of about 3.5km spacing. Three steel moment frame and three steel braced frame building models will be analyzed at each site for damage caused by the 3-component motion of the 36 scenario earthquakes. The results will be probabilistically analyzed to quantify the expected annualized economic loss for each building at each of the sites. Remedial measures that prevent collapse of the buildings will be investigated. The study will resolve long-standing questions related to failure modes, degradation characteristics, and collapse mechanisms of steel moment frame and braced frame buildings. This will also provide a quantitative measure of the economic risk due to the seismic activity on the San Andreas fault to the hundreds of high-rise buildings that exist in Southern California.
The proposed research will lead to fundamental understanding of tall steel building response and performance under strong ground motion. It will provide necessary data needed for formulating seismic hazard mitigation strategies and for better land-use planning to keep the impending San Andreas earthquakes from becoming catastrophic. The proposed Caltech Virtual Shaker e-analysis facility, established for wider dissemination of the methodology developed in the project, will allow practicing structural engineers to evaluate the performance of various innovative structural systems. The project will educate and train graduate and undergraduate students in earthquake engineering to advance the profession. Demonstrations about the application of high-performance computing for solving some of the most challenging earthquake engineering problems faced by society will be made to motivate K-12 students.
