Probability of damage due to earthquakes for buildings in Puerto Rico using the HAZUS methodology

This research presents the results obtained from a study carried out at the Civil Engineering and Surveying Department of the University of Puerto Rico at Mayaguez to evaluate if the capacity curves used by the computer program HAZUS to estimate the structural damage due to earthquakes are applicable for the typical concrete and steel buildings in Puerto Rico. Based on the results obtained by the computer software SAP2000RTM, it was demonstrating that the HAZUS capacity curves are applicable for buildings in the Island, but taking into account some considerations. Using the capacity data calculated in the first phase, this work describes and employs the methodology used by the HAZUS program to estimate the probabilities of structural damage due to earthquakes. The earthquake is represented by the UBC-97 design spectrum. The methodology was based on the Capacity Spectrum Method described in the ATC-40 report, and in the HAZUS fragility curves. The discrete probabilities of being in the None, Slight, Moderate, Extensive or Complete damage state are determined for each building type. The results for actual buildings in Puerto Rico were compared with the standard buildings in HAZUS. It was found from the comparison that the majority of the structures in the Island perform equal or better than the typical buildings in HAZUS when subjected to an earthquake compatible with the UBC-97 design spectrum.