Ground Motion Prediction for Urban Earthqueak Disaster Mitigation

Urs Group, Inc., Los Angeles CA

Investigators

Abstract

Although building codes and practices in the United States and Japan have been developed to the point where they provide a large measure of protection of life safety, the recent 1994 Northridge and 1995 Kobe earthquake have demonstrated that near-field ground motions present severe challenges even to structures designed according to current codes. While the response spectrum provides the basis for the specification of design ground motions in all current design guidelines and code provisions, there is a growing recognition that the response spectrum alone does not provide an adequate characterization of near-fault ground motions. This indicates the importance of developing an improved representation of near-fault ground motions using time domain parameters such as the amplitude, period and number of cycles of the near fault pulse, and its energy characteristics, in addition to the response spectrum, for use in analysis and design of structures. The objectives of this project is to develop methods for characterizing near-fault ground motion for use in engineering design and evaluation. The project will be done in collaboration with Professor Iwata of Kyoto University, and colleagues from several other Japanese research organizations, with whom the Principal Investigators have a long term collaborative relationship.