Ground Motion Prediction for Urban Earthquake Disaster Mitigation

本研究项目的目的是开发用于工程设计和评估的近断层地震动的表征方法。 要解决的具体问题包括近断层破裂方向性效应和盆地边缘效应。 这两种效应被认为是1994年北岭地震和1995年科比地震中破坏性地面运动的主要原因。 本项目是与日本京都大学的入仓教授和其他几个研究机构的同事合作进行的，主要研究人员与他们有着长期的合作关系，具体目标包括：（1）开发用于预测未来地震近断层强地面运动的震源特征的改进程序;（2）改进模拟近断层地震运动的程序，包括复杂结构的影响，如引起盆地边缘效应的地下基岩地形;开发一种改进的近断层地面运动表示方法，用于工程分析和设计，结合频谱特性使用时域特性。 最后一项任务是与斯坦福大学的Helmut Krawinkler教授合作，期望这项研究能产生：（1）可靠的方法，具有良好的理论和经验基础，用于产生近断层地震动，以供实际设计和评估使用;（2）一套改进的地震动参数，用以描述近断层地震动;（3）改进了近断层地震动的表示方法，使用了多组近断层地震动时程和简化的近断层脉冲，以供设计使用。

The objective of this research project is to develop methods for characterizing near-fault ground motion for use in engineering design and evaluation. The specific issues to be addressed include near-fault rupture directivity effects and basin edge effects. These two effects have been identified as principal causes of the damaging ground motions in the 1994 Northridge and 1995 Kobe earthquakes. This project involves a collaboration with Professor Irikura of Kyoto University and colleagues from several other Japanese research organizations, with whom the Principal Investigators have a long term collaborative relationship.Specific objectives include: (1) develop improved procedures for earthquake source characterization for use in the prediction of near-fault strong ground motion of future earthquakes; (2) develop improved procedures for simulating near-fault ground motions, including the effects of complex structure such as subsurface bedrock topography that cause basin edge effects; develop an improved representation of near-fault ground motion for use in engineering analysis and design, using time domain characteristics in conjunction with spectral characteristics. The last task involves collaboration with Professor Helmut Krawinkler of Stanford University.It is expected that this research will lead to: (1) reliable procedures, having a sound theoretical and empirical basis, for the generation of near-fault ground motions for use in practical design and evaluation; (2) an improved set of ground motion parameters with which to describe near-fault ground motions; and (3) an improved representation of near-fault ground motions; using sets of near-fault ground motion time histories and simplified near-fault pulses, for use in design.