In this paper, near-fault strong ground motions caused by a surface rupture fault （SRF） and a buried fault （BF） are numerically simulated and compared by using a time-space-decoupled, explicit finite element metho...In this paper, near-fault strong ground motions caused by a surface rupture fault （SRF） and a buried fault （BF） are numerically simulated and compared by using a time-space-decoupled, explicit finite element method combined with a multi-transmitting formula （MTF） of an artificial boundary. Prior to the comparison, verification of the explicit element method and the MTF is conducted. The comparison results show that the final dislocation of the SRF is larger than the BF for the same stress drop on the fault plane. The maximum final dislocation occurs on the fault upper line for the SRF; however, for the BE the maximum final dislocation is located on the fault central part. Meanwhile, the PGA, PGV and PGD of long period ground motions （≤ 1 Hz） generated by the SRF are much higher than those of the BF in the near-fault region. The peak value of the velocity pulse generated by the SRF is also higher than the BE Furthermore, it is found that in a very narrow region along the fault trace, ground motions caused by the SRF are much higher than by the BF. These results may explain why SRFs almost always cause heavy damage in near-fault regions compared to buried faults.展开更多
Taking Tianjin as an example, this paper proposed a methodology and process for evaluating near-fault strong ground motions from future earthquakes to mitigate earthquake damage for the metropolitan area and important...Taking Tianjin as an example, this paper proposed a methodology and process for evaluating near-fault strong ground motions from future earthquakes to mitigate earthquake damage for the metropolitan area and important engineering structures. The result of strong ground motion was predicted for Tianjin main faults by the hybrid method which mainly con- sists of 3D finite difference method and stochastic Green＇s function. Simulation is performed for 3D structures of Tianjin re- gion and characterized asperity models. The characterized asperity model describing source heterogeneity is introduced fol- lowing the fault information from the project of Tianjin Active Faults and Seismic Hazard Assessment. We simulated the worst case that two earthquakes separately occur. The results indicate that the fault position, rupture process and the sedi- mentary deposits of the basin significantly affect amplification of the simulated ground motion. Our results also demonstrate the possibility of practical simulating wave propagation including basin induced surface waves in broad frequency-band, for seismic hazard analysis near the fault from future earthquakes in urbanized areas.展开更多
从一个异于传统研究方法的角度出发,利用最近发展的地震动 3D 瞬态参数分析理论,有选择的研究了有关近场地震动记录的3D 瞬态特征;通过对典型近场地震动作用下结构模型的算例分析,探讨了速度脉冲型地震动与结构延性需求之间的关系,指出...从一个异于传统研究方法的角度出发,利用最近发展的地震动 3D 瞬态参数分析理论,有选择的研究了有关近场地震动记录的3D 瞬态特征;通过对典型近场地震动作用下结构模型的算例分析,探讨了速度脉冲型地震动与结构延性需求之间的关系,指出结构坏固然与地震动的反复作用有关,但对于大多数结构的关键破坏起控制作用的却可以归因于近场地震动的脉冲特性,这对认识结构破坏的根本原因具有重要意义。展开更多
基金National Natural Science Foundation of China Under Grant No. 50408003National Scientifi c and Technical Supporting Programs Funded by Ministry of Science & Technology of China Under Grant No. 2006BAC13B01
文摘In this paper, near-fault strong ground motions caused by a surface rupture fault （SRF） and a buried fault （BF） are numerically simulated and compared by using a time-space-decoupled, explicit finite element method combined with a multi-transmitting formula （MTF） of an artificial boundary. Prior to the comparison, verification of the explicit element method and the MTF is conducted. The comparison results show that the final dislocation of the SRF is larger than the BF for the same stress drop on the fault plane. The maximum final dislocation occurs on the fault upper line for the SRF; however, for the BE the maximum final dislocation is located on the fault central part. Meanwhile, the PGA, PGV and PGD of long period ground motions （≤ 1 Hz） generated by the SRF are much higher than those of the BF in the near-fault region. The peak value of the velocity pulse generated by the SRF is also higher than the BE Furthermore, it is found that in a very narrow region along the fault trace, ground motions caused by the SRF are much higher than by the BF. These results may explain why SRFs almost always cause heavy damage in near-fault regions compared to buried faults.
基金supported by the National Natural Science Foundation of China (40674016)Earthquake Research Fund of Ministry of Science and Technology of China ((2007)203/8-53)
文摘Taking Tianjin as an example, this paper proposed a methodology and process for evaluating near-fault strong ground motions from future earthquakes to mitigate earthquake damage for the metropolitan area and important engineering structures. The result of strong ground motion was predicted for Tianjin main faults by the hybrid method which mainly con- sists of 3D finite difference method and stochastic Green＇s function. Simulation is performed for 3D structures of Tianjin re- gion and characterized asperity models. The characterized asperity model describing source heterogeneity is introduced fol- lowing the fault information from the project of Tianjin Active Faults and Seismic Hazard Assessment. We simulated the worst case that two earthquakes separately occur. The results indicate that the fault position, rupture process and the sedi- mentary deposits of the basin significantly affect amplification of the simulated ground motion. Our results also demonstrate the possibility of practical simulating wave propagation including basin induced surface waves in broad frequency-band, for seismic hazard analysis near the fault from future earthquakes in urbanized areas.
文摘从一个异于传统研究方法的角度出发,利用最近发展的地震动 3D 瞬态参数分析理论,有选择的研究了有关近场地震动记录的3D 瞬态特征;通过对典型近场地震动作用下结构模型的算例分析,探讨了速度脉冲型地震动与结构延性需求之间的关系,指出结构坏固然与地震动的反复作用有关,但对于大多数结构的关键破坏起控制作用的却可以归因于近场地震动的脉冲特性,这对认识结构破坏的根本原因具有重要意义。
