Seismic hazard analysis of Tianjin area based on strong ground motion prediction

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 consists of 3D finite difference method and stochastic Green’s function.Simulation is performed for 3D structures of Tianjin region and characterized asperity models.The characterized asperity model describing source heterogeneity is introduced following 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 sedimentary 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.