| Active fault is the root cause to earthquake.Disaster Earthquake is in the first place of disasters.Earthquake is unexpected and irresistible,so it can have tremendous harm.A lot of damage data indicate that earthquakes along the fault lines make the most serious damage,casualties is obviously greater than other regions on both sides of the fault.During the 10th Five-Year Plan period,China invested in the 24 large and medium-sized cities in urban areas to active fault detection and evaluation of seismic danger.The numerical simulation of near-fault endangered field of the focus active faults in Zibo City(Zhangdian-Renhe fault) against near-fault is a priority "Ten-five" project of Shandong Seismological Bureau.The main works completed in this paper include:1) The typical seismic data of many districts is collected,such as Japan and Taiwan,and preliminary analysis of the typical active Near-fault endangered field is made.The research methods of the near-fault ground motion are systemically reviewed and compared.The basic characteristics of near-fault ground motion are summarized,such as the hanging wall effect,the vertical effect,the rupture directivity effect,the fling step effect and so on.2) Based on the correlative data and geology information of moderate and upwards earthquakes of Zibo City,sixteen 3D geology models of the main active fault of Zibo City(Zhangdian-Renhe Fault) are created according to the nearby and on the base of active fault detection and the small-area earthquake analyses.Especially, Moore-Coulomb model is used in the simulation of the nature of soil,it is more realistic than only adopting a flexible model in the past.3) Explicit Lagrangian finite difference method is adopted because it is needn't to form the stiffness matrix in solving the basic equation of the process of movement. Numerical simulations of the near-fault disservice field are performed.The simulation results,including the various circumstances deformation,stress,displacement,and acceleration field,numerical simulation results are graphically displayed.The results can show the characteristics of mutual contact blocks' movement and deformation, and because of the stiffness puzzling equation in the computer easy to achieve, calculation is fast and taking up small storage space.4) In this paper,a FEM parallel algorithm based on a domain decomposition algorithm is given,parallel finite element calculation procedure based on Linux operating system is developed for PC cluster.Through the simulation calculation to the geological models established in Chapterâ…£,the numerical simulation results are got.The procedure has a good parallel speedup.The finite element method(FEM) is more suitable to the medium with complex space changes,more convenient to deal with the free surface,and it can get accurate calculation of wave propagation.FEM is very suitable for the PC cluster with distributed memory,can increase the calculation speed for large-scale Earth's medium model.5) Through the analysis of the simulation results,it is obviously that the results better reflect the basic features of near-fault seismic,such as the basin effect,the vertical effect,the hanging wall effect,and so on.The results can provide guidance and reference for Earthquake Disaster Mitigation and engineering design.In addition,it is necessary to further improve and research more on many aspect of simulation.For example,more research is needed in building three-dimensional structural model of the earthquake,because the scientific nature of the seismic model constraints and affects the calculated results directly,any of these parameters change, the results will change.Therefore,prediction of surface deformation zone in earthquake is a very complex task,it is required that different professional research staff cooperated closely.With the accumulation of information and in-depth research, these will be gradually resolved and the simulation of near-fault ground motion will be more complete.
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