NUMERICAL SIMULATION OF INFLUENCE OF THE WENCHUAN M_S8.0 EARTHQUAKE UPON FAULTS IN THE SOUTHWEST MARGIN OF THE ORDOS BLOCK

Based on inversed parameters of Wenchuan M_S8.0 earthquake,using the FEM and Static Displacement Analytical Solution Theory,this paper analyzes the influence of the great earthquake on faults in southwestern margin of Ordos block.The numerical result shows that the Wenchuan M_S8.0 earthquake,which is the type of thrust with right-lateral component,leads to clockwise disturbance displacement field to the east of the line of Wenchuan-Baoji and anticlockwise disturbance displacement field to the west,which is consist with slide direction of the active faults near the line.The distribution of horizontal shear stress extreme values is consisted with seismicity in the fault zones to the southwest of Ordos block during the year after the great earthquake.The numerical result also indicates that the Wenchuan earthquake may enhance the seismicity in the Haiyuan and Xiangshan-Tianjingshan fault zones.The region with higher shear stress value and lower seismicity may be the area that we should pay close attention to in the future.