Influence Of Source Parameters On Seismic Effects Of 3D Sedimentary Basins

Fault earthquakes often cause serious damage to the cities above the basin,and the source parameters have a significant effect on the seismic effects of the basin.The seismic effect of the basin is often reflected in the amplification effect of the basin,the edge effect of the basin,the focusing effect of the basin.The near-field effect of the fault ground motion is often reflected in the directional effect of the rupture,the concentration,the hanging wall effect.when the near-field effect of the fault is coupled with the amplification effect of the basin,it is difficult to predict the location causing the earthquake damage.(1)In this paper,the simulation accuracy of near-field ground motion of finite faults based on kinematic focal model is verified by using 3D spectral element method.(2)Furthermore,by comparing the characteristics of seismic intensity and amplification factor distribution between the basin-bearing model and the one-dimensional horizontal-layered model without basin,The distribution characteristics of seismicity and magnification factor of the basin under the finite fault rupture are studied in detail.(3)The influence of finite fault fracture velocity and fault location on the seismic effect of the basin is studied.The results show that the distribution characteristics of seismic movement of near faults can be significantly changed in the basin.The distribution characteristics of strong ground motions of different components in the basin are different.The amplification coefficient of the basin as a whole shows a trend of decreasing with the increase of fracture velocity,but the influence degree of the amplification coefficient of different components is obviously different.The fault location has a significant effect on the margin amplification area of the basin,and the margin effect of different sizes for basins with different long and short sides.At the same time,The location of the strong amplification area in the basin is also significantly affected by the source parameters,but generally concentrated in the area on both sides of the fault and near the basin edge perpendicular to the fracture direction.