断层位置对三维盆地地震效应的影响

采用谱元法模拟了盆地模型和一维水平成层模型的地震动强度和放大系数的分布特征,探究了直下型断层与盆地的相对位置对盆地地震效应的影响.结果显示:盆地地震动受断层位置的影响显著,特别是当断层邻近且平行于盆地边缘时,盆地地表地震动的边缘效应更加明显,强烈地震动区域的位置随断层位置的移动而改变明显;不同分量放大系数的分布特征差别...

Influence of the finite fault location on the three-dimensional basin seismic effect

The earthquake caused by underneath faults often causes serious damage to the cities above the basin. In this paper, by comparing the distribution characteristics of ground motion intensity and amplification factor between the basin model and the one-dimensional horizontal layered model, the influence of the fault location （FL） on the basin seismic effect is investigated in detail. The results show that the FL has significant influence on the strong motion inside the basin. The basin edge effect is more significant when the fault is close to and parallel to the basin boundary, and the locations of the strongest ground motion regions change with the FL. The amplification factor （AF） exhitbits different distribution characteristics for three components. The main amplification regions of the fault-parallel and vertical components generally locate on both sides of the fault trace or near the basin edge close to it, while the main amplification regions for the fault-normal component locate inside the basin, which also displays the smallest AF. Both the strong motion and AF show greatest values when the fault just beneath the basin short-side edge, which is the most hazardous case.