含子盆地的二维沉积盆地非线性地震反应分析

Within the sedimentary basins, it is easy to form new sedimentary due to the long-term sedimentation of rivers and lakes, which is widely known as sub-basin. The soil physical properties of the sub-basin are very different from the surrounding soil, so the existence of sub-basin would have a significant impact on the seismic response of the whole basin. Based on the ABAQUS finite element calculation platform, this paper studied the earthquake response of basin-and-sub basin model. The basin shape was assumed as an ideal two-dimensional trapezoidal. The influence of basin size, basin-sub-basin relative position, shear wave velocity of sub-basin medium and peripheral basin dip angle on the basin-and-sub basin seismic response was analyzed. The results show that the presence of sub-basins significantly affects the ground motion within the basin. When the sub-basins were in the central area of the basin, the amplification effect of ground motion is the most significant, and the maximum amplification of PGA can be about 2 times with respect to the no-sub basin model. In addition, the smaller the shear wave velocity of sub-basin medium, the most significant effect on the basin seismic response, but the change of the shear wave velocity of sub-basin medium has no obvious effect on the ground motion far away from the sub-basin. With the increase of the marginal dip angle of the peripheral basin, the PGA amplitude of the sub-basin decreases and moves to the left, and the PGA amplitude of the central area of sedimentary basin also decreases.