【摘要】 在沉积盆地中，由于地表河流和湖泊等的长期沉积作用，容易在盆地内形成新的沉积盆地，称为子盆地。子盆地土体物理性质和周围土体有显著差别，因此子盆地的存在会对整个盆地的地震响应产生显著的影响。本文基于ABAQUS有限元计算平台，以理想二维梯形沉积盆地为例，针对盆地-子盆地这一特殊场地，重点分析了盆地尺寸、盆地-子盆地相对位置、子盆地介质波速和外围盆地倾角等影响因素对盆地-子盆地地震反应的影响。结果表明：子盆地的存在显著影响了盆地内的地震动，子盆地位于盆地中央区域时，对地震动的放大效果最为显著，PGA最大可被放大2倍左右；此外，子盆地介质波速越小，对盆地地震反应的影响最显著，但子盆地介质波速的变化对远离子盆地区域的地震动影响不明显；随外围盆地边缘倾角的增大，子盆地区域PGA幅值随之减小并向左移动，沉积盆地中央区域PGA幅值也随之减小。更多还原

【Abstract】 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.更多还原