基于数值模拟的二维盆地地震动放大效应

Ground Vibration Amplification in Two-dimensional Basins Based on Numerical Simulation

文章利用数值模拟的方法,结合土体的非线性影响,评价二维盆地模型的放大系数,对盆地地震的放大效应研究取得了一定的成果,但对盆地土体非线性影响的放大系数研究不足。结果表明:(1)不同周期、不同沉积层波速盆地放大效应有显著差异;(2)当一维的黏弹性数值模拟得到的加速度反应谱不变时,将二维的黏弹性数值模拟的加速度反应谱变成二维的非线性数值模拟的加速度反应谱,将两者的放大系数AGF的幅值进行比较,使两者的幅值整体呈下降趋势。

Adequate research has been done on the amplification effect of basin earthquakes,but the amplification coefficient of the nonlinear effects of the soil body in the basin has not been adequately investigated.In this paper,we use numerical simulations to evaluate the amplification coefficients of the two-dimensional basin model in combination with the effects of the nonlinearities of the soil body.The results show that:(1)there are significant differences in the amplification effect of the basin with different periods and different sedimentary wave velocities;(2)when the acceleration response spectrum derived from the one-dimensional viscoelastic numerical simulation remains unchanged,and when the acceleration response spectrum from the two-dimensional viscoelastic numerical simulation is changed into the acceleration response spectrum from the two-dimensional nonlinear numerical simulation,the amplitude of the amplification coefficients of the two AGF shows a decreasing tendency for the whole comparison.