Abstract This study investigates the effect of near-surface soil properties on the topographic amplification of ground motions, based on the seismic response analysis of a 2D slope model with horizontally stratified soil medium. Finite difference simulations are performed to calculate the nonlinear elastoplastic response of the slope model, using strong motion records as excitation. Then a series of parametric analyses are carried out to quantitatively evaluate the influence of several factors, such as the shear-wave velocities of the superficial layers, thickness of the surface layer and soil material of the surface layer. The numerical results indicate that the decrease in the average shear-wave velocity of superficial layers would enhance the topographic effect in the area close to slope crest. In order to further assess the influence of different superficial soil profiles, seismic response analysis is conducted for a group of 2D slope models, which are built based on borehole data. The regression analysis of simulation results further confirms that the intensity of topographic effect gradually increases with decreasing VS30. Finally, the results of numerical analyses are compared with current seismic code provisions.

中文翻译：

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近地表土壤性质对地震动地形放大影响的参数研究

摘要 本研究基于具有水平分层土壤介质的二维斜坡模型的地震响应分析，研究了近地表土壤特性对地震动地形放大的影响。执行有限差分模拟以计算斜坡模型的非线性弹塑性响应，使用强运动记录作为激励。然后进行一系列参数分析，定量评价表层横波速度、表层厚度、表层土质等多种因素的影响。数值结果表明，表层平均横波速度的降低会增强坡顶附近地区的地形效应。为了进一步评估不同表层土壤剖面的影响，对基于钻孔数据建立的一组二维边坡模型进行地震响应分析。模拟结果的回归分析进一步证实，随着VS30 的减小，地形效应的强度逐渐增大。最后，将数值分析结果与现行抗震规范规定进行了比较。