ABSTRACT

In this paper, a simple numerical model is presented for analyzing arbitrarily shaped alluvial valleys subjected to propagating obliquely incident plane SH-waves. A time-domain half-plane boundary element method (BEM) was successfully used to prepare the model in which the interface needs only to be discretized. First, the problem was decomposed into two parts, a half-plane valley-shaped feature and a closed filled alluvium. Then, the method was applied to each part to obtain the considered matrices. Finally, by satisfying the continuity conditions at the interface, the coupled equation was transiently solved to determine the boundary values. All ground surface responses were also obtained in a secondary solution as internal points. After implementing the method in a general algorithm, several practical examples were analyzed to validate the responses. Moreover, an advanced numerical study was performed to sensitize the surface motion of semi-cylindrical alluvial valleys with variable shape ratios as synthetic seismograms and three-dimensional (3D) amplification patterns. The proposed method can easily be combined with other numerical methods to achieve nonlinear site responses.

摘要

在本文中，提出了一个简单的数值模型来分析任意形状的冲积河谷在传播的倾斜入射平面SH下。-波浪。时域半平面边界元法（BEM）成功地用于制备模型，其中界面只需要离散化。首先，问题被分解为两部分，一个半平面的谷形特征和一个封闭的填充冲积层。然后，将该方法应用于每个部分以获得考虑的矩阵。最后，通过满足界面处的连续性条件，对耦合方程进行瞬态求解，确定边界值。所有地表响应也在二次解中作为内部点获得。在以通用算法实现该方法后，分析了几个实际示例以验证响应。而且，进行了一项先进的数值研究，以使具有可变形状比的半圆柱形冲积山谷的表面运动敏感，如合成地震图和三维 (3D) 放大模式。所提出的方法可以很容易地与其他数值方法相结合，以实现非线性场地响应。