Dynamic behavior of underground structures in multi-layered media

This study performs dynamic analysis of underground structures on multi-layered half planes in frequency domain by using the coupled finite and boundary element method. The near field including underground structures is modeled with conventional finite elements, while the far field is modeled with boundary elements which satisfies radiation conditions. In evaluating the dynamic fundamental solutions, semi-analytical solutions due to line loads are employed. Therefore, the range of wavenumber integration can be reduced significantly. These solutions satisfy the reflection and transmission conditions of waves at each layer interface, so that the multi-region problem can be analyzed. Numerical examples are given to demonstrate the accuracy and efficiency of the proposed method.