Wave propagation in irregularly layered elastic models: A boundary element approach with a global reflection/transmission matrix propagator

A direct boundary element method that uses the full-space Green's function is proposed for calculating elastic wave propagation in two-dimensional irregularly stratified models. The global matrix equation becomes larger as the number of layers increases. These equations are usually solved by improved block Gaussian elimination, conjugate gradient algorithms, or other approaches based on different approximations. In this article, we adopt the global generalized reflection/transmission matrix method (Chen, 1990, 1995, 1996) to solve this problem. This method can prevent excessive requirement of both computer memory and CPU time. The method is validated by comparing its results with those obtained using the finite-difference method.