Fast 3D FEM-BEM coupling for dynamic soil-structure interaction

We propose a fast method for solving soil-structure interaction problems in frequency domain. Finite Elements are applied to discretize the structure, while boundary elements are applied to discretize the interface between the structure and the unbounded horizontally layered soil. Some mild restrictions imposed on the boundary element mesh allow for storing the fully populated N × N soil flexibility matrix in only O(N) storage and in negligible time. For solving the soil-structure interaction problem a hybrid linear equation system is solved with direct and indirect solvers. Though our current implementation of the method in a commercial FE code does not allow for fully exploiting the superior properties of the proposed method, it is shown that iterative solvers are superior to direct solvers for the solution of the soil-structure interaction problems investigated here.