The internal substructure method for seismic wave input in 3D dynamic soil-structure interaction analysis

An internal substructure method for seismic wave input in 3D soil-structure systems is proposed in this paper. In this method, we convert seismic waves into equivalent input seismic loads through a dynamic analysis of the internal substructure intercepted from the original soil-structure model. Compared to the wave method and the boundary substructure method for seismic wave input, this newly proposed method has a smaller substructure size and requires less data management. Moreover, it avoids the participation of the artificial boundaries in the process of inputting seismic waves and thus overcomes the limitations of traditional methods on artificial boundaries. We provide a detailed description of the steps required to implement the proposed method. Wave propagation in homogeneous and layered half-space sites and the scattered wave problem of a hemispherical cavity under incident plane waves are adopted as numerical examples to validate this new method.