A time-domain soil structure interaction analysis for wave scattering in 3D layered half-space

A direct time-domain Soil Structure Interaction (SSI) model is proposed to analyze the scattering problems in 3D horizontal layered half-space. This model uses the scaling surface based Scaled Boundary Finite Element Method (SBFEM) to simulate the infinite domain. Additionally, it employs a combined approach, merging the Domain Reduction Method (DRM) with ray tracking algorithm to calculate the effective nodal forces of seismic input. Compared to the original SBFEM, the scaling surface based SBFEM overcomes the limitation of scaling requirements, and the acceleration unit-impulse response function computed by this method satisfies the radiation damping of 3D horizontal layered half-space. For the seismic input, seismic waves are introduced to the system through effective nodal forces, which are applied exclusively to a single layer of elements adjacent to the truncated boundary in the near field. Importantly, these forces only depend on the free field motion. The accuracy and applicability of the proposed SSI analysis model in solving scattering problems in 3D horizontal layered half-space are demonstrated through various examples.