In-plane soil–structure interaction in layered, fluid-saturated, poroelastic half-space I: Structural response

• Dynamic soil–structure interaction in layered poroelastic half-space.
• Biot waves in saturated poroelastic medium and Indirect Boundary Element Method.
• Two-dimensional structure on rigid foundation with horizontal and rocking response.
• In-plane excitation by plane P and SV waves.
• Shifts of system frequencies due to water saturation of soil may exceed 10%.

Linear in-plane soil–structure interaction in two dimensions (2D) is studied in fluid-saturated, poroelastic, layered half-space using the Indirect Boundary Element Method (IBEM). The structure is a shear wall supported by a rigid embedded foundation. Exact stiffness matrices for the soil layer and half-space, and Green׳s functions of uniformly distributed loads and pore pressure on an inclined line are derived. Results of the system response in the frequency domain are presented for the special case of single soil layer over bedrock, semi-circular foundation and zero seepage force. The effects of water saturation, soil porosity, depth of soil layer, rigidity contrast between layer and bedrock are investigated in the frequency domain for incident plane P- and SV waves. The results suggest that water saturation may cause increase of the system frequency by more than 10%.