Effects of Liquefied Saturated Sand Filling Joints in Complex Strata on Seismic P‐Wave Transmission for Oblique Incident

This study investigates the effects of liquefied saturated sand infilling joints within complex strata on the transmission of obliquely incident seismic P‐wave. Using the boundary transformation method, analytical solutions were derived for the propagation of obliquely incident seismic P‐wave through joints filled with liquefied saturated sand. The relationship between transmission coefficients and the incident angle was analyzed. The influences of normalized joint thickness, elastic modulus of the joint filling material, and the wave impedance ratio (WIR) of the rock media on the transmission coefficients accounting for the liquefaction of saturated sand were examined. The results were compared with those obtained without considering liquefaction. The findings indicate that the liquefaction of saturated sand in filled joints significantly affects the transmission of obliquely incident seismic P‐wave, while it has a negligible impact on normally incident P‐wave propagation. Moreover, an increase in normalized joint thickness reduces the transmission coefficients for both P‐wave and SV‐wave under liquefaction conditions. Increasing the elastic modulus of the joint filling material leads to higher transmission coefficients when liquefaction is considered, which is different from the transmission behavior of SV‐wave without liquefaction. The results also show that as WIR increases, the transmission coefficients for both P‐wave and SV‐wave eventually decrease to zero.