Seismic Response of Sloping Site Under Near-Field Velocity Pulse Ground Motions
摘要
Near-fault pulse-like (NF-P) ground motions has significant influence on the liquefaction mechanism and lateral expansion of soil in sloped sites In this study, a two-dimensional numerical model of sloping site considering pressure-dependent and pressure-independent multi-yield surface plasticity models was established using OpenSees and validated by centrifuge shaking table test and then employed to investigate the difference in response of sloped site subjected to near-fault pulse-like (NF-P) ground motions and non-pulse-like (NF-NP) ground motions. The validated model is employed to perform a comparative analysis of soil excess pore water pressure and residual displacement in inclined liquefiable site. The results demonstrated convincingly that: (1) the excess pore water pressure exhibits significant oscillations under NF-P ground motion, with the degree of liquefaction diminishing with increasing soil depth; (2) the horizontal residual displacement of soil in sloped site is more than 8 times greater than that in horizontal site, with more pronounced lateral expansion; and (3) the horizontal residual displacements at the top and bottom of the slope under NF-P ground motion increased by 188% and 139%, compared to NF-NP ground motion. It was also found that the soil average subsidence and uplift approximately 2.68 times and 1.38 times greater, respectively, than those under NF-NP ground motion.