Seismic response of sloping sites subject to near-fault pulse-like ground motions

Sloping sites are highly vulnerable to strong ground motions, which can induce lateral spreading and, in extreme cases, flow failure. This study investigates the seismic behavior of sloping sites subjected to Near-fault pulse-like (NF-P) ground motions. A two-dimensional finite element model of a sloping site was developed, utilizing a multiple yield surface plasticity constitutive model, which was validated with centrifuge test data. The validated model was then employed to analyze the pore pressure ratio, acceleration response, peak shear strain, and lateral displacement of soil subjected to both NF-P and Near-fault non-pulse (NF-NP) ground motions. The results demonstrate that, at high intensity levels, NF-P ground motions induce more severe liquefaction in loose sand layers, exacerbating shear deformations, as evidenced by a 43.18 % increase in peak shear strain. Liquefied loose sand layers are less effective at mitigating the effects of NF-P ground motions, resulting in persistently high peak accelerations at the surface. Furthermore, sloping sites experience substantially greater lateral displacements under NF-P ground motions, with lateral spreading displacement increasing by 150 %. NF-P ground motions also cause significantly larger lateral and vertical displacements compared to NF-NP ground motions, with lateral displacements reaching 0.97 m, and the soil maximum settlement and uplift being 2.67 and 2.60 times greater, respectively.