地震波斜入射下土质边坡的稳定性分析*

地震诱发的边坡失稳是重要的地质灾害类型之一，数值方法是对地震边坡进行分析的一项重要工具。基于黏弹性人工边界，通过将地震记录转化为等效地震荷载实现地震波在场地中的施加；并采用Mohr?Coulomb准则模拟土体的非线性特征。根据非线性有限元软件ABAQUS，建立了双面边坡的数值模型，通过分析地震波在不同角度入射下不同坡角边坡的地震响应，讨论了地震波入射角以及边坡坡角对破坏的影响。结果表明，地震波入射角和边坡形状改变了地震波在坡体内的传播规律，因此影响了边坡的破坏。随着地震波入射角的增加，靠近波源一侧坡面的滑动位移和滑动区域逐渐增加，而远离波源一侧的滑动位移和滑动区域逐渐减小。边坡坡度的增加引起坡面危害的逐渐加剧。本文讨论了不同尺寸边坡在不同地震作用下的破坏规律，从而为地震诱发边坡的失稳破坏提供了理论支撑，具有重要的现实工程意义。

Stability Analysis of Soil Slopes with Oblique Incident Seismic Waves

Earthquake-induced slope instability is one of the important types of geological disasters. Numerical method is an important tool to analyze earthquake induced landslides. Based on the viscoelastic artificial boundary, seismic wave was applied on the site by converting seismic records to equivalent seismic loads. Mohr-Coulomb criterion was adopted to simulate the nonlinear characteristics of soil. Based on the nonlinear finite element software ABAQUS, the seismic numerical analysis model of a double-sided slope was established to analyze the slope stability at different slope angles together with the varied angles of wave incidence. Then, the impact of the incident angles and the slope angles was discussed according to the slope failure modes. The results indicated that incident angles of seismic waves and slope angles changed the propagation paths of the seismic waves, and thus controlled the failure mode of the slope. With the increase of the wave incident angle, the sliding displacements and the sliding areas gradually increased at the slide near the epicenter, and decreased at the slide away from the epicenter. The slope angle controlled the slope stability, i.e., the steeper the slope was, the more serious the failure occurred. The slope failure was discussed at different seismic events. The results provided theoretical support for slope failure mitigation under earthquake events and had important practical engineering significance.