基于拟动力法考虑土体张拉截断的边坡抗震稳定性上限分析  

Upper limit analysis of seismic stability of slope considering soil tensile strength cutoff based on pseudo-dynamic method

作　　者：梁承龙[1] 刘芳[1] LIANG Chenglong;LIU Fang(College of Civil Engineering and Architecture,Guangxi Transport Vocational and Technical College,Nanning 530012,China)

机构地区：[1]广西交通职业技术学院土木建筑工程学院,南宁530012

出　　处：《世界地震工程》2023年第3期239-248,共10页World Earthquake Engineering

摘　　要：针对边坡失稳时坡顶后缘拉应力区对边坡稳定性影响问题,对Mohr-Coulomb屈服准则中土体的抗拉强度进行完全折减(张拉截断),基于极限分析上限定理,构建“点到点”的离散运动学破坏机构,采用拟动力法对边坡的抗震稳定性进行分析。结果表明:张拉截断效应会降低边坡稳定性;考虑张拉截断效应与引入张拉裂缝所得安全系数基本相同,而临界滑动面差异明显,考虑张拉截断效应的临界滑动面更深且破坏规模更大;边坡安全系数随土体放大系数增大,并在地震波周期大于0.3 s时基本保持不变。In order to solve the problem of the influence of the tensile stress zone on the slope stability at the back edge of the slope top when the slope is unstable,the tensile strength of the soil in the Mohr-Coulomb yield criterion is completely discounted(tension cutoff),and the discrete kinematic damage mechanism of"point to point"is constructed based on the upper limit theorem of limit analysis,and the seismic stability of the slope is analyzed by the pseudo-dynamic method.The results show that the tension cutoff effect reduces the slope stability;the safety factor obtained by considering the tension cutoff effect and introducing tension cracks is basically the same,but the critical failure surface differs significantly,and the critical failure surface is deeper and the scale of landslides is larger when considering the tension cutoff effect;the safety factor of the slope increases with the amplification factor of the soil,and remains constant when the seismic wave period is greater than 0.3 s.

关 键 词：极限分析 边坡稳定性 安全系数 拟动力法 张拉截断 

分 类 号：TU431[建筑科学—岩土工程]