水平柔性拉筋式重力墙-坡体地震整体稳定性分析方法  

Analysis method of seismic overall stability of soil slopes retained by gravity walls anchored horizontally with flexible reinforcements

作　　者：肖世国[1,2] 刘航 于昕左 XIAO Shi-guo;LIU Hang;YU Xin-zuo(Department of Geological Engineering,Southwest Jiaotong University,Chengdu,Sichuan 610031,China;Key Laboratory of High-speed Railway Engineering of Ministry of Education,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]西南交通大学地质工程系,四川成都610031 [2]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031

出　　处：《岩土力学》2020年第6期1836-1844,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51578466)。

摘　　要：为合理分析水平柔性拉筋式重力墙-墙后坡体地震整体稳定性,考虑坡顶条形均布荷载作用以及拉筋拔出和拉断两种破坏模式,采用拟静力法与分区水平条分及斜条分极限平衡法,基于Fellenius法与简化Bishop法的条间力假定,推导了相应的墙-坡地震整体稳定系数计算公式,并通过数值模拟方法对不同水平地震影响系数的情况予以验证,且讨论了墙后填土与地基土的内摩擦角及黏聚力、筋带间距、长度及其极限拉力对墙-坡地震整体稳定性的影响特征。实例分析结果表明,简化Bishop法与数值模拟得到的墙-坡地震整体稳定系数较为接近,比Fellenius法的结果约高出6%;墙-坡地震整体稳定系数随填土及地基土抗剪强度参数的增大呈近似线性增大,随筋带拉力及顶层筋带长度在一定范围内的增加呈非线性增大,随筋带竖向间距的增大呈非线性减小;理论方法与数值模拟得到的潜在滑面也较为一致。In order to reasonably analyze seismic stability of filling slopes retained by gravity walls anchored horizontally with flexible reinforcements, the quasi-static method combined with the horizontally and obliquely slicing limit equilibrium methods are adopted to derive the safety factor of the wall-slope overall stability based on the hypothesis of interslice forces proposed by the Fellenius and the simplified Bishop methods. Considering the tensile rupture and the potential pulling out failure mechanism of the reinforcements, the proposed method is verified through numerical simulations under various horizontal seismic effect coefficients. Then the influences of the internal friction angle, the cohesion of the backfill and foundation soil, the vertical spacing, the ultimate tensile force, and the length of the reinforcements on the seismic wall-slope overall stability are studied, respectively. The results show that the safety factor calculated by the proposed method with the simplified Bishop’s hypothesis is fairly identical with the numerical results, which is about 6% higher than that calculated by the proposed method with the Fellenius hypothesis. Besides, the safety factor increases approximately linearly with the increase of shear strength of the filling and foundation soil, increases nonlinearly with the increase of the ultimate tensile force and the length of the top reinforcement, but decreases nonlinearly with the increase of the vertical spacing of the reinforcements. Additionally, potential slip surfaces of the retained slope by the proposed methods are close to the numerical results.

关 键 词：水平柔性拉筋式重力墙 墙-坡地震整体稳定性 水平条分法 拟静力法 极限平衡 

分 类 号：TU435[建筑科学—岩土工程]