成层软土地基上土堤填筑稳定性的塑性极限分析  

Plasticity limit analysis of stability of embankment fill on layered soft soil ground

作　　者：雷国辉[1,2] 张惠敏 刘芳雪 张飞[1,2] 庄妍[1,2] LEI Guo-hui;ZHANG Hui-min;LIU Fang-xue;ZHANG Fei;ZHUANG Yan(Key Laboratory of Geomechanies and Embankment Engineering of Ministry of Education,Hohai University,Nanj ing 210098,China;Jiangsu Research Center for Geotechnical Engineering Technology,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学江苏省岩土工程技术工程研究中心,江苏南京210098

出　　处：《岩土工程学报》2018年第8期1522-1527,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51578213,51508160);中央高校基本科研业务费专项资金项目(2017B00814,2017B20614);高等学校学科创新引智计划(“111计划”)项目(B13024)

摘　　要：针对成层软土地基上土堤填筑的稳定性分析问题,考虑地基土体的不排水抗剪强度既随土层变化又随深度任意线性变化,根据工程实践中揭示的堤基深层破坏模式,基于塑性极限分析的上限理论,构建满足运动许可的对数螺旋线与圆弧组合的转动破坏机制,建立了便于快速评估成层软土地基上土堤填筑稳定性的临界高度、无量纲化的稳定数、稳定图、最小安全系数和临界滑动面的分析计算方法,并将计算结果与2个土堤失稳现场试验工程案例的实测结果进行了对比。结果表明,采用本文方法计算得到的土堤最小安全系数接近于土堤失稳时的最小安全系数的理论值1.0,计算确定的临界滑动面也与实测的临界滑动面比较接近,从而验证了本文方法的适用性。The stability of embankment fill on layered soft soil ground is analyzed. For each layer of soft soil, arbitrarily linearly increasing undrained shear strength with depth is considered. According to the deep-seated failure mode revealed from engineering practice, a logarithmic spiral and an arc combined rotational failure mechanism is constructed for the fulfillment of the kinematical admissibility based on the upper bound theory of plasticity limit analysis. The methods for the analysis of the critical embankment height, non-dimensional stability number, stability charts, the minimum factor of safety and the critical slip surface are established for rapid evaluation of the stability of embankment fill on layered soft soil ground. Comparisons are made of the calculated results with the measured ones from two case histories of field tests of embankment failure. It is shown that the minimum factor of safety derived from the proposed method is basically identical to the theoretical value of 1.0 of the minimum factor of safety for embankment instability. The critical slip surface determined by the proposed method is approximately consistent with the measured one. The applicability of the proposed method is thus verified.

关 键 词：成层软土地基 土堤填筑 稳定性 极限分析 稳定数 

分 类 号：TU751[建筑科学—建筑技术科学]