基于路堤稳定性的斜坡软土碎石桩复合地基面积置换率确定研究  

A Method to Determine the Area Replacement Rate of Gravel Pile Composite Sloped Soft Foundation Based on Embankment Stability

作　　者：沙马伍呷 蒋鑫[1,2,3] 向嫣然 李政贤 邱延峻[1,2,3] SHAMA Wuga;JIANG Xin;XIANG Yanran;LI Zhengxian;QIU Yanjun(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Highway Engineering Key Laboratory of Sichuan Province,Southwest Jiaotong University,Chengdu 610031,China;MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]西南交通大学道路工程四川省重点实验室,成都610031 [3]西南交通大学高速铁路线路工程教育部重点实验室,成都610031

出　　处：《交通科技》2023年第2期7-11,共5页Transportation Science & Technology

基　　金：西南交通大学重点实验室向本科生开放工程实践项目(ZD2022010072)资助。

摘　　要：现行国家行业标准从路堤稳定性角度出发,要求斜坡软土地基路堤的稳定安全系数下限值根据地基横向坡度大小进行修正,即尝试通过提高路堤稳定性间接地对斜坡软土地基侧向变形予以控制。采用碎石桩复合地基可提高斜坡软土地基路堤稳定性,但其面积置换率可调整范围较宽,易致碎石桩复合地基处理设计时面积置换率确定方面随意性偏强。文中基于有限元剪切强度折减法,构建斜坡软土地基路堤碎石桩处治数值模型,分析在不同地基横向坡度条件下路堤稳定性随碎石桩复合地基面积置换率变化的规律,提出从路堤稳定性角度出发的斜坡软土碎石桩复合地基面积置换率确定方法,讨论了经碎石桩置换后土体重度、黏聚力和内摩擦角三者变化的综合作用。From the perspective of embankment stability,the current national industrial standard requires that the lower limit value of stability safety factor of embankment over sloped soft ground should be adjusted according to the transverse slope of soft ground,that is,it tries to indirectly control the lateral deformation of sloped soft ground by improving the stability of embankment.The use of gravel piles to make foundation composite can improve the stability of embankment,but its area replacement rate can be adjusted in a wide range,which is easy to make the determination of area replacement rate of gravel pile composite foundation more arbitrary during improvement design.Based on the finite element shear strength reduction method,a numerical model of embankment over sloped soft ground treated by gravel piles is developed,the variation rule of embankment stability with the area replacement rate of gravel pile composite foundation under different transverse slopes of soft ground is analyzed,and a method is proposed to determine the area replacement rate of gravel pile composite foundation on sloped soft ground from the perspective of embankment stability.The comprehensive effects of soil unit weight,cohesion and internal friction angle after replacement by gravel pile are discussed.

关 键 词：斜坡软土地基路堤 剪切强度折减法 稳定安全系数 面积置换率 碎石桩 

分 类 号：U416.12[交通运输工程—道路与铁道工程]