考虑裂隙分布及强度的膨胀土边坡稳定性分析  

Stability analysis considering fracture distribution and strength for expansive soil slope

作　　者：陈善雄[1] 戴张俊[1] 陆定杰[1] 罗红明[1] 李扬帆[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,湖北武汉430071

出　　处：《水利学报》2014年第12期1442-1449,共8页Journal of Hydraulic Engineering

基　　金："十二五"国家科技支撑计划项目课题(2011BAB10B02)

摘　　要：为完善现有膨胀土边坡稳定分析方法中概化处理土体结构,特别是裂隙面、软弱夹层等因素的局限,将边坡视为均质土层、裂隙充填薄层及张拉裂隙的组合,将现场勘测得到的典型控制性裂隙的空间信息(高程、倾角、厚度、长度)纳入模型,同时考虑裂隙面夹层的强度参数,建立膨胀土裂隙边坡地质模型。基于Slide程序中能够满足条块间作用力与力矩平衡,并且适合于折线滑动面的边坡稳定分析的Janbu、Spencer和Morgenstern方法,以南水北调中线工程典型滑坡为稳定性分析算例,分析含裂隙膨胀土边坡的稳定性及其特征。结果表明,边坡地质模型与真实边坡的吻合度越高,其稳定性亦越接近。在考虑了地表垂直裂隙、地下水及坡脚缓倾裂隙后,边坡的安全系数显著降低,并产生了由坡顶的垂直裂隙与从此裂隙底部开始发展、剪出口在坡脚的滑面组合而成的折线型滑动面,该滑动面型式与现场典型滑坡破坏特征基本一致。To complement the limitations of existing stability analysis method for expansive soil slope with generalized soil structure, especially fracture surface and weak interlayer, a new geological model of expansive soil slope with fractures has been established, which takes the slope as a combination of homogeneous soil filling with cracks and tension cracks, fitting the spatial information such as height, angle, thickness and length of typical controlling fracture of site survey into the slope model, and meanwhile, considering the strength parameters of the fracture surface. Based on the equilibrium methods, such as Janbu, Spencer and Morgenstern in the Slide program, which meet the equilibrium among the forces and moment of slices and are suitable for the broken line sliding surface,a typical landslide on the South-to-North Water Transfer Project is taken as an example for analyzing the stability and features of the expansive soil slope with fractures. The results show that with the model closer to the real slope conditions, the stability of the slope is also getting closer to the engineering practice. After considering the vertical fracture from surface, groundwater and gentle-dipping fracture at toe of the slope, safety factor falls significantly, and sliding surface, which made of vertical crack at slope top and slip surface developed from the bottom of the vertical cracks to the slope foot, assumes broken line form and its failure characteristics is basically the same as that of actual landslide.

关 键 词：膨胀土 边坡 裂隙面 稳定性分析 滑动面 

分 类 号：TU443[建筑科学—岩土工程]