考虑分区各向异性和渗流作用的边坡稳定性研究  

Slope stability considering zonal anisotropy and seepage effects

作　　者：张帮鑫 贾剑青[1] 赖远明 王宏图[3] 辛成平 ZHANG Bangxin;JIA Jianqing;LAI Yuanming;WANG Hongtu;XIN Chengping(School of Transportation,Lanzhou Jiaotong University,Lanzhou 730070,P.R.China;Northwest Institute of Ecological and Environmental Resources,Chinese Academy of Sciences,Lanzhou 730000,P.R.China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,P.R.China)

机构地区：[1]兰州交通大学交通运输学院,兰州730070 [2]中国科学院西北生态环境资源研究院,兰州730000 [3]重庆大学资源与安全学院,重庆400044

出　　处：《土木与环境工程学报（中英文）》2023年第4期41-48,共8页Journal of Civil and Environmental Engineering

基　　金：甘肃省科技计划(20YF8FA042);兰州交通大学“百名青年优秀人才培养计划”(152022)。

摘　　要：土体强度各向异性和渗流作用是影响边坡稳定性的重要因素。为使稳定性计算时边坡土体强度的各向异性更切合实际,提出对成层边坡土体进行分级加载和分区考虑强度各向异性的方法:将边坡土体最大主应力方向角与成层土相交区域设置为初始分区,然后结合有限元计算结果,推导各成层土各向异性强度参数计算公式,并即时计算各分区内土体强度参数;在逐级施加荷载过程中,根据计算所得土体强度参数,进一步调整初始分区,通过初分、细分和精分3级控制,确定耦合计算分区和各分区土体强度参数。在此基础上,建立考虑土体分区各向异性、未分区各向异性和未分区各向同性3种工况的流固耦合模型,分析边坡体应力场、位移场和渗流场的变化规律和特点,并采用强度折减法计算边坡稳定性。结果表明:考虑土体分区各向异性时,坡体平均应力最大值较未分区各向异性时有所减小,但较未分区各向同性时有所增大,其渗流域和流速较其他两种工况均有所减小;考虑土体分区各向异性时,计算所得边坡稳定性系数为1.109,较其他两种工况分别下降了2.8%和21.3%。Soil strength anisotropy and seepage are important factors affecting the stability of slopes.In order to make the anisotropy of slope soil strength more practical in stability calculation,a method of graded loading and zoning of layered slope soil considering strength anisotropy is proposed.Firstly,the initial zoning is established according to the size distribution of the maximum principal stress direction angle of the slope soil and the intersection area of layered soil, and then, combined with the finite element calculation results, the formula fordetermining the anisotropy strength parameter of each layered soil is derived and the strength parameter of eachzoning is calculated instantly. Secondly, in the process of applying load step by step, the initial partition isfurther adjusted according to the calculated soil strength parameters, the partition and the correspondingstrength parameters of the coupling calculation are determined through three-level control of initial partition,subdivision and fine partition. On this basis, a flow-solid coupling model considering three working conditions:zoned anisotropy, unzoned anisotropy and unzoned isotropy of the soil body is established, and the change lawsand characteristics of the stress field, displacement field and seepage field of the slope body are analyzed, andthe stability of the slope is calculated using the strength reduction method. The results show that the averagestress maximum value of zoned anisotropy is lower than that of unzoned anisotropy, but greater than that ofunzoned isotropy, the seepage and flow velocities are lower than those of the other two cases;the calculatedslope stability coefficient of zoned anisotropy is 1.109, which is 2.8% and 21.3% lower than those of the othertwo cases respectively.

关 键 词：土体强度 各向异性 渗流 边坡稳定性 强度折减 

分 类 号：TU413.62[建筑科学—岩土工程]