土体强度分区各向异性对边坡稳定性影响研究

Study on slope stability influenced by partition anisotropy of soil strength

土体强度各向异性的空间分布会随边坡受力状态变化出现一定程度的重新调整。文中以石人足成层土边坡工程为研究对象,首先,根据土体最大主应力方向角以及土层几何特征进行初始分区划分,并结合数值分析结果确立各向异性强度参数方程,计算各分区土体强度参数;其次,根据计算结果对初始分区进行即时调整,确定调整后的耦合分区并再次计算其土体强度参数;最后,考虑土体强度各向同性和分区各向异性,建立了流固耦合数值计算模型,研究了边坡体渗流、位移和应力的演化特点,确定了加固前后边坡稳定性系数,分析了该边坡工程采用挡土墙和抗滑桩联合加固的效果。结果表明:考虑分区各向异性计算所得边坡平均应力最大值大于各向同性,但其渗流域和流速均小于后者;考虑分区各向异性时,坡体位移理论计算结果与现场监测结果更吻合。

The spatial distribution of strength anisotropy of soil has a certain change with the stress state of slope.In this paper,the Shirenzu slope is presented as an example,firstly,the initial partitions are divided based on the direction angle of the maximum principal stress and geometric characteristics of each soil layer,and then applying the calculaton results of numerical simulation,the equations of anisotropic strength parameters are built and the parameters of soil in each partition are calculated.Secondly,the initial partitions are changed timely based on the calculation results,the coupling calculation partitions are determined,and the strength parameters are calculated again.And finally,the flow-solid coupling models thinking about isotropy and the partition anisotropy of soil strength are built,and the properities of seepage,displacement and stress of this slope are studied.Stability coefficients of the slope before and after reinforcement are all calculated,and slope stability reinforced by retaining wall and anti-slip pile is analyzed.The results show that if the partition anisotropy of soil strength is considered,the maximum value of average stress is larger than that of isotropy,while the seepage field and flow velocity will decrease,and the calculation results of displacement are more similar with the monitored results.