用有限元强度折减法评价节理岩质边坡稳定性

Slope Stability Evaluation of the Rock Mass by Using Finite Element Strength Reduction Method

以某边坡为例,论述了在ABAQUS软件中实现节理岩质边坡稳定性评价的建模过程。采用具有一定厚度的、低强度实体单元模拟节理组,按连续介质处理,节理组与岩块之间创建相互接触作用,通过不断折减结构面强度参数,以模拟达到失稳状态。通过分析坡顶典型质点场变量与X方向的位移关系,以数值计算不收敛作为边坡失稳评价标准的稳定性安全系数为1.41,以坡顶质点出现明显位移作为失稳标准的稳定性安全系数为1.32,两种判断标准均表明边坡目前处于稳定状态。通过积分等效塑性应变区演化图,模拟得到了强度折减状态下边坡失稳时的潜在滑动面,滑动面直观可视且物理意义明确,无需像极限平衡法一样要事先假定滑动面的位置和形状。

Taking a slope as an example,the modeling process of the slope stability evaluation of the physiotic rock mass has been discussed in detail by using finite meta-software ABAQUS.In ABAQUS,a simulated section group with a certain thickness and low strength solid unit has been used,which is treated according to continuous medium,and the contact between the section group and the rock block is created to simulate the unstable state by continuously reducing the strength parameters of the structural surface.By analyzing the relationship between the displacement in X direction and the typical particle field variables at the top of the slope,the safety factor of non convergence of numerical calculation is 1.41,the safety factor is 1.32 when the apparent displacement of the particle at the top of the slope is taken as the instability criterion.The two criteria indicate that the slope is in a stable state at present.Based on the PEMAG integral equivalent plastic strain zone evolution diagram,the sliding surface under strength reduction state is simulated,sliding faces are intuitive and physically significant,eliminating the need to pre-assume the position and shape of the sliding faces as with extreme balancing.