基于M-C等面积圆屈服准则的岩土混合边坡稳定分析

The Stability Analysis of Rock-soil Slope Based on the Mohr-Coulomb Equivalent Area Circle Yield Criterion

针对有限元软件基于外角外接圆D-P准则计算边坡稳定安全系数偏大的问题,采用M-C等面积圆屈服准则进行改进,推导了二者计算安全系数的关系.基于MC等面积圆屈服准则计算岩土混合边坡,计算前对输入的土质和岩质的黏聚力及内摩擦角进行转换,结果表明,计算安全系数与Morgenstern-Price法得到的结果较为接近,并且塑性区与滑动面形状近似,表明了M-C等面积圆屈服准则在分析岩土混合边坡稳定问题是可行的.分析发现,岩土混合边坡安全系数随土质黏聚力和内摩擦角正切值的减少而减少,并且塑性区形状保持不变.

In view of the larger safty factor when calculating the slope stability in the finite element software with circumscribed Drueker-Prager criterion,it can be improved by Mohr- Coulomb equivalent area circle yieht criterion, the relationship of safty taetors obtained by two yield criteria is reduced. Based on the equal area circle yield criterion, the cohesion and internal friction angle of soil and rock were switched before calculating for rock-soil slope. The results show that safty factors are close to that calculated by Morgenstern-Priee method, considering the similarity between the plastic zone and sliding surface, the feasibility in the stability analysis of rock-soil slope based on Mohr-Coulomb equivalent area circle yieht criterion is proved.The analysis show that the safty factor of rock-soil slope reduces when cohesion and tangent value of internal friction angle of soil reduces, while the shape of plastic zone wouht remain unchanged.