孔隙水压力作用下抗滑桩加固边坡的极限分析上限解

Nonlinear upper bound analysis of slope stability reinforced by piles subjected to pore water pressure

用对数螺旋线形的破坏机制和极限分析上限法,对抗滑桩加固边坡的稳定性进行了研究。基于构建的抗滑桩加固边坡的破坏机制,推导了抗滑桩加固边坡的内、外功率表达式。通过切线法将土体的非线性破坏准则引入到极限分析方法中,并结合强度折减法建立了抗滑桩加固边坡的安全系数隐式表达式。用最优化方法,计算得到了孔隙水压力作用下的边坡安全系数。在此基础上,分析了抗滑桩加固位置、孔隙水压力以及非线性抗剪强度等参数对抗滑桩加固边坡安全系数的影响。结果表明:土体抗剪强度对抗滑桩最佳布设位置的影响较小;非线性条件下,边坡安全系数随着初始黏聚力的增大而增大,随着抗拉强度和非线性系数的增大而减小。

According to the logarithmic failure mechanism and the upper bound method of limit analysis,thestability of slope reinforced with piles is studied.Based on the failure mechanism of slope strengthened by piles,theinternal and external power expressions are derived.The tangent method is also introduced to consider the non-linearcriterion of soil,and then the implicit expression of safety factor is obtained.The safety factor of slope under porewater pressure is calculated by the optimization method.On the base of this,the effects of the reinforcement positionof pile,pore water pressure and nonlinear shear strength parameters on safety factor are studied.The calculationresults show that shear strength has less impact on optimum placement of anti-slide piles,and under nonlinearcriterion,the safety factor increases with the increasing initial cohesion but decreases with the increasing tensilestrength and nonlinear coefficient.