有限元强度折减法边坡失稳判据适用性分析  

Analysis on the Applicability of Criterions for Evaluating Slope Stability Based on Strength Reduction FEM

作　　者：史俊涛[1] 孔思丽[1] 任琪[1] 

机构地区：[1]贵州大学土木工程学院,贵州贵阳550025

出　　处：《人民黄河》2014年第2期135-137,140,共4页Yellow River

摘　　要：为了研究各种边坡失稳判据的适用性和合理性,针对某均质土坡建立理想弹塑性有限元分析模型,将数值计算不收敛、塑性区贯通、坡体内特征部位位移发生突变作为边坡失稳的判据,运用强度折减法计算边坡的安全系数,并与极限平衡法计算出的结果进行对比分析。结果表明:3种失稳判据均与极限平衡法计算结果较为接近,特征部位位移突变和塑性区贯通作为边坡失稳判据所得安全系数具有一致性,且与极限平衡法的差别较小;考虑到收敛准则及收敛限值对有限元数值计算收敛性影响较大,将数值计算的不收敛作为边坡失稳判据其适用性有一定限制;建议采用塑性区贯通结合特征点位移突变作为边坡失稳的判据。In order to study the applicability and rationality of various instability criterions, the safety factors of an specific slope used ideal elastic- plastic finite element analytical model were calculated by using strength reduction technique respectively according to the convergence of numerical computations, the displacement catastrophe at a certain characteristic position and the connectivity of plastic zone. The computed results were com- pared with the solution of limit equilibrium method. It is shown that ： the safety factors calculated by three criterions of slope instability are ap- proached to the solution of traditional limit equilibrium method, and the computed result by using the displacement catastrophe at certain character- istic site is consistent with the result based on the connectivity of plastic zone, while the computed result on the basis of convergence of numerical computations may give a little bigger estimation of safety factor than other two criterions compared with procedures of traditional limit equilibrium. Considering the effect of convergence criteria and limit value on convergence of numerical computations, the combination of displacement catastro- ohe at a certain characteristic oosition and connectivity of plastic zone are suggested as the comprehensive evaluation of slope failure criterions.

关 键 词：强度折减法 失稳判据 稳定性分析 屈服准则 安全系数 塑性区域 

分 类 号：TU457[建筑科学—岩土工程]