强度折减有限元法分析边坡稳定性的精度探讨  

Feasibility of strength reduction FEM used in slope stability analysis

作　　者：董璞[1] 刘金龙[2] 李亮辉 

机构地区：[1]惠州学院建筑与土木工程系,广东惠州516015 [2]合肥学院建筑工程系,安徽合肥230022 [3]深圳市勘察测绘院有限公司,广东深圳518028

出　　处：《四川建筑科学研究》2009年第2期146-150,共5页Sichuan Building Science

基　　金：安徽省高等学校省级自然科学研究项目(KJ2008B259);合肥学院引进人才启动基金资助项目(RC027)

摘　　要：对强度折减有限元法分析边坡稳定性中的精度进行了探讨。对比分析表明:边坡安全系数随着剪胀角ψ的增大略有增大,但总体上可以忽略不计,有限元计算中,可取ψ=0°进行边坡稳定性分析;弹性模量E和泊松比ν对安全系数基本上没有影响;采用位移是否突变和塑性区是否贯通作为边坡的失稳判据,对比前后计算步骤中的位移和塑性区特性,可以减少或消除非确定性因素对安全系数的影响;计算模型的边界范围大小,需根据具体边坡的变形需要来确定,其大小应足以让边坡的破坏滑动面自由发展。通过算例分析表明,在采用合理的失稳判据条件下,用有限元强度折减法得到的边坡安全系数与极限平衡法的结果相当,说明采用强度折减有限元法分析边坡稳定性是合理可行的。The feasibility of shear strength reduction FEM used in slope stability analysis has been comparatively studied. It is shown that the dilative angle ψ has a minute effect on factor of safety（ FOS）, so ψ =0° can be used in the slope stability analysis. Basically, different value of young＇s modulus E and poisson＇s ratio t, have no effect on FOS. Furthermore, the effect of uncertain conditions on FOS can be lessened by using the failure criteria based on the abruptness of the deformation at a certain characteristic location and overlapping of plastic zone. In a certain degree,the scope of FEM module should be decided by the distortion of the slope. An example slope has been studied with shear strength reduction FEM,resuhs shown that the FOS of slope got by shear strength reduction FEM is consistent with the limiting equilibrium method.

关 键 词：强度折减有限元法 边坡稳定 安全系数 误差分析 

分 类 号：TU452[建筑科学—岩土工程]