基于非线性有限元法的高拱坝坝肩岩体抗滑稳定分析

高拱坝的安全性在很大程度上依赖于坝肩岩体的稳定性,目前在设计中,高拱坝坝肩岩体稳定性分析方法主要是刚体极限平衡法,但该法不能考虑岩体的应力-应变关系,不能很好地反映坝肩岩体的破坏机理以及拱坝与坝肩岩体的相互作用效应。本文从摩擦理论和矢量几何出发,导出了三维可能滑体的抗滑稳定安全系数计算公式,并通过等参逆变换的方法,将非线性有限元法的计算成果纳入到所建立的公式中,形成了“基于非线性有限元的高拱坝坝肩岩体抗滑稳定分析方法“。具体工程的应用成果表明,所给出的基于非线性有限元的坝肩岩体抗滑稳定分析方法充分反映大坝与坝基岩体的共同作用效应,是进行高拱坝坝肩岩体稳定性分析的一种有效方法。

An analysis of high arch dam abutment rock stability based on nonlinear FEM

The safety of arch dam depends on the stability of dam abutment rock in a large degree.Presently,the analysis of the stability of the dam abutment rock mainly employs limit equilibrium method in design.But the method does not consider the rock stress-strain relation or reflect the destructive mechanism of the dam abutment rock and the interaction between arch dam and the abutment rock.The paper educes the calculating formula of the stability safety factor for the three-dimensional possible sliding body based on the friction principle and vector geometry.The formula reflects the results of non-linear FEM by the inverse isoparametric mapping,and provides the method of high arch dam abutment stability analysis based on nonlinear FEM.The results in a practical engineering show that the method suggested in this paper can well reflect the interaction between arch dam and the abutment rock,thus being regarded as an ideal method of high arch dam abutment stability analysis.