拱坝坝肩岩体渐近破坏及可靠度分析

The Pregressive Failure of Arch Dam Abutment and the Analysis of Its Reliability

常用的对拱坝坝屑岩体稳定分析方法多采用刚体极限平衡法。此法在遇到复杂地基情况时,则甚难得到合理的结果。本文建议采用岩体渐近破坏模型及可靠度分析。本文采用了渐近破坏的岩体弹塑性断裂模型,有限元分析方法和可靠度分析方法。并将此法用于我国某高坝基础岩体的稳定研究。文中给出了刚体极限平衡方法、有限元方法、地质力学模型试验方法以及可靠度方法计算的结果。研究结果表明了,用刚体极限平衡法对局部的关键块的安全系数往往得出较高的数值,引起不安全的结果。用作者建议的方法则可得到合理的结果。

In this paper, the stability of arch dam abutments is examined. The authors propose a progressive failure model with reliability analysis for the rock mass, which is different from the conventional ones used by Rigid Limit Equilibrium Method. Different from the conventional method in analysis stability of abutments, the reliability of an abutments in China. has been computed with a simplified approach by the authors.The case study results for that dam including conventional method, F. E.M.geomechanical rupture tests and pregressive failure model with reliability analysis,are given in comparison in this paper, A conclusion drawn from the above mentioned study is that the S.F.from the conventional method cannot ensure the safety of arch dam satisfactorily.