滑块稳定分析FEM-LEM法的精度及动力稳定性评价

Accuracy and Dynamic Stability Evaluation of FEM-LEM Method for Slider Stability Analysis

为研究拱坝坝肩滑块在动荷载下的超载承受能力,在研究有限元法与刚体极限平衡法相结合(FEM-LEM法)分析滑块稳定的精度及计算结果对滑块网格及泊松比敏感性,验证了FEM-LEM法的精确性及实用性后,通过对滑块加速度、速度及位移的关系研究,提出了1种动力稳定性评价方法,以滑块累积位移与超载系数的关系曲线来判定滑块的动力超载系数,并结合工程实例进行计算分析。研究结果表明,滑块的动力超载系数-累积位移关系曲线具有突变性质,突变点对应的超载系数反映了拱坝坝肩滑块的超载承受能力及动力条件下的安全储备。

In order to study the overload bearing capacity of slider of arch dam abutment under dynamic load,this paper studies the accuracy of stability analysis of slider by combining finite element method with rigid limit equilibrium method(FEM-LEM method)and the sensitivity of calculation results to slider grid and Poisson ratio.After verifying the accuracy and practicability of FEM-LEM method,a method for evaluating dynamic stability is put forward by studying the relationship between acceleration,velocity and displacement of slider.The dynamic overload coefficient of the slider is determined by the relation curve between the cumulative displacement of the slider and the overload coefficient,and is calculated and analyzed with an engineering example.The results show that the dynamic overload coefficient-cumulative displacement relation curve of the slider has catastrophic property.The overload coefficient corresponding to the catastrophic point reflects the overload bearing capacity of the slider of the arch dam abutment and the safety reserve under dynamic conditions.