基于有限元极限平衡法的尾矿坝坝体稳定分析

Stability analysis of tailings dam based on finite element limit equilibrium method

在平面应变条件下,采用基于弹塑性应力应变分析的有限元极限平衡法对尾矿坝坝体的稳定性进行研究。该方法可较好地结合极限平衡分析方法和有限元应力分析方法的特点。通过弹塑性有限元分析,合理准确地考虑结构整体应力场的影响,进而结合Hooke-Jeeves法优化搜索最危险滑动面的位置及其对应的最小安全系数。以某尾矿坝实际工程为例,比较分析了考虑正常、洪水以及特殊工况运行下有限元极限平衡法与极限平衡条分法和有限元强度折减法在安全系数大小及滑动面形状和位置的差异,重点运用有限元极限平衡法对尾矿坝坝体的稳定性进行验算并作出安全评价,为尾矿坝的安全设计施工提供可靠依据和技术支撑。

Under the condition of plane strain, finite element limit equilibrium method is applied to evaluate the stability of tailings dam. This method can be better combined with characteristics of the limit equilibrium analysis methods and finite element stress analysis. And it is based on the elastoplastic stress-strain analysis. Considering the overall stress field of the structure reasonably and accurately; the most dangerous location of slip surface and the corresponding minimum safety factor are determined by Hooke-Jeeves optimized searching method. An example of stability analysis of tailings dam engineering practice is proposed. The differences of safety factor quantity, shape and location of slip surface among stability methods： finite element limit equilibrium method, limited equilibrium slice method and finite element shear strength reduction method, are compared and studied in the normal, flood and special conditions. The safety assessment of tailings dam is made by using finite element limit equilibrium method. The results can provide a reliable basis and technical support for the safety of the design and construction oftailings dams.