电解锰渣库失稳概率分析

Study on slope failure probability of manganese slag stack

以流固耦合的极限平衡法为基础,运用了泰勒级数法,对一铺膜防渗锰渣库在不同堆积高度的可靠度和失稳概率进行了计算分析,并参照美国陆军工程兵团对于岩土边坡的失稳概率评价标准,对锰渣库在运行过程中的边坡失稳风险进行了评估。分析表明:铺膜防渗的电解锰渣坝,当沿用常规不防渗尾矿坝设计时,边坡失稳概率过高,应通过增加导渗体数量、降低边坡坡度、放缓渣库上升速度等设计优化措施,降低锰渣库边坡失稳风险;对于影响渣库边坡稳定的重要参数,如抗剪强度、渗透系数、界面抗剪强度等,有必要通过高质量的取样和审慎的试验获得可靠的试验数据,以降低参数的不确定性,进而增加预期安全水平。

The reliability and slope failure probability of a geomembrane-lined manganese slag stack were calculated using the limit equilibrium method with coupled consolidation-seepage and the Taylor series expansion method. Based on the calculated reliability values, the risks of slope stability failure at different stack heights were evaluated in general accordance to the Expected Performance Level standard proposed by the US Army Corps of Engineers The results showed that the risk of slope stability failure would be high if the lined manganese slag stacks were designed and operated as conventional unlined tailings stacks. The engineering measures such as increasing the number of drains, flattening stack slopes and raising the stack at a slower pace, can be used to enhance safety. The expected performance level can also be improved by decreasing the uncertainties of such critical parameters as permeability and density of the stacking materials, interface shear strength between geomembrane and manganese slag, and shear strength of the foundation soil, which can be achieved through qualified sampling and meticulous laboratory tests.