分层排土场边坡降雨入渗过程及稳定性分析

Analysis on rainfall infiltration process and stability of layered dump slope

针对岭南沿海地区露天矿山排土场边坡分层特征,基于分层边坡降雨入渗模型,计算在一定降雨强度下雨水入渗深度,采用有限元强度折减法计算得出安全系数,结合工程实例,用数值模拟确定不同降雨入渗条件下的体积含水率、降雨入渗深度以及安全系数的变化,进行边坡稳定性分析。结果表明:降雨强度与渗透系数的关系对土体体积含水率的分布影响显著,建立的分层边坡雨水入渗深度理论计算结果与数值分析得到的结果基本一致,表明该公式能较好地反映分层边坡降雨入渗过程,在降雨初期以及湿润锋到达土体分层界面时,安全系数降幅最大,随后安全系数降幅逐渐减小且趋于稳定。边坡整体稳定性良好,现场位移监测结果验证了计算结果的合理性。研究成果为分层边坡降雨入渗灾害防治提供理论依据。

According to the layered characteristics of open-pit mine dump slope in south of the Five Ridges coastal area,based on the layered slope rainfall infiltration model,the rainfall infiltration depth under certain rainfall intensity was calculated,and the safety factor was calculated by using the finite element strength reduction method.Combined with the engineering example,the volume moisture content,rainfall infiltration depth,and safety factor changed under different rainfall infiltration conditions were determined by numerical simulation,then analyzed the slope stability.The results showed that:the relationship between rainfall intensity and permeability coefficient had significant influence on the distribution of soil volume moisture content.The theoretical calculation results of rainwater infiltration depth of layered slope were basically consistent with the results of numerical analysis,which shows that the formula can better reflect the rainfall infiltration process of layered slope,and the safety factor decreased most at the initial stage of rainfall and when the wetting peak reached the layered interface.After that,the safety factor decreased gradually and tended to be stable.The overall stability of the slope was good,and the rationality of the calculation results was verified by the field displacement monitoring results.The research results can provide a theoretical basis for the prevention and control of rainfall infiltration disaster of layered slope.