加筋尾矿稳定性及界面剪切模型

Research on slip stability and interface shear model of reinforced tailings slope

为分析加筋尾矿坝的边坡抗滑移稳定性,探讨上覆荷载和尾矿砂含水率对加筋尾矿界面初始剪切刚度的影响,采用土工合成材料直剪拉拔试验摩擦系统,对加筋尾矿开展直剪试验并建立剪切模型,通过拟合试验结果求得初始剪切刚度值。结果表明:在加筋尾矿直剪试验过程中,剪切应力达到峰值后会略有降低;新剪切模型计算出的试验结果接近实际值,初始剪切刚度值误差在1 kPa以内,优于常规剪切模型;随着含水率的增加,初始剪切刚度先增大到峰值,后逐渐减小。当上覆荷载增加到一定值时,初始抗剪刚度将保持稳定。依据试验结果,可求出各组试验的最大初始剪切刚度值,从而判断尾矿坝是否稳定。

In order to analyze slope-sliding stability of reinforced tailings dams and explore influence of overlying load and tailings water content on initial shear stiffness of reinforced tailings interfaces,direct shear test on such tailings was conducted and a shear model was established by using geosynthetics direct shear pull-out test friction system.Then,initial shear stiffness value was obtained by fitting the test results.The results show that during the test,shear stress will decrease slightly after reaching peak value.The outcomes calculated by new shear model are close to the actual value,and the error of initial shear stiffness is less than 1 kPa,which is better than the conventional model.With the increase of water content,the stiffness first increases to the peak value and then decreases gradually.However,as overlying load increases to a certain value,it will be stable.Moreover,the maximum initial shear stiffness of each group can be obtained,which can judge whether the tailings dam is stable or not.