红土镍矿尾渣三轴抗剪强度试验研究

Triaxial Shear Strength Test of Laterite Nickel Ore Tailings

抗剪强度指标的准确测定对尾渣堆场的设计和稳定性评价具有非常重要的意义。采用TSZ-2全自动三轴仪,开展了三种不同含水率条件下的红土镍矿尾渣试样固结不排水强度试验,确定了红土镍矿尾渣的应力-应变、孔隙水压力及抗剪强度指标的变化规律。试验结果表明:红土镍矿尾渣的应力-应变关系呈应变硬化型;尾渣含水率接近最优含水率时,孔压-应变关系表现出剪胀倾向,含水率为31%时,孔压-应变关系表现出剪缩倾向;随着含水率的增加,尾渣的有效黏聚力逐渐减小,有效内摩擦角逐渐增大;尾渣的黏聚力受含水率影响较大。

Accurate measurement of the shear strength index is of great significance to the design and stability evaluation of tailings yard.The TSZ-2 automatic triaxial instrument was used to carry out the consolidated undrained shear strength test of the laterite nickel ore tailings samples under three different water content conditions,the changes of stress-strain,pore water pressure and shear strength indexes of laterite nickel ore tailings are determined.The results indicate that the stress-strain relationship of laterite nickel ore tailings is strain hardening.When the water content of tailings is close to the optimal water content,the pore pressure-strain relationship shows a tendency to dilate,and when the water content is 31%,the pore pressure-strain relationship shows a tendency to shrink.With the increase of the water content,the effective cohesion of the tailings sample gradually decreases while the effective internal friction angle gradually increases.The cohesion of tailings is greatly affected by the water content.