人工冻结尾矿力学特性单轴压缩试验研究

尾矿的冻结会影响尾矿坝的稳定性.通过室内单轴压缩试验,研究了经人工冻结四类尾矿的力学特性及其4个影响因素.研究结果显示,冻结尾矿单轴压缩破坏形式有三种,即斜面剪切破坏、径向拉伸破坏和复合式破坏.冻结尾矿单轴压缩全应力-应变曲线可分4个阶段:初始应变软化阶段、线性应变硬化阶段、非线性应变硬化阶段和非线性应变软化阶段.在4个影响因素中,冻结尾矿的单轴抗压强度与平均粒径呈对数关系,与干密度呈指数关系,与含水率呈线性递增关系,与加载速率呈二次抛物线增长关系.而冻结尾矿的变形模量与平均粒径呈自然对数关系,与干密度亦呈指数函数关系,与含水率则呈二次抛物线关系,与加载速率呈指数函数增长关系.

Experimental Study on the Mechanical Properties of Frozen Tailings by Uniaxial Compression Tests

The frozen of tailings can affect the stability of the tailing dam. The uniaxial compression tests were carried out to study the mechanical characteristics of artificial frozen tailing and its four influence factors. There are three types of failure modes for frozen tailing specimen， i.e. shear failure in oblique section， tensile failure in radial direction and composite failure mode. The stress-strain curve of the frozen tailings samples can be divided into four stages: the axial compressive tests as initial stain softening stage， linear strain hardening stage， nonlinear strain hardening stage and softening stage. In the four factors， the uniaxial compressive strength is logarithmically related to the average particle size， exponentially related to the dry density ，linearly related to the moisture and parabolically related to the loading rate. The deformation modulus of frozen tailings is logarithmically related to the average particle size， exponentially related to the dry density and loading rate， and parabolically related to the water content.