尾矿砂的动力变形及动强度特性研究

通过对某钼矿尾矿砂在不同固结应力状态下进行的动三轴试验，研究了该尾矿砂的动力变形和动强度特性。试验结果表明：该尾矿砂的动应力应变关系可用Hardin等效黏弹性模型描述，模型中的起始动剪切模量和最大动剪应力皆随固结应力比和有效固结围压的增大而增大，这两个参数与有效固结轴压成幂函数关系，且其受固结应力的影响较小。同时，该尾矿砂的阻尼比随动剪应变的增大而增大，有效固结围压和固结应力比的变化对阻尼比与动剪应变关系的影响较小；在不同固结应力条件下，阻尼比与最大阻尼比之比与动剪切弹性模量比的减小量之间在双对数坐标系中呈较好的线性关系。在振动条件下，该尾矿砂达到破坏时对应的动剪应力随有效固结围压和固结应力比的增大而增大，其动剪应力比受固结围压的影响较小，并随固结应力比的增大而减小。

Experimental study on dynamic deformation and dynamic strength of tailing sands

The properties of dynamic deformation and strength of tailing sands under various consolidation conditions are studied by triaxial tests. The result shows that the relationship between stress and strain can be described by Hardin model. The maximum dynamic shear elastic modulus and maximum dynamic shear in the model increase with the increase of consolidation stress ratio and effective confining pressure. The influences of consolidation stress ratio and effective confining pressure can be expressed by power function relationships with axial compressive pressure. The damping ratio increases with the increase of dynamic shear strain. The relationship between damping ratio and dynamic shear strain is almost independent of consolidation stress ratio and effective confining pressure. In spite of the consolidation condition, the relationship between damping ratio and reduction of dynamic shear elastic modulus ratio is linear in log-log coordinate. Dynamic shear stress at failure increases with the increase of consolidation stress ratio and effective confining pressure. The dynamic shear stress ratio is almost independent of effective confining pressure, but it decreases with the increase of consolidation stress ratio.