加载频率与循环应力比影响下的饱和尾粉砂变形特性

Deformation Characteristics of Saturated Tailings Sand Considering Effect of Loading Frequency and Cyclic Stress Ratio

细粒化高堆尾矿库受地震作用影响,其潜在安全隐患突出。为了解加载频率和循环应力比对饱和尾粉砂变形特性的影响,针对西南地区某尾矿库的深埋尾粉砂开展了一系列不同加载频率及循环应力比的动三轴试验。系统地研究了不同加载频率与循环应力比对饱和尾粉砂累积塑性变形的影响,并从滞回曲线的形态特征(整体倾斜程度k、宽窄程度α、面积S、不闭合程度ε)重点分析了加载频率与循环应力比对饱和尾粉砂变形特性的影响。结果表明:变形呈反“L”型破坏,存在累积塑性应变转折点;随着循环振次的增加,k、α逐渐减小,S、ε逐渐增加,即刚度和黏滞性越来越小、耗散的能量和塑性应变越来越大,而加载频率和循环应力比均会影响这一过程。

Fine-grained high reactor tailings pond is affected by earthquake,and its potential safety hazard is prominent.In order to solve the effect of loading frequency and cyclic stress ratio of saturated tailings sand deformation characteristics,a series of dynamic triaxial tests with different loading frequencies and cyclic stress ratios were carried out for the deep buried silt of a tailings pond in southwest China.The effects of different loading frequencies and cyclic stress ratios on the cumulative plastic deformation of saturated tailings sand were studied,and the effect of loading frequency and cyclic stress ratio on the properties of saturated tailings sandwas analyzed by the characteristics of the hysteresis curve.The experimental results show that the deformation is an anti-L type failure and there is a turning point of accumulated plastic strain.With the increase of cyclic vibration times,k andαdecrease gradually,S andεincrease gradually,the stiffness and viscosity become smaller and smaller,and the dissipated energy and plastic strain become larger and larger,while the loading frequency and cyclic stress ratio will affect this process.