不同固结度尾矿砂应力应变分析

Stress and Strain Analysis of Tailings Sand with Different Consolidation Degrees

尾矿坝增高填筑的过程也是下部坝体逐渐排水固结的过程,为了研究固结度对尾矿砂应力应变的影响,并为尾矿坝安全管理和稳定性评价提供理论依据,分别对尾矿砂在不同围压(100kPa、200kPa、300kPa、400kPa)下进行了不同固结度(25%、50%、75%、100%)的固结不排水三轴试验。试验结果表明,围压越大试样强度越大,ε1越大,应力出现峰值后,试样仍然能承受很大的应力;发生相同的变形量,固结度高时所对应的轴向应力大,同时变形速率也在增大,而固结度低时所对应的轴向应力则小;σ3较大时尾矿砂的固结度对轴向应力影响较大,反应更加明显。

The process of filling of tailings dam is also the process of gradual drainage and consolidation of the lower dam.In order to study the influence of consolidation degree on the stress and strain of tailings sand,and provide theoretical basis for the safety management and stability evaluation of tailings dam,in this paper,the consolidation undrained triaxial tests of different consolidation degrees(25%,50%,75%and 100%)are carried out under different confining pressures(100kPa,200kPa,300 kpa and 400kPa).Tests show that the larger the confining pressure,the greater the strength of the sample,the larger theε1,and the higher the stress,the sample can still bear large stress after the peak stress value.The same amount of deformation occurs,the axial stress corresponding to the high degree of consolidation is large,and the deformation rate is also increased,and the axial stress corresponding to the low degree of consolidation is small;and when theσ3 is larger,the consolidation degree of the tailings sand has a greater influence on the axial stress,and the reaction is more obvious.