干密度和粒径对非饱和尾矿砂土水特征曲线的影响

Effect of Dry Density and Particle Size on Soil-water Characteristic Curve of Unsaturated Tailing Sand

为了得到干密度与粒径对非饱和尾矿砂土水特征曲线的影响规律,利用GEO-Experts压力板仪,开展了不同干密度、粒径的尾矿砂土水特征曲线试验,探讨了干密度与粒径对尾矿砂土水特征曲线的影响,并采用F-X模型对试验数据进行拟合。结果表明:尾矿砂粒径越小,进气值越高,残余含水率越大,且小于0.25 mm粒径的含量增加能有效提高尾矿砂的持水能力;干密度对尾矿砂土水特征曲线的影响集中表现在过渡阶段,粒径相同时随着干密度的增大,脱水速率减小,残余含水率增大,但残余基质吸力基本不变;F-X模型对于尾矿砂土水特征曲线具有较高的拟合精度,能较好地反映尾矿砂的持水性能。

In order to get the influence law of dry density and particle size on unsaturated soil-water characteristic curve of tailings,tests on different dry density,particle size of test-tailing sand soil-water characteristic curves were carried out using GEO-Experts pressure plate apparatus.The influences of dry density and particle size of tailing sand soil-water characteristic curve were analyzed,and the F-X model was used to fitting the experimental data.The results show that:when the tailing sand has a smaller particle size,the intake value is higher,and the residual water rate is larger.The influence of dry density on tailing sand soil-water characteristic curve is concentrated in the transition stage.With the increase of dry density,the dehydration rate decreases and the residual water content increases,but the residual matric suction is basically unchanged.The F-X model has a high fitting accuracy for the tailing sand soil-water characteristic curve,and can reflect the water holding performance of the tailing sand well.