冻融循环作用下尾矿砂孔隙率变化规律研究

摘要

The variation of tailings sand porosity under different freezing-thaw cycles was studied through mercury intrusion method. The results show that, under the action of freeze-thaw cycles, the pore volume of tailings sand increases nonlinearly with the increase of freeze-thawing cycle index; The porosity of tailings increases first and then decreases slowly and then increases with the increase of freeze-thaw cycle index; The pore fractal dimension reflects the pore structure variation of the sand body, and the pore fractal dimension decreases rapidly and then increases slowly and finally reaches a plateau with the increase of the freeze-thawing cycle index, at the same time reflects the variation tendency of the internal microstructure of the sand body.%冻融循环作用对砂土的孔隙率和孔隙体积变化具有重要影响.采用压汞法对冻融作用下尾矿砂孔隙率和孔隙体积变化规律进行研究,使用分形维数定量表征冻融循环作用下尾矿砂内部孔隙结构变化.研究结果表明,冻融循环作用通过破坏尾矿砂颗粒的大小和改变尾矿砂颗粒间骨架结构是导致尾矿砂孔隙体积和孔隙率变化的主要原因,随着冻融循环作用次数的增加,尾矿砂孔隙体积呈现出非线性增大趋势,孔隙率呈先增大后减小再缓慢增大的趋势,孔隙分形维数先急速下降后缓慢升高最终趋于稳定;尾矿砂内部结构微结构调整出现在冻融循环前期.