全尾砂胶结充填体的渗透特性试验设计与分析

Experiment Design and Analysis on the Permeability Characteristic of Cemented Unclassified Tailings Backfill

为了获得全尾砂胶结充填体的渗透特性,设计了养护时间、水泥掺量与围压对充填体渗透性影响的试验方案。借助三轴剪切渗透仪,进行了不同条件下的充填体渗透参数测试试验。基于微观测试结果,揭示了充填体渗透性能演化的内在机理。结果表明:养护时间越长、水泥掺量越大,充填体的渗透系数越小;充填体的渗透系数随围压的升高呈先急剧降低后趋于稳定的变化规律,且符合幂函数递减模型;养护时间和水泥掺量的增加降低了充填体的孔隙率,改变了其孔径分布,导致充填体内部渗流通道的迂曲率升高,致使充填体渗透系数降低。试验结果可以为设计与优化井下采场充填料浆配比提供参考。

To obtain the permeability characteristic of cemented unclassified tailings backfill(CUTB),the experiments of curing age,cement content and confining pressure on the permeability of CUTB samples were designed.With the help of triaxial shear permeability instrument,the permeability parameters of backfill under different conditions were tested.Based on the microscopic test results,the internal mechanism of the permeability evolution of backfill was revealed.The results show that the longer curing age is and the more cement content is,the smaller permeability coefficient is.The permeability coefficient decreases instantly and then tends to be stable as the confining pressure increases,and the change law conforms to the power function model.The increase of cement content and curing age decreases the porosity of backfill and changes the pore size of CUTB,which leads to the increase the tortuosity of the seepage channel in the CUTB and the decrease of the permeability coefficient of the CUTB.The results can provide a reference for design and optimization of filling slurry in underground stope.