粗粒土的渗透特性与物质成分、颗粒级配、颗粒形状、密实度等因素相关。通过室内垂直渗透试验，探讨了土体颗粒形状、颗粒级配和试样密实度对粗粒土渗透系数的影响。九组正交试验结果的极差及方差分析表明，级配对渗透性的影响最大；两组颗粒形状对比分析试验结果表明，试样渗透系数随着颗粒球形度增大而增大。通过对试验结果反映的渗透特性进行分析，总结了以渗透系数作为变量的临界水力梯度估算公式。

The permeability property of coarse grained soils is closely related to material composition, grain size distribution, particle shape, and particle density. Based on the laboratory permeability test, the effects of particle shape, grain size distribution, and particle density on the permeability property of coarse grained soils were studied. Nine orthogonal experiments and two particle shape experiments were performed. The results showed that grain size distribution has the largest impact on permeability based on the range analysis and variance analysis of the orthogonal tests, and permeability increases with the increasing of particle sphericity based on the comparative analysis of two particle shape tests. The estimation formula of critical hydraulic gradient was proposed using the permeability coefficient as a variable based on the analysis of permeability characteristics reflected by the above tests.

重庆交通大学研究生教育创新基金资助项目（2011（上）第06号）；“十二五”国家科技支撑计划课题（2012BAB05B04）