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为了详细探讨颗粒流程序在计算多孔介质渗流规律的适用性问题,采用三维颗粒流程序对不同级配砂土的渗流规律进行了数值模拟。结果表明,对于层流状态,在相同的渗透坡降下,球形颗粒渗透系数大于实际砂土的渗透系数,对其原因进行了深入分析;采用棒状颗粒并选取合适的形状系数,可大大缩小数值试样的渗透系数与实测值的差距;数值试样的渗透系数随着平均粒径和孔隙率的增大而增大,与室内渗流试验的结果一致;在用颗粒流进行渗流分析时,对于引起颗粒起动、渗透变形等的水力条件,建议选用渗透流速作为判别标准,而不是施加的渗透坡降。
In order to investigate in detail the applicability of particle flow program in calculating the seepage law of porous media, three-dimensional particle flow program was used to simulate the seepage law of different grade sand. The results show that for the laminar flow state, the permeability coefficient of spherical particles is larger than that of actual sand under the same infiltration slope, and the reason is deeply analyzed. By using rod-shaped particles and choosing proper shape factor, The permeability coefficient of the sample increases with the increase of the average particle size and the porosity, which agrees with the result of the indoor seepage test. When using the particle flow to carry out the seepage analysis, Particle start, infiltration deformation and other hydraulic conditions, it is recommended to use the permeate flow rate as a criterion, rather than the infiltration gradient applied.