Abstract: The splitting sandstone from Yichang is taken as the research object. The authors make a study of the seepage velocity variation rules caused by different loading paths, axial compressions, confining pressures, particle diameters of filler and filler thickness, when the splitting sandstones are respectively filled by medium-fine sand, coarse sand and mixed sand. The rsearch results show that under different fillers and a certain stress, the seepage velocity changes with the loading path, which is one of the reasons for discreteness of seepage data measured in projects. The axial compression and seepage velocity are in linear relation; while the low confining pressure has a greater impact on the seepage velocity, but the high confining pressure has smaller effect. The particle size is positively correlated with the seepage velocity; and confining pressure has a larger influence on the non-filler sandstone than on the filled one. The seepage velocity and the filler thickness are in an increasing exponentially relationship within a certain range. The research also gives a quantitative analysis formula of axial compression, confining pressure and the seepage velocity in specified conditions.

Key words: splitting sandstone, loading paths, seepage velocity, particle diameters