Abstract:Based on permeability test,the varitional characteristics of rockmass permeability under loading- unloading of confining pressure are studied. The test results show that both the permeability of sandstone and that of granite with a single fracture declines with the increasing effective pressure,following the law of exponential decay. The permeability sensitivity of granite with a single fracture to effective stress is much stronger than that of sandstone,but the recovery capability of permeability of sandstone is more stronger than that of granite with a single fracture. Moreover,for sandstone and granite with a single fracture,there is obvious hysteresis effect for the restitution of permeability in the process of unloading of confining pressure.