TEST AND THEORETICAL RESEARCH ON PERMEABILITY CHARACTERISTICS OF SHEAR FRACTURE IN ROCK MASS
XU Lihua1，2，XIE Ni1，2
(1. School of Civil and Architectural Engineering，Wuhan University，Wuhan，Hubei 430072，China；2. Hubei Provincial Key Laboratory of Geotechnical and Structural Engineering Safety，Wuhan University，Wuhan，Hubei 430072，China)
Abstract：Under the triaxial stress state，a shear fracture of the diabase samples from Danjiangkou reservoir is obtained by shear failure. Permeability tests under different confining pressures and fracture water pressures(i.e. permeability pressure gradients) are carried out to study the permeability characteristics of the shear fracture. The test results show that overwhelming majority of the rock samples produces a single running-through fracture after shear failure，of which the permeability coefficient decreases with the increase of net confining pressure，following the law of exponential function. The effect of axial strain on the permeability coefficient of rock samples is relatively weak，while the circumferential strain has strong influence on it，as well as the fracture water pressure. The permeability coefficient of fracture increases with the increase of fracture water pressure while the net confining pressure is the same，which is mainly for the additional compressive deformation of the rock matrix caused by the comparatively big fracture water pressure that leads to the widening of fracture aperture. Based on test data，theoretical analysis and the displacement model of fracture and rock under three-dimensional stress condition，a formula for permeability calculating is obtained with the effect of fracture water pressure taken into consideration. The formula corresponds with the changing trend of permeability coefficient under different confining pressures and fracture water pressures fairly well；and all the parameters can be obtained by triaxial compression test simply. The calculated and measured values of permeability coefficient of fracture match with well each other.
徐礼华,谢妮，. 岩石剪切裂隙渗流特性试验与理论研究[J]. 岩石力学与工程学报, 2009, 28(11): 2249-2257.
XU Lihua1，2，XIE Ni1，2. TEST AND THEORETICAL RESEARCH ON PERMEABILITY CHARACTERISTICS OF SHEAR FRACTURE IN ROCK MASS. , 2009, 28(11): 2249-2257.
