Abstract: The impact of confining pressure on the permeability of fractured Maokou limestone.Maokou limestone sample was cored from coal dam was analyzed MTS815 rock mechanical system was used to research the permeability under different confining pressures and the same axial pressure.The test results showd that permeability decreased with confining pressure increase under the same axial pressure,and when confining pressure was low,permeability of fractured Maokou limestone changed largely with confining pressure increase;on the contrary,the permeability changed relatively little when confining pressure was high.Volumetric stress,permeability coefficient and osmotic pressure were fitted well by exponential function.

Key words: permeability, confining pressure, volumetric stress, osmotic pressure