Abstract:It is of practical importance to investigate the permeability of rock under high stress,especially under post-peak stress with low confining pressure. A patented device,combined with MTS815.02 Rock Mechanics System,makes the measurement of non-Darcy permeability possible. The configuration of test system of permeability measurement of non-Darcy flow in post-failure rock,test principle and plan,and the processing method for test data are presented. The permeability of non-Darcy flow in post-peak rock is carefully measured by using steady seepage method. Sandstone specimens are divided into five groups. Every group consists of ten specimens,which undergo same axial strain before permeability measurement. The permeability of each specimen is obtained by fitting the seepage velocity-pressure gradient curve. The statistical indexes of every group of specimens are calculated. The relation between the indexes and axial strain are established by linear regression. It is shown that the permeability of post-peak rock is remarkably larger than that of pre-peak rock. The permeability of post-peak rock varies parabolically with axial strain. This study provides the method and technique for measuring permeability of non-Darcy flow in post-peak rock,which can be employed in mining,civil and other engineerings.