ABSTRACT
The permeability characteristics of jointed coal and sandstone are investigated in the laboratory under triaxial conditions. A high pressure triaxial apparatus was designed for measuring the triaxial strength and permeability of both intact and fractured rocks. In this equipment, air or water can be made to flow through the rock specimens depending upon the porosity of the rock in order to estimate the air or water permeability. Test results verify that the permeability of the fractured rock decreases with the increasing confining pressure. It is also observed that the air permeability is greater than the water permeability for a fractured coal specimen. The laboratory measurements agree with the field permeability data obtained from hydro-fracturing test conducted on coal.
