The Permeability of an Intact Granite

Abstract

The permeability of intact Barre granite is determined by conducting transient hydraulic pulse tests that induce radial flow in saturated granite cylinders containing a water-filled co-axial cavity. Saturated specimens of granite are also subjected to uniform heating on the outer cylindrical surface and the permeability of the granite is measured at the termination of a heating sequence. The theoretical basis for the use of simplified analytical solutions for evaluating the decay of the pressure pulse is examined and the permeability of the granite in the pre-heating and post-heating states is inferred from the results of pulse tests. The reported investigations document one of the limited numbers of large-scale laboratory tests conducted to determine the permeability characteristics of intact granite. The results of the permeability measurements indicate the absence of any appreciable influences of micro structural alterations in the fabric of the granite due to its heating in a saturated condition, at an average temperature of 140 °Celsius.