Experimental study on permeability of Beishan granite

Abstract

Rock engineers involved in the design and construction of nuclear waste repositories need to know the permeability of Beishan granite under high stress. A series of permeability tests were performed on specimens of Beishan granite at different axial stress levels and confining stresses. The results indicate that the permeability evolution can be identified in four distinct stages during the test. The permeability decreases during the first stage of loading due to the progressive closure of initial microcracks of rock under compressive stresses. During the second stage, the permeability is nearly constant or slightly increases. In the third stage, there is a significant increase of permeability in this stage in relation with the volumetric dilation. In the fourth phase, the permeability increases to the highest value, and then presents a decreasing trend. © 2012 Taylor & Francis Group.