|
Abstract Fluid flow through rock joints is commonly described by the smooth parallel plate model，which includes cubic law. However，the real rock joint surfaces are rough，and the fluid flow through a single fracture is not always consistent with the cubic law. Based on the typical joint roughness profiles proposed by N. Barton and V. Choubey(1977)，the templates with different joint roughness coefficients(JRCs) are manufactured by using numerical control wire cut electron discharge machining，and then，ten single-fracture column concrete samples with various JRCs from 0 to 20 are produced(50 mm in diameter and 100 mm in height). The single fracture¢s permeability tests were conducted at various effective stresses using RCCP test system. The test results show that：(1) The JRC has significant effect on the permeability of a single joint under low effective stress，and the effect of JRC on the permeability of a single joint decreases rapidly with the increasing effective stress. (2) The relationship between the permeability and the effective stress of a single joint follows the law of negative exponent，showing an obvious nonlinear behavior. For a single joint，the rate of change in the permeability versus the effective stress under low stress level is greater than that under middle-high stress level. Moreover，under the low stress level，the permeability of a single joint has a trend of decreasing with the increase of JRC at the same effective stress conditions.
|
|
Received: 26 December 2009
|
|
|
|
