DISCRETE FRACTURE NETWORK MODEL FOR〓HYDRAULIC CONDUCTIVITY OF FRACTURED ROCK MASS

Quantification of hydraulic conductivity and principal hydraulic directions of fractured rock mass is very important for its permeability. The hydraulic property of rock mass around geological repository of highlevel radioactive waste directly determines its safety in operation. The permeability property of rock mass around the 3# borehole in Beishan Area,Gansu Province is analyzed using the discrete fracture network model. The fracture transmissivity of the fluid flow model is calibrated via simulating the packer test process conducted in the depth range 1715～178m of the 3# borehole. The REV(Representative Element Volume)size and principal hydraulic conductivity of the rock mass near the 3# borehole are determined via performing the flow calculations based on the tranmissivity calibrated discrete fracture network model. It is found that the results are compared quite well with those obtained through the radial flow continuum porous media model．