| Abstract |
The newly developed rubber-confining pressure vessel (R-CPV) enabled simple and easy permeability measurement for large fractures under high confining pressure. The permeability measurements for granite samples including single tensile fractures of 100 x 150mm with various lateral displacement along fracture surfaces were performed under the confining pressures up to 100MPa using the R-CPV. For fractures without lateral displacement, the permeability decreased with increasing confining pressure until 40-50MPa, beyond which the permeability decreased gently or became constant. For fractures with lateral displacement, significant increase of permeability occurred even for lateral displacement as small as 1mm. The permeability, however, decreased with increasing confining pressure, and a rapid decrease occurred at 80MPa for 1mm displacement. For the fracture with sufficiently larger lateral displacement -more than 3mm, obvious decrease of permeability did not occur as increasing confining pressure and remained large even under high confining pressure. ) |