Abstract:The coupled shear-flow behavior of rock joints is an important issue in rock mechanics. A number of coupled shear-flow tests were carried out under different normal loading conditions. By means of visualization system,flow images during shear process were taken and processed. Using the finite element method,with a special algorithm by treating the contact areas as zero-aperture elements,numerical simulations of fluid flow in joints were conducted. Numerical simulations providea good agreement with the flow rate obtained from tests,revealing that the flow paths and aperture distributions in a joint change remarkably with shear displacements,loading conditions and joint surface roughness.