Abstract:Owing to the long-term geological processes,there are all sorts of discontinuities such as joints in the rockmass. In the jointed rock,the fluid flows are dictated mainly through the passage of the discontinuities. Under the current increased environmental and regulatory controls,the accurate prediction of total inflow to the tunnel excavation is significant factors in the design and construction stages of the underwater tunnel. The surface roughness of discontinuities in rock masses is an important factor to analyze the mechanical and hydraulic characteristics of rock joints. The hydro-mechanical behaviors and properties of rock joints are usually determined by laboratory experiments on fracture specimens. Laboratory testing of rock fractures involves a number of technical issues that may have significant impacts on the reliability and applicability of the testing results;for example,the quantitative estimation of the evolutions of hydraulic transmissivity fields of fractures during shear under different normal constraint conditions,and the sealing techniques when fluid flow during shear is involved. In this study,a new hydro-mechanical test apparatus for rock joint is developed. The surfaces of rock joints are measured before shear by using a 3D laser scanning profilometer system.Thus,a number of shear-flow coupling tests were carried out on three kinds of rock fracture specimens under constant normal load(CNL) or constant normal stiffness(CNS) constraint to evaluate the influences of morphological properties of rock fractures on their hydro-mechanical behaviors. Combined with the cubic law for fluid flow,the test results are analyzed and discussed;and some conclusions about the tests are drawn.