Abstract:In geotechnical engineering,it is difficult to determine micro-mechanical parameters of large-scale rock mass. However,the depth-dependent permeability,due to coupling of seepage field and stress field in large-scale rock mass,suggests a chance to solve the problem. According to the hydro-mechanical coupling behaviors of rock mass under geostatic pressure,simplified models in estimating deformation module of rocks by using depth- dependent permeability is developed. Porosity and opening of rock fractures are applied to the transition factors in deriving equations for bulk modules of intact rock and normal stiffness of joints. The models is limited with assumptions such as the rock mass is relatively uniform,containing one group of joints and without tectonic stress. However,the assumptions are not serious limitations in suggesting this new way to determine micro-mechanical parameters of large-scale rock mass.