Abstract：The rock masses of underground cavern of Jinping II Hydropower Station are enriched in abundant joints. A shear creep experimental program is carried out on hard discontinuities of marble mass using double-axis creep apparatus. Surface of hard discontinuities of marble masses is measured，and roughness of the surface is described by average roughness angle. The variation law of shear displacement of marble with the time is analyzed under different roughness. Test results show that instantaneous deformation of rock sample with large roughness angle is less than that of rock sample with small roughness angle rock sample. In addition，decay and steady creep occur when stress level is relatively low，however，when shear stress level reaches a certain level，rock specimen fails rapidly within a short period of time，and acceleration creep doesnt occur in the process of shear rheology experiment. Consequently，a standard linear shear creep model of marble is identified by shear creep experimental data，and model parameters of marble specimen are gained. The comparison between fitting curve and test curve shows that the standard linear shear creep model is reasonable. Finally，the variation law of average roughness angle of marble specimen and shear creep model parameters is analyzed.
