Abstract: The rheological property of surrounding rock is one of the key factors affecting the safety and stability of tunnel engineering. Research of constitutive model is the most essential and important part of rock rheological mechanics theory and is a necessary step to apply the results to practical engineering. A research method integrating experimental investigation, theoretical analysis and numerical simulation is applied in this paper to analyze the rheological mechanics characteristic and the establishment of constitutive equations of the sandrock of kilometers deep shaft roadway in Huainan Mining Group’s Zhuji coal mine. Based on a large number of relevant theoretical and experimental data,a nonlinear creep model expressed as an exponential function of stress and time is constructed to combine with Burgers model. The new creep model of six elements demonstrates the three phrases of rock creep process and takes into consideration the accelerated creep characteristic. Triaxial compressive rheology test under high confining pressure condition was performed on sandstone taken from Zhuji deep mine. Creep parameters for the proposed model were identified from the test creep data to verify the rationality of the model.

Key words: sandstone, deep mine, nonlinear visco-elastic-plastic, creep model, triaxial creep test