Creep damage model of roadway surrounding rock considering the influence of water content on strength parameters

In order to study the influence of water content on the creep characteristics of rock, the creep characteristics test of rock under different water content is carried out. The influence of water content on the long-term strength and creep properties of rock is analyzed. On this basis, the influence of water content on the deterioration of strength parameters is further analyzed. A new creep damage constitutive model of rock is established based on damage mechanics. The model parameters are identified by experimental data. Then, the rationality and correctness of the established model are verified. The results show that for the decay creep, the greater the water content, the shorter the decay creep time and the faster it can enter the stable creep deformation stage. For stable creep deformation, high water content may make rock more prone to stable deformation. In terms of accelerated creep deformation, high water content conditions will promote the acceleration of rock deformation rate. The creep damage model of roadway surrounding rock considering the influence of water content on strength parameters is excellent in describing the whole process curve of rock creep. The correlation coefficient between the model curves and the test curves are higher than 0.93. This indicates that the proposed creep damage model is highly correct in describing the creep behavior of rock. This model can not only accurately describe the characteristics of rock in the attenuation and stable creep stage, but also describe its accelerated creep more accurately, which helps to fully understand the creep behavior of rock.