Development of a shear creep damage model of jointed rock masses considering the influence of freeze-thaw and chemical corrosion

To conduct a more realistic numerical simulation analysis of jointed rock mass engineering in cold regions, shear creep tests were conducted on the jointed rock masses under freeze-thaw and chemical corrosion. Based on test results, a shear creep damage model of jointed rock masses was established. The FISH language was used on the 3DEC platform to implement the secondary development of the model, and the rationality of the model was verified through degradation analysis and test data. Finally, the developed model was used to numerically calculate the creep characteristics of tunnel in cold regions, the research results show that: (1) The maximum creep deformations of tunnel subjected to 0, 20, 40, and 60 freeze-thaw cycles and chemical corrosion are 16.0 mm, 20.9 mm, 24.2 mm, and 34.1 mm, respectively. With the increase of freeze-thaw cycles and chemical corrosion, the creep deformation and plastic zone gradually increase. (2) As the joint plane inclination angle increases from 0° to 90°, the creep deformation gradually decreases. When the joint plane inclination angle are 0°, 30°, 60°, and 90°, the maximum creep deformations are 29.7 mm, 27.6 mm, 24.2 mm, and 22.5 mm, respectively. (3) With the increase of creep time, the creep deformation of the tunnel gradually increases. The arch deformation is 9.3 mm, 18.6 mm, 24.2 mm and 27.3 mm after 10 days, 30 days, 60 days and 90 days respectively. The research results provide an effective computational method for the stability analysis of rock mass engineering in cold regions.