Abstract: To study the effect of freeze-thaw on the shear creep characteristics of engineering rocks in cold regions, the granite samples from Huibai tunnel in Jilin province were taken as the research object, and the microscopic characteristics and shear creep tests of samples under different freeze-thaw cycles were carried out. The results show that: 1) With the increase of freeze-thaw cycles, the cracks and voids in the samples develop continuously, and the damage of rock surface becomes more and more obvious. 2) The pores in the sample are mainly composed of small and medium pores, and the porosity increases nonlinearly with the increase of freeze-thaw cycles. 3) With the increase of freeze-thaw cycles, creep deformation and creep rate increase gradually, while creep time, failure stress and long-term strength decrease obviously. According to the test results, expressions of unsteady creep parameters of freeze-thaw rocks are established, the damage viscous element of freeze-thaw rock is proposed, and the freeze-thaw shear creep constitutive model of granite is constructed. By comparing creep test curve with theoretical model fitting curve, the correctness and applicability of the model are verified. Through sensitivity analysis of creep parameters, the influence of creep parameters on granite creep deformation is studied, and the variation law of creep parameters with the number of freeze-thaw cycles is given. The research results have guiding significance for long-term stability evaluation of rock mass engineering in cold regions.

Key words: granite, freeze-thaw cycles, meso-damage, shear creep, experimental study, creep model