Study of Shear Creep Properties of Granite Under Freeze-Thaw Cycles in Acid Environment

To study the effect of acid freeze-thaw cycles on the shear creep properties of granite, the meso-characteristics and shear creep tests of Huibai tunnel granite in Jilin Province after acid freeze-thaw cycles were carried out.The experimental results show that:(1) the deterioration of rock surface damage is aggravated with the increase of freeze-thaw cycles, and the damage of samples in acidic environment is obviously greater than that in neutral environment;(2) the creep properties of granite under acidic solution are more significant than that under neutral environment, and the shear creep deformation and average shear creep rate increase with the increase of freeze-thaw cycles.The instantaneous shear modulus and long-term strength of granite show a trend of obvious decrease;(3) Quantitative analysis of the total deterioration degree and stage deterioration degree of granite, the total deterioration degree and stage deterioration degree in acidic environment are greater than their values in neutral environment, and the stage deterioration degree of sample is the largest when freeze-thaw cycles are 50 times; In the same hydrochemical environment, with the increase of freeze-thaw cycles, the sample deterioration degree is the largest.The total deterioration degree increases gradually.According to the non-linear characteristics of shear creep of granite, considering the influence of acid solution and freeze-thaw cycling on the creep characteristics of granite, the creep damage model of granite is constructed, and the parameters of the model are identified.The research results have guiding significance for the study of long-term stability of acid rain erosion projects in cold regions.