Abstract:The artificial freezing method is widely used in western well construction projects due to its unique advantages. Therefore, it is particularly important to study the strength characteristics of the rock in the frozen state. Based on the creep test of frozen red sandstone, the long-term strength of the rock was obtained by the transitional creep method, isochronous stress-strain method, crack damage stress method, steady-state creep rate intersection method. The results show that: (1) The long-term strength of frozen sandstone can be obtained by the transition creep method, which is about 45-65% of the triaxial compressive strength. (2) The volumetric strain isochronous curve cluster can better reflect the relationship between time and rock deformation, and the long-term strength is about 48% of the triaxial compressive strength. (3) The steady-state creep rate method can easily determine the long-term strength of the rock. However, due to its own limitations, considering the three-dimensional creep rate comprehensively, the steady-state creep rate method is improved to obtain the steady-state creep rate intersection method, which can reflect the strength of sandstone more accurately. The long-term strength is about 49% of the triaxial compression strength. (4) The calculation method of crack volume strain is introduced, and the isochronous curve clusters of crack volume strain are obtained according to its relationship with time. It is found that the long-term intensity value is very similar to the isochronous curve method. Therefore, the crack damage stress method can also be used as a basis for determining the long-term strength of rocks. The long-term strength of frozen red sandstone is used as the standard for monitoring the deformation of the frozen wall, which provides theoretical support and experimental basis for evaluating the instability and failure induced by the creep of the frozen wall.