Abstract: Hard rock in cold region with surface cracks contact with atmosphere, therefore water in cracks would congeal caused by low temperature environment. The temperature would be mutation near the cracks, and the expansion caused by phase transition would produce frost heaving force. While the temperature field and frost heaving force are in the dynamic evolution on the freezing effects. Because the complex multi field problems include temperature field, seepage field and stress field. At present, a lot of related researches are based on the results of numerical simulation to summarize the distribution characteristics and rules of temperature field as well as stress field in fractured rock masses. While considering the perspective of analysis and calculation on basic theory, study on the evolution of temperature field and frost heaving force in fractured rock mass under low temperature environment is rarely reported. Depending on the freezing phenomenon of hard rock with surface cracks under low temperature environment, and according to the theory of heat transfer, phase transition, elastoplastic mechanics and fracture mechanics. This paper explores the evolution process of temperature field and rost heaving load in hard rock with surface cracks. Corresponding analytical expressions are put forward and introduce to the multi-physics coupling program Comsol-Multiphysics to analog computation. Comparison results show that the evolution analytical expressions of the temperature field and the frost heaving load are very close to the numerical simulation. The expressions can basically be suitable for the evolution analysis of temperature field and stress field on the semi-infinite plate model containing surface cracks. So the study provides a good reference value to the temperature field and stress field evolution analysis in fractured rock mass under low temperature.

Key words: surface crack, temperature field, frost heaving force, ice water phase transition, Comsol-Multiphysics