The frost heave force is one of the main reasons that induces the tunnel freezing damage. The frost heave force of tunnel is mainly caused by the differential frost heave of surrounding rock. The fracture will further affect the differential frost heave of rock mass. In this article

the calculation formulation for differential frost heave coefficient of rock mass is derived

and some findings concerning the coefficient of differential frost heave are drawn as follows. The differential frost heave coefficient increases with increasing the angle ? between fracture and temperature gradient. As temperature gradient rises

the differential frost heave coefficient increases. The influence of fracture ratio on differential frost heave of surrounding rock depends on the angle ? between fracture and temperature gradient. When ? is small

decreases with the increase of fracture ratio. When ? is large

increases with the increase of fracture ratio. The influence of fracture on differential frost heave of rock mass is related to the lithology of rock mass. The fracture has greater influence on the rock mass with smaller porosity. According to the calculation formula of differential frost heave coefficient of fissured rock mass

the range of differential frost heave coefficient of fissured rock mass with different lithology and different grades can be obtained. Therefore

in the design of tunnel in cold area

the frost heave force of tunnel surrounding rock acting on lining can be calculated more accurately

which plays an important role in the design of tunnel in cold area

and also promotes studies of the frost heave force of subgrade

slope and other projects in cold area.