Abstract: It is found that the main heat transfer calculation methods of tunnel surrounding rock cannot demonstrate the heat transfer process of surrounding rock with lining. Based on the heat conduction differential equation and Fourier′s law, the analytical algorithm of onedimensional steady heat transfer of surrounding rock with and without lining layer are established, the influence of six parameters on inner wall temperature of tunnel tw are analyzed, i.e.〖ＫＧ－４〗, thermal conductivity of surrounding rock λy , heat transfer coefficient between rock wall, and air hc, equivalent radius of tunnel rw, radius of heat regulating circle ro, initial temperature of surrounding rock to and air temperature in tunnel tf. The results show that: (1) The sensitivity degree of each factor to tw are tf, to, λy, hy, rw, and ro , in an order from large to small. (2) The effect of ro on tw is very little; when ro is set at 100 m and 3 000 m, the change of tw is less than 12%. (3)Compared with the nonlining layer, the outer wall temperature of lining layer increases slightly, while the inner wall temperature of the lining layer decreases slightly as the thermal conductivity of lining layer λc is lower than that of surrounding rock. (4) The use of thermal insulation layer is helpful to the decrease in temperature of tunnel inner wall; if the heat transfer coefficient is 0.025 W/(m·℃) and the thickness of thermal insulation layer is 11 cm, the temperature of tunnel inner wall can be reduced by more than 10%. (5) The marginal effect of insulation layer thickness on inner wall temperature decreases with its thickness.

Key words: tunnel construction, high ground temperature, heat transfer model, thermal insulating layer