Study On The Temperature Field Of Long And Large-span Highway Tunnel In Cold Regions

Along with the rapid economic development of our country, a lot of tunnels incold areas are being built in large-scale in the eastern and western cold regions,compared with the common areas, tunnels in cold regions will confront with more andcomplex technical problems, especially frozen damage problems. In domestic, many ahighway tunnels and railway tunnels are suffered to different degrees of frozen damageproblems, which affect the stability of tunnel structure and the safety of driving andcause serious economic loss. In view of the grim situation which cold regions tunnelsare suffered to, research on surrounding temperature field and thermal insulationtechnology is particularly important.Combining with the Tianhengshan highway tunnel in Harbin and the temperaturefield data monitored in the joblocation, the temperature inside the tunnel andtemperature field of surrounding rock are systematically analyzed. Firstly, this papercreates the plane and transient temperature model considering the phase change andsimulates the temperature field of the tunnel using ANSYS finite element software. Theresult shows the change rule of tunnel and surrounding rock temperature field indifferent period after tunnel operation. Secondly, the paper analyses three differentworking conditions of the thermal insulation layer with the same thickness, the resultsshow that the thermal insulation layer set in the initial support layer surface and thesecondary lining surface can effectively protect the tunnel suffering to frozen damage.Compare PU, XPS, EPS and choose more effective more economic insulation materials. Finally, according to the basic theory of finite element and heat transfer, thispaper has research on hot-stress field coupling analysis about tunnel structure in twodifferent kinds of working conditions which insulation layer is not set and thermalinsulation layer is set. The result reveals that temperature field has a major effect onthe stress field. So when design the tunnel structure in cold regions, must consider theinfluence of thermal stress.