Study On Distribution Of Temperature Field And Cold Insulation Technology On Tunnel In High Attitude And Cold Zones

In recent years, more and more tunnels are constructed in the cold areas ofthe high altitude. Because of the adverse climate, effective measures are necessarilyadopted in the design and construction of the Alpine tunnel to eliminate or mitigatethe damage phenomenon. The current research is based on the Jiangluling Tunnelon country214line. Field test are combined with theoretical calculation to analyzethe temperature field distribution of the alpine highway tunnel. This paper systematically expounded the cold insulation measures adopted in highway tunnel. The main contents are demonstrated as follows:①Analysis of field test data obtained from monitoring, and summary variation ofambient temperature and the temperature of surrounding rock of tunnel.②This paper introduces the basic theory of rock and soil heat transfer, and usenumerical calculation methods to discuss the law of the temperature field of thesurrounding rock with the exposure time. Besides, the author established thethree-dimensional model, analyzed the temperature field of the surrounding rock withoutthe thermal insulation layer, and compared it with the field measured data.③Best materials are selected through investigation and experimental detection on thethermal insulation material. Calculation analysis is used to compared the insulation effectunder the conditions of the different laying mode, the different thermal conductivity andthe different thickness of insulation layer. In addition, the author also analyzed the stress ofthe lining and insulating layer under the conditions of thermal insulation layer withdifferent elastic modulus. Subsequently, the author puts forward the valuable suggestionsfor the project on the problem of setting insulation layer. Finally, it established thethree-dimensional model, and analyzed the temperature field of the surrounding rock withthe thermal insulation layer.④The paper introduces the cold insulation measures on the relying engineering (TheJiangluling tunnel). The main contents include the sunshade nets setting in the slope, andthe head pipe setting on the top of the tunnel. At the same time, it introduces the freezeprotection measures of the early-strength concrete in the construction phase, and theinsulation measures in the drainage system, and of course include Anti snow shed in theentrance of the tunnel. ⑤The cold tunnel is designed between the main hole in The Jiangluling Tunnel. Thishas innovative significance. Numerical calculation method is used to analysis the variationof the freeze thaw cycles when the cold tunnel is set at different positions between the twomain tunnel. This can verify the rationality of the design in theory.