Study On The Distribution Law Of Temperature Field And Thermal Insulation Technology On Tunnel In The Seasonal Cold Regions

In order to meet the convenience and timeliness of traffic,more and more tunnel engineering were built in cold area of our country,and according to the problems of seasonal frost damage of tunnel engineering in cold area,this thesis was based on the regional climate of birchbark Ridge Tunnel,analyzed the numerical value that tunnel in cold region in winter and the operating period environment with the temperature field of the surrounding rock,and made optimizational analysis for the laying of insulation layer integrated thermal technology.The main research contents and achievements include:(1)Introducing briefly the general situation of the project,analyzed the air temperature monitoring data for two years in the tunnel portal,provided the factual basis for the numerical loading temperature.It is concluded that the environmental temperature in the mouth of the cave appear a periodic trigonometric function.(2)Combined with the fluid mechanics,heat transfer and other disciplines,using Fluent to establish three-dimensional solid-gas tunnel in winter convective heat transfer and heat conduction of solid-solid coupling model,analyzed the supply air velocity,air distance,air delivery under the warm air heating and distance from the tunnel face and wind tunnel environment the temperature field and velocity field of the surrounding rock and the changes of temperature distribution,and gives the corresponding parameters to ensure the wind tunnel in winter construction requirements.(3)By establishing a two-dimensional numerical model of tunnel cross-section,analyzed laying different insulation materials in tunnel surface and the same material under different laying ways,the radial temperature of surrounding rock with low temperature exposured time and environmental temperature variation law,and made an evaluation and choice of different insulation materials and different laying of the heat preservation effect.(4)Established the numerical model of two-dimensional longitudinal section in tunnel operation,and analyzed the distribution law under low temperature environment of different wind speed,different ventilation time,different tunnel length,tunnel environment and surrounding rock temperature.Target presentation that the cold insulation measures of tunnels use the function.The results obtained in this paper have some reference and guidance value for the design and construction of the seasonal cold tunnel.