Analysis And Research On Thermal Insulation Technology Of Tunnel In Cold Region And Its Influencing Factors

As one of the infrastructure facilities in China,the tunnel is of great importance to the development of China’s economy,among which the inevitable existence of a large number of frost damage problems in the cold zone tunnel seriously affects the normal use of the tunnel,so the research is carried out from the two aspects of tunnel insulation and antifreeze technology and its frost heave force.In terms of tunnel insulation and antifreeze technology,the basic rules of the tunnel in four insulation layer laying methods,the thickness of different insulation layers,and the temperature field under different insulation materials are studied from two aspects: steady-state analysis and transient analysis.The conclusions obtained mainly are: the insulation effect of the four laying methods is from good to secondary:double-layer laying,surface laying,sandwich laying and no insulation layer,but the actual project recommends the use of surface laying;With the increase of the thickness of the insulation layer,the insulation effect also increases,but the growth rate is getting smaller and smaller,so in the actual project,it is not necessary to blindly pursue the insulation effect and increase the thickness of the insulation layer;And because the performance parameters of different insulation materials vary widely in all aspects,for the selection of insulation materials,it is necessary to comprehensively consider the specific use requirements of the project,and this paper provides a performance index tool to provide ideas for comprehensively considering the selection of insulation materials under different requirements.In terms of the frost heave force of the tunnel,the relationship between the frost heave force of the tunnel and the thickness of the freeze-thaw ring,the frost heave rate of the surrounding rock,and the elastic modulus of the lining is explored from the two aspects of theoretical calculation and numerical simulation.For theoretical calculations,a new elastic solution of frost heave force is proposed for some problems existing in the existing elastic mechanical formula of frost heave force.Using the combination of parameter calculation and numerical simulation,it is obtained that the tunnel freeze heave force is positively correlated with the thickness of the freeze-thaw ring,the surrounding rock frost heave rate,and the elastic modulus of the lining.The sensitivity analysis tool is used to obtain the degree of influence of each influencing factor on the frost heave force,from high to low: freeze-thaw thickness,surrounding rock frost heave rate,lining elastic modulus.Figure [140] Table [18] Reference [100]...