Study Insulation Antifreeze Alpine Tunnel Technology Based On The Calculated Thermal Theory

With the advance of western development strategy,more and more tunnels in high-altitude areas like Tibetan Plateau is completed.Plateau climate is cold,effective measures must be taken on the design and construction of the tunnel to protect the tunnel against the cold and keep warm.The diseases such as lining ice,cracking,the ice accretion on road have frequently occurred in tunnels built in cold regions.These diseases affect the normal use of the tunnel,as well as traffic and pedestrian‘s safety.Effect of temperature on permafrost is very obvious,the temperature field of surrounding rock in the highway tunnel in high-altitude mountain areas changes with the air temperature in tunnel.The rise of the Inside ambient air temperature will transfer heat to the surrounding rock,leading to the increase of melting depth of surrounding rock,which may affect operational safety of the tunnel.In addition,the piston air of traffic will make the exchange of the heat inside and outside the cave,affecting the tunnel longitudinal temperature field,afterwards affecting the layout of the longitudinal length of the insulation layer.Accurate forecasting and analysising of the tunnel of temperature field come to the distribution of the actual tunnel temperature field,Congealment and heat preservation is very important.Negative temperature zone in surrounding rock and lining of tunnel result in freezing damage in tunnel.We must have a correct understanding of the temperature field distribution of the tunnel in cold region to design a more effective antifreeze tunnel in cold region from the root.This paper is based on Tibet Latin La Mountain Tunnel Project,summarizing the distribution law of the temperature field in the surrounding rock in the vertical and radial direction according to field measured data and numerical simulation analysis.Based on the law,heat insulation and freeze resistant measures in the freezing cold regions' tunnel is summarized.The main content of this paper is as follows:(1)By collecting relevant literature,the research results of temperature field in cold regions tunnels is analysed,prevention and treatment programs heaving Mechanism of tunnels in cold regions at home and abroad typical cold regions tunnels.(2)From research on Site actual monitoring data,changes rule of temperature field in the tunnel surrounding rock and the environmental inside the tunnel is summarized?(3)Introduced the basic theory of thermodynamics,and is calculated by numerical simulation methods to study after the tunnel before excavation not support change with exposure time,temperature field variation of surrounding rock.(4)Numerical simulation of thermal insulation layer in t he laying of different ways,different thicknesses and different thermal insulation effect coefficients were compared and analyzed for insulation design provides a theoretical basis.(5)Support projects of this article Ladingla mountain tunnel before going to frost measures are affixed to the inner surface of the insulation lining,concrete lining of the addition of cellulose fibers,Deformation set,central heating and electrical insulation drains.In addition,also presented a comprehensive program of heat preservation in cold regions tunnels,including anti-drainage measures,thermal insulation and heating measures to strengthen the structures lining structural performance measures.