| Tunnel construction in China is now in a period of rapid development,its prospects and importance is self-evident.There is a strong cross regional in our country.At present our country has a lot of already built,under construction and various forms of tunnel will be constructed.Tunnel construction in our country and even the world is a full of vigor,full of opportunities and the industry of the future.However,the construction of the complex environment for tunnel construction industry is full of challenges,such as freeze injury problem of cold regional tunnel,and builders of the same industry must overcome the difficulties.Through the literature of cold regions tunnel we can found:serious freeze injury in cold regions tunnel,great economic waste,traffic safety hazard.Japan is an Asian country with multiple tunnels.Some scholars statistics,in nearly 4000 railway tunnels in cold regions,a large number of tunnels in operation affected by frost.Although the state has invested a lot of money without solving the problem at the source.China is a country with many frozen soil,engineering construction and scientific research workers are facing severe challenges in the new era.Due to the absence of cold damage at the first time,The problems of climate,material,and construction technology of tunnel have led to the occurrence of tunnel frost damage,and pay a huge economic losses.Japan has conducted a survey on the domestic railway tunnel line:All the leakage of cold tunnel,all the formation of frost damage.Compared with the general area,the tunnel engineering in cold regions should solve many complicated technical problems,one of the most important problems is the effect of seasonal freezing thawing and frost heave,the periodic loading and unloading will destroy the main structure of the tunnel,and the final result is the impact of construction personnel and operational safety and structural life,Causing huge economic loss and waste of resources.Concrete is the most common and most priority material in tunnel construction even all construction industry.In the field of construction of concrete has been used for 1.5 centuries.Researching on high performance concrete,high concrete antifreeze performance and improving the conditions of temperature and water environment conditions of the tunnel to prevent frostbite,is the main measure of frost resistance in cold tunnel at home and abroad.How to take effective measures in the construction of tunnels in cold areas and avoid the occurrence of tunnel frost damage is the urgent problem to be solved in the field of tunnel engineering.In this paper,base on a series of special problems in the construction of tunnels in cold regions,by a lot of literature,on the basis of the existing technology,and the methods of theoretical analysis,laboratory test and numerical simulation are adopted.The research and development of high performance frost resistant concrete in cold region tunnel lining structure and the comprehensive frost resistance construction technology of cold tunnel in winter.The following work was conducted:(1)This paper gets the change law of cement hydration heat through the hydration heat test,and on this basis,the research and development of frost resistant concrete,and get the mixture ratio of concrete with good frost resistance which is obtained through the relevant tests;(2)By elastic mechanics method,tunnel frost heaving force of theory solution is obtained,using the thermo-solid coupling numerical simulation method to analyze the change of tunnel temperature field,the research of frost heave force of tunnel.It is found that the frost heaving force of the tunnel is larger than that of the actual engineering,because the frost heave force in the actual project is the result of energy release.(3)Literature review,domestic and foreign research,combined with the actual project,the winter construction of the control and management measures are explored,summed up the winter tunnel construction in the anti freeze research experience. |
PDF Full Text Request