Alpine Permafrost Region Highway Bridges Of Disease Mechanism And Strengthening Methods Of Research

Over the past 39 years since the reform and opening up,China has become the second largest economy in the world with its rapid development and rapid economic growth.China's urbanization is now at 57 percent,and more rural areas are beginning to form smaller cities,with more and more big cities forming economic circles.Correspondingly,China's transport network,which is also a highway construction,grew from 890 miles to 358 million miles between 1978 and 2007.From 2007 to 2015,total road mileage increased to 450 million.Especially in recent decades,with the continuous improvement of technology upgrade,the country started building roads in alpine permafrost region,where has been constructed of the Qinghai-Tibet railway and the Qinghai-Tibet highway,Qingkang highway,Ningzhang highway and so on.other important road network,like heilongjiang,xinjiang,has been basically set up perfect.But Qinghai,Heilongjiang,Tibet and other alpine frozen areas,because of climate terrain reasons.Frost heave caused by highway bridge fog,drum package,cracking,uneven subsidence and other bridge disease.It poses a great threat to the safety and smoothness of road traffic.Therefore,it is a very worthy subject to study the disease mechanism of highway bridge in alpine permafrost region and adopt reasonable and effective reinforcement method for different bridge diseases.The whole idea of this paper is divided into three parts:the theoretical analysis of frost and concrete frost heave,the study of the types and mechanisms of bridge diseases,and the reinforcement of bridge diseases.In the first part,we mainly describe the characteristics of frost heaving and melting,and expounded its influence on the foundation,pier and superstructure of highway bridge.At the same time,it is found that the vulnerability of permafrost in China is becoming more and more obvious,especially in the Qinghai-Tibet Plateau and many permafrost regions.And then analyzes the mechanism and phenomenon of concrete in the cold and cold areas.This paper analyzes the frost heaving mechanism of concrete.Because the concrete capillary voids are frozen and the water in the gel pores does not freeze,causing the concrete to freeze and moisture in the alpine region.According to its mechanism,the types and causes of concrete diseases in alpine permafrost regions were studied.In the second part,the bridge is divided into three parts:the upper part,the lower part and the bridge.We followed the disease classification and disease mechanism.Which includes the basis of the piers in the frozen soil under the action of freeze-thaw cycle.The bridge structure produces temperature joints and structural joints and other diseases.Pavement pits,shedding and other diseases.This part not only explains the type of disease,but also analyzes the mechanism of disease,and puts forward the reinforcement method and improves the theoretical basis for the third part.In the third part,according to the bridge disease,this paper puts forward a reinforcement scheme for various diseases of concrete and various diseases of pavement.For the basis and the pontoon disease,this paper to take preventive measures,so as to avoid the impact of freeze-thaw cycle to avoid the impact of disease,thereby reducing the disease.In this paper,the disease and reinforcement technology of highway bridge in the alpine permafrost region are further studied systematically,which provides some reference for bridge fault analysis and reinforcement scheme in alpine region.I hope to help with the actual project.