Key issues of highway construction in permafrost regions in China

In the demand of highway construction in permafrost regions in our country, some key issues have been analyzed in this paper, such as the heat transfer process in embankment, the major influential factors as well as the cooling efficiency of engineering measures during the construction of highway in permafrost regions in China. It is found that the heating intensity of the embankment will be doubled, and more heat will be gathered in the center of subgrade which is hard to spread, resulting in the speeding of the permafrost degradation and the increase of the degraded permafrost in the condition of highway in permafrost regions compared with railway and ordinary way in Qinghai-Tibet Plateau. The existing typical engineering measures of protecting permafrost will suffer from problems such as insufficient cooling efficiency, hard to fulfill the need of overall and uniform cooling, longitudinal cracks, and uneven settlement in the condition of highway. It is found that the key way to solve these problems is the adoption of separate building or the research of new effective engineering measures.