Interaction study of permafrost and highway along Qinghai-Xizang Highway

Eight monitoring sites are set along the Qinghai-Xizang Highway (QXH) to investigate the characteristics and process of interaction between permafrost and highway, including the upper and down boundaries of active layer under natural surface, seasonally freezing-thawing depth under asphalt pavement, permafrost table temperature and roadbed stability. The investigation results show that the changes of active layer thickness and permafrost table temperature under asphalt pavement are greater than these under natural surface due to the absorbing heat action and less evaporation of asphalt pavement, as a result, the engineering geological problems such as thaw settlement and frost heave present frequently along QXH line and produce the adverse impact on roadbed stability.