青藏公路铺筑沥青路面后路基下多年冻土的变化

The Change of Permafrost under Roadbed with Asphalt Pavement along the Qinghai-Tibet Highway

由于黑色沥青路面强烈吸热,使多年冻土区内约60％路段的路基下人为上限逐年下降,造成冻土在垂向上呈不衔接状,形成融化核,它加剧了路基不均匀沉陷,最后导致路面破坏,一些路段路基下冻土类别发生变化或多年冻土层已完全融化。

Because dark asphalt pavement absorbes heat strongly, a subsidence of the artificial permafrost table takes place on about 60% of the highway length under roadbed year by year in the permafrost region. An unlinked condition of permafrost in vertical is caused, and a 'thawing core' is formed. There is a great influence of thawing cores on the stability of roadbed. The permafrost layer has been thawed completely or the permafrost classification has been changed under the roadbed at some sections of the road.