Analysis of the Subgrade Deformation of the Qinghai-Tibetan Highway
YU Qi\|hao,\ LIU Yong\|zhi,\ TONG Chang\|jiang ( State Key Laboratory of Frozen Soil Engineering, CAREERI, CAS, Lanzhou Gansu 730000, China)
In order to understand the impact of artificial permafrost table to the subgrade deformation of the Qinghai-Tibetan Highway in degenerating process, three experimental observation fields were set up to measure the deformation of the road being built in south of the Tanggula Range. Measurement of two years shows that, when the artificial permafrost table descending, the deformation of the subgrade, such as frost heaving, thaw settlement, is quite different in some aspects, depending on subgrade structure and permafrost type. In the frozen zone with high ice content, if the road is half\|dug and half\|filled, the subgrade deformation is the strongest. In the zone with less ice, if the road is a high embankment, the subgrade deformation process is comparative slow and low\|grade. The freezing time and thawing time under roadbed is reverse with natural conditions.