DYNAMIC ASSESSMENT OF PERMAFROST UNDER ORDINARY EMBANKMENT OF QINGHAI-XIZANG RAILWAY

After the railroad has been constructed in permafrost regions, the balance of heat income and expense will be changed to a new one. At the same time, the change acts on the feature of permafrost. Based on the monitored data along the Qinghai-Tibet railway, the changes of permafrost under the railway are analyzed. The results indicate that the permafrost table was raised and the ground temperature increased. The permafrost thermal thawing sensitivity and permafrost thermal stability of permafrost under the roadbed have respectively increased and decreased comparing with those of permafrost under the nature surface after construction of ordinary embankments. All the changes of permafrost may influence the stability of the railway embankment.