Thermal Interaction between Permafrost and the Qinghai-Tibet Railway

Abstract

Measures were taken to protect the thermal regime of the roadbed embankment after construction and to lower permafrost temperatures in the rich-ice and warm permafrost regions along the Qinghai-Xizang Railway. However, these measures were taken only for some sections of the railway, leaving many sections unprotected. This article addresses those areas where no measures were taken and presents analysis of the variation of soil temperatures under the embankment in seasonal frozen soil areas, degrading permafrost areas, and warm and cold permafrost areas. The results show that soil temperatures, maximum seasonal freezing depth, and the permafrost table under the embankment differ according to the different frozen soil areas after embankment construction. In seasonal frozen soil areas and degraded permafrost areas, the seasonal frost layer remained frozen the next year under the shaded shoulder of the embankment. In degrading permafrost areas, a thaw layer between the permafrost table and the bottom of the se...