In situ test study on the application effect of the thermosyphon along the chaimu railway

摘要

The Chaimu Railway (CMR) is being constructed for the coal resource transportation in northern Qinghai-Tibet plateau. The total length of the line is 142km. The permafrost in this region is warm, icerich and unstable. For the purpose of cooling soil and stabilizing the subgrade, thermosyphon technique was adopted in a quarter of the whole line. Three monitoring sites with different mean annual ground temperatures have been arranged to study the thermosyphon effect since 2007. According to the ground temperature observation results, from 2007 to 2009, the thermosyphon could cool down the underlying permafrost and raise the artificial permafrost table. Analysis of the observational settlement data from 2008 to 2009 showed that the maximum accumulated settlements of test sections were about 5cm. The thermosyphon technology has obvious effect on decreasing the subgrade base temperature and protecting permafrost. Thus thermosyphon is applicable in railway construction in warm, ice-rich permafrost regions.