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 northernQinghai-Tibet plateau. The total length of the line is 142km. The permafrost in this region is warm, icerichand unstable. For the purpose of cooling soil and stabilizing the subgrade, thermosyphon technique wasadopted in a quarter of the whole line. Three monitoring sites with different mean annual ground temperatureshave been arranged to study the thermosyphon effect since 2007. According to the ground temperature observationresults, from 2007 to 2009, the thermosyphon could cool down the underlying permafrost and raise theartificial permafrost table. Analysis of the observational settlement data from 2008 to 2009 showed that themaximum accumulated settlements of test sections were about 5cm. The thermosyphon technology has obviouseffect on decreasing the subgrade base temperature and protecting permafrost. Thus thermosyphon isapplicable in railway construction in warm, ice-rich permafrost regions.