Analysis of the Cooling Mechanism of a Crushed Rock Embankment in Warm and Lower Temperature Permafrost Regions along the Qinghai-Tibet Railway

Based on data monitored in situ and theoretical analysis, the characteristics of the temperature field and mechanism of thermal conduction of a crushed rock embankment were studied along the Qinghai-Tibet Railway. The results of experiments in the field revealed that the cooling effect of a crushed rock embankment is influenced mainly by the natural convection in winter and shield effect in summer, the ventilation of crushed rocks, and the ground temperature regime beneath the embankment. Consequently, these three factors should be taken into account in numerical simulations, but it is as a result of natural convection only.