Analysis of temperature features within crushed rock revetment and cooling mechanism of embankments for the Qinghai-Tibet Railway

The cooling mechanism of crushed rock revetment of embankment was studied by monitoring the heat transfer in crushed rock layers of revetment at the experimental sections.It was shown that the effect of thermal insulation and natural convection could be occurred in crushed rock layers of revetment.With daily variation and seasonal variation of air temperatures,the combining processes of daily and seasonal variation were shown in the effect of thermal insulation and natural convection in crushed rock layers of revetment.As a consequence,the variation of heat transfer processes in crushed rock layers of revetment results in the variation of permafrost thermal regime under embankments.It was shown by the thermal regime of soil under crushed rock revetment of embankments that the crushed rock revetment could effectively reduce the soil temperature under embankments.