Temperature Adjustment Mechanism of Composite Embankment with Perforated Ventilation Pipe and Blocky Stone

Based on the advantages of perforated ventilation characteristic of perforated ventilation pipe embank- ment and large porosity of blocky stone embankment, composite embankment with ventilation pipe and blocky stone is more efcient to protect the underlying permafrost. The temperature fields and cooling efect of com- posite embankment with air doors are simulated by examining the efects of holes' position drilled in the pipe, diameter in pipe and density of holes. It is shown that the underlying permafrost temperature obviously reduces by composite methods, the location of 0 C isotherm raises significantly, especially permafrost temperature under the center and shoulder of embankment reduces more quickly, the composite embankment with holes drilled in the lower side of pipe is the most efcient, the increase of diameter has a slight influence on the 0 C isotherm's raising, and the density of holes slightly influences the raising of 0 C isotherm.

Based on the advantages of perforated ventilation characteristic of perforated ventilation pipe embankment and large porosity of blocky stone embankment, composite embankment with ventilation pipe and blocky stone is more efficient to protect the underlying permafrost. The temperature fields and cooling effect of composite embankment with air doors are simulated by examining the effects of holes＇ position drilled in the pipe, diameter in pipe and density of holes. It is shown that the underlying permafrost temperature obviously reduces by composite methods, the location of 0℃ isotherm raises significantly, especially permafrost temperature under the center and shoulder of embankment reduces more quickly, the composite embankment with holes drilled in the lower side of pipe is the most efficient, the increase of diameter has a slight influence on the 0℃ isotherm＇s raising, and the density of holes slightly influences the raising of 0℃ isotherm.