Abstract：Railway roadbed ventilation，as a positive roadbed cooling technique，has attracted much attention from researchers，which can effectively protect the frozen roadbed and maintain the roadbed stability by raising the permafrost table. At present，the ventilation pipes are generally made by concrete or PVC without holes on the pipe walls，whose cooling effects are realized by airflow and heat transference. But the tightness of pipe walls will reduce cooling effect to some extent. Perforated ventilation pipes can cool the railway roadbed through convection heat transference between airflow and soil around the pipes as well as airflow and heat transference. In order to study the roadbed cooling effect of the perforated ventilation pipes，a comparative experiment has been conducted with both ordinary and perforated ventilation pipes. The short-term observation data have shown that the perforated ventilation pipes，raising higher permafrost tables，are superior to the ordinary ones. Through optimization of roadbed structure the cooling effect will be obviously enhanced. However，the long-term effect of the perforated ventilation pipes depends upon long-term observations and further analyses.
