The cooling performance of crushed-rock interlayer embankments with ventilation ducts is evaluated.
The cooling performance can be greatly enhanced if the ventilation ducts are perforated.
A good cooling effect can still be achieved even if the centerline spacing of the perforated ventilation ducts is enlarged to 4 m.
The crushed-rock interlayer embankment with perforated ventilation ducts is a better candidate structure for permafrost expressways.