Study of the cooling effect of parallel rectangular ventilation with pores in runway engineering

This study addresses the unique challenges of airport runway engineering in permafrost regions, which differ significantly from those of railway and road engineering because of the absence of embankments, wider pavements, shorter lengths, and extensive flatness requirements. This study proposes a novel approach using parallel rectangular ventilation with porous structures to enhance the cooling effect on the subgrade. Moreover, the cooling effect of parallel rectangular ventilation with pores is studied by numerical simulation and verified by indoor scale-down model testing. The results show that the cooling effect of parallel rectangular ventilation with porosity is very small for the surface layer, the base layer, the subbase layer, and the strongly weathered rock layer, is remarkable for the silty clay layer, and is best for the crushed rock layer. Moreover, parallel rectangular ventilation can guarantee that the crushed rock layer, silty clay layer and strongly weathered rock layer have negative temperatures throughout the year. From January to February, the cooling range in the silty clay layer gradually increases, and the temperature distribution is uneven because of different ventilation inlets. From March to October, the cooling range in the silty clay layer gradually expands, the temperature gradient gradually decreases, and the temperature distribution tends to be uniform. From November to December, the cooling range and temperature tend to be stable. This study provides technical support for the design and construction, operation and maintenance, and stability guarantee of the subgrade in the permafrost region.