The use of a convective heat flow model in road designs for Northern regions

Abstract

Roads and highways in northern environments are exposed to harsh climatic conditions. In particular, changes in temperature of several tens of degrees centigrade between the seasons, and substantial precipitation as well as permafrost conditions are common. These environmental conditions result in significant damages to the infrastructure that requires extensive maintenance. Road damage is directly related to problems associated with the foundation, frequently resulting in differential settlements. Significant increase in these problems is expected as a result of changing climate, thus reducing the expected service life of various roads in arctic regions. The highway system within the permafrost region is extremely vulnerable to these climate changes because the mechanical property of the soil changes dramatically with temperature increases and as ice within the frozen soil thaws. This paper presents a numerical investigation of a novel approach for an improvement of road foundations resulting from convective heat flow. The proposed foundation is capable of compensating for some of the expected warming of the permafrost by storing and maintaining the cold winter temperatures through the summer months. The numerical model demonstrated the importance of considering convective heat flows to optimize the design of the foundation with a focus on minimizing the effect of climate warming.

Permafrost and climate in Europe: Monitoring and modelling thermal, geomorphological and geotechnical responses

“…Even during pre-construction activities, thermal disturbances should be minimised through the use of insulation materials (Thalparpan 2000) and drilling using chilled air flushing rather than fluids (Arenson, 2002;. Passive cooling systems such as thermosyphons, thermoprobes, air-duct cooling systems and gravity-driven air convection offer another possibility (Smith et al, 1991;McKenna and Biggar, 1998;Goering et al, 2000;Goering, 1998;Cheng, 2005;Wen et al, 2005;Arenson et al, 2006;Ma et al, 2006), but their efficiency in alpine environments is still to be tested.…”

Wind-driven device for cooling permafrost

“…Notable techniques include the utilization of ventilation ducts [4][5][6][7] , crushed rock embankments [8][9][10] , and thermosyphons 1,[11][12][13][14] . For instance, in the case of subgrades incorporating ventilation ducts, the thermal energy within the subgrade can be transferred to the cold air through the air ducts in cold seasons 5,15 . During warm seasons when wind strength is relatively weak, subgrades overlain by ventilation ducts experience a net cooling effect.…”