Thermal protection of power transmission line foundations against permafrost thawing due to climate change

Several studies have indicated that the active layer in permafrost regions is increasing as a result of climate change. This could cause extreme damage to infrastructure in northern areas. This paper presented a thermal analysis of a power transmission line foundation and discussed thermal protection methods against permafrost thawing around the foundation. The paper also discussed the development of an analytical model to predict the transient thermal effects of the metal tower, along with measured results of ground freezing and thawing in an experimental test cell. Specifically, the paper discussed a variety of thermal protection methods, including ground surface insulations; a new thermal barrier made of phase change materials; ground cooling devices; and a snow/radiation shade. It was concluded that the thermal barriers reduced the amplitude of temperature cycles in the foundation and could thereby effectively alleviate possible damage caused by seasonal freezing/thawing cycles in the ground. 22 refs., 1 tab., 11 figs