This chapter discusses ground heat transfer from underground structures, particularly with seasonal freezing and thawing in permafrost regions. Ground freezing and thawing cycles and permafrost degradation can cause severe foundation problems for infrastructure in cold regions. Better understanding of ground heat transfer and the associated frost actions is essential for successful foundation design and development of protection techniques to overcome these foundation problems. This chapter briefly reviews mechanisms of water freezing in soil systems, related frost actions, as well as advances in the modeling of ground heat transfer and active layer thickness. Foundation design methods for infrastructure in permafrost are also discussed, with a focus on traditional and latest techniques for reducing the effects of ground freezing and thawing cycles and for maintaining the frozen ground as a stable foundation. In a case study, recent research results are presented of ground heat transfer from a power transmission line foundation.
