Factors influencing soil friction forces on buried pipes used for district heating

This paper identifies several approaches to account for different factors that influence the soil friction forces on buried pipes for district heating. Much of the current understanding of soil-pipe interaction have been based on investigations conducted on pipes buried in cohesionless soil backfill. In practice, due to economic reasons, trench excavation spoil typically with a significant fine-grained fraction is often reused as trench backfill; hence, there is a need to better understand the soil-pipe interaction in pipes buried in fine-grained soil backfill. It is clear that research work on a number of additional fronts is needed to obtain a better understanding of the soil loads on buried pipes while taking into account real operating conditions and modern pipe laying technologies.