Abstract:
This paper discusses soil structure interaction analyses performed to aid in the design of a rock berm to provide restraint to a surface laid pipeline in the case of full bore rupture of the line. The motivation behind this analysis related to the planned removal of an unexploded World War II mine, which was located against a high pressure gas transmission pipeline, in the UK Sector of the North Sea. Since soil conditions at the location consisted principally of soft clay, the analyses undertaken also highlighted the significant influence of the soft soil layer on rock berm stability under lateral pipeline loading, which is not well defined according to industry accepted design guidelines. As a result of the analysis presented this paper provides recommendations with regard to the design of a rock berm founded on soft clay.