Effect of pipe-soil interface roughness on undrained uplift capacity of buried offshore pipelines

Abstract

Estimation of undrained uplift capacity of buried offshore pipelines involves several soil, structure and interface parameters. For buried pipelines, undrained uplift capacity is significantly influenced by pipesoil interface roughness coefficient. Design guidelines for obtaining uplift capacity exist in literature for perfectly smooth and fully rough interfaces. This paper aims at estimating undrained uplift capacity over entire range of interface roughness coefficient. For this purpose, a number of finite element analyses have been carried out by varying interface roughness coefficient and other parameters. The obtained results are validated with plasticity theory based solutions. Present study shows that the simplistic approach of linear interpolation of capacity with roughness coefficient leads to slightly conservative design.