Flotation of pipes and cables in consolidating backfill

Abstract

This paper discusses the flotation of cables and pipelines that have been trenched using jet trenching during reconsolidation of the seabed soil. Utilising previously published data on the variation of clay strength with liquidity index, it is demonstrated for the first time that while current industry guidance is appropriate for the low plasticity clays for which much previous research has been carried out, it may be overly-conservative for high plasticity clays such as those found in the Gulf of Guinea or the Gulf of Mexico owing to the differing strength and density characteristics of these soils.