Buried Seafloor Pipeline Crossing a Fault

Steel tubular structures are widely used in offshore structures and seafloor pipeline. Soil movement due to storm or earthquake could cause costly damage to buried pipelines or piles of the offshore fixed platform. The objective here is to prevent such failure by strengthening a single wall tubular with double wall, in which the annulus is grouted with polymer. The strength and ductility of the steel-polymer composite section is expected to be significantly improved. Strain based design for double wall steel pipe with polymer filler has been described by Marshall [1]. However, no test has been performed on his calculated results. The purpose of this work is to verify the hand calculations done by Marshall using finite element analysis (FEA).