chapter  72
Defining geotechnical parameters for surface-laid subsea pipe-soil interaction
ByJ. Peuchen, Z. Westgate
Pages 6

The interaction between surface-laid pipelines and the seabed typically takes place within the upper 0.5 m of the seabed. The key geotechnical parameters for assessing pipe-soil interaction are intact and remoulded undrained shear strength, interface shear resistance, submerged soil unit weight, and coefficient of consolidation. This paper summarises experience deriving design geotechnical parameters for various shallow stratigraphy conditions characteristic of different geographic regions. It is shown that characterisation of the upper 0.5 m of the seabed can require site-specific evaluations and ranking of geotechnical investigation tools. This is illustrated for (1) stratigraphic definition and (2) geotechnical parameterisation. The ranking includes cone penetration tests, T-bar/ball penetrometers, free fall penetrometers, box core sampling and in-box miniature T-bar or ball penetration testing, piston core sampling, push sampling and laboratory testing.