Relationship between texture of polypropylene coatings and interface friction for sand at low stress levels

Pipelines in the offshore sector make common use of polypropylene (and other polymer) coating systems to protect infrastructure and provide thermal insulation. High pressure high temperature pipelines are subject large axial loads due restraint by seafloor soils strains pipe wall. Friction between material soil plays a defining role build-up stress formation lateral buckling. Accurate quantification pipe–soil interface friction is key robust pipeline stability design possibilities enhance or manipulate coefficient may be attractive designers. An extensive campaign tests using range granular materials surface specimens engineered achieve varying textures was carried out. The results show that primarily depends on level magnitude texture relation particle size. Herein, new relative parameter, T , developed that, unlike alternative roughness parameters, can obtained conventional profilometry measurement techniques. expression for estimating proposed serve as useful predictor friction.