Skip to content

Polypropylene pipe interface strength on marine sandy soils with varying coarse fraction

Research output: Contribution to journalArticle

Original languageEnglish
Number of pages16
JournalProceedings of the ICE - Geotechnical Engineering
Early online date27 Jan 2020
DateAccepted/In press - 21 Jan 2020
DateE-pub ahead of print (current) - 27 Jan 2020


The interface shear strength of polypropylene pipeline coatings and marine sandy soils was investigated through direct and surface-over-soil interface shear box testing. Polypropylene specimens were acquired by removal from existing manufactured steel pipes and test soils were fabricated to closely resemble typical compositions and particle size distributions of North Sea marine sediments. The test sands varied according to their coarse particle fractions, with 0, 15 and 35% being retained on a 0·4 mm sieve. Testing was carried out at the very low stresses pertinent to pipeline interfaces, between 2·5 and 37·5 kPa, in both loose and dense states. The experimental results suggest a dependency of the interface shear strength on the stress level and relative density, with the coarse particle fraction playing a modest role. Surface characterisation and lack of volumetric deformation suggests that the shearing kinematic is predominantly grain sliding rather than rolling. Interface efficiency was largely constant despite some scatter due to variability in surface specimens. The distinct seams apparent on some of the polypropylene surfaces as inherent manufacturing artefacts had a negligible influence on interface strength. The relationship between interface strength, normalised roughness and Shore D hardness was assessed, discussed and compared with results from other works.

    Research areas

  • laboratory tests, pipes, pipelines, offshore engineering



  • Full-text PDF (author’s accepted manuscript)

    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via Thomas Telford (ICE Publishing) at . Please refer to any applicable terms of use of the publisher.

    Accepted author manuscript, 1.63 MB, PDF document

    Embargo ends: 27/01/21

    Request copy


View research connections

Related faculties, schools or groups