The University of Southampton
University of Southampton Institutional Repository

Lateral resistance of "rigid" pipelines and cables on rocky seabeds

Lateral resistance of "rigid" pipelines and cables on rocky seabeds
Lateral resistance of "rigid" pipelines and cables on rocky seabeds
Accurate assessment of lateral resistance is critical to ensure the on-bottom stability and integrity of subsea pipelines and cables in the oil/gas and marine renewable energy industries. However, on rocky seabeds recommend practices provide limited recommendations on pipe/seabed interaction, suggesting only a single value for the friction coefficient of 0.6. This paper reports on a programme of physical experiments and theoretical modelling investigating the lateral resistance of pipes on rocky seabeds. It is shown that the peak and mean effective friction can significantly exceed the interface (or Coulomb) friction coefficient when the pipe diameter (D) is similar to the median rock diameter (dn50). Only when the pipe diameter becomes large compared to the rock size does the mean effective friction approach the interface friction. The effective friction coefficient was found to vary with variability in rock size and shape, as well as the length of pipe relative to median rock diameter. Each of these findings is reproduced well using the theoretical model and demonstrating that the effective lateral friction coefficient maybe higher than 0.6 for mean friction, and significantly higher for peak friction. This implies that inaccuracy may exist in current design, which may be rectified using the theoretical model.
0008-3674
823-839
Griffiths, Terry
24b3e648-f03d-4597-a69b-c2f90c2f70eb
White, David
a986033d-d26d-4419-a3f3-20dc54efce93
Draper, Scott
efe46b7d-3989-403b-8b19-0b17dd54194f
Leighton, Adam
89e7a9dc-39b1-4a66-bad5-a883e21aac9f
Cheng, Liang
0ce99dcc-f682-4ec6-97aa-59fd87174385
An, Hongwei
e8b6f5ed-c6bd-4253-b6d1-aab7b60e8cb3
Fogliani, Antonino
10bd8e2f-fda7-4f3b-94af-93047361164f
Griffiths, Terry
24b3e648-f03d-4597-a69b-c2f90c2f70eb
White, David
a986033d-d26d-4419-a3f3-20dc54efce93
Draper, Scott
efe46b7d-3989-403b-8b19-0b17dd54194f
Leighton, Adam
89e7a9dc-39b1-4a66-bad5-a883e21aac9f
Cheng, Liang
0ce99dcc-f682-4ec6-97aa-59fd87174385
An, Hongwei
e8b6f5ed-c6bd-4253-b6d1-aab7b60e8cb3
Fogliani, Antonino
10bd8e2f-fda7-4f3b-94af-93047361164f

Griffiths, Terry, White, David, Draper, Scott, Leighton, Adam, Cheng, Liang, An, Hongwei and Fogliani, Antonino (2019) Lateral resistance of "rigid" pipelines and cables on rocky seabeds. Canadian Geotechnical Journal, 56 (6), 823-839. (doi:10.1139/cgj-2018-0208).

Record type: Article

Abstract

Accurate assessment of lateral resistance is critical to ensure the on-bottom stability and integrity of subsea pipelines and cables in the oil/gas and marine renewable energy industries. However, on rocky seabeds recommend practices provide limited recommendations on pipe/seabed interaction, suggesting only a single value for the friction coefficient of 0.6. This paper reports on a programme of physical experiments and theoretical modelling investigating the lateral resistance of pipes on rocky seabeds. It is shown that the peak and mean effective friction can significantly exceed the interface (or Coulomb) friction coefficient when the pipe diameter (D) is similar to the median rock diameter (dn50). Only when the pipe diameter becomes large compared to the rock size does the mean effective friction approach the interface friction. The effective friction coefficient was found to vary with variability in rock size and shape, as well as the length of pipe relative to median rock diameter. Each of these findings is reproduced well using the theoretical model and demonstrating that the effective lateral friction coefficient maybe higher than 0.6 for mean friction, and significantly higher for peak friction. This implies that inaccuracy may exist in current design, which may be rectified using the theoretical model.

Text
Griffiths et al 2018 AM - Accepted Manuscript
Download (2MB)

More information

Accepted/In Press date: 10 July 2018
e-pub ahead of print date: 14 August 2018
Published date: June 2019

Identifiers

Local EPrints ID: 422542
URI: http://eprints.soton.ac.uk/id/eprint/422542
ISSN: 0008-3674
PURE UUID: b9633485-7e08-4f78-bccc-1359850e5b02
ORCID for David White: ORCID iD orcid.org/0000-0002-2968-582X

Catalogue record

Date deposited: 25 Jul 2018 16:30
Last modified: 07 Oct 2020 04:31

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×