Observations Of Pipe Soil Response From In Situ Measurements

Published: This paper was prepared for presentation at the Offshore Technology Conference held in Houston, Texas, USA, 6–9 May 2013, Paper No. 24154

06 May 2013
J.C. Ballard, C. de Brier, K. Stassen and R.A. Jewell

The force mobilized through the interaction between a pipeline and the seabed is a key to the design of pipelines.  Fugro Smartpipe® is a site investigation tool that is designed to measure pipe-soil interaction forces in-situ, at the seabed and at close to full-scale. The tool has been deployed at several offshore sites and valuable data has been collected. This paper presents some results and observations from recent testing offshore West Africa and focuses mainly on (i) the vertical pipe penetration tests, (ii) the dissipation of excess pore pressures generated during vertical penetration, and (iii) the subsequent axial pipe-soil response. In particular, the effect of pipeline unloading between the consolidation phase and the axial testing phase is examined in terms of the pore water pressure response at the pipe surface and the measured axial friction factor. The results indicate that the use of a drained friction factor could be justified if the pipeline is overloaded by a factor of the order two. Such pre-loading is quite typical for light pipelines that are hydrotested or installed in waterfilled conditions.


Make a media enquiry