New DNVGL Recommended Practice: DNVGL-RP-F114

In May 2017, DNVGL introduced a new Recommended Practice DNVGL-RP-F114, with the main objective to provide guidance and recommendations on the evaluation of pipe-soil interaction and its application for various conditions experienced during the lifecycle of submarine a pipeline.

The new DNVGL-RP-F114 supersedes the pipe-soil interaction guidance provided in the following:

  • DNVGL-RP-F105 Free Spanning Pipelines
  • DNVGL-RP-F107 Risk Assessment of Pipeline Protection
  • DNVGL-RP-F109 On-bottom Stability Design of Submarine Pipelines
  • DNVGL-RP-F110 Global Buckling of Submarine Pipelines
  • DNVGL-RP-F111 Interference Between Trawl Gear and Pipelines
  • DNVGL-RP-F113 Pipeline Subsea Repair

Pipe-soil interaction is an important aspect of submarine pipeline design; influencing the structural behaviour and performance of the pipeline. Early versions of pipe-soil interaction models considered the friction soil resistance term and deliberately ignored or simplified the passive soil resistance term to make analysis simpler and to reduce the analysis effort. However, underestimating or simplifying the pipe-soil interaction model could lead  to uneconomic pipeline design and in some cases compromise integrity.

The dynamic pipe-soil interaction models of the new Recommend Practice have the capability to update and accumulate pipeline embedment and the soil passive resistance for discrete time steps; simulating cyclic loads resulting from storms or thermal cycling. The models capture the pipe-soil interaction behaviour in a time domain with improved representation of the soil resistance. As a consequence the models are more complex than previous; requiring expertise in pipeline system design, geotechnical engineering and programing.

 

In response to the new Recommended Practice, Atteris has successfully completed a number of verification and validation cases against previous DNVGL validation cases of Atteris’ proprietary dynamic pipeline modelling software, CORUS-3D. With the new models now included in CORUS-3D’s pipe-soil interaction model library, engineers can choose between various models to simulate pipeline behaviour.

Atteris’ fundamental understanding of pipe-soil interaction, acquired through pipeline physical modelling using the Large O-tube and Beam Centrifuge facilities at the University of Western Australia, has enabled a thorough understanding and seamless implementation of DNVGL‑RP‑F114 into software and engineering design and analysis.

For more details regarding CORUS-3D pipeline modelling capability please visit (https://atteris.com.au/youssef-b-obrien-d-2017-bottom-stability-analysis-submarine-pipelines-umbilicals-cables-using-3d-dynamic-modelling-offshore-technology-conference-2017-ho/)