Pipeline Geotechnics
Introduction
Pipe soil interaction for surface laid pipelines on normally consolidated very soft clay has probably seen the greatest advance understanding over the past 10 - 15 years. This was largely driven by the Safebuck Joint Industry Project (JIP). As such, a new framework for assessment of pipeline embedment and the calculation of axial / lateral friction factors was developed.
In area's of the world/water depths that are subject to fishing activity it is common to protect smaller diameter pipelines from interaction with trawl gear by lowering them below the seabed (after they have been laid). This may introduce the requirement for mitigation of Upheaval Buckling depending on the particulars of the pipeline and product. Lowering may be achieved by using a submarine pipeline plough, cable plough, jet trencher, or cutter. The backfill that can be generated by these tools varies significantly and as such, so does the uplift resistance it can provide. It stands to reason therefore that efficient design for UHB mitigation requires significant cross discipline interaction and collaboration. When this goes wrong it has significant cost implications.
Codes / Guidance
The following foundation design codes are most commonly adopted in offshore geotechnical detailed design:
Published Data
See blogs to follow.
Pipe soil interaction for surface laid pipelines on normally consolidated very soft clay has probably seen the greatest advance understanding over the past 10 - 15 years. This was largely driven by the Safebuck Joint Industry Project (JIP). As such, a new framework for assessment of pipeline embedment and the calculation of axial / lateral friction factors was developed.
In area's of the world/water depths that are subject to fishing activity it is common to protect smaller diameter pipelines from interaction with trawl gear by lowering them below the seabed (after they have been laid). This may introduce the requirement for mitigation of Upheaval Buckling depending on the particulars of the pipeline and product. Lowering may be achieved by using a submarine pipeline plough, cable plough, jet trencher, or cutter. The backfill that can be generated by these tools varies significantly and as such, so does the uplift resistance it can provide. It stands to reason therefore that efficient design for UHB mitigation requires significant cross discipline interaction and collaboration. When this goes wrong it has significant cost implications.
Codes / Guidance
The following foundation design codes are most commonly adopted in offshore geotechnical detailed design:
- Safebuck JIP
- DNVGL RP F114 (recently introduced with the intention of combining the pipeline geotechnics guidance in all existing DNV guidance)
Published Data
See blogs to follow.