Abstract

This paper presents a refined analytical solution for pipe-laying on an elasto-plastic seabed. The solution builds on previous work, extending it to include elastic rebound of the pipe. The approach simplifies the pipeline as the combination of four segments: a natural catenary through most of the water column; a boundary-layer segment in the water close to the seabed where the bending stiffness of the pipe modifies the shape of the catenary; a beam under uniform tension through the touch down zone up to the point where maximum pipe–soil load concentration occurs, within which the soil responds plastically; and finally a rebound segment, also modelled as a beam under uniform tension, where the soil rebounds elastically as the pipe–soil contact force reduces back to the submerged pipe weight. Continuity of displacement, gradient, bending moment, shear and deduced tension along the pipeline are preserved. In comparison with previous models, such as a rigid-plastic seabed model, the distribution of seabed resistance is continuous. Results from the solution are presented for the case of seabed resistance to pipe penetration increasingly proportionally with depth, as is approximately the case at very shallow depths within the seabed. The lower the gradient of seabed resistance, the greater is the pipe embedment, but the maximum contact force and curvature of the pipe both reduce. Analyses also show that the rebound stiffness can have a marked effect on pipeline embedment, which increases with increasing rebound stiffness. However, the effect on pipe embedment becomes small beyond a certain ratio of rebound stiffness to shear strength.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.