Seafloor-Riser Interaction Model
Publication: International Journal of Geomechanics
Volume 9, Issue 3
Abstract
Fatigue stresses associated with extreme storms, vessel movements, and vortex-induced vibrations are critical to the performance of steel catenary risers. The critical location for fatigue damage often occurs within the touchdown zone, where cyclic interaction of the riser with the seabed occurs. Developing a model for seabed stiffness requires characterization of a number of complex nonlinear processes including trench formation, nonlinear soil stiffness, soil suction, and breakaway of the riser from the seafloor. The analytical framework utilized in this research considers the riser-seafloor interaction problem in terms of a pipe resting on a bed of springs, the stiffness characteristics of which are described by nonlinear load-deflection curves. The model allows for first penetration and uplift, as well as repenetration and small range motions within the bounding loop defined by extreme loading. The backbone curve is constructed from knowledge of the soil strength, the rate of strength increase with depth, trench width, and two additional parameters, while three parameters are necessary for the cyclic response.
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Acknowledgments
The writers would also like to acknowledge the support of Department of the Interior Minerals Management Service (Cooperative Agreement No. UNSPECIFIED35515), the Offshore Technology Research Center, and their colleagues at Texas A&M University.
References
Aubeny, C. P., and Shi, H. (2006). “Interpretation of impact penetration measurements in soft clays.” J. Geotech. Geoenviron. Eng., 132(6), 770–777.
Aubeny, C. P., Shi, H., and Murff, J. D. (2005). “Collapse load for cylinder embedded in trench in cohesive soil.” Int. J. Geomech., 5(4), 320–325.
Bridge, C., Howells, H., Toy, N., Parke, G. A. R., and Woods, R. (2003). “Full-scale model tests of a steel catenary riser.” Fluid structure interaction II, S. K. Chakrbarti, C. A. Brebbia, D. Almorza, and Gonzalez-Palma, eds., WIT Press, Southhampton, U.K., 107–116.
Bridge, C., Laver, K., Clukey, E., and Evans, T. (2004). “Steel catenary riser touchdown point vertical interaction model.” Proc., Offshore Technology Conf., Houston, OTC 16628.
Bridge, C., and Willis, N. (2002). “Steel catenary risers—Results and conclusions from large scale simulations of seafloor interactions.” Proc., Int. Conf. on Deep Offshore Technology, New Orleans, Penn Well.
Bruton, D., White, D., Cheuk, C., Bolton, M., and Carr, M. (2006). “Pipe-soil interaction behavior during lateral buckling, including large amplitude cyclic displacement tests by the Safebuck JIP.” Proc., 2006 Offshore Technology Conf., Houston, OTC 17944.
Clukey, E. C., Houstermans, L., and Dyvik, R. (2005). “Model tests to simulate riser-soil interaction effects in touchdown point region.” Proc., Int. Symp. on Frontiers in Offshore Geotechnics, Perth, Australia, 651–658.
Dunlap, W. A., Bhohanala, R. P., and Morris, D. V. (1990). “Burial of vertically loaded offshore pipelines.” Proc., 22nd Annual Offshore Technology Conf., Houston, OTC 6375, 263–270.
Hale, J. R., Morris, D. V., Yen, T. S., and Dunlap, W. A. (1992). “Modeling pipeline behavior on clay soils during storms.” Proc., 24th Annual Offshore Technology Conf., Houston, OTC 7019, 339–349.
Hornbeck, R. (1975). Numerical methods, Quantum, New York.
Morris, D. V., Webb, R. E., and Dunlap, W. A. (1988). “Self-burial of laterally loaded offshore pipelines.” Proc., 20th Annual Offshore Technology Conf., Houston, OTC 5855, 421–428.
Murff, J. D., Wagner, D. A., and Randolph, M. F. (1989). “Pipe penetration in cohesive soil.” Geotechnique, 39(2), 213–229.
Pesce, C. P., Aranha, J. A. P., and Martins, C. A. (1998). “The soil rigidity effect in the touchdown boundary-layer of a catenary riser: Static problem.” Proc., 8th Int. Offshore and Polar Engineering Conf., International Society of Offshore and Polar Engineers, Montreal.
Stewart, D. P., and Randolph, M. F. (1994). “T-bar penetration in soft clay.” J. Geotech. Engrg., 118(12), 2230–2235.
Thethi, R., and Moros, T. (2001). “Soil interaction effects on simple catenary riser response.” Proc., Deepwater Pipeline & Riser Technology Conf., Houston.
Willis, N. R. T., and West, P. T. J. (2001). “Interaction between deepwater catenary risers and a soft seabed: Large scale sea trials.” Proc., Offshore Technology Conf., Houston, OTC 13113.
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© 2009 ASCE.
History
Received: Sep 13, 2007
Accepted: Dec 8, 2008
Published in print: May 2009
Published online: May 15, 2009
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