Numerical analysis of pipe-soil interaction of steel catenary riser based on co-rotational coordinate method
In order to analyze the vertical and lateral pipe-soil interaction of the steel catenary riser(SCR)in the touchdown zone under the small-scale vertical drop and lateral drift motion of the top floating object,taking the initial penetration into the seabed and the lateral displacement process of the riser as quasi-static problems,a three-dimensional finite beam element model was established in the co-rotational coordinate framework,and the p-y loading curve was coupled to simulate the initial penetration of the riser into the seabed.The differences between linear,bilinear and nonlinear pipe-soil models in pipe-soil response were compared,the effects of horizontal traction force at the top of the riser,current and soil shear strength on the vertical pipe-soil interaction of the riser touchdown section were analyzed,and the effects of lateral traction force and soil parameters on the lateral and vertical pipe-soil interaction of the riser touchdown section under the different conditions of small-scale drift were further studied.The results show that the nonlinear pipe-soil model simulates the response of riser penetration into the seabed more accurately in the co-rotational coordinate framework;the increase of the top horizontal traction force and the current flow velocity will lead to the decrease of penetration depth and vertical soil resistance;the increase of the shear strength of the soil will lead to the decrease of the riser penetration depth but the increase of the vertical and lateral soil resistance;as the lateral traction force of the top floating body increases,the lateral displacement and soil resistance of the riser touchdown section increases,but the vertical soil resistance decreases;and the increase of the lateral friction coefficient can significantly improve the riser's lateral stability of the touchdown section.In this paper,the global motion of the riser and the pipe-soil interaction are efficiently solved by using the co-rotational coordinate method with the property of decoupling the rigid body and the deformation,which provides a reference for the study of riser-seabed interaction.
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维普
