Dynamic Analysis of the Interaction Between Catenary Riser and Soft Seabed

This study proposed a novel experimental platform to conduct dynamic loading tests of a truncated model steel catenary riser (SCR) within the touchdown zone (TDZ). The facilities of the platform, including a soil tank, a loading system, and a soil stirring system, are introduced in detail. A steel pipe with the same diameter as the in situ SCR has been used in the laboratory tests to investigate the vertical motion of the pipe and the effect of the trench on the lateral motion. As the amplitude of the vertical motion increases, the depth of the trench deepens, the bending moment range increases, and the excess pore water pressure at the bottom of the pipeline first accumulates and then dissipates during loading. The development trend of the trench depth and the influence of the soil strength on the SCR bending moment are also studied. During the test, a seabed trench develops, and its shape is similar to that of the in situ trench.