Centrifuge modeling of steel catenary risers at touchdown zone part I: Development of novel centrifuge experimental apparatus

The critical location for fatigue damage in Steel Catenary Risers (SCRs) is often located within the touchdown zone (TDZ), where cyclic interaction of the riser with the seabed occurs. Riser–fluid–soil interaction at the TDZ is a complex phenomenon with significant room for improving the understanding of the interaction, the trench formation mechanism, and their influence on fatigue life. This paper describes a novel experimental tool developed for SCR testing in a geotechnical centrifuge. It discusses the modeling parameters, scaling considerations, and developed actuation system. Further, it presents the results of a series of trial tests done on an elastic seabed model and compares the measurements to the results of finite element analysis. Finally, it discusses the potential of the tool in modeling SCRs at TDZ using seabed soil and dual frequency Response-Amplitude-Operator (RAO) motions.

► A novel tool for simulating dynamic motion of steel catenary risers at the touchdown zone.
► Verified scaling laws for simulating continuous SCR in a geotechnical centrifuge.
► Physical test and numerical modeling results for model riser on elastic seabed.