Fatigue performance of deepwater steel catenary riser considering nonlinear soil

Y.T. Kim, D.K. Kim, H.S. Choi, S.Y. Yu and K.S. Park

Abstract

The touch down zone (TDZ) and top connection point of the vessel are most critical part of fatigue damage in the steel catenary riser (SCR). In general, the linear soil model has been used to evaluate fatigue performance of SCRs because it gives conservative results in the TDZ. However, the conservative linear soil model shows the limitation to accommodate real behavior in the TDZ as water depth is increased. Therefore, the riser behavior on soft clay seabed is investigated using a nonlinear soil model through time domain approach in this study. The numerical analysis considering various important parameters of the nonlinear soil model such as shear strength at mudline, shear strength gradient and suction resistance force is conducted to check the adoptability and applicability of nonlinear soil model for SCR design.

Key Words

steel catenary riser; touch down zone; nonlinear soil; vortex-induced vibration; fatigue damage

Address

Y.T. Kim: Environmental and Plant Engineering Research Team, Daewoo Institute of Construction Technology, 16297 Suwon, Republic of Korea D.K. Kim: Ocean and Ship Technology, Deepwater Technology Mission Oriented Research, Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia; Graduate School of Engineering Mastership, Pohang University of Science and Technology, 37673 Pohang, Republic of Korea H.S. Choi: Graduate School of Engineering Mastership, Pohang University of Science and Technology, 37673 Pohang, Republic of Korea S.Y. Yu: Ocean and Ship Technology, Deepwater Technology Mission Oriented Research, Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia K.S. Park: Steel Structure Research Group, POSCO Global R&D Center, 21985 Incheon, Republic of Korea

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