Collision Analysis Between Spudcan and Seabed During the Process of Jack-up Platform Lowering Jack-up Legs

• Published in: China ocean engineering Vol. 35; no. 5; pp. 779 - 788
• Main Authors: Le, Cong-huan, Li, Yan-e, Huang, Lei, Ren, Jian-yu, Ding, Hong-yan, Zhang, Pu-yang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2021; Springer Nature B.V; State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China; School of Civil Engineering,Tianjin University,Tianjin 300072,China%State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China%China Classification Society (CCS),Tianjin 300457,China
• Subjects: Clay soils; Coastal Sciences; Dynamic response; Engineering; Finite element method; Fluid- and Aerodynamics; Impact loads; Jack up platforms; Jackup platforms; Legs (structural); Marine & Freshwater Sciences; Modulus of elasticity; Motion stability; Nonlinearity; Numerical and Computational Physics; Ocean floor; Oceanography; Offshore; Offshore Engineering; Sea state; Sea states; Shear strength; Simulation; Soil; Soil conditions; Soil investigations; Soil structure; Stability analysis; Wave direction; Wave period; collision; jack-up platform; dynamic response; spudcan
• ISSN: 0890-5487; 2191-8945
• DOI: 10.1007/s13344-021-0069-1

In the leg-lowering process, the offshore jack-up platform is in a floating state, and the spudcan may collide with the seabed due to the platform motion in waves, thereby threatening the safety and stability of the platform. This paper first analyzed the hydrodynamic response of a jack-up platform under different sea states. Then a finite-element model was established which considered the material and geometrical nonlinearity in the structure and the nonlinear interaction between soil and structure to investigate the collision response between the spudcan and seabed during lowering jack-up legs. The results show that the dynamic response of the platform decreases and gradually tends to be stable as the wave period increases. The motion response of the platform reach the largest value when the wave period is 8 s and the wave direction is 0°. The collision angle between the spudcan and seabed has a large influence on the collision response, while the velocity of leg-lowering has little influence on the collision response. The collision response is also significantly affected by soil conditions. For clay, the increase in undrained shear strength and Young’s modulus will increase the impact force.