Spudcan Penetration Behaviour on a Sloping Seabed by Numerical Analysis and Centrifuge Modeling
- Yunsup Shin (Norwegian Geotechnical Institute) | Huynh Dat Vu Khoa (Norwegian Geotechnical Institute) | Jung Chan Choi (Norwegian Geotechnical Institute) | Heon-Joon Park (Korean Advanced Institute of Science and Technology) | Jae-Hyun Kim (Korean Advanced Institute of Science and Technology) | Dong-Soo Kim (Korean Advanced Institute of Science and Technology) | Jintae Han (Korea Institute of building Construction and Technology) | Seongwon Lee (Korea Institute of building Construction and Technology) | Jungin Choi (Samsung Heavy Industries)
- Document ID
- International Society of Offshore and Polar Engineers
- The 28th International Ocean and Polar Engineering Conference, 10-15 June, Sapporo, Japan
- Publication Date
- Document Type
- Conference Paper
- 2018. International Society of Offshore and Polar Engineers
- CEL method, spudcan foundation, large deformation, jack-up platform, finite element analysis, centrifuge test, sloping seabed
- 0 in the last 30 days
- 19 since 2007
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Installation of a jack-up platform is challenging on a hard sloping seabed. The installation and pre-loading can generate large bending moments on the spudcan and hence in the legs. Consequently, it may reduce the safety of the whole jack up system. The ISO jack-up standard (ISO 19905-1, 2012) states that issues associated with positioning of spudcan on a hard sloping stratum shall be carefully considered. However, only few studies have been done on spudcan penetration resistance on a sloping seabed. This study aims to evaluate the spudcan penetration resistance on a sloping seabed by using numerical method. Three dimensional large deformation finite element (LDFE) analyses are performed to investigate the spudcan penetration behaviour on a sloping seabed. The foundation responses including failure mechanism, displacements, vertical and horizontal resistance calculated from the LDFE analyses are compared to a centrifuge modeling tests.
It is observed that the spudcan penetration into the sloping seabed generates asymmetric stress distribution, which induces horizontal resistance and moment on the spudcan leg. The increase and decrease of the horizontal resistance is depending on the initial stress distribution under the seabed. Overall, the vertical and lateral penetration resistances from the centrifuge model testing and the numerical analysis present consistent trends. In addition, the failure mechanism are presented at the different stages during the spudcan penetration.
A jack-up platform has been utilized favourably in the offshore industry because it has high capacity to self-installation and high performance in moderate water depth. Prior to mobilize a jack-up platform to the site, it is required to have a site investigation, which can identify any potential risk related to spudcan foundation safety during installation. However sometimes a jack-up platform is supposed to be installed on a sloping seabed or next to existing footprint, which generates asymmetric stress distribution on the spudcan foundation and leg. Therefore, predicting the load-penetration response on uneven ground condition prior to jack-up installation requires much higher caution.
|File Size||2 MB||Number of Pages||6|