Numerical investigation of spudcan footing penetration in layered soil
Gutz, P.; Peralta, P.; Abdel-Rahman, K.; Achmus, M. (2013). Numerical investigation of spudcan footing penetration in layered soil, in: Brinkmann, B. et al. (Ed.) Computational Methods in Marine Engineering V (MARINE 2013). pp. 842-853 In: Brinkmann, B.; Wriggers, P. (Ed.) (2013). Computational Methods in Marine Engineering V (MARINE 2013). International Center for Numerical Methods in Engineering (CIMNE): Barcelona. ISBN 978-84-941407-4-7. , more |
| Keyword | | | Author keywords | Spudcan; Layered Soil; Coupled Eulerian-Lagrangian;Soil-Structure-Interaction |
| Authors | | Top | - Gutz, P.
- Peralta, P.
- Abdel-Rahman, K.
- Achmus, M.
| | |
| Abstract | Spudcans are a type of foundation for mobile jack-up rigs and are connected to each of the three or four independent legs of a rig. These rigs are widely operating in the offshore industries such as oil and gas exploration and offshore wind park constructions. The diameter of a spudcan is typically between 10 and 16 m, but has steadily increased in recent years with some exceeding 20 m. An accurate prediction of the leg or spudcan penetration is required to assess the minimum leg length of a jack-up rig and to predict any hazards such as risk of rapid leg penetration that can destabilize the rig and lead to catastrophic accidents. Rapid and sudden leg penetration can occur in layered soils where a strong layer overlies a weak layer. This type of failure mechanism in soil is called "punch through". The current state-of-practice to assess the penetration depth of a spudcan is to evaluate the bearing capacity of the footing applying analytical methods at discrete depths. Analytical bearing capacity methods strongly simplify the penetration process and rely on empirical factors. Continued investigation of the spudcan penetration process by means of physical or numerical models can reduce the amount of empiricism in applied methods in practice, thereby increase accuracy in penetration predictions and reduce risk of rig instability. The results of a finite element numerical model to investigate the spudcan penetration process in layered soils are presented in this paper. The numerical model combines conventional Lagrangian elements, which represent the spudcan, with Eulerian elements that idealize the soil. The utilization of this so-called Coupled Eulerian-Lagrangian finite element method enables the numerical simulation of large deformation processes such as the spudcan footing penetration. Preliminary results are presented and compared with state-of-practice analytical solutions. |
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