Finite Element Analysis and Parametric Study of Spudcan Footing Geometries Penetrating Clay Near Existing Footprints

Abstract

Most existing research on the stability of spudcans during reinstallation nearing footprints is based on centrifuge tests and theoretical analyses. In this study, the reinstallation of the flat base footing, fusimform spudcan footing and skirted footing near existing footprints are simulated using the coupled Eulerian–Lagrangian (CEL) method. The effects of footprints’ geometry, reinstallation eccentricity (0.25D–2.0D) and the roughness between spudcan and soil on the profiles of the vertical force, horizontal force and bending moment are discussed. The results show that the friction condition of the soil–footing interface has a significant effect on H profile but much less effect on M profile. The eccentricity ratio is a key factor to evaluate the H and M. The results show that the geometry shape of the footing also has certain effects on the V, H, and M profiles. The flat base footing gives the lowest peak value in H but largest in M, and the performances of the fusiform spudcan footing and the skirted footing are similar. From the view of the resultant forces, the skirted footing shows a certain potential in resisting the damage during reinstallation near existing footprints by comparing with commonly used fusiform spudcan footings. The bending moments on the leg–hull connection section of different leg length at certain offset distances are discussed.

Mitigation Effect of Perforation Drilling on the Sliding Risk during Spudcan Installation Close to Footprints

“…The Coulomb friction model is adopted to model the tangential behavior of the contact, and the friction coefficient µ between the spudcan and soil is set as 0.3. However, a shear stress limit τ limit at the contact interface is set as the undrained shear strength of the soil, which is the same as the work of Yu et al [12]. This is to allow sliding between the soil and spudcan if the frictional shear stress exceeds the undrained shear strength of the soil.…”

“…Yuan et al [9] conducted a 1g test of the re-installation of a three-legged jack-up unit. Besides experimental studies, further insights were recently provided by some numerical studies conducted by Mao et al [10], Zhang [11], and Yu et al [12]. Furthermore, Zheng et al [13] numerically studied the spudcan-footprint interaction in non-uniform clay.…”

Study on spudcan reinstallation next to a footprint using large deformation finite element method

“…Considering this reason, the strain softening effect is not considered in this paper which is also adopted by recent studies. 20 The spudcan in this paper is modeled as a discrete rigid body. It is a round flat-based spudcan with a diameter of D = 10 m and a thickness of t = 1.8 m. The uniform and non-uniform clays are respectively discretized with eight-node linear Eulerian brick with reduced integration (EC3D8R) in pure mechanical analysis or thermally coupled elements EC3D8RT in thermomechanical coupled analysis, which are the only available Eulerian element types in Abaqus.…”

“…Considering this reason, the strain softening effect is not considered in this paper which is also adopted by recent studies. 20…”

New Advances in Marine Engineering Geology

“…The issue collected 14 papers that cover different aspects of marine engineering geology and geotechnics using different approaches. Some of them used numerical simulations [1][2][3][4][5], some conducted laboratory experiments [6][7][8][9][10], and others acquired and analyzed field or laboratory tests to establish a theoretical modeling framework for predicting marine sediment properties and the potential hazards [11][12][13][14]. Moreover, with a timely and well-organized publication, it is believed that the state-of-the-art data, analyses, and methodologies presented in this Special Issue could be of great interest to all readers of Journal of Marine Science and Engineering.…”