Micromechanical analysis of suction pile-granular soil interaction under inclined pulling load: Effect of pulling angle

Analyses of the Suction Anchor–Sandy Soil Interactions under Slidable Pulling Action Using DEM-FEM Coupling Method: The Interface Friction Effect

“…The deformation of the suction anchors in the centrifuge tests was small relative to the displacement, satisfying the criteria for employing the one-way transient coupled DEM-FEM simulations [24,25]. Similar to previous investigations [14,19,26], the one-way transient coupling method was employed in simulations. This method encompasses the analysis of boundary data, specifically particle contact forces on the structure's surfaces in the DEM simulation; then, these forces are integrated into the FEM simulation as boundary conditions at each step, without any feedback from the FEM part to the DEM part.…”

“…The model suction anchors, as shown in Figure 2b, were constructed using a smooth steel tube. The model suction anchor had an underwater weight of 40.3 g. Pulling actions during the tests were applied on the pad eye at a depth of h = −45 mm (75% depth), which is approximately the location with the highest anti-pullout capacity [14,18,19]. The tests were carried out at the gravitational acceleration of 100 g (981 m/m 2 ).…”

“…DEM simulations are well suited for sandy soil, while FEM is commonly used for modeling solid structures [22,23]. Following the approach of previous studies [14,18,19], a DEM-FEM coupling method was adopted in this research. Balls in DEM were utilized to simulate the sandy soil, while meshes in FEM were employed to create the suction anchors.…”

“…Consequently, assuming a constant load or displacement instead of contact action between hangers and pad eyes (structure-structure interaction) is improper. Although continuous numerical methods including the finite element method (FEM) are capable of simulating the deformation of suction anchors and structure-structure interactions, these methods fall short in terms of accurately simulating large soil deformation and failure (see Figure 1d) [13,14]. Consequently, the discrete element method (DEM) is popular among many researchers, as it can analyze sandy soil behavior on a microscale and model significant soil deformations [15,16].…”

“…Consequently, the discrete element method (DEM) is popular among many researchers, as it can analyze sandy soil behavior on a microscale and model significant soil deformations [15,16]. However, modeling the contact behaviors between hangers and suction anchors poses challenges for existing discrete element method (DEM) approaches in structure-structure interaction simulation [14]. Hence, harnessing the strengths of both DEM and FEM could offer valuable insights into the interactions between suction anchors and sandy soils under pulling action from mooring lines.…”