Micromechanical analysis of the suction bucket-granular soil interactions under the pull action of anchor lines: Embedded length effect

Abstract

The micro-mechanism of interactions between suction buckets and granular soil under different embedded lengths remains unclear. This study investigates the micro-to-macro interactions between suction buckets and granular soil under an inclined pull action of anchor lines, taking the embedded length effect into consideration. The granular soil was modeled using the discrete element method (DEM), while the suction bucket was modeled using the finite element method (FEM). The peak pull force in DEM-FEM simulations was validated using model test results, while macro and micro behaviors of the structure-soil interaction were analyzed. The findings demonstrated that the embedded length effect shaped the pull force-displacement curve by influencing the interaction modes between structures and granular soil. Discontinuity and large soil deformation occurrences can be successfully simulated using the DEM-FEM method and the relationships to embedded lengths were discovered. Besides, clear relationships among bucket rotation angles, the effective supporting areas, vertical pull-out displacement, shear wear, and deformation of buckets, were established. Furthermore, a detailed investigation of particle-scale behaviors led to an identification of mechanical failure modes of suction bucket-granular soil interaction. The findings suggest that ignoring the embedded length effect could lead to misestimating the uplift capacity and failure modes of the suction buckets.