A Micro-Mechanical Study of the Influence of Penetrometer Geometry on Failure Mechanisms in Granular Soils

A discrete element, analysis can provide much useful information on failure mechanisms for large displacement problems in geotechnical engineering. This study involved a series of 2D distinct element method (DEM) simulations of the penetration of a CPT cone, a closed-ended pile and an open ended pile into a rectangular tank containing over 29,000 disk particles. The objective was to explore the influence of penetrometer geometry on the distribution of disk displacements, rotations, and contact forces. The findings of the study indicated that increasing the penetrometer- soil friction coefficient resulted in a slightly deeper failure mechanism. The penetrometer-pile friction value had a significant influence on the formation of plugs in the open ended piles. In all cases localizations could clearly be identified by considering the particle rotations, with clockwise rotations being more dominant to the left of the penetrometer, and anti-clockwise rotations being more dominant to the right of the penetrometer.