Large deformation FE analysis of end-bearing piles installing in sand

Significant uncertainty exists in terms of the underlying soil failure mechanisms governing the behaviour of displacement piles in sand. In addition, the installing pile (diameter D = 0.5∼3 m) with a trapped soil wedge at the base and/or the using of a driving shoe often creates a conical tip. This resembles the geometry of finless torpedo anchor (D = 0.8∼1.2 m) and cone penetrometer (in lower scale with D = 0.035∼0.0437 m). This paper describes large deformation finite element (LDFE) analysis of the penetration of conical pile foundations in silica sand, identifying the evolving soil failure mechanisms around the object and the end bearing resistance. The results are validated against centrifuge test data, with reasonable agreement obtained. The pile tip angle and sand relative density are shown to have significant influence on the mobilised soil deformation patterns and consequent end bearing resistance. Higher penetration resistance and more proportion of vertical soil flow (concentrating adjacent to the advancing pile) are in associated with higher relative density and greater tip angle. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).