Numerical analysis of helical piles in cohesionless soil

The paper presents a numerical investigation carried out for helical pile installed in loose cohesionless soil with varying density and dimensions of the helical blade/shaft. The analyses are carried out using three-dimensional finite-element software, Plaxis 3D AE. The load-deformation behaviour under axial compression and tension is compared with the results from a case study of field investigation and numerical analysis reported. The model thus calibrated is then used for a parametric study and the results were used to arrive at a set of generic equations to estimate the axial capacities. The investigation shows that relative density of sand plays an important role in the response of ultimate axial capacities towards various geometrical variations. Presence of helical blade and its embedment ratio (H/D (h) ) were found to influence axial capacity significantly. However, the shaft diameter is found to play a relatively less important role compared to increase in helical blade diameter while considering ultimate axial load capacities.