Three-dimensional numerical analysis of under-reamed pile in clay under lateral loading

Unlike the bearing and uplift capacities of under-reamed pile, the lateral resistance of under-reamed pile is studied by a very few researchers. Therefore, in the present study, a three-dimensional numerical analysis is carried out to study the response of under-reamed pile in clay under lateral loading. In the numerical analysis, various parameters such as embedment length to shaft diameter ratio (L-u/D), top bulb distance from the base to bulb diameter ratio (h(b)/D-u), undrained cohesion (c(u)), rate of increase of undrained cohesion (m), number of bulbs, and bulb spacing to bulb diameter ratio (s/D-u) are considered as variables. From the present study, load-deflection curve, variations of deflection, shear force, and bending moment, displacement contour, and soil stress in front of the pile are obtained. The lateral load-carrying capacity of under-reamed pile is estimated based on displacement-based criteria. The lateral load-carrying capacity of under-reamed pile (Q(hur)) is found to increase with increase in L-u/D, h(b)/D-u, number of bulbs, c(u), m, and decrease in s/D-u. The deflection at the pile head is found to decrease significantly with increase in h(b)/D-u and number of bulbs, and decrease in s/D-u. It is expected that the present results will be useful from serviceability point of view.

Automated summary

This study conducted a three-dimensional numerical analysis to investigate the lateral response of under-reamed pile in clay under lateral loading, considering various parameters. It was found that the lateral load-carrying capacity of under-reamed pile increases with certain factors such as L-u/D, h(b)/D-u, number of bulbs, c(u), and m, while decreases with s/D-u. The deflection at the pile head is significantly affected by h(b)/D-u, number of bulbs, and s/D-u.