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

Abstract

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 (Lu/D), top bulb distance from the base to bulb diameter ratio (hb/Du), undrained cohesion (cu), rate of increase of undrained cohesion (m), number of bulbs, and bulb spacing to bulb diameter ratio (s/Du) 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 (Qhur) is found to increase with increase in Lu/D, hb/Du, number of bulbs, cu, m, and decrease in s/Du. The deflection at the pile head is found to decrease significantly with increase in hb/Du and number of bulbs, and decrease in s/Du. It is expected that the present results will be useful from serviceability point of view.