Parametric Study of Under-Reamed Piles in Sand

Abstract

Under-reamed piles are bored cast-in-situ concrete piles having one or more number of bulbs formed by enlarging the pile stem. These piles are best suited in soils where considerable ground movements occur due to seasonal variations, filled up grounds or in soft soil strata. Provision of under reamed bulbs has the advantage of increasing the bearing and uplift capacities. It also provides better anchorage at greater depths. An experimental work was programmed and carried out to understand the behaviour of under-reamed piles subjected to vertical load. The type of soil used in the present laboratory investigation was sand and mild steel under-reamed pile models. This study presents the results of analyses conducted on the influence of geometrical features of the under-reamed pile on its ultimate load carrying capacity. The geometrical features include the length of the pile, number, spacing and position of the bulb.