A. Alhassani - Engineering Faculty, University of Kufa, Najaf, Iraq

Underreamed piles with one or more bulbs have been widely used in almost all types of soil to support a range of structures. In some cases, in addition to vertical compressive or uplift loads, piles must withstand a considerable lateral load. A ۳-D finite element study using ABAQUS software was conducted to examine the behavior of underreamed piles in clay soil under pure lateral, pure uplift, and combined uplift and lateral loads. In this study, pile (L/D) ratios of ۱۱.۶۶, ۱۵, ۲۰, and ۲۵ were considered by adjusting the pile length to simulate the behavior of rigid and flexible piles. The piles were modeled as a linear elastic material, and the soil behavior was simulated using the Drucker-Prager constitutive model. The findings show that the lateral resistance of piles with (L/D) ratios of ۱۱.۶۶ and ۱۵ increased slightly when underreamed piles were used. However, no change in lateral resistance was observed for underreamed piles with (L/D) ratios of ۲۰ and ۲۵ compared with straight piles. The uplift capacity of underreamed piles was significantly greater than that of a straight pile. The lateral capacity was marginally influenced by the prior uplift loading, such that it decreased for a rigid underreamed pile, and increased for a flexible underreamed pile.

Underreamed piles, Finite Element, lateral resistance, uplift capacity