Behavior of Vertical and Battered Piles Under Combined Axial and Lateral Load

Abstract

Three-dimensional FE analyses using PLAXIS 3D have been carried out to study the behavior of single vertical and battered piles under combined action of axial and lateral load in different homogenous non-cohesive soil conditions. The variation of ultimate lateral load with pile head deflection with and without axial load has been obtained to examine the effect of friction angles (ϕ) of sand and batter angles of pile (β) on the ultimate pile capacity. Results indicate that the axial load, pile batter angle and sand friction angle significantly influence the lateral response of battered piles. Under the influence of axial load, P (=0.2 Pu, 0.4 Pu, Pu being ultimate axial load), the percentage increase in lateral capacity (IH) increases with the increase in pile batter angle, β. For a negative battered pile, IH values are almost same for both medium and dense sands. While for positive battered piles, in case of dense sands, IH varies considerably with friction angles of sand, reaching a value of 44% for β = 20°. Further, a multiple linear regression equation, with R2 value = 0.921, has been developed using MS-Excel with lateral capacity (H) as response and angle of internal friction of sand bed, ϕ (=a), diameter of pile (=b), the ratio of P/Pu (=c) and batter angle, β (=d) as predictors. The variation of results predicted by the regression model and that computed from the numerical model are found to be within 25%.