Investigation of the vertical responses of 2 × 2 square flexible batter pile groups in sand

Abstract

The vertical bearing behaviors of the flexible batter pile groups in sand are investigated in this study. A series of model tests are carried out to study the effects of the batter angle (θ) on the vertical bearing capacities (V g) and distributions of internal forces of the pile groups. In addition, finite-element (FE) analysis is performed to explore the vertical bearing behaviors of the pile groups with various configurations, and the vertical bearing mechanism of the batter pile groups is analyzed. Moreover, a design method is proposed for predicting the bearing ratios (β) of the batter pile groups. The results show that the batter pile groups generally can provide higher vertical bearing capacities than the vertical pile groups with the same configuration. The batter angles for providing the greatest vertical stiffness are decreased with the increase of length–diameter ratio (R) and are not affected by the variation of relative density (D r). The predicting results obtained from the design method match well with the model test and FEM results. Some suggestions are proposed for guiding the application of the batter pile groups in practice engineering.