An analytical solution for load transfer mechanism of Plum blossom pile foundations

Plum blossom pile, a recently developed non-cylindrical pile, exhibits a load transfer mechanism distinct from conventional circular piles due to its unique cross-section. This study presents an analytical approach to characterize its load transfer behavior based on cross-sectional geometry and vertical shearing mechanisms. Based on the equilibrium analytical method, expressions for axial force/dragload and skin friction are derived. The effects of pile-soil shear action, cross-sectional shape, and effective vertical stress were investigated. The results indicate that the convex zone of the pile increases the soil squeezing stress at the pile-soil interface, and the sharp corner zone creates a semi-soil-plug space made up of circular segments, which increases the vertical effective stress of surrounding soil and then increases the skin friction, which means the cross-section of plum blossom pile has a significant enhancement effect on the shaft resistance. The proposed analytical method provides an effective approach for describing the bearing behavior of the plum blossom pile.