Abstract
In this paper, we first set up a mathematical model of a single pile subjected to axial load with initial horizontal displacement in elastic soil, of which pile head is free; then obtained critical loads and expressed them in nondimensional parameters. Based on the results obtained from the parametric study, we found that the critical load decreased with the increment of the initial displacement, but the effect of it was very small. On the contrary, the effect of the reduction of soil spring coefficient due to liquefaction on the decrease of the critical load was significant. Finally, the effect of the difference of the boundary condition at the pile head, i. e, free vs hinge, could be seen for short piles, but the effect could not be seen for long piles.
