Buckling Analysis for Tapered Pile Considering Self-Weight of Pile

To study the effect of pile shape on the buckling behaviour of a tapered pile, the first-type stability of the tapered pile was analyzed based on the cusp catastrophe model of the pile-soil system with considering the self-weight of the pile. By determining the potential function and the equations of the bifurcation sets of the pile-soil system, the cusp catastrophe model was established, and the instability condition of the pile-soil system was derived based on the cusp catastrophe theory and the principles of the energy method. Meanwhile, the buckling load of the tapered pile was determined by the Rayleigh-Ritz method, and the reliability of the results from the cusp catastrophe theory was verified. Finally, the influences of the self-weight of the tapered pile and the variation ratio of pile diameters on the buckling load were analyzed. The result shows that when h/L increases from 0 to 0.4, the ratio of the buckling load reduction of the tapered pile with considering the self-weight of the pile to the buckling load without considering the self-weight of the pile decreases to 42.82%, and the ratio of the buckling load reduction for an equal-diameter pile with considering the self-weight to the buckling load without considering the self-weight decreases to 75.27%. Under the identical conditions, the greater the tapering angle of the tapered pile, the better the stability. When the dimensionless length of the pile tends to be zero, the calculation length of a tapered pile with a free end and a fixed end tend to be zero and that of a tapered pile with a free end and a hinged end tend to be infinite.