Vertical Vibration of Tapered Piles

Abstract

A new, simple and approximate method of analysis for tapered piles under vertical vibration is presented. The method of analysis accounts for soilpile interaction in a relatively simple manner. Since cross‐section and dynamic soil reaction per unit length of tapered piles vary with depth, the solution for dynamic response is obtained by a finite difference method. The analytical solutions agree satisfactorily with reported experimental results. The dynamic response and the results of a parametric study of tapered concrete piles are presented in non‐dimensional form. With an increase of angle of taper, resonant amplitude decreases and resonant frequency increases. In general, dimensionless stiffness and damping parameters are frequency dependent and also vary with the slenderness ratio and Poisson's ratio of the soil medium. In all cases, however, stiffness increases and damping decreases with increase of angle of taper of piles.