Experimental and theoretical study on the nonlinear response of full-scale single pile under coupled vibrations

In this study, an attempt is made to investigate the complex nonlinear behaviour of a reinforced concrete full-scale single pile of 22.0 m length and 0.45 m diameter subjected to machine induced coupled i.e. horizontal and rocking vibrations. The forced vibration tests were conducted in the field to determine frequency-amplitude responses of the single pile for different eccentric moments. The continuum approach of Novak was used to determine the nonlinear responses of the single pile after incorporating precise values of soil-pile separation lengths and boundary zone parameters. The analytical responses were compared with the experimental responses and it was found that the analytical resonant frequencies and amplitudes were within a reasonable range with the coupled vibration test results. Variation of stiffness and damping of the single pile with frequency were also presented using continuum approach analysis.