Prediction of boundary zone parameters and soil–pile separation under horizontal and rocking vibrations

Abstract

This paper attempts to study the dynamic soil–pile interaction on the non-linear response under coupled vibration by both experimental and analytical study. Dynamic response characteristics of reinforced concrete piles under varying levels of vertical and horizontal harmonic excitation are investigated in the present study. Single and group (2×2) piles are used in the investigation. The horizontal exciting force applied on the pile cap through the oscillator causes coupled motion to the foundation. The measured response is compared by the two different analytical approaches: linear analysis – Novak’s plane strain theory with static interaction factor approach and non-linear analysis – Novak’s continuum model with dynamic interaction factor approach. For non-linear analysis, allowance is made for the separation between the pile and soil in boundary zone model. Reasonable match between the measured and predicted response by non-linear analysis is found. The test data are used to establish the empirical relationship between the extent of soil separation around the pile and the maximum vibration amplitudes under coupled vibration.