Abstract
This paper deals with the theoretical study concerning the soil-pile interaction in vertical vibration for pile groups with fixed tip condition. The analysis is performed by application of the elastic wave theory to a visco-elastic layer on the rigid bedrock. The dynamic behaviour of the pile group subjected to the vertical harmonic excitation at the pile head is analyzed by considering the pile-soil-pile interaction and the variation of the stiffness of the soil around the pile. This theory indicates that the dynamic response of the pile group differs from that of the single pile and is greatly affected by the excitation frequency, the interval between piles and the number of piles. In order to verify this theory, the vertical vibration test was conducted for the pile group in the field. From a comparison between theoretical and experimental results, it can be seen that the numerical values agree with the experimental data by reducing the stiffness of the soil around the pile. This analytical method is convenient and effective to evaluate the fundamental characteristics of the pile foundation in vertical vibration.
