Dynamic soil stiffness on a pile in a vibrating group of floating piles

Abstract

Author's approximate analyses to determine the soil stiffness on a single vibrating pile in vertical, torsional and lateral modes of vibration is extended to that on a pile belonging to a pile-group. As previously stated the soil is assumed to be homogeneous and elastic. Explicit formulae have been developed for the stiffness in vertical and lateral modes of vibration. However, for pursuing the analysis, it is assumed that the wave length of the elastic waves in the soil is much larger than the pile-group diameter. Numerical results have been presented for two piles. These are indicative of the results being valid for wider ranges of wave length than the assumption just mentioned. For symmetric vibrations the computed stiffnesses decrease with decreasing spacing of the piles, while in antisymmetrical vertical vibrations the corresponding stiffnesses increase.