Non-axisymmetric analysis of the vertical dynamic response of large-diameter pile in layered soil

Abstract

In the low-strain integrity test, the excitation hammer usually impacts the center of the pile top. However, in practice, the excitation hammer is often not applied precisely at the center of the pile top. The hammer-pile-soil system, especially for the large-diameter pile, is no longer axisymmetric. The existing axisymmetric models are no longer suitable for describing the propagation of these stress waves in piles under vertical non-axisymmetric excitation load. This paper introduces a simplified three-dimensional (3D) model to investigate the non-axisymmetric dynamic characteristics of the large-diameter pile under non-axisymmetric excitation load in layered soil. The suitability and accuracy of the simplified 3D model are verified by comparison with the numerical solutions and other existing results. Meanwhile, the applicable pile radius range of the simplified 3D model is obtained by comparing it with the numerical solution. Finally, the influence of the excitation load and the pile properties on the non-axisymmetric dynamic characteristics of the large-diameter pile is discussed. Some valuable suggestions for weaking the high-frequency interference of normal large-diameter piles are provided for practical engineering.