Vertical vibration of a large diameter pile partially-embedded in poroelastic soil

摘要

This paper presents an analytical study on the vibration characteristics of partially-embedded single piles subjected to vertical harmonic loads. The derived solution allows accounting for the contribution of the second-order lateral vibrations of the pile to its response, by modelling the pile as a Rayleigh-Love rod. In addition, the effects of dynamic stress-flow coupling on the propagation of ground waves resulting from pile vibrations are considered in the solution, by modelling the soil surrounding the pile shaft and underlying the pile base as poroelastic material of finite thickness. Following the verification of the derived solution against an existing solution for fully-embedded piles in single-phase soil, we investigate the effects of pile geometry and free length as well as soil stratigraphy, stiffness and flow characteristics on the response of the soil-pile system. Results of this parametric analysis suggest that ignoring the vibration characteristics of the free length of the pile can introduce significant inaccuracies in the estimation of the response for high-frequency loads, a finding that is particularly important for certain ocean and bridge engineering applications.