Lateral dynamics of offshore pipe piles in layered viscoelastic soils with soil plug effect: An analytical investigation

Abstract

The dynamic lateral response of offshore pipe piles in layered viscoelastic soils is investigated in this article, with a focus on the role played by the height of the soil plug formed within the pile. A key scenario considered is when the soil plug does not fully extend along the embedded depth of the pile, resulting in part of the pile interacting with both water and soil at the same time. The analytical approach proposed here is validated by comparing its outcomes with those from previous works. These comparisons confirm the effectiveness of the method. One of the main findings is that hydrodynamic forces must be taken into account to ensure accurate dynamic predictions. Increasing the pile’s stiffness is shown to be an effective way to reduce resonance amplitudes and shift the natural frequency to higher values. Additionally, it was observed that the properties of the uppermost soil layers significantly affect the pile response, whereas deeper layers and the soil plug itself have a comparatively minor effect. Changes in the height of soil plug are found to influence the pile impedance, underscoring the importance of incorporating this factor in more precise assessments.