Abstract 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.

中文翻译：

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多孔弹性土中部分埋入大直径桩的竖向振动

摘要 本文对部分埋入式单桩在竖向谐波荷载作用下的振动特性进行了分析研究。通过将桩建模为 Rayleigh-Love 杆，导出的解决方案允许考虑桩的二阶横向振动对其响应的贡献。此外，通过将桩轴周围和桩基下方的土壤建模为有限厚度的多孔弹性材料，在解决方案中考虑了动态应力流耦合对桩振动引起的地波传播的影响。在针对单相土中全埋桩的现有解验证导出解之后，我们研究了桩几何和自由长度以及土壤地层的影响，土桩系统响应的刚度和流动特性。该参数分析的结果表明，忽略桩的自由长度的振动特性可能会导致高频载荷响应估计出现严重不准确，这一发现对于某些海洋和桥梁工程应用尤为重要。