Abstract The one-dimensional (1D) rod model, which is used in several pile dynamics applications, has two main simplifying assumptions: only vertical reaction is considered and excitation on the pile top is treated as uniform. These two simplifications negatively affect its application in pile integrity tests, especially for large-diameter piles. To overcome these two limitations, a new non-uniform axisymmetric loading (NAL) theoretical model that considers bidirectional (vertical and radial) reactions of the pile body and the non-uniformity of the excitation on the pile top is proposed. Based on the developed model, displacement and velocity fields of an end-bearing pile embedded in homogeneous soil under non-uniform impact are solved theoretically. Analytical solutions are then verified by existing solutions and finite element results. Compared with 1D rod pile model, the NAL model can predict accurately the three-dimensional (3D) effect in the pile integrity test. Extensive parametric analysis is conducted using the present solutions to evaluate the 3D effect in the pile integrity test and provide practical suggestions to diminish the 3D effect in the actual test.

中文翻译：

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桩身完整性试验三维效应的理论分析

摘要 用于多种桩动力学应用的一维 (1D) 杆模型有两个主要的简化假设：仅考虑垂直反作用力，并且将桩顶上的激励视为均匀的。这两种简化对其在桩完整性测试中的应用产生了负面影响，尤其是对于大直径桩。为了克服这两个限制，提出了一种新的非均匀轴对称加载 (NAL) 理论模型，该模型考虑了桩体的双向（垂直和径向）反作用力和桩顶激励的非均匀性。基于所建立的模型，从理论上求解了非均匀冲击下均质土中端承桩的位移场和速度场。然后通过现有解决方案和有限元结果验证分析解决方案。与一维杆桩模型相比，NAL 模型可以准确预测桩身完整性测试中的三维（3D）效应。使用本解决方案进行了广泛的参数分析，以评估桩完整性测试中的 3D 效应，并提供实际建议以减少实际测试中的 3D 效应。