The effect of cyclic loading is an essential factor leading to progressive soil strength degradation. Therefore, a comprehensive analysis of the pile‐soil system behavior under cyclic loading is required to ensure the stability of pile group. There is room for improvement in the inherent constraint of the conventional numerical model in terms of approximating the soil resistance distribution along the pile by point loads at element nodes, necessitating a specific element that integrates considerations of pile group effect and cyclic loading within a unified framework. This study aims to develop a newly specific type of element for efficiently predicting nonlinear behavior within the pile‐soil system, addressing simulations involving nonlinear pile‐soil interaction, pile group effect, and cyclic loading. Modified element formulations based on soil stiffness matrices and soil resistance vectors specifically address pile group effect and consider parameters that influence pile behavior under cyclic lateral loading. The numerical solution procedure with Newton‐Raphson iteration allows the calculation of pile responses in geometric and material nonlinear analyses. The validation of the proposed method includes several examples, comparing it with existing numerical solutions and experimental tests of single piles and pile groups under cyclic loading. These comparisons further support the consistency of the proposed method with measured data and validate its accuracy in considering group effect and cyclic loading. The parametric study illustrates the ability of the proposed method to capture cyclic loading parameters while considering the influence of the number and magnitude of load cycles, the cyclic load direction, and the installation methods.

中文翻译：

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开发循环荷载下群桩行为分析的改进有限元公式


循环荷载的影响是导致土体强度逐渐退化的重要因素。因此，需要对循环荷载下的桩土系统行为进行全面分析，以确保群桩的稳定性。传统数值模型的固有约束还有改进的空间，即通过单元节点处的点荷载来近似沿桩的土阻力分布，需要在统一框架内综合考虑群桩效应和循环荷载的特定单元。本研究旨在开发一种新的特定类型的单元，用于有效预测桩-土系统内的非线性行为，解决涉及非线性桩-土相互作用、桩群效应和循环荷载的模拟。基于土壤刚度矩阵和土壤阻力矢量的修改元素公式专门解决了群桩效应，并考虑了在循环侧向荷载下影响桩行为的参数。使用牛顿-拉夫森迭代的数值求解过程可以计算几何和材料非线性分析中的桩响应。该方法的验证包括多个算例，与现有的数值解以及循环荷载下单桩和群桩的实验测试进行比较。这些比较进一步支持了所提出的方法与测量数据的一致性，并验证了其在考虑群体效应和循环载荷方面的准确性。参数研究说明了所提出的方法在考虑负载循环的数量和大小、循环负载方向和安装方法的影响的同时捕获循环负载参数的能力。