Abstract The installation process changes the state of the soil in the vicinity of a pile and therefore influences its load-displacement behaviour during the operational phase following the installation. The installation process itself and its effect on the pile behaviour under a subsequent high-cyclic loading are numerically investigated in this work. Two different installation techniques, namely impact driving and jacking, are investigated using a coupled Eulerian-Lagrangian approach in combination with a hypoplastic material model. Either ideally drained or partially drained conditions are assumed. Afterwards the pile response to a high-cyclic loading with up to five million load cycles is studied using a high-cycle accumulation (HCA) model. Compared to a wished-in-place (WIP) pile, the simulations accounting for the installation process showed considerable less permanent pile displacements in case of initially medium dense sand. However, the opposite was observed in case of initially dense sand. Current practice assuming a WIP state as the starting point in numerical simulations seems thus to be conservative for initially medium dense sand but leads to an underestimation of permanent deformations for initially dense sand.

中文翻译：

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安装对沙中桩长期循环行为的影响：数值研究

摘要 安装过程会改变桩附近土壤的状态，从而影响安装后运行阶段的荷载-位移行为。在这项工作中，对安装过程本身及其在随后的高循环载荷下对桩行为的影响进行了数值研究。两种不同的安装技术，即冲击驱动和顶升，使用耦合的欧拉-拉格朗日方法结合非塑性材料模型进行研究。假设理想排水或部分排水条件。之后，使用高循环累积 (HCA) 模型研究了桩对高达 500 万次荷载循环的高循环荷载的响应。与原地愿望 (WIP) 桩相比，考虑到安装过程的模拟显示，在最初为中等密度沙子的情况下，永久桩位移要小得多。然而，在最初密集的沙子的情况下观察到相反的情况。目前的做法假设 WIP 状态作为数值模拟的起点，因此对于初始中密砂似乎是保守的，但会导致对初始密砂永久变形的低估。