Abstract It is in general difficult to construct piled foundations in karst area due to the lack of a stable holding layer. A new large step-tapered hollow pile (LSTHP) is used to address this issue. In this work, the load transfer model and the theoretical solution for the settlement of the new pile are presented. FLAC3D was used to study the load transfer mechanism of LSTHP and the load transfer model was then derived based on the mechanism in combination with the theory of disturbed states concept to characterize the non-linear pile-soil interactions. In this framework, the relatively intact state is defined by a linear elastic model while the fully adjusted state is described by the Mohr-Coulomb model. The analytical solution of pile settlement is then established based on the proposed load transfer model and the equilibrium equations governing the pile-soil interactions. The solution is cross-validated using numerical simulations. It was demonstrated that the proposed load transfer model can describe correctly the non-linear load transfer mechanism at the pile-soil interface and the analytical solution is capable of assessing the settlement of LSTHP.

中文翻译：

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基于扰动状态概念的大型阶梯锥形空心桩沉降理论新模型

摘要 岩溶地区由于缺乏稳定的保持层，桩基施工普遍存在困难。一种新的大型阶梯锥形空心桩 (LSTHP) 用于解决这个问题。在这项工作中，提出了荷载传递模型和新桩沉降的理论解决方案。使用FLAC3D研究LSTHP的荷载传递机制，并基于该机制结合扰动状态概念理论推导出非线性桩土相互作用的荷载传递模型。在该框架中，相对完整的状态由线弹性模型定义，而完全调整的状态由 Mohr-Coulomb 模型描述。然后基于所提出的荷载传递模型和控制桩土相互作用的平衡方程，建立桩沉降的解析解。该解决方案使用数值模拟进行交叉验证。结果表明，所提出的荷载传递模型可以正确描述桩土界面处的非线性荷载传递机制，并且解析解能够评估 LSTHP 的沉降。