大桩群基桩广义剪切位移UnitCells模型

GENERALIZED SHEAR DISPLACEMENT MODEL FOR PILE LOAD TRANSFER OF LARGE PILE GROUPS BASED ON UNIT CELLS

基于Unit Cells和剪切位移原理,引入镜像桩-桩的弹性耦合原理,建立了考虑大桩群相互作用的基桩荷载传递剪切位移单元模型;并引入桩土剪切位移与相对滑移叠加的广义剪切位移概念,推导出了基桩单元模型的广义剪切位移解析表达式,提出了根据桩端位移协调条件迭代求解的方法。通过算例分析,揭示了疏桩间距、荷载水平对疏桩地基减沉效果的重要影响,阐明了疏桩与基体的荷载位移传递特征,以及桩顶相对位移、桩端持力层刚度对疏桩基体体系工作性状的影响机制,且验证了该模型的正确性和算法的灵活性。

Based on the Unit Cells theory and the shear displacement theory, the pile-to-pile elastic coupling principle of mirroring image method was introduced, and shear displacement cell mode was built for analyzing the load transfer of piles in large pile group. The generalized shear displacement analytical expression was deduced by introducing the generalized shear displacement concept, which can be explained as a superposition of shear displacement and relative slippage of pile-soil interface. The iterative solving method was presented based on the pile tip displacement coordination condition. An case analysis reveals the effects of sparse piles space and the load level on the settlement-reducing property of sparse pile foundation. The load-displacement transfer characteristics of sparse piles and foundation are described. The contact mechanism of the sparse-pile foundation working property of the pile top relative displacement and the stiffness of the pile end bearing layer is explained. The validity of the model and the flexibility of the algorithm are also verified.