The increasing use of rock‐socketed piles highlights the importance of developing a suitable design method for their bearing capacity. This study quantifies the shear behavior of the rock–pile interface, which generally dominates the bearing capacity of rock‐socketed piles under service load. A micromechanics‐based rock–pile interface model with idealized nonuniform profile is proposed with two enhancements: (1) the slip line method together with nonlinear Hoek–Brown failure criteria is integrated to identify the critical shear displacement of rock asperity; and (2) the residual stage of shear behavior is properly considered with the rounding progress of sheared rubbles. The enhanced interface model is first validated by the direct shear test results under constant normal stiffness. Then, the interface model is implemented via user‐defined FRIC into the finite element code ABAQUS without the need of explicitly building the rock–pile interface profile. Accordingly, the model is applied to simulate and analyze two field cases involving rock‐socketed piles. Comparison between the predictions and field observed results shows this method can well capture the axial load transfer behavior of pile socket into weak rock.

中文翻译：

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一种增强的微机械岩石-桩界面模型，应用于嵌岩桩建模


嵌岩桩的使用越来越多，凸显了开发合适的承载能力设计方法的重要性。这项研究量化了岩石-桩界面的剪切行为，该界面通常主导着使用荷载下嵌岩桩的承载能力。提出了一种基于微力学的具有理想化非均匀轮廓的岩石桩界面模型，该模型具有两个增强功能：（1）将滑移线方法与非线性 Hoek-Brown 破坏准则相结合，以识别岩石粗糙度的临界剪切位移； (2)随着剪切碎石的磨圆进度，适当考虑剪切行为的残余阶段。增强的界面模型首先通过恒定法向刚度下的直剪试验结果进行验证。然后，通过用户定义的 FRIC 将界面模型实现到有限元代码 ABAQUS 中，而无需显式构建岩桩界面轮廓。因此，该模型用于模拟和分析两个涉及嵌岩桩的现场案例。预测结果与现场观测结果的比较表明，该方法可以很好地捕捉桩窝向软弱岩石中的轴向载荷传递行为。