碎石桩在工程中应用广泛,其承载力是评价碎石桩工程性能的重要指标。基于圆孔扩张理论,引入拓展Lade-Duncan破坏准则推导了碎石桩单桩承载力计算公式,考虑应力扩张叠加效应,推导了方形布桩方案下碎石桩承载力计算公式。开展了室内缩尺模型试验,得出碎石桩最大鼓胀深度位于约二倍桩径深度处,为理论计算提供了依据。最后,通过现场试验与已有研究成果,对提出的计算方法进行了对比验证,结果表明:已有碎石桩承载力计算公式计算结果较为保守,引入拓展Lade-Duncan破坏准则的计算公式得出的承载力与实测值更为接近,可为相关工程及研究提供参考。
Gravel piles are widely used in engineering, and their bearing capacity is an important indicator for evaluating the performance of gravel pile projects. Based on the cavity expansion theory, the calculation formula of bearing capacity of single gravel pile is derived by introducing the extended Lade-Duncan failure criterion, and considering the superimposed effect of stress expansion, the calculation formula of bearing capacity of single gravel pile under square layout scheme is derived. The laboratory scale model test shows that the maximum swelling depth of stone column is about twice the depth of pile diameter, which provides a basis for theoretical calculation. Finally, the proposed calculation method is compared and verified by field tests and existing research results. The results show that: The calculation results of the existing bearing capacity calculation formula of the crushed stone column are conservative, and the bearing capacity obtained by introducing the calculation formula of the extended Lade-Duncan failure criterion is closer to the measured value. This study can provide reference for related engineering and research.
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