承压水基坑抗突涌稳定判定方法研究

 以离心模型试验提出的承压水基坑突涌模式(整体顶升破坏、表面砂沸破坏及接触面涌水涌砂破坏)为基础，借助数值模拟、理论分析的手段，研究基坑发生突涌的判定方法。结果表明：基坑发生整体顶升突涌的破裂面形式主要有2种：铅直面以及与隔水层呈45°+ 的圆弧面，在此基础上建立破裂面抗剪力的计算公式，推导基坑发生整体顶升突涌的定量判定公式；根据承压水基坑发生表面砂沸突涌的机制及土体的拉剪强度指标，推导基坑发生表面砂沸突涌破坏的判定公式。通过与室内试验结果对比可知，该判定公式具有一定的适用价值。

STUDY OF STABILITY JUDGEMENT METHOD OF CONFINED WATER INRUSHING IN FOUNDATION PIT

Based on the bursting modes such as overall heaving,water and sand inrushing in contact between soil and underground structures and surface boiling,judgment methods that determine whether inrushing happens were studied by numerical and theoretical analyses.Results show that the rupture surface modes include vertical plane and circular plane with the angle of with impermeable layer.Then the shear force formula of rupture surface was established and a quantitative calculation method to determine whether overall heaving occurs was gained through theoretical derivation.Based on the mechanism of surface boiling and the index of tensile-shear failure,the judgment formulus that determines whether surface boiling happens was gained.By comparison,it is shown that the calculated values have a good agreement with the experimental values.