膨胀土边坡的水平膨胀力及桩板结构内力分析

Analysis of lateral swelling pressure of expansive soil slope and internal force of pile-sheet structure

通过分析自然环境下膨胀土含水率随深度的变化规律,建立竖向膨胀力与膨胀率、上覆荷载的关系方程,并探讨水平膨胀力的计算方法。开展桩板结构水平膨胀力室内模型试验研究,结合试验结果与已有研究基础,提出膨胀土边坡桩板结构水平膨胀力的“反K形”分布模式。根据桩板结构特点,基于水平膨胀力的“反K形”分布、梯形分布模式推导桩板结构的桩体剪力和弯矩计算公式,并将桩体弯矩计算结果与现场试验结果进行对比。研究结果表明:基于水平膨胀力“反K形”分布得到的桩身内力具有较高的可靠性,验证了桩板结构水平膨胀力“反K形”分布的合理性和有效性。研究成果可为膨胀土边坡桩板结构的工程设计提供借鉴和参考。

The relationship equation among the vertical swelling pressure and the swelling ratio and the overburden loading was established by analyzing the variation law of the water content of the expansive soil with depth under the natural environment.Subsequently,the calculation method of the lateral swelling pressure was discussed.The indoor model test on the lateral swelling pressure of the pile-sheet structure was carried out.The"reverse K-shaped"distribution mode of the lateral swelling pressure of the pile-sheet structure supporting the expansive soil slope was put forward by combining the test results and the existing research foundation.With regard to the characteristics of the pile-sheet structure,the calculation formulas for the shear force and bending moment of the pile in pile-sheet structure were derived based on the"reverse K-shaped"distribution and trapezoidal distribution mode of the lateral swelling pressure.The calculation results of the bending moment of pile were compared with the field test results.The results show that the theoretical results of internal force of pile based on the"inverse K-shaped"distribution of the lateral swelling pressure are reliable,which verifies the rationality and effectiveness of the"reverse K-shape"distribution of the lateral swelling pressure in pile-sheet structure.The research results can provide references for the engineering design of pile-sheet structures supporting expansive soil slopes.