考虑负摩阻力的刚性桩复合地基工作性状分析

以带褥垫层的刚性桩复合地基为研究对象，在考虑桩体负摩阻力作用的条件下，讨论了桩身侧摩阻力分布状况，建议了侧摩阻力线性简化计算模型。分析了带褥垫层刚性桩复合地基桩体与褥垫层的相互作用，计算了桩顶对褥垫层的刺入量。推导了桩体位移微分方程，并根据方程，同时结合中性面的定义，给出了求解中性面深度比的计算方法，讨论了其影响因素及取值范围。算例显示，按该方法计算的结果符合工程经验。

Analysis of working behavior of rigid pile composite ground considering influence of negative skin friction

The working behavior of rigid pile composite ground with mat is analyzed. With considering the negative skin friction of the pile, the distribution of side skin friction resistance is discussed. A simplified linear model of this side skin friction resistance is then proposed. Moreover, the interaction between the pile and the mat is analyzed and the penetration magnitude of the pile into the mat is calculated. A theoretical differential equation of pile displacement is then derived. According to this equation and the definition of the neutral plane, a new method is proposed to calculate the depth ratio of the neutral plane. The influencing factors and their value ranges are also discussed. Finally, a case study shows that the calculation results agree well with practical experiences.