管道沟槽等窄条形基坑隆起稳定性计算方法

坑底抗隆起稳定常作为软土地区围护结构嵌固深度的控制条件。现行行业规范并未考虑基坑宽度对隆起稳定性的影响,导致深厚软弱土地区窄条形基坑工程设计中挡土构件过大的插入深度,造成浪费。实际基坑工程有显著的空间效应。通过分析基坑宽度效应对坑底抗隆起稳定性的影响,得出了基于宽度的基坑分类标准,提出了窄条形基坑坑底抗隆起稳定计算方法,表明窄条形基坑有更好的抗隆起稳定性,并通过工程案例进行了分析验证。最后对窄条形基坑坑底抗隆起稳定性影响因素进行参数敏感性分析。研究成果对规范公式进行了补充改进,为软土地区窄条形基坑设计提供了依据。

Calculation Method for Uplift Stability of Narrow Strip Foundation Pit Such As Pipe Groove

The anti-uplift stability of pit bottom is often used as the control condition of the build-in depth of enclosing structure in the soft soil regions. The influence of pit width on the uplift stability is not considered in the current industry standards, which leads to the overlarge insertion depth of retaining components in the design of the narrow strip foundation pit project in the deep, thick and soft soil regions and results in waste. The practical foundation pit engineering has the obvious spatial effect. By analyzing the influence of pit width effect on the anti-uplift stability of pit bottom, the classification standards of foundation pit based on the width are obtained. The calculation method of the anti-uplift stability at the bottom of narrow strip foundation pit is put forward. It is showed that the narrow strip foundation pit has the good anti-uplift stability, and its stability is analyzed and verified through the engineering cases. Finally, the parametric sensitivity analysis of the influencing factors on the anti-uplift stability at the bottom of narrow strip foundation pit is carried out. The study results complement and improve the standard formula, and provide the basis for the design of narrow strip foundation pits in the soft soil regions.