抗滑桩合理桩间距分析

Analysis of Pile Space of Anti-Slide Piles

摘要: 土拱效应是抗滑桩发挥支挡作用的前提。而桩间距与桩的土拱效应是密切相关的。然而，前人的研究对桩侧摩擦土拱的考虑不够充分且大多将土拱的轴应力视为均匀分布的。考虑桩端直接土拱和桩侧摩擦土拱同时作用，本文提出了一种计算合理桩间距的新方法。本方法考虑了两种土拱的整体剪切破坏与屈服条件并使用Moho-Coulomb准则分别推导了直接土拱拱脚的内缘点与外缘点的屈服应力。基于极限平衡理论，提出了合理桩间距的控制方程。案例研究表明，本文的计算结果更符合工程实际。最后根据本文的公式推导了两种土拱的极限承载力之比。

Abstract: The soil arching effect is the prerequisite for the anti-slide pile to play the supporting role. Pile space is closely related to the soil arching behind piles. However, previous studies rarely considered the friction soil arching effect between piles and regarded the axis stress uniformly distributed. Considering end-bearing soil arching and friction soil arching simultaneously, a new method was proposed to calculate the reasonable pile spacing. The said method considered the general shear failure and the yielding failure of these two soil arching. The yielding stress of inner-edge point and outer-edge point at arch-foot of the end-bearing soil arching were taken into consideration respectively. Based on the ultimate balance theory, the controlling equations of pile spacing were established. The case study showed that the method in this research conforms better to practice compared to previous researches. Finally, the ratio of the ultimate bearing capacity of the two soil arches was deduced according to the formulas in this research.