承力盘间距对支盘桩抗拔承载特性分析

Analysis of the effect of bearing plate spacing on the anti-pull bearing characteristics of branch and plate piles

支盘桩作为一种新型的钻孔灌注桩,可以充分利用桩周土体的承载能力,提高桩的承载能力,但对于支盘桩的抗拔承载特性的研究成果较少,理论分析不够完善,因此采用ABAQUS软件,考虑了初始应力场,桩土之间的非线性接触以及土体材料的非线性,设计了三根不同盘间距双盘支盘桩,研究支盘桩在上拔荷载作用下的承载特性,分析表明:存在临界盘间距,达到临界盘间距之前,盘间距较小时,下支盘承载力无法完全发挥,双支盘桩的承载性能随着支盘间距增加而变大,临界盘间距之后,上下盘开始独立发挥作用,再增大盘间距,双支盘承载性能增加幅度变缓,且会导致较大位移变形,研究发现双支盘桩上下承力盘承载力发挥与时间效应有关系。

As a new type of bored pile,the branch pile can make full use of the bearing capacity of the soil around the pile and improve the bearing capacity of the pile.However,there are few research results on the uplift bearing characteristics of branch piles and the theoretical analysis is not perfect.Therefore,using the ABAQUS software,considering the initial stress field,the nonlinear contact between the pile and the soil,and the nonlinearity of the soil material,three double-disc branch piles with different disc spacings were designed to study the effect of the branch piles under the uplift load.The analysis shows that there is a critical inter-disk spacing.Before reaching the critical inter-disk spacing,when the inter-disk spacing is small,the bearing capacity of the lower support trays cannot be fully utilized.After the distance between the plates,the upper and lower plates begin to function independently.If the distance between the plates is increased,the increase in the bearing capacity of the double-branch plate will slow down,and it will cause greater displacement and deformation.The study found that the upper and lower bearing plates of the double-branch piles exert their bearing capacity and time effect is related.