CFG桩与PHC管桩组成的刚性桩复合地基联合承载机理与协调变形研究
Research on Joint Bearing Mechanism and Coordinated Deformation of Rigid Pile Composite Foundation Composed of CFG Pile and PHC Pipe Pile

刚性桩复合地基凭借其工后沉降小、施工周期短、整体稳定性强、社会经济效益高等优势，逐渐得到广泛应用。为研究刚性桩复合地基的承载特性与变形规律，以某市某建筑地基处理工程作为实例，通过Midas/GTS/NX建立了PHC管桩与CFG桩复合地基有限元分析模型，研究了此刚性桩复合地基的承载力与变形特性，对于两种桩分别选取了合适的桩端持力层以及桩参数。结果表明，采用PHC管桩与CFG桩进行地基处理能很好的发挥复合地基承载力，且两种桩变形均在合理范围之内，沉降较为均匀。随荷载增加桩土应力比发生变化，桩承担荷载逐步增大。选择第8、9层土层分别作为PHC管桩与CFG桩的桩端持力层是合理的。
Rigid pile composite foundations have been widely used by virtue of their advantages such as small post-construction settlement, short construction period, strong overall stability and high social and economic benefits. In order to study the bearing characteristics and deformation law of rigid pile composite foundation, a building foundation treatment project in Kaifeng city is taken as an example, and a finite element analysis model of PHC pipe pile and CFG pile composite foundation is established by Midas/GTS/NX, and the bearing capacity and deformation characteristics of this rigid pile composite foundation are studied, and suitable pile end holding layer and pile parameters are selected for the two kinds of piles respectively. The results show that the foundation treatment with PHC pipe pile and CFG pile can play a good role in the composite foundation bearing capacity, and the deformation of both piles is within a reasonable range, and the settlement is more uniform. The pile-soil stress ratio changes with the increase of load, and the pile bearing load increases gradually. It is reasonable to choose the 8th and 9th soil layers as the pile end bearing layer of PHC pipe piles and CFG piles respectively.