大直径扩底灌注桩抗拔承载力试验研究  

EXPERIMENTAL STUDY ON UPLIFT BEARING CAPACITY OF LARGE DIAMETER CAST-IN-PLACE PILE WITH ENLARGED BOTTOM

作　　者：李保安 王永成 李东彬 郭豪 高识涵 LI Bao-an;WANG Yong-cheng;LI Dong-bin;GUO Hao;GAO Shi-han(Beijing Jingtou Xingye Estate Co.,Ltd.,100097,Beijing,China;China Railway Design Corporation,300000,Tianjing,China;China Building Technique Group Co.,Ltd.,100013,Beijing,China)

机构地区：[1]北京京投兴业置业有限公司,北京100097 [2]中国铁路设计集团有限公司,天津300000 [3]中国建筑技术集团公司,北京100013

出　　处：《建筑技术》2022年第2期148-151,共4页Architecture Technology

摘　　要：通过现场对2根等直径桩和2根扩底桩进行竖向抗拔静载荷试验得出U-δ曲线、桩身轴力曲线和桩侧摩阻力分布图。分析U-δ曲线得到等直径桩和扩底桩的极限抗拔承载力和上拔量,得出扩底桩单桩抗拔承载力明显高于等直径桩,且在相同荷载下扩底桩上拔量小于等直径桩的结论。对桩身轴力和桩侧摩阻力进行分析,得出等直径桩和扩底桩桩身受力特性。扩底桩不仅使桩端阻力得到明显提高,还可提高桩顶侧摩阻力,改善桩身结构的受力性状。In this paper, the U-δ curves, axial force curves of test piles and distribution charts of lateral friction resistance of test piles are obtained through the static load tests on 2 normal piles and 2 under-reamed piles. Through the analysis of U-δ curve, the ultimate uplift bearing capacity and uplift amount of the piles are obtained. The uplift bearing capacities of the under-reamed piles are significantly higher than the normal piles, and the uplift amounts of the under-reamed piles are less than the normal piles under the same load. Based on the analysis of axial force and lateral friction,the stress characteristics of the normal piles and the under-reamed piles are obtained. And the underreamed piles not only increases the pile tip resistance, but also increases the pile tip lateral friction resistance, and improves the stress behavior of pile structure.

关 键 词：大直径桩 扩底桩 抗拔承载力 受力形式 

分 类 号：TU74[建筑科学—建筑技术科学]