密实砂土中竖向受压PCC桩端阻力计算方法研究  

The Calculation Method of Tip Resistance of PCC Pile Subjected to Vertical Compressive Load in Dense Sand

作　　者：陈亚东[1] 于艳[2] 陆凡 蔡江东[1] 王旭东[3] Chen Yadong;Yu Yan;Lu Fan;Cai Jiangdong;Wang Xudong(Faculty of Architecture and Civil Engineering,Huaiyin Institute of Technology,Huaian,Jiangsu 223001,P.R.China;Jiangsu Huaian Architecture Design Institute Co.,Ltd.,Huaian,Jiangsu 223300,P.R.China;College of Transportation Science&Engineering,Nanjing Tech University,Nanjing 210009,P.R.China)

机构地区：[1]淮阴工学院建筑工程学院,江苏淮安223001 [2]淮安市建筑设计研究院有限公司,江苏淮安223300 [3]南京工业大学交通学院,南京210009

出　　处：《地下空间与工程学报》2020年第3期780-786,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51408254,51708245);江苏省六大人才高峰资助项目(JZ-051);江苏省研究生科研与实践创新计划。

摘　　要：采用基于可视化摄影测量技术的室内试验和理论分析方法,对密实砂土中竖向受压现浇混凝土大直径管桩(PCC桩)桩端土体变形破坏规律及其端阻力估算方法进行研究。结果表明:PCC桩桩端周围土体在极限荷载阶段形成楔形竖向压缩区和侧向剪切变形区,桩端土体竖向位移在相同深度处始终高于等直径实心桩,呈现冲压破坏特征。在此基础上,利用普朗德尔地基理论,构建了考虑地基滑动面角度变化的PCC桩桩端土体破坏模型,给出了桩端阻力的理论计算方法,并通过承载力系数分析以及理论与试验结果的对比,初步验证了计算方法的合理性,为进一步完善与发展PCC桩设计计算理论提供了科学依据。Based on the visualization photogrammetry technology,combined with laboratory test and theoretical analysis method,the sand deformation rules and tip resistance estimation method of the cast-in-place concrete large diameter pipe pile(PCC)are studied under vertical compressive load.It is found that the sand around the pile tip forms a cuneate vertical compression zone and a lateral shear deformation zone at the ultimate loading stage.The vertical displacement beneath the pile tip is still higher than that of the single pile at the same depth and presents the characteristics of stamping failure.Based on the Prandtl bearing capacity theory,the tip resistance failure model is established considering the angle variation of the sand sliding plane.The theoretical calculation method of tip resistance is given,and the rationality of the calculation method is preliminarily verified by the analysis of bearing capacity coefficient and the comparison between theoretical and experimental results.The research results provide a scientific basis for further improving and developing the design and calculation theory of PCC pile.

关 键 词：桩基础 破坏模式 端阻力 计算方法 

分 类 号：TU473[建筑科学—结构工程]