劲性复合桩承载性能现场试验研究  

Field test study on bearing capacity of strength composite pile

作　　者：苏刚 陈信升 李志越 戴国亮[2] 邓亚光 SU Gang;CHEN Xinsheng;LI Zhiyue;DAI Guoliang;DENG Yaguang(Nantong Yanglv Railway Development and Construction Co.,Ltd.,Nantong 226601,China;School of Civil Engineering,Southeast University,Nanjing 211189,China;Jiangsu Hengtang Construction Technology Co.,Ltd.,Nantong 226400,China)

机构地区：[1]南通洋吕铁路开发建设有限公司,江苏南通226601 [2]东南大学土木工程学院,江苏南京211189 [3]江苏恒棠建筑科技有限公司,江苏南通226400

出　　处：《甘肃科学学报》2024年第4期76-82,共7页Journal of Gansu Sciences

基　　金：国家自然科学基金面上项目(52078128,52178317)。

摘　　要：劲性复合桩是一种在水泥土桩中植入混凝土管桩的新型桩基础形式,是实现绿色低碳建造的重要技术手段。为研究劲性复合桩在近海地基土层中的承载性能,基于南通市洋吕铁路项目场地开展了劲性复合桩及其对应管桩的竖向和水平静载试验,通过对比劲性复合桩和PHC管桩的现场试验结果,探讨了劲性复合桩的加固机理及变形规律。试验结果表明:劲性复合桩极限承载力提高显著,竖向承载力较PHC管桩提高了48%,其中桩侧阻力最高增幅达58%,桩端阻力仅占比3.75%,属于摩擦型桩;水平承载力提高了50%,桩顶转角稳定;在变形上,劲性复合桩桩头刚度提升明显,且回弹率高\,卸载后残余变形小;此外无论是竖向受荷时的桩侧阻力峰值点还是水平受荷时的桩身弯矩峰值点,劲性复合桩较管桩均呈明显上移,充分发挥了浅层土体的承载性能,在未来工程设计中可采用此桩基形式进一步优化桩长。Strength composite pile is a new type of pile foundation in which concrete pipe piles are embedded in cement-soil piles.It is an important technical means to realize green and low-carbon construction.In order to study the bearing capacity of stiff composite pile in offshore foundation soil,the vertical and horizontal static load tests of strength composite pile and its corresponding pipe pile were carried out based on the site of Nantong Yanglv railway project.By comparing the field test results of strength composite pile and PHC pipe pile,the reinforcement mechanism and deformation law of stiff composite pile were discussed.The results show that the ultimate bearing capacity of the composite pile is significantly improved,and the vertical bearing capacity is 48%higher than that of the PHC pipe pile.The maximum increase of the pile side resistance is 58%,and the pile tip resistance is only 3.75%,which belongs to the friction pile.The horizontal bearing capacity is increased by 50%,and the rotation angle of pile top is stable.In terms of deformation,the stiffness of the rigid composite pile head is obviously improved,and it has the characteristics of high rebound rate and small residual deformation after unloading.In addition,whether it is the peak point of pile side resistance under vertical load or the peak point of pile bending moment under horizontal load,the rigid composite pile is obviously higher than the pipe pile,which gives full play to the bearing capacity of shallow soil.In the future engineering design,this pile foundation form can be used to further optimize the pile length.

关 键 词：劲性复合桩 现场试验 极限承载力 桩侧阻力 桩身弯矩 

分 类 号：TU473.1[建筑科学—结构工程]