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
苏刚 1陈信升 2李志越 2戴国亮 2邓亚光3
作者信息
- 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
- 折叠
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.
Abstract
Strength composite pile is a new type of pile foundation in which concrete pipe piles are embed-ded 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 hori-zontal 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 dis-cussed.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 characteris-tics 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 ca-pacity of shallow soil.In the future engineering design,this pile foundation form can be used to further opti-mize 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Key words
Strength composite pile/Field test/Ultimate bearing capacity/Side friction/Pile bending mo-ment引用本文复制引用
基金项目
国家自然科学基金面上项目(52078128)
国家自然科学基金面上项目(52178317)
出版年
2024
NETL
NSTL
万方数据