桥梁挤扩支盘桩受力分析与承载能力研究  

Load Analysis and Bearing Capacity Research of Pile with Branches and Plates for Highway Bridge

作　　者：刘广宇 李勇 孙克强 易绍平[2] 张国梁 LIU Guangyu;LI Yong;SUN Keqiang;YI Shaoping;ZHANG Guoliang(CCCC Highway Consultants Co.,Ltd.,Beijing 100088;Guangdong Road and Bridge Construction Development Co.,Ltd.,Guangzhou 510623;不详)

机构地区：[1]广东省路桥建设发展有限公司,广州510623 [2]中交公路规划设计院有限公司,北京100088 [3]北京支盘地工科技开发中心,北京100049

出　　处：《广东公路交通》2019年第5期42-48,59,共8页Guangdong Highway Communications

摘　　要：围绕广东潮汕环线项目,依托环线高速公路工程开展常规桩以及支盘桩现场试桩试验,对挤扩支盘桩的受力机理进行了研究并分析了挤扩支盘桩的承载性能。结果表明:不同于传统的等截面灌注桩,当挤扩支盘桩支盘腔成孔时,周围土体受到挤压,进一步提升桩周土体的模量以及承载力;同时支盘桩的支盘结构体发挥作用承载,对应的Q-S曲线为缓变型,桩的支盘处轴力有显著变化,呈现多支点端承摩擦桩受力特征,支与盘的荷载分担比可达60%左右;相同土层条件下,极限承载能力明显强于一般的常规桩,同等设计荷载下挤扩支盘桩的桩长更短;支、盘、桩端、桩侧荷载分担比受地质条件、荷载大小影响明显,随着竖向力的增大,支盘力的发挥具有明显的时序性,盘的承载力增长潜力远大于支结构,且由上至下逐步发挥承载作用。Being based on field tests of conventional piles and squeezed branch pile of Chaoshan Loop Line Expressway in Guangdong Province,the bearing characteristics and stress mechanism of squeezed branch pile have been studied by numerical method.The results have shown that,being compared with conventional piles,the deformation modulus and bearing capacity of soil around piles have been improved due to the squeezing effect.The settlement curve of pile with branches and plates has shown slow deformation.The axial force of branches and plates section changes significantly,which presents mechanical characteristics of multi-fulcrum end-bearing friction pile.The load-sharing ratio of branches and plates is about 60%.Under the same soil condition,the vertical bearing capacity of pile is significantly higher than that of conventional pile,and the length of pile can be significantly shortened.The load sharing ratio of branches,plates,pile end and pile side is obviously affected by geological conditions and load size.With the increase of vertical force,the exertion of branches and plates force has obvious time sequence.The bearing capacity growth potential of plates is much larger than that of branch structure and it gradually plays a bearing role from the top to the bottom.

关 键 词：挤扩支盘桩 荷载分担 承载机理 轴力分布 

分 类 号：U445.551[建筑科学—桥梁与隧道工程]