Y型沉管灌注桩荷载传递机制的现场试验研究  

IN-SITU STUDY ON LOAD TRANSFER MECHANISM OF Y-SHAPED VIBRO-PILE

作　　者：王新泉[1] 陈永辉[1] 刘汉龙[1] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室

出　　处：《岩石力学与工程学报》2008年第3期615-623,共9页Chinese Journal of Rock Mechanics and Engineering

摘　　要：通过在Y型沉管灌注桩桩身埋设钢筋测力计,完整测试路堤填筑过程中及预压期内路堤荷载作用下Y型沉管灌注桩的荷载传递机制,详细介绍钢筋测力计的焊接及埋设方式,对钢筋测力计在混凝土凝固硬化过程中的受力情况进行详细研究。指出数据处理过程中需要对钢筋测力计进行重新标定,详细介绍标定方法。随着填土荷载的增大,不同深度处桩身轴力均呈现增大的趋势,但增加幅度不同,桩身轴力最大点位置随填土荷载增大变化很小,路基进入预压期后桩身轴力仍逐渐增大,但变化幅度逐渐减小。在距离桩顶3.0～6.0 m的区域存在负摩擦,桩侧摩阻力随着填土荷载的增大而增大,测试期间内负摩擦区域始终存在,且负摩擦最大点位置及中性点位置随填土荷载增大变化很小。The load transfer mechanism of Y-shaped vibro-pile in construction and preloading periods of embankment is adequately studied by reinforcement metre. The buried and connected modes of reinforcement metre are introduced in detail. The stress of reinforcement metre during courses of concrete freezing and hardening is studied. The recalibration of reinforcement metre is needed when dealing with test data; and the calibration method is introduced in detail. The test data show that the axial force of pile at any position all increase under embankment load, but the increasing amplitudes are different. The position of the maximum axial force of pile hardly changes. The process of pile-soil load transfer is still not over when the embankment has been preloaded. But the variable amplitude decreases gradually. The negative friction exists in the distance 3.0 to 6.0 m from pile tip. The friction increases with the increase of embankment load. The negative friction exists all the time in testing period; and the position of the maximum negative friction point and neutral point of pile hardly change with the increase of embankment load.

关 键 词：桩基工程 Y型沉管灌注桩 钢筋测力计 荷载传递机制 桩身轴力 负摩擦 

分 类 号：TU473[建筑科学—结构工程]