基于BOTDR技术的超长灌注桩承载机理研究

本文结合工程实例，展开了BOTDR光纤传感技术在超长灌注桩检测中的应用研究，分析了其沉降特性和荷载传递机理。试验结果表明：超长灌注桩的荷载一沉降曲线为缓变型，没有明显的沉降拐点；桩身竖向荷载主要由桩侧摩阻力承担，桩端承担比例很小；超长桩的侧摩阻力在桩身中部发挥最佳，桩身下部发挥很小，在超长桩设计中应考虑有效桩长来确定桩的长度。

Research on the bearing mechanism of the super-long pile based on BOTDR

Combined the engineering example, the settlement characteristics and load transfer mechanism of the super-long grouting pile are analyzed by the BOTDR optical fiber sensing in this paper. The results showed that the load-settlement curve of the super-long grouting pile varies slowly with no apparent settlement inflection point; the vertical load is mainly borne by the pile lateral friction and the pile tip bears very little. The optimum lateral friction always occur at the central section of the super-long pile and the lower part is very small, so the effective length should be considered to determine the length of the super-long pile in design.