FBG-BOTDA联合感测管桩击入土层模型试验研究

发布时间：2018-06-21 11:54

本文选题：打桩 + 布拉格光纤光栅(FBG)　；参考：《岩土力学》2014年S2期

【摘要】：管桩施工过程中常出现桩身裂缝、爆桩等病害。将具有实时动态监测功能的布拉格光纤光栅(FBG)准分布式光纤传感监测技术和具有分布式监测功能的布里渊散射光时域分析技术(BOTDA)联合应用到管桩打入过程中的监测,提出了分布式光纤传感技术数据处理方法,设计了管桩打入过程的模型试验。试验结果表明,FBG传感技术能够较好地动态监测打入过程中桩身应变变化特征,反映桩身不同部位随不同深度应变变化规律;BOTDA分布式光纤传感技术能够较好地监测管桩在打入过程中暂停(接管)状态下桩身应变变化特征;根据应变变化分析管桩受偏心荷载程度,分析管桩是否出现裂缝、破坏等病害,研究管桩打入过程中桩土作用规律。试验结果还表明,FBG联合BOTDA光纤监测技术在管桩打入过程中监测管桩质量具有广阔的技术优势和应用前景。
[Abstract]:In the process of pipe pile construction, cracks in pile body, pile blasting and other diseases often occur. The fiber Bragg grating (FBG) quasi-distributed optical fiber sensing monitoring technology with real-time dynamic monitoring function and Brillouin scattering optical time domain analysis technology (BOTDAA) with distributed monitoring function are jointly applied to the monitoring of pipe pile driving process. The data processing method of distributed optical fiber sensing technology is presented, and the model test of pipe pile driving process is designed. The experimental results show that the FBG sensing technology can better dynamically monitor the strain characteristics of the pile during the penetration process. The distributed optical fiber sensing technology of BOTDA can better monitor the characteristics of strain variation of pipe pile under the condition of suspended (pipe) in the process of driving. According to strain variation, the degree of eccentricity load on pipe pile is analyzed, whether there are cracks or failure of pipe pile is analyzed, and the law of pile-soil action in the process of pipe pile driving is studied. The test results also show that FBG combined with BOTDA optical fiber monitoring technology has broad technical advantages and application prospects in monitoring the quality of pipe piles during the driving process.
【作者单位】：南京大学地球科学与工程学院;无锡山水城规划建设局;
【基金】：国家自然科学基金重点项目(No.41230636) 国家科技支撑计划(No.2012BAK10B05)
【分类号】：TU753.3

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