基于BOTDA的光纤传感技术在抗滑桩变形监测中的应用

Application of Optical Fiber Sensing Technology to Monitoring the Deformation of Slide-resistant Pile Based on BOTDA

针对BOTDA光纤传感技术的特点和工作原理,结合目前滑坡监测的问题和要求,本文首次提出将BOTDA光纤传感技术应用到滑坡抗滑桩的内力监测中,通过在抗滑桩桩体内布置光纤传感器,监测抗滑桩在滑坡推力和混凝土收缩共同作用下的连续变形特征,并结合实例,探讨了光纤监测系统在人工挖孔桩中的建设方式,验证了BOTDA光纤传感技术在抗滑桩变形监测中的可行性和有效性,同时指出该技术在抗滑桩变形监测中应注意的问题。该原位监测手段克服了传统原位桩体内力、应变监测手段精度低、耐久性差、操作繁琐等缺点,具有广泛的应用前景。

This paper introduces the characteristics and working principle of optical fiber sensing technology based on Brilouin optical time-domain analysis （BOTDA）. Combining the problems and requirements of landslide monitoring at present, the paper applies the optical fiber sensing technology to monitoring the in- ternal force of the slide-resistant pile by arranging optical fiber sensors in the slide-resistant pile and moni- toring the continuous deformation of the slide-resistant pile under the effect of landslide thrust. The re sults show that the technology can overcome the shortcomings of low precision,poor durability and tedious operation by the traditional monitoring methods in monitoring the in situ stress and strain in the pile body. And then, by combining a practical case,the paper discusses the construction method of setting up the opti- cal fiber monitoring system in the manual hole digging piles and verifies that it is feasible for BOTDA to be applied to monitoring the slide-resistant pile,and it also puts forward the problems of BOTDA in monito- ring the slide-resistant pile.