应用光纤传感技术进行岩溶塌陷监测预报的关键问题探讨

A discussion on the key technical problem in monitoring and predicting sinkhole with optical fiber sensing(BOTDR) technique

在总结上世纪80年代以来岩溶塌陷监测预报方法的基础上,从岩溶塌陷自身特点和光纤传感技术监测原理出发,对目前光纤传感技术应用于岩溶塌陷监测预报急需解决的关键技术问题进行了探讨分析,主要包括环境温度影响、光纤敷设和预报模型建立三个方面。光纤本身的光学特性决定环境温度变化会影响光纤的变形测量,其解决办法主要是进行温度补偿和监测数据修正处理;光纤敷设,主要是解决光纤与岩土体同步变形问题,其办法是通过室内实验确定适宜的胶结剂和最优配比;建立光纤应变与岩土体变形的关系模型是应用光纤传感技术进行岩溶塌陷监测预报的关键,其解决办法为室内模拟实验。

The key technical problem in monitoring and predicting of the sinkhole with optical fiber sensing technology（BOTDR） are summarized and analyzed based on the features of the sinkhole and the principle of BOTDR.The study mainly includes temperature effect,optical fiber laying and model building.The optical fiber deformation by temperature effect can be eliminated by compensating and amendments of the additional temperature sensor.The deform in same pace of optical and soil can be solved by the laying way,and the jointing compound and the proportion are the key factors.The core of monitoring and predicting of the sinkhole by optical fiber sensing technique is to build a strain relation model between optical and soil,it can be achieved by the simulation experiment in the lab.