FBG应变传感系统在巷道涌水模型试验中的研究

Research of FBG strain system in laneway water inrush model test

针对传统的电类应变传感器防水性能差、测量精度低和不能满足巷道涌水模型试验的需要等问题,基于模型相似材料研制了一种新型光纤光栅(FBG)应变传感器。采用波分复用(WDM)技术和Fabry-Perot(F-P)腔解调技术组成FBG应变传感网络,并编写了具有实时显示和自动预警功能的系统软件。将该系统用在巷道涌水模型试验中,在巷道周围布置了14个FBG应变传感器,对巷道推进过程以及模型加载和巷道扩挖过程中围岩应变进行实时监测。试验结果表明,设计的FBG应变监测系统测量精度高,防水性能强,并且提前4 206 s成功捕获了巷道涌水前兆信息,为预测煤矿矿等涌水事故提供了一种新的有效手段。

Traditional electric strain sensors have poor waterproof performance and low precision,so they are unsuitable for laneway water inrush model test.To solve these problems,a novel fiber-optic grating strain sensor based on similar material to model is developed.The fiber-optic sensing network is established using the wavelength division multiplexing（WDM） technology and F-P demodulating technology,and the software with real-time display and automatic warning is compiled.The system is used in laneway water inrush model test and 14 fiber-optic Bragg grating strain sensors are pre-embedded around the laneway to monitor the strain of surrounding rock in the processes of laneway pushing,model loading and laneway expanding excavation.The results indicate that the presented system has higher precision and is waterproof.Moreover,it can successfully capture the precursory information 4206 s before water inrush.Therefore,it provides a novel and effective approach for forecasting water inrush of mine.