钻孔植入光纤Bragg光栅检测岩层变形的模拟实验

Simulation Experiment of Embedded Fiber Bragg Grating Monitoring in Rock Deformation Through Borehole

为了探索煤矿岩层变形的钻孔光纤检测方法,采用物理相似材料模型模拟岩层的压缩和沉降过程,设计并制作一个埋入3个光纤Bragg光栅传感器的水泥砂浆预制棒,用于模拟钻孔。测试了岩层压缩沉降变形过程中水泥砂浆预制棒的变形和由此引起的光纤Bragg光栅波长变化,并与对应位置的应变片监测结果进行了对比分析。实验表明,光纤光栅传感器具有精度高、可靠及耐久等优点,能实现岩层变形的实时监测,钻孔植入式光纤Bragg光栅传感系统为岩层变形监测提供了一种有效的方法。

To explore the rock deformation in coal mine by the monitoring of embedded fiber Bragg grating（FBG） through deep borehole,an experimental physical simulation model was built for simulating the strata compression and subsidence process.Additionally,a prefabricate concrete bar with three embedded FBG sensors was designed to simulate deep borehole,and was placed in the physical model.The deformation of the prefabricate concrete bar during strata compression and subsidence processes was measured by the wavelength changes of FBG sensors,and was compared to the strain changes monitored by a resistance strain gauge located on the prefabricate concrete bar at the same location.The test results show that the FBG monitoring system has the advantages of high sensitive,reliable and stable,etc,and can realize the real-time monitoring of rock deformation.It is proved that the FBG monitoring system is an efficient method for measuring and understanding deformation of deep rock strata through a surface borehole.