【摘要】 为了监测松散地层沉降变形,提出了一种用于钻孔中植入式光纤Bragg光栅传感器(FBG)的结构和传感网络系统。基于室内实验结果,给出了用于岩层变形检测的传感光栅波长带宽为6nm,分析了多点传感信号分辨因子,由光源带宽决定的测试系统最大实际复用能力为6个传感器。设计并实现了一个由18个光纤光栅组成的具有特色的光纤Bragg光栅波分复用/空分复用混合阵列。工程实践表明,光纤光栅传感系统采用双回路布置,可提高系统下放后光纤光栅传感器的成活率。更多还原

【Abstract】 In order to monitor the subsidence and deformation of the unconsolidated strata,a monitoring structure with fiber Bragg grating(FBG) sensors embedded in the borehole and the sensing network system are proposed.With the results from laboratory,the 6 nm wavelength bandwidth of the FBG sensors used for rock strata deformation monitoring is presented.By analyzing the signal resolution factor of the multi-point sensor,the maximum practical six-channel multiplexing of the testing system determined by dominated optical source bandwidth has been researched.A distinctive FBG array composed of 18 FBGs based on wavelength division multiplexing/spatial division multiplexing is designed and implemented.Engineering practice shows the double-loop design can improve the survival rate of FBGs in mines.更多还原