Development And Application Of Mining Stress Monitoring System Of Surrounding Rock In Roadway Based On Fiber Bragg Grating Borehole Stress Meter

In safe mining of coal mine,the research on the stress state of rock mass is very important to revealling the distribution characteristics and evolution rules of surrounding rock and studying the dynamic disaster and the support design of roadway.Based on a main idea that sensor and sensing system should be designed before field application and evaluation,fiber Bragg grating borehole stress meter were designed,fiber Bragg grating mining stress monitoring system were developed,applied and evaluated.Combined with the principles and characteristics of FBG,a mechanical model of the interaction between borehole stressmeter and surrounding rock was established and mechanism was deduced theoretically.To improve the monitoring accuracy,initial stress and the expansion performance of stressmeter should be increased.Additionally,by designing a kind of tubular and cystic structural FBG borehole stressmeter and carrying out performance tests,the defects that insufficient initial stress and expansion performance were proved.At the same time,in view of the two above,a better grading combination structural stressmeter was created.In order to improve the sensing efficiency,a new fiber Bragg grating pressure gauge which consists of a diaphragm and connecting rod was designed which had good linearity and repeatability after being tested.According to the above studied,a FBG mining stress monitoring system was developed.To be more open,integrated and intelligent,multi-platform and model of the system were designed.The system consisted of hardware and software systems and had the characteristics of multifunctional real time data display and historical information query.Applied in abutment pressure monitoring of roadway surrounding rock,the system can obtain stress data.Besides,the pressure distribution curves of roadway surrounding rock were simulated and the results compared with field application showed that pressure distribution trends are similar and rules are close.In view of these conclusions,the design of system is reasonable,reliable and practical.It achieves the expected results and operates successfully.