Roadway surrounding rock stress monitoring device based on fiber bragg grating sensing

Abstract

The invention discloses a roadway surrounding rock stress monitoring device based on fiber bragg grating sensing. Grooves are symmetrically carved in a metal rod along the axial center, an FBG set is fixedly installed inside each groove, FBGs serve as sensitive elements, when roadway surrounding rock is deformed, the stress of the surrounding rock will be changed, therefore, force is generated through the metal rod, surface micro-deformation is generated, the grating distances of the FBGs attached to the metal rod are changed along with the metal rod, the center reflection wavelength of the FBGs can be caused to generate drifting, wavelength signals are demodulated into electrical signals through an FBG interrogator, and the stress situations of different sites can be obtained. The roadway surrounding rock stress monitoring device has the advantages that installation is easily achieved, and the roadway surrounding rock stress monitoring device is suitable for wide popularization; power is not required to be supplied to the working face end, and site safety is guaranteed; all-optical measurement and fiber transmission are adopted, and influences of electromagnetic interference are effectively avoided; the temperature error is compensated, and the accuracy is improved; the surrounding rock stress monitoring results can be timely and accurately provided, and guidance on site production and scientific research is facilitated.

Description

technical field [0001] The invention relates to a coal mine roadway surrounding rock stress monitoring device, in particular to a roadway surrounding rock stress monitoring device based on optical fiber grating sensing. Background technique [0002] In recent years, among all kinds of coal mine accidents in my country, accidents caused by surrounding rock disasters have remained high, and have seriously destroyed roadways, transportation and ventilation systems. With the increasing depth of coal mining, surrounding rock disasters have become more serious. Rock disasters have become an important factor affecting the safety of coal mine production. In order to ensure the stability of the roadway surrounding rock and prevent surrounding rock accidents from affecting safe production, the existing coal mines usually support the roadway immediately after excavation, and more and more attention is paid to the monitoring of the surrounding rock stress. The requirements for reliabili...

AI Technical Summary

Problems solved by technology

[0003] However, the existing mine roadway surrounding rock monitoring technology is highly dependent on a certain special purpose or equipment, and basically belongs to the traditional safety monitoring technology.

For example, although strain gauge type force-measuring metal rods and hydraulic metal rod dynamometers have different advantages, the most critical problem is that the data monitored by these devices is actually the force status of the metal rods, not the roadway surroundings. Actual stress state of rock

At the same time, there are various shortcomings in these devices. The specific manifestations are: the use of manual intermittent observation and collection, the monitoring results lag behind and the data obtained have large errors; processing; susceptible to electromagnetic interference and underground wet environment, low reliability; monitoring efficiency is not high, sensing element life is short; remote monitoring cannot be carried out, and real-time online monitoring and long-term monitoring cannot be realized

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