In-situ mining-induced stress monitoring method and device for underground workface of coal mine

Abstract

The invention provides an in-situ mining-induced stress monitoring method and device for an underground workface of a coal mine. The device comprises a stress meter which is arranged in a filling drilling hole; the drilling hole is filled with solid filling materials which are prepared by solidifying liquid with flowability; the stress meter is connected with a fiber static demodulating instrument for measuring the stress through an optical fiber. According to the method and the device, the traditional passive pressure measuring method is replaced; the pressure is actively borne by a manner of completely coupling with the surrounding rock; the obtained stress value is the true mining-induced stress value; the stress values of different fiber stress sensors can be compared as the same type, so as to provide true and valid data to the mining-induced stress monitoring of the workface.

Description

technical field [0001] The invention relates to the field of mining stress monitoring of an underground working face of a coal mine, in particular to an in-situ mining stress monitoring method and device for an underground working face of a coal mine. Background technique [0002] At present, the general method is to drill holes in front of the working face and arrange drilling stress gauges to monitor the mining stress of the working face. The method is to drill a borehole with a certain depth slightly larger than the diameter of the borehole stress gauge on the advanced working face, and place the borehole stress gauge into the bottom of the borehole. By presetting a certain initial pressure, the top of the stress gauge is in contact with the coal wall. During the mining process, when affected by the mining of the working face, the stress is transmitted to the surface of the stress gauge through the coal wall, reflecting the incremental change of the mining stress. , and ...

AI Technical Summary

Problems solved by technology

By presetting a certain initial pressure, the top of the stress gauge is in contact with the coal wall. During the mining process, when affected by the mining of the working face, the stress is transmitted to the surface of the stress gauge through the coal wall, reflecting the incremental change of the mining stress. , and the current drilling stress gauge measurement method, due to the difference in the initial pressure of different drilling stress gauges, and because the stress drilling is usually not sealed, the hole forming time of each hole is different, resulting in the hole wall There are different ranges of plastic zones around, making the stress values ​​of different measuring points incomparable, which can only reflect the relative change process, and cannot reflect the real mining stress change of the coal body

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