CN114737960A - A method of mine active tomography monitoring coal body stress - Google Patents

Abstract

The invention discloses a method for monitoring coal body stress by mining active tomography, relates to the technical field of coal body stress monitoring in a mining process, and can be applied to monitoring and analyzing stress fields such as mine production and the like. The method mainly comprises the following steps: the device comprises an explosion-proof electric spark source, a power switch, a micro-seismic sensor, a cable, a ground host and the like. The anti-explosion electric spark seismic source is arranged in the transportation gate way and connected with a power switch, and the excitation interval and the seismic source energy can be set; the microseism sensor is arranged on the return air gateway and fixed on an anchor rod of the coal side and can receive a signal generated by an electric spark seismic source; the cable is connected with the microseismic sensor and the ground host and is used for signal transmission; the ground host computer comprises a data acquisition instrument and a data analyzer, the data acquisition instrument can acquire data such as a seismic source point coordinate, a seismic origin signal starting time, an arrival time and a microseismic sensor coordinate, and the data analyzer can perform wave velocity inversion to obtain a real-time coal body stress cloud picture. The method has the advantages that the power of the explosion-proof electric spark seismic source is adjustable, real-time monitoring is realized, the change of the stress field of the whole coal bed is reflected, the influence on the coal rock mass is avoided, the coordinates of the seismic source are known, the propagation paths are basically consistent, and the like, so that the reliability of the coal body stress inversion result is improved, and the problem that the traditional stress meter is limited in monitoring is solved.

Description

A method of mine active tomography monitoring coal body stress

technical field

The invention relates to the technical field of coal body stress monitoring in the mining process, in particular to a mine active tomographic imaging monitoring method for coal body stress.

Background technique

With the depletion of shallow resources, the depth of coal mining gradually increases, and the stress of the coal body becomes larger. During the process of pushing and mining at the working face, the stress of the coal body will also increase, and even the rock burst will be induced under the mining disturbance. Therefore, monitoring the stress of the coal body and taking pressure relief measures can help prevent accidents caused when the stress is large. At present, the existing methods for monitoring the stress of coal body generally use a borehole stress meter to monitor the stress of the coal body, but the reliability of the test results is not high due to the broken coal body and the errors caused during installation due to drilling holes; Some researchers use natural sources or blasting sources for inversion, and the stress field of coal can also be obtained. However, due to the limited number of rays generated by natural sources and different energy levels, the location of the source is different, and the source signal will be different in different media. Different degrees of attenuation occur, resulting in low reliability of the inversion results.

Therefore, based on the above, the present invention aims at the shortcomings of the existing monitoring methods, and provides the power of the explosion-proof spark source with adjustable power, real-time monitoring, reflecting the change of the overall coal seam stress field, no influence on the coal and rock mass, known source coordinates, and basic propagation path. Consistent, etc., improve the credibility of the inversion of coal stress results, in order to achieve a more practical purpose.

SUMMARY OF THE INVENTION

In view of the existing problems, the present invention provides a mine active tomography monitoring method for coal body stress, so as to solve the problems raised in the above background technology. In the present invention, the explosion-proof electric spark source can adjust the appropriate power according to the distance between the two parallel grooves, so as to ensure the signal reception without affecting the coal and rock mass; the source coordinates are known, and the source generates the same signal continuously, which is received by the microseismic sensor with the known coordinates. , the propagation path is consistent, which improves the credibility of the result of the wave velocity inversion of the coal body stress field; reflects the overall coal seam stress field change, and solves the problem of the limited monitoring range of the traditional stress gauge; Different to invert the stress field, the stress monitoring results will not be affected by the uneven stress concentration caused by the crushing of the coal body after the pressure relief of the borehole.

To achieve the above object, the present invention provides the following technical solutions:

A mine active tomography monitoring method for stress of coal body, comprising an explosion-proof electric spark source, the explosion-proof electric spark source is connected to a power switch, the explosion-proof electric spark source is arranged in a transport trough, and the explosion-proof electric spark source can be The excitation interval and source energy are set; the signal generated by the spark source is received by the microseismic sensor arranged in the return air channel; the microseismic sensor is fixed on the coal gang with a bolt; the microseismic sensor is connected to the ground by a cable The host is connected to transmit and analyze signals; the ground host is composed of a data acquisition instrument and a data analyzer. The data acquisition instrument can collect the coordinates of the source point, the onset time, arrival time, and coordinates of the microseismic sensor of the source signal, etc. The data analysis instrument can perform wave velocity inversion to obtain a real-time coal mass stress cloud map.

As a further solution of the present invention, the microseismic sensor is connected with the anchor rod through threads, and is anchored on the coal gang.

As a further solution of the present invention, the microseismic sensor is installed in a sleeve prefabricated with an internal thread matching the external thread of the anchor rod.

As a further solution of the present invention, the sleeve is sealed.

The beneficial effect of the invention is that the power of the explosion-proof electric spark source can be adjusted, and the appropriate power can be adjusted according to the distance between the two parallel grooves, so as to ensure that the microseismic sensor can receive the signal without affecting the coal and rock mass; the coordinates of the source of the present invention are known, And it can ensure that the same signal is continuously generated by the seismic source and is received by the microseismic sensor with known coordinates, ensuring that the propagation path is basically consistent, and improving the reliability of the result of the coal body stress field obtained by the wave speed inversion; the present invention can reflect the overall The change of the stress field of the coal seam solves the problem that the monitoring range of the traditional stress meter is limited; the present invention inverts the stress field based on the different propagation speeds of the wave speed in the coal body with different stress, and will not cause uneven stress concentration due to the fragmentation of the coal body after the pressure relief of the drilling. It affects the stress monitoring result; the present invention can obtain the real-time stress field change of the coal body.

Description of drawings

FIG. 1 is a schematic diagram of the layout of the present invention.

FIG. 2 is a schematic diagram of the installation of the microseismic sensor in the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figures 1 and 2, a mine active tomography monitoring method for coal stress includes an explosion-proof spark source, which is connected to a power switch, and the explosion-proof spark source is arranged in a transport trough , the explosion-proof spark source can set the excitation interval and source energy.

The signal generated by the electric spark source is received by the microseismic sensor arranged in the return air slot; the microseismic sensor is fixed on the coal gang with an anchor rod; the tail of the anchor rod has a prefabricated external thread, and the microseismic sensor is installed on a prefabricated Inside the sleeve of the internal thread that matches the external thread of the anchor.

The sleeve is waterproof and sealed to ensure that the microseismic sensor is not damaged and the received signal is stable.

The microseismic sensor is connected with a ground host by a cable for transmitting and analyzing signals; the ground host is composed of a data acquisition instrument and a data analyzer.

The data acquisition instrument can collect data such as the coordinates of the source point, the onset time of the source signal, the arrival time, and the coordinates of the microseismic sensor, and the data analysis instrument can perform wave velocity inversion to obtain a real-time coal mass stress cloud map.

The number of the spark source and the microseismic sensor and the height from the base plate during installation can be adjusted according to the actual situation. After the equipment is arranged, the power of the spark source is adjusted according to the actual situation on site to ensure that all the microseismic sensors can receive signals; Next, test the effect of the signal receiver and signal analyzer. When everything is ready, you can start to generate the coal body stress nephogram.

The working process of the present invention is as follows: when using the present invention, firstly arrange the electric spark source and the microseismic sensor, then connect the cables, debug the effect of the ground signal acquisition instrument and the signal analyzer, and then start to generate the coal body stress field in real time.

The specific working process is: set the power and excitation interval of the spark source. During the mining process, the spark source continuously generates the same signal, which is received by the microseismic sensor through basically the same path, and then uploaded to the data acquisition instrument and data analyzer. , the coal stress field is generated by the wave velocity inversion procedure in the data analyzer. During the mining process, the spark source can continuously generate stable source signals and generate enough rays. The changes in the stress of the coal body will be accurately reflected on the data analyzer through the wave velocity inversion program. Changes in stress take corresponding measures to ensure the safety of production, as well as the safety of underground facilities and personnel.

It will be apparent to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, but that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments are to be regarded in all respects as illustrative and not restrictive, and the scope of the invention is to be defined by the appended claims rather than the foregoing description, which are therefore intended to fall within the scope of the claims. All changes within the meaning and range of the equivalents of , are included in the present invention. Any reference signs in the claims shall not be construed as limiting the involved claim.

In addition, it should be understood that although this specification is described in terms of embodiments, not each embodiment only includes an independent technical solution, and this description in the specification is only for the sake of clarity, and those skilled in the art should take the specification as a whole , the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

Claims (7)

1. A mining active tomography coal body stress monitoring method is characterized in that: the system mainly comprises an anti-explosion electric spark seismic source, a power switch, a micro-seismic sensor, a cable, a ground host and other equipment, wherein the anti-explosion electric spark seismic source is arranged in a transportation crossheading and is connected with the power switch, and an excitation interval and seismic source energy can be set; the microseism sensor is arranged on the return air gateway and fixed on an anchor rod of the coal side and can receive a signal generated by an electric spark seismic source; the cable is connected with the microseismic sensor and the ground host and is used for signal transmission; the ground host computer comprises a data acquisition instrument and a data analyzer, the data acquisition instrument can acquire data such as a seismic source point coordinate, a seismic origin signal starting time, an arrival time and a microseismic sensor coordinate, and the data analyzer can perform wave velocity inversion to obtain a real-time coal body stress cloud picture.

2. The method for monitoring the stress of the coal body by the mining active tomography according to claim 1, wherein the excitation interval is adjustable, the source power is adjustable, and the micro-seismic sensor can receive signals without damaging the coal body.

3. The mining active tomography coal body stress monitoring method as claimed in claim 1, wherein the coordinates of the seismic source point are known, and the accuracy of the inversion result can be improved.

4. The mining active tomography coal body stress monitoring method as claimed in claim 1, wherein a prefabricated external thread is provided at the tail of an anchor rod for fixing the microseismic sensor.

5. The mining active tomography coal body stress monitoring method as claimed in claims 1 and 4, characterized in that the microseismic sensor is installed in a sleeve which is prefabricated with internal threads matching with the external threads of the anchor rod.

6. The mining active tomography coal body stress monitoring method as claimed in claim 5, wherein the sleeve is subjected to water gel sealing treatment.

7. The mining active tomography coal body stress monitoring method as claimed in claim 1, wherein the ground data analyzer has an inversion application program for analyzing data, and can generate a coal body stress cloud picture in real time.

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