Coal rock stress inversion monitoring system and method for stope face

Abstract

The invention provides a coal rock stress inversion monitoring system and method for a stope face. The system comprises a seismic source device, a seismic source operation track, a seismic source receiver and a ground monitoring center. The ground monitoring center is used for controlling the seismic source equipment to move in the roadway of the stope face along the seismic source operation track and controlling the seismic source equipment to emit seismic source signals to the stope coal rock wall at intervals in the roadway at a preset frequency on the stope face; the seismic source receiver is used for sequentially receiving seismic source signals in a roadway; and the ground monitoring center is used for generating a grid model of the stope face according to the spatial data of the stope face, performing stress inversion operation according to the received seismic source signal and the grid model of the stope face, and generating stress nephogram data of the stope face. Therefore, according to the scheme, clear stress distribution in the coal rock mass can be obtained, accurate identification and division of a high stress concentration area are facilitated, and an important basis is provided for prediction and prevention of rock burst.

Description

Technical Field

[0001] The present application relates to the technical field of coal mining, and in particular to a coal rock stress inversion monitoring system and method for a mining working face. Background Art

[0002] Rock burst refers to the sudden stress release in underground rocks or soil during the construction of tunnels, mines and other projects. This stress release will cause an instantaneous increase in ground pressure, posing a safety hazard to the project construction. Therefore, rock burst stress monitoring is an important safety measure. Rock burst stress monitoring is an important link in underground mining such as coal mines. It is of great significance to prevent rock burst disasters and ensure mine safety. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the first purpose of this application is to propose a coal rock stress inversion monitoring system for a mining face.

[0005] The second purpose of this application is to propose a coal rock stress inversion monitoring method for a mining face.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application proposes a coal rock stress inversion monitoring system for a mining face, comprising: a seismic source device, a seismic source running track, a seismic source receiver and a ground monitoring center; the ground monitoring center is used to control the seismic source device to move along the seismic source running track in the tunnel of the mining face, and control the seismic source device to transmit seismic source signals to the mining coal rock wall at intervals in the tunnel at a preset frequency; the seismic source receiver is used to receive the seismic source signals in sequence in the tunnel; the ground monitoring center is used to generate a grid model of the mining face according to the spatial data of the mining face, and perform stress inversion operations according to the received seismic source signals and the grid model of the mining face to generate stress cloud map data of the mining face.

[0007] To achieve the above-mentioned purpose, the second aspect of the embodiment of the present application proposes a coal rock stress inversion monitoring method for a mining working face, comprising: controlling the seismic source to transmit seismic source signals to the mining coal rock wall at intervals in the tunnel at a preset frequency at the mining working face; receiving the seismic source signals emitted by the seismic source in sequence based on the seismic source receiving sensor in the tunnel; generating a grid model of the mining working face based on the spatial data of the mining working face; performing stress inversion operation based on the received seismic source signal and the grid model of the mining working face to generate stress cloud map data of the mining working face.

[0008] The coal rock stress inversion monitoring system and method for the mining face provided in the present application, by using the ground monitoring center to control the movement of the source equipment in the tunnel, and transmit the source signal at a set frequency interval, and then the source receiver receives the source signal sent by the source equipment. Further, the received source signal is sent to the ground monitoring center, and the ground monitoring center performs stress inversion operation on the source signal to obtain the stress cloud map data of the mining face. The stress inversion operation can provide a high-resolution stress distribution image, so that the stress state inside the coal rock body can be clearly presented, which is helpful to accurately identify and divide the high stress concentration area, and provide an important basis for the prediction and prevention of rock burst. Based on the stress cloud map data to reveal the stress change trend, a real-time warning state can be achieved, which can effectively avoid the harm of rock burst to coal mine production, and provide more accurate technical support for the prevention and control of rock burst during coal mining.

[0009] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0011] Figure 1 A schematic diagram of the structure of a coal rock stress inversion monitoring system for a mining working face provided in an embodiment of the present application;

[0012] Figure 2 A schematic diagram of the structure of another coal rock stress inversion monitoring system for a mining working face provided in an embodiment of the present application;

[0013] Figure 3 A schematic diagram of an electromagnetic controllable vibrator provided in an embodiment of the present application;

[0014] Figure 4 A schematic diagram of the structure of the coal rock stress inversion monitoring system provided in the embodiment of the present application;

[0015] Figure 5 A schematic flow chart of a coal rock stress inversion monitoring method for a mining working face provided in an embodiment of the present application;

[0016] Figure 6 A schematic diagram of displaying a source signal provided in an embodiment of the present application;

[0017] Figure 7 A schematic diagram of the stress cloud map data provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0019] The following describes the coal rock stress inversion monitoring system and method for the mining working face in an embodiment of the present application with reference to the accompanying drawings.

[0020] Figure 1 FIG. 1 is a schematic diagram of a structure of a coal rock stress inversion monitoring system for a mining working face according to an exemplary embodiment. Figure 1 As shown, the coal rock stress inversion monitoring system 100 for the mining working face includes:

[0021] Seismic source equipment 101, seismic source operating track 102, seismic source receiver 103 and ground monitoring center 104.

[0022] The ground monitoring center 104 is used to control the seismic source device 101 to move along the seismic source running track 102 in the tunnel of the mining face, and control the seismic source device 101 to transmit seismic source signals to the mining coal rock wall at intervals in the tunnel at a preset frequency at the mining face.

[0023] The seismic source receiver 103 is used to sequentially receive seismic source signals in the tunnel.

[0024] The ground monitoring center 104 is used to generate a grid model of the mining face according to the spatial data of the mining face, and perform stress inversion calculation according to the received source signal and the grid model of the mining face to generate stress cloud map data of the mining face.

[0025] In some implementations, multiple seismic source emission points can be determined in advance in the tunnel of the mining face, and the seismic source receivers 103 can be installed at the seismic source emission points. That is, the seismic source device 101 is controlled by the ground monitoring center 104 to move in the tunnel of the mining face, and when it moves to the seismic source emission point, the seismic source signal is emitted to the mining coal rock wall, and the seismic source receiver 103 can receive the seismic source signal.

[0026] Optionally, the source receiver 103 can be set on the other side of the source device 101 transmitting the source signal, that is, the source device 101 transmits the source signal at the source transmitting points marked in the tunnel in turn, and the source receiver 103 in the tunnel on the other side receives the source signal in turn, and uploads the source signal to the ground monitoring center 104. When the source receiver 103 completes the transmission of all the source signals in the tunnel, it notifies the ground monitoring center 104 to perform stress inversion calculation. Among them, the source device 101 and the source receiver 103 are strictly time synchronized.

[0027] Optionally, the seismic source running track 102 may be installed in the tunnel, and the location of the seismic source emission point may be determined according to set intervals, so that the seismic source device 101 can move in the tunnel and emit seismic source signals at intervals.

[0028] Optionally, the source running track 102 can be arranged in double layers in the vertical direction of the roadway, and the ground monitoring center 104 can receive the source signals of the upper and lower layers of the mining face to generate stress cloud map data that can three-dimensionally display the mining face. By measuring and inverting the upper and lower layers of the mining face roadway, it is possible to achieve no-dead-angle monitoring, monitor the full-cycle production process of the mining face, and provide more accurate technical support for the prevention and control of rock burst during coal mining.

[0029] By way of example, a seismic source emission point may be marked every 100 meters in the return air tunnel of the mining face, and according to the tunnel height, two seismic source operating tracks 102 may be installed along the tunnel direction from 1 / 3 of the tunnel height from the bottom plate and 1 / 3 of the tunnel height from the top plate, so that the seismic source device 101 may move along the seismic source operating tracks 102 in the tunnel of the mining face.

[0030] In some implementations, the ground monitoring center 104 can send a control command to the seismic source device to control the seismic source device 101 to move along the seismic source operating track 102 in the tunnel of the mining face, and transmit seismic source signals to the mined coal rock wall at intervals in the tunnel at a preset frequency at the mining face.

[0031] In some implementations, when the seismic source device 101 completes signal transmission in the tunnel, the seismic source receiver 103 can upload the received seismic source signal to the ground monitoring center 104, and the ground monitoring center 104 can perform stress inversion based on the received seismic source signal to determine the stress cloud map data of the mining face.

[0032] In some implementations, a grid model of the mining face can be first established based on the spatial data of the mining face, and the grid model can be used to perform stress inversion operations based on the seismic source signal to obtain stress cloud map data of the mining face.

[0033] Optionally, after obtaining the stress cloud map data, the accuracy of the stress cloud map data can be determined, and it can be judged whether the accuracy of the stress cloud map data reaches the set target accuracy. If the target accuracy is reached, the stress cloud map data can be displayed; if the target accuracy is not reached, the stress cloud map data can be recalculated until the accuracy of the stress cloud map data reaches the target accuracy.

[0034] The coal rock stress inversion monitoring system for the mining face provided in the embodiment of the present application controls the movement of the source device in the tunnel by using the ground monitoring center, and transmits the source signal at a set frequency interval, and then the source receiver receives the source signal sent by the source device. Further, the received source signal is sent to the ground monitoring center, and the ground monitoring center performs stress inversion operation on the source signal to obtain the stress cloud map data of the mining face. The stress inversion operation can provide a high-resolution stress distribution image, so that the stress state inside the coal rock body can be clearly presented, which is helpful to accurately identify and divide the high stress concentration area, and provide an important basis for the prediction and prevention of rock burst. Based on the stress cloud map data to reveal the stress change trend, a real-time warning state can be achieved, which can effectively avoid the harm of rock burst to coal mine production, and provide more accurate technical support for the prevention and control of rock burst during coal mining.

[0035] Figure 2 FIG. 1 is a schematic diagram of a structure of a coal rock stress inversion monitoring system for a mining working face according to an exemplary embodiment. Figure 2 As shown, the coal rock stress inversion monitoring system 200 of the mining working face includes: a seismic source device 201, a seismic source running track 202, a seismic source receiver 203 and a ground monitoring center 204.

[0036] In some implementations, the source device 201 includes an electromagnetic controllable seismic source 2011 and a seismic source controller 2012. The ground monitoring center 204 is connected to the seismic source controller 2012. That is, the seismic source controller 2012 is used to receive control commands from the ground monitoring center 204, and control the electromagnetic controllable seismic source 2011 to generate a seismic source signal based on the control command, thereby controlling the seismic source signal to be emitted in the tunnel at a preset frequency at the mining face.

[0037] In some implementations, by using the electromagnetic controllable seismic source 2011 as the seismic source, the waveform it excites can be controlled by humans, and the excitation waveform with a known time function relationship is sent into the underground for a long time, that is, a controllable small-energy, long-time excitation wave is used to achieve the high-energy excitation wave generated instantaneously by the impact seismic source.

[0038] like Figure 2 The coal rock stress inversion monitoring system 200 for the mining face shown in the figure also includes: a seismic source transmitter 205, a seismic source control cable 206, a communication cable 207, a centralized control substation 208, a fiber optic ring network 209 and a fiber optic ring network switch 210.

[0039] Among them, the source controller 2012 and the source transmitter 205 are connected to the centralized control substation 208 through the source control cable 206.

[0040] The centralized control substation 208 is connected to the ground monitoring center 204 via the optical fiber ring network 209 and the optical fiber ring network switch 210 .

[0041] The source receiver 203 is connected to the centralized control substation 208 via a communication cable 207 .

[0042] That is, the source receiver 203 receives the source signal emitted by the source transmitter 205, and can upload the source signal to the centralized control substation 208 based on the communication cable 207. Further, the centralized control substation 208 uploads the received source signal to the ground monitoring center 204 through the optical fiber ring network 209 and the optical fiber ring network switch 210, so that the ground monitoring center 204 performs stress inversion calculation based on the source signal to obtain stress cloud map data.

[0043] In some implementations, the seismic source transmitter 205 and the seismic source receiver 203 have a strict clock synchronization mechanism. The seismic source transmitter 205 records the time when the seismic source transmits the signal, and the seismic source receiver 203 receives the seismic source signal and compares it with the time when the seismic source transmits the signal recorded by the seismic source transmitter 205 to obtain the time difference of signal propagation.

[0044] In some implementations, the ground monitoring center 204 generates a control command and transmits the control command to the centralized control substation 208 based on the fiber optic ring network 209 and the fiber optic ring network switch 210. The centralized control substation 208 sends the control command to the seismic source controller 2012 based on the seismic source control cable 206 to control the electromagnetic controllable seismic source 2011 to generate a seismic source signal, thereby using the seismic source transmitter 205 to transmit the seismic source signal.

[0045] In some implementations, the centralized control substation 208 receives control commands from the ground monitoring center 204, and then controls the operation and stop of the electromagnetic controllable vibrator 2011 through the source controller 2012. The centralized control substation 208 supports up to 48 source receivers 203, and can ensure absolute time synchronization of all source receivers 203 and source transmitters 205.

[0046] In some implementations, Figure 2 The coal rock stress inversion monitoring system 200 for the mining face shown in the figure also includes: a wireless signal transmitter 211, a wireless signal base station 212 and a wireless signal substation 213. The wireless signal transmitter 211 is connected to the wireless signal base station 212, the wireless signal base station 212 is connected to the wireless signal substation 213, and the wireless signal substation 213 is connected to the centralized control substation 208 via the source control cable 206.

[0047] Optionally, the wireless signal transmitter 211 transmits a wireless signal, which is transmitted to the wireless signal substation 213 via the wireless signal base station 212, and the wireless signal substation 213 uploads the wireless signal to the centralized control substation 208. The centralized control substation 208 transmits the wireless signal to the ground monitoring center 204 via the optical fiber ring network switch 210.

[0048] That is to say, the ground monitoring center 204 is used to receive the wireless transmission signal, and determine the cutting eye position based on the wireless transmission signal, and according to the cutting eye position, determine the real-time working position of the mining working face and the corresponding stress diagram information, so as to fully display the real-time position and stress diagram information of the current mining working face.

[0049] In some implementations, the coal rock stress inversion monitoring system 200 for the mining face further includes: a first display screen 214 and a second display screen 215. The first display screen 214 is an above-ground display screen, and is connected to the ground monitoring center 204, and is used to display stress cloud map data. The second display screen 215 is an underground display screen, and the ground monitoring center 204 transmits at least one of the stress cloud map data and the warning information to the second display screen 215 through the optical fiber ring network switch 210.

[0050] That is, after the surface monitoring center 204 generates stress cloud map data of the mining face, the stress cloud map data can be displayed on the first display screen 214. At the same time, the stress cloud map data can also be transmitted to the second display screen 215 via the optical fiber ring network switch 210 for display, so as to provide early warning information.

[0051] In some implementations, the second display screen 215 can be installed in the tunnels on both sides of the mining working face and at the tunnel entrances, with one display screen installed at a certain distance in each tunnel. The content of each display screen shows three parts: one is the most recent stress cloud map data of the entire tunnel, the second is the change in stress values ​​at the same position for the last 10 times, and the third is early warning information, which displays the level indicators of dangerous areas to protect the safe production of coal mines.

[0052] In some implementations, real-time display of stress cloud map data on large screens in multiple areas above and below the mine can reveal stress change trends, achieve real-time early warning purposes, and effectively avoid the harm of rock bursts to coal mine production.

[0053] In some implementations, the ground monitoring center 204 issues a control command, controls the seismic source device 201 to move along the seismic source running track 202 in the roadway of the mining face based on the seismic source controller 2012, and transmits the seismic source signal to the mining coal rock wall at a fixed distance in the roadway according to the set frequency. The seismic source receiver 203 is installed on the other side of the roadway to sequentially receive the seismic source signal emitted by the seismic source device 201. The seismic source device 201 completes the signal transmission at all the seismic source triggering points in a roadway, and all the seismic source receivers 203 in the roadway on the other side upload all the received seismic source signals to the centralized control substation 208, and the centralized control substation 208 then uploads the collected signals to the ground monitoring center 204 via the optical fiber ring network switch 210. The ground monitoring center 204 performs inversion calculation on the synchronized seismic source signal, generates the stress cloud map data of the working face and displays it on the first display screen 214.

[0054] In some implementations, the electromagnetic controllable seismic source 2011 includes: a moving mechanism 21, a shell 22, and a signal generator 23. The moving mechanism 21 is used to move along the running track in the tunnel of the mining face. The signal generator 23 is used to generate an alternating magnetic field inside the shell 22 to generate a seismic source signal.

[0055] In some implementations, the walking mechanism 21 includes: a lifting ring 1, a walking bearing 1, a cable fastening port, a ball bearing 1, a ball bearing 2, a lifting ring 2, and a walking bearing 2; the signal generator 23 includes: an impact plate fastening hole 1, a spring 1, a spring 2, a magnetic pole plate 1, a magnetic pole plate 2, a spring 3, an impact plate, and a magnetic pole plate 3. Among them, the spring 1 and the spring 2 connect the magnetic pole plate 1 and the magnetic pole plate 2, and the spring 3 connects the impact plate and the magnetic pole plate 3.

[0056] In some implementations, the shell 22 can be the outer shell and inner shell of the electromagnetic controllable seismic source 2011, that is, the outer shell contacts the supporting ball bearing 1, the ball bearing 1 contacts the supporting inner shell, the outer shell is suspended by the lifting ring 1, and the lifting ring 1 is connected to the seismic source running track through the moving bearing 1, the cable fastening port is connected to the outer shell to fix the power cable, the lifting ring 2 suspends the outer shell, and the lifting ring 2 is connected to the seismic source running track through the moving bearing 2.

[0057] like Figure 3 Schematic diagram of the electromagnetic controllable source shown. Figure 3 The invention comprises: a lifting ring 1 (17), a movable bearing 1 (18), a cable fastening opening (19), a ball bearing 2 (20), a lifting ring 2 (21), a movable bearing 2 (22), an impact plate fastening hole 1 (23), an inner and outer shell (24), a spring 1 (25), a spring 2 (26), an outer shell (27), a magnetic pole plate 1 (28), a magnetic pole plate 2 (29), a spring 3 (30), an impact plate (31) and a magnetic pole plate 3 (32), and a ball bearing 1 (33).

[0058] In some implementations, energy can be added to the electromagnetic controllable vibrator 2011 through the vibrator controller 2012, and an interactive magnetic field is generated inside the electromagnetic controllable vibrator 2011, thereby generating a vibration signal, which is transmitted to the coal rock mass through the impact plate (31).

[0059] The coal rock stress inversion monitoring system for the mining face provided in the embodiment of the present application controls the movement of the source device in the tunnel by using the ground monitoring center, and transmits the source signal at a set frequency interval, and then the source receiver receives the source signal sent by the source device. Further, the received source signal is sent to the ground monitoring center, and the ground monitoring center performs stress inversion operation on the source signal to obtain the stress cloud map data of the mining face. The stress inversion operation can provide a high-resolution stress distribution image, so that the stress state inside the coal rock body can be clearly presented, which is helpful to accurately identify and divide the high stress concentration area, and provide an important basis for the prediction and prevention of rock burst. Based on the stress cloud map data to reveal the stress change trend, a real-time warning state can be achieved, which can effectively avoid the harm of rock burst to coal mine production, and provide more accurate technical support for the prevention and control of rock burst during coal mining. The embodiment of the present application uses the seismic source generated by the electromagnetic controllable seismic source as the signal source for stress monitoring inversion. Compared with conventional seismic sources such as explosives, it is non-destructive and will not cause any damage or destruction to the coal rock mass. It is of great significance for protecting the integrity and stability of the coal rock mass.

[0060] Figure 4 Shown is a schematic diagram of the structure of the coal rock stress inversion monitoring system. Figure 4 The invention comprises: an artificial seismic source (1), an artificial seismic source controller (2), an artificial seismic source transmitting sensor (3), an explosion-proof display screen (4), an artificial seismic source control cable (5), an artificial seismic source running track (6), a seismic source receiving sensor (7), a seismic source receiving sensor communication cable (8), a seismic source signal centralized control substation (9), an optical fiber ring network (10), an optical fiber ring network switch (11), a computing center (12), a wireless signal transmitter (13), a wireless signal base station (14), a wireless signal substation (15) and a large screen display center (16).

[0061] The artificial seismic source (1) moves and runs on the artificial seismic source running track (6); the artificial seismic source (1) is connected to the artificial seismic source controller (2) and the artificial seismic source transmitting sensor (3); the artificial seismic source controller (2) and the artificial seismic source transmitting sensor (3) are connected to the seismic source signal centralized control substation (9) through the artificial seismic source control cable (5); the explosion-proof display screen (4) is connected to the seismic source signal centralized control substation (9) through the artificial seismic source control cable (5); the seismic source signal centralized control substation (9) is connected to the optical fiber ring network switch (11) through the optical fiber ring network (10); the ground computing center (1 2) The optical fiber ring network switch (11) is connected to the seismic source signal centralized control substation (9), the ground computing center (12) is connected to the large screen display center (16), the seismic source receiving sensor (7) is connected to the seismic source receiving sensor communication cable (8), the seismic source receiving sensor communication cable (8) is connected to the seismic source signal centralized control substation (9), the wireless signal transmitter (13) transmits the signal to the wireless signal substation (15) via the wireless signal base station (14), and the wireless signal substation (15) is connected to the seismic source signal centralized control substation (9) via the artificial seismic source control cable (5).

[0062] Figure 4 The process of performing stress inversion in the coal rock stress inversion monitoring system shown in the figure to obtain stress cloud map data is as follows: the ground computing center (12) issues a control command to control the artificial seismic source (1) through the artificial seismic source controller (2) along the artificial seismic source running track (6) at a specified frequency in the mining working face to transmit the seismic source signal at a fixed interval in the tunnel on the mining coal rock wall, and the seismic source receiving sensor (7) is installed on the other side of the mining tunnel to receive the seismic source signal emitted by the artificial seismic source (1) in turn. The artificial seismic source (1) completes the detection of all trigger points in a tunnel. The signal is transmitted, and all sensors in the tunnel on the other side upload all received seismic source signals to the control substation (9). The control substation (9) then uploads the collected signals to the ground computing center (12) via the optical fiber ring network switch (11). The ground computing center (12) performs inversion calculation on the synchronized seismic source signals, generates stress cloud map data of the working face and displays it on the large screen display center (16). At the same time, the stress cloud map data of the working face is transmitted to the explosion-proof display screen (4) underground via the optical fiber ring network switch (11) for display, thereby improving the early warning information.

[0063] A wireless signal transmitter (13) is installed on the crusher at the end of the working surface. The signal emitted by the wireless signal transmitter (13) is transmitted to the wireless signal substation (15) via the wireless signal base station (14). The wireless signal substation (15) uploads the signal of the wireless signal transmitter (13) to the control substation (9). The control substation (9) then uploads the collected signal to the ground computing center (12) via the optical fiber ring network switch (11). The ground computing center (12) calculates the current cutting position and fully displays the real-time position and stress cloud map status of the current working surface.

[0064] Among them, the artificial seismic source (1) refers to the electromagnetic controllable seismic source in the above embodiment, the artificial seismic source controller (2) refers to the seismic source controller in the above embodiment, the artificial seismic source transmitting sensor (3) refers to the seismic source transmitter in the above embodiment, the explosion-proof display screen (4) refers to the second display screen in the above embodiment, the artificial seismic source control cable (5) refers to the seismic source control cable in the above embodiment, the artificial seismic source running track (6) refers to the seismic source running track in the above embodiment, the seismic source receiving sensor (7) refers to the seismic source receiver in the above embodiment, the seismic source receiving sensor communication cable (8) refers to the communication cable in the above embodiment, the seismic source signal centralized control substation (9) refers to the centralized control substation in the above embodiment, the ground computing center (12) refers to the ground monitoring center in the above embodiment, and the large screen display center (16) refers to the first display screen in the above embodiment.

[0065] Figure 5 FIG. 1 is a flow chart showing a method for inversion monitoring of coal rock stress in a mining face according to an exemplary embodiment. Figure 5 As shown, the coal rock stress inversion monitoring method of the mining working face in the embodiment of the present application includes but is not limited to the following steps:

[0066] S501, control the seismic source to transmit seismic source signals to the mined coal rock wall at intervals in the tunnel at a preset frequency at the mining face.

[0067] In some implementations, multiple seismic source emission points can be determined at set intervals in the tunnel of the mining face to control the seismic source to emit seismic source signals at the seismic source emission points, thereby achieving the emission of seismic source signals to the mining coal rock wall at intervals in the tunnel. Figure 6 What is shown is a schematic diagram of the display of the seismic source signal. For example, a seismic source emission point can be marked every 100 meters in the return air tunnel of the mining face.

[0068] S502, based on the seismic source receiving sensors in the tunnel, the seismic source signals emitted by the seismic sources are received in sequence.

[0069] In some implementations, a source receiving sensor may be provided on the other side of the tunnel to receive the source signal emitted by the source. In other words, the source receiver may be provided on the other side of the tunnel from which the source emits the source signal. When the source emits the source signal at the source emission points marked in the tunnel in turn, the source receiver on the other side may receive the source signal in turn. The source and the source receiver are strictly time synchronized to reduce the deviation of the data.

[0070] S503, generating a grid model of the mining face according to the spatial data of the mining face.

[0071] In some implementations, the mining face can be monitored to obtain spatial data of the mining face, such as the width, length, height, shape and position of the coal wall, and other information. Furthermore, modeling is performed based on the spatial data to obtain a grid model of the mining face.

[0072] Optionally, the mining face can be segmented into different areas based on spatial data, such as compaction area, transition area, uncompacted area and working face, etc. In each segment, the mining face is divided into a series of polygonal grid units of similar size and shape according to the accuracy of spatial data to obtain a grid model, in which the grid unit represents the actual position of the mining face.

[0073] S504, performing stress inversion calculation according to the received seismic source signal and the grid model of the mining face to generate stress cloud map data of the mining face.

[0074] In some implementations, the stress inversion operation includes performing forward calculations using a mesh model of the mining face, and performing inversion calculations based on the forward calculation results to obtain stress cloud map data of the mining face. The forward calculation mainly uses a ray tracing method to calculate the propagation path and travel time of seismic waves from the source to the source receiver.

[0075] That is to say, the source signal can be used as a ray, and forward calculation can be performed based on the grid model of the mining face and the source signal to obtain the calculated travel time of the ray. Optionally, the calculation formula for calculating the travel time is as follows:

[0076]

[0077] Among them, T theoi represents the calculated travel time, n represents the number of travel times, m represents the number of grid units, and u j represents the slowness of the jth grid, L ij Represents the ray length of the i-th ray in the j-th grid.

[0078] Furthermore, stress inversion can be performed based on the calculated travel time to obtain stress cloud map data, and determine whether the stress cloud map data reaches the set calculation accuracy. If the accuracy is greater than or equal to the set accuracy, the calculated stress cloud map data can be used as the stress cloud map data of the mining working face.

[0079] That is to say, stress inversion operation is performed according to the received seismic source signal and the grid model of the mining face, the settlement result of the grid unit in the grid model is obtained, and the calculation accuracy of the calculation result is determined. In response to the calculation accuracy of the calculation result being lower than the set calculation accuracy, the control seismic source is returned to execute the transmission of seismic source signals to the mining coal rock wall at intervals in the tunnel at a preset frequency in the mining face and the subsequent inversion operation, until the accuracy of the calculation result of the inversion operation is greater than or equal to the set accuracy, and the stress cloud map data of the mining face is obtained. Figure 7 Schematic diagram of the stress contour data shown.

[0080] In some implementations, the settlement result of the grid cell includes the slowness value of the grid cell, that is, the slowness value of the grid cell can be calculated as a process of stress inversion operation. Optionally, by taking the source signal as a ray, the ray lengths of each of the n rays passing through the grid cell in the grid model and the total ray length of the grid cell are obtained, where n is a positive integer.

[0081] Further, the calculated travel time and measured travel time of the mth ray passing through the grid unit are obtained, where m is a positive integer and m≤n. Optionally, the calculated travel time of the mth ray can be determined based on the above formula (1).

[0082] Furthermore, the travel time error corresponding to the mth ray assigned to the grid cell can be determined based on the ray length of the mth ray, the calculated travel time and the measured travel time, and the total ray length. m , calculate the travel time as T m ', the measured travel time is T m , the total ray length is L m , then the travel time error ε m =(T m -T m ')l m / L m .

[0083] Furthermore, the total travel time error corresponding to the grid cell can be determined based on the travel time error of each ray passing through the grid cell. In other words, the total travel time error of n rays passing through the grid cell is The total ray length is

[0084] Furthermore, the slowness value of the grid cell can be corrected according to the total travel time error and total ray length corresponding to the grid cell to obtain the target slowness value of the grid cell. The correction formula of the target slowness value is as follows:

[0085]

[0086] Among them, S (k+1) Indicates the target slowness value, S k represents the average slowness value, represents the total travel time error, Represents the total ray length, m represents the mth ray, and n represents a total of n rays.

[0087] Optionally, the average slowness value of the grid cell can be determined based on the time distribution and length distribution of the mth ray passing through the grid cell. That is, suppose there are n rays passing through a grid cell, l m is the length of the mth ray passing through the grid unit, and its total ray length is L m , calculate the travel time as T m The time taken by the mth ray to pass through the grid unit is: t m =T m l m / L m , then the total time distribution of n rays passing through the grid unit is t n , the total length is allocated to l n , then the average slowness of the grid unit is: S = t n / l n .

[0088] In some implementations, the slowness values ​​of the grid cells may be repeatedly corrected, and the convergence degree of the slowness values ​​may be determined based on the average error of the slowness values. When the average error is less than a set value, or the average error no longer decreases, the stress cloud map data corresponding to the target slowness value may be determined to be the stress cloud map data of the mining face.

[0089] In some implementations, early warnings can also be issued for different locations in the tunnel based on the stress cloud map data, by determining the detection location in the tunnel and determining the first stress value corresponding to the detection location in the tunnel based on the stress cloud map data.

[0090] Further, the second stress value in the stress cloud map data of the corresponding detection position in the tunnel in the first N monitoring cycles is obtained, where N is a positive integer greater than or equal to 1. Then, the stress change trend of the detection position can be determined based on the first stress value and the N second stress values. Optionally, a difference calculation can be performed based on the first stress value and the second stress value to obtain the stress change trend.

[0091] Furthermore, according to the stress variation trend of the detection position, early warning information of the detection position can be generated, and the early warning information of the detection position can be sent to the ground display screen and the underground display screen.

[0092] The coal rock stress inversion monitoring method of the mining face provided in the embodiment of the present application controls the movement of the seismic source in the tunnel and transmits the seismic source signal at a set frequency interval, and then the seismic source receiver receives the seismic source signal. A grid model is established according to the spatial data of the mining face, and a stress inversion operation is performed based on the seismic source signal and the grid model to obtain the stress cloud map data of the mining face. The stress inversion operation can provide a high-resolution stress distribution image, so that the stress state inside the coal rock body can be clearly presented, which is helpful to accurately identify and divide the high stress concentration area, and provide an important basis for the prediction and prevention of rock burst. Based on the stress cloud map data to reveal the stress change trend, a real-time early warning state can be achieved, which can effectively avoid the harm of rock burst to coal mine production, and provide more accurate technical support for the prevention and control of rock burst during coal mining.

[0093] The collection, storage, use, processing, transmission, provision and application of user personal information involved in this application are in compliance with relevant laws and regulations and do not violate public order and good morals.

[0094] It should be noted that personal information from users should be collected for legitimate and reasonable purposes and should not be shared or sold outside of these legitimate uses. In addition, such collection / sharing should be carried out after receiving the user's informed consent, including but not limited to notifying the user to read the user agreement / user notice and sign the agreement / authorization including authorization of relevant user information before the user uses the function. In addition, any necessary steps should be taken to protect and safeguard access to such personal information data and ensure that others who have access to personal information data comply with its privacy policy and procedures.

[0095] This application is expected to provide an implementation scheme for users to selectively block the use or access of personal information data. That is, this application is expected to provide hardware and / or software to prevent or block access to such personal information data. Once the personal information data is no longer needed, risks can be minimized by limiting data collection and deleting data. In addition, when applicable, personal identifiers are removed from such personal information to protect the privacy of users.

[0096] In the description of the aforementioned embodiments, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0097] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0098] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0099] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0100] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0101] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0102] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0103] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A coal rock stress inversion monitoring system for a mining face, characterized in that: The system includes a seismic source device, a seismic source running track, a seismic source receiver and a ground monitoring center; The ground monitoring center is used to control the seismic source device to move along the seismic source running track in the roadway of the mining working face, and control the seismic source device to transmit seismic source signals to the mining coal rock wall at intervals in the roadway at a preset frequency at the mining working face; The seismic source receiver is used to sequentially receive seismic source signals in the tunnel; The ground monitoring center is used to generate a grid model of the mining face based on the spatial data of the mining face, and perform stress inversion calculations based on the received seismic source signal and the grid model of the mining face to generate stress cloud map data of the mining face.

2. The system according to claim 1, characterized in that The seismic source equipment includes an electromagnetic controllable seismic source and a seismic source controller; The ground monitoring center is connected to the seismic source controller, and the seismic source controller is used to receive control commands from the ground monitoring center and control the electromagnetic controllable seismic source to generate a seismic source signal based on the control commands.

3. The system according to claim 2, characterized in that The system further comprises: Source transmitters, source control cables, communication cables, centralized control substations, optical fiber ring networks and optical fiber ring network switches; The seismic source controller and the seismic source transmitter are connected to the centralized control substation via a seismic source control cable; The centralized control substation is connected to the ground monitoring center via an optical fiber ring network and an optical fiber ring network switch; The source receiver is connected to the centralized control substation via a communication cable.

4. The system according to claim 3, characterized in that The system further comprises: Wireless signal transmitters, wireless signal base stations and wireless signal substations; The wireless signal transmitter is connected to the wireless signal base station, the wireless signal base station is connected to the wireless signal substation, and the wireless signal substation is connected to the centralized control substation via the source control cable; The ground monitoring center is used to receive wireless transmission signals, determine the cutting position based on the wireless transmission signals, and determine the real-time working position of the mining face and the corresponding stress diagram information according to the cutting position.

5. The system according to any one of claims 1 to 4, characterized in that: The system further comprises: a first display screen and a second display screen; The first display screen is an on-well display screen, and is connected to the ground monitoring center, and is used to display the stress cloud map data; The second display screen is an underground display screen, and the ground monitoring center transmits at least one of the stress cloud map data and the warning information to the second display screen through the optical fiber ring network switch.

6. The system according to any one of claims 2 to 4, characterized in that: The electromagnetic controllable vibrator comprises: Walking mechanism, housing and signal generator; The moving mechanism is used to move along the running track in the tunnel of the mining working face; The signal generator is used to generate an alternating magnetic field inside the shell to generate the seismic source signal.

7. A coal rock stress inversion monitoring method for a mining face, characterized in that: Applicable to the system according to any one of claims 1 to 6, the method further comprising: Control the seismic source to transmit seismic source signals to the coal and rock wall at intervals in the roadway at a preset frequency at the mining working face; Based on the seismic source receiving sensors in the tunnel, the seismic source signals emitted by the seismic source are received in sequence; Generating a grid model of the mining working face according to the spatial data of the mining working face; A stress inversion operation is performed based on the received seismic source signal and the grid model of the mining face to generate stress cloud map data of the mining face.

8. The method according to claim 7, characterized in that The step of performing stress inversion calculation according to the received seismic source signal and the grid model of the mining face to generate stress cloud map data of the mining face includes: Performing stress inversion calculation according to the received seismic source signal and the grid model of the mining working face to obtain the settlement results of the grid units in the grid model, and determining the calculation accuracy of the calculation results; In response to the calculation accuracy of the calculation result being lower than the set calculation accuracy, the control source is returned to execute the transmission of source signals to the mined coal rock wall at intervals in the tunnel at a preset frequency at the mining face and subsequent inversion operations until the accuracy of the calculation result of the inversion operation is greater than or equal to the set accuracy, thereby obtaining the stress cloud map data of the mining face.

9. The method according to claim 8, characterized in that The settlement result of the grid unit includes the slowness value of the grid unit. The process of the stress inversion operation includes: Taking the seismic source signal as a ray, obtaining the ray lengths of n rays passing through the grid unit in the grid model and the total ray length of the grid unit, where n is a positive integer; Obtaining the calculated travel time and the measured travel time of the mth ray passing through the grid unit, where m is a positive integer and m≤n; Determine the travel time error corresponding to the mth ray assigned to the grid unit according to the ray length of the mth ray, the calculated travel time and the measured travel time, and the total ray length; Determine a total travel time error corresponding to the grid unit according to the travel time error of each ray passing through the grid unit; The slowness value of the grid cell is corrected according to the total travel time error corresponding to the grid cell and the total ray length to obtain a target slowness value of the grid cell.

10. The method according to any one of claims 7 to 9, characterized in that: The method further comprises: Determining a first stress value corresponding to a detection position in the tunnel according to the stress cloud map data; Obtaining a second stress value in the stress cloud map data of the corresponding detection position in the lane in the first N monitoring cycles, where N is a positive integer greater than or equal to 1; determining a stress change trend of the detection position according to the first stress value and N second stress values; Generating early warning information of the detection position according to the stress change trend of the detection position; The warning information of the detection position is sent to the ground display screen and the underground display screen.

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