A method and device for detecting a danger zone of a stope face based on direct current method

Abstract

This invention discloses a method and apparatus for detecting impact hazard zones in a longwall mining face based on direct current resistivity. The method includes: setting up a data measurement device in the impact hazard zone of the longwall mining face, including electrodes, measuring lines, and a measurement host; the electrodes are connected sequentially by measuring lines, and the ends of the measuring lines are connected to the measurement host; after selecting the observation device type, the measurement host emits current outward using the power supply electrodes, and the measuring electrodes receive the current emitted by the power supply electrodes, forming a covered measurement range through the emission and reception of current; the measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the current differences received by the measuring electrodes; the apparent resistivity distribution characteristic data within the measurement range is processed according to a three-dimensional resistivity inversion algorithm to obtain the three-dimensional apparent resistivity distribution result within the measurement range; and the impact hazard level within the impact hazard zone of the longwall mining face is determined based on the three-dimensional apparent resistivity distribution result.

Description

Technical Field

[0001] This invention relates to detection technology, and more particularly to a method and apparatus for detecting impact hazard zones in longwall mining faces based on direct current electrical resistivity tomography. Background Technology

[0002] In underground exploration activities, existing methods for detecting impact hazards can be categorized into empirical analogy methods, rock mechanics methods, and geophysical methods. Among these, empirical analogy methods are heavily influenced by human subjectivity and are only applicable to specific production environments. Rock mechanics methods, such as drill cuttings analysis and borehole stress monitoring, have limited monitoring ranges, only monitoring near tunnels, and their warning times are discontinuous. Geophysical methods, such as electromagnetic radiation analysis, acoustic analysis, and microseismic analysis, are complex to maintain and manage, susceptible to external interference, and require highly skilled data analysts.

[0003] It is evident that existing technologies and methods used in underground exploration activities have drawbacks such as limited monitoring range, poor accuracy of detection results, and the potential to cause damage to the objects being explored. Summary of the Invention

[0004] To address the aforementioned technical problems and overcome the shortcomings of existing impact hazard detection technologies, such as limited monitoring range and poor accuracy of detection results, this invention provides a method and device for detecting impact hazard areas in longwall mining faces based on direct current resistivity. This method can calculate and obtain the three-dimensional distribution results of apparent resistivity, thereby determining the impact hazard level within the impact hazard area of ​​the longwall mining face.

[0005] On one hand, embodiments of the present invention provide a method for detecting impact hazard zones in longwall mining faces based on direct current resistivity tomography, the method comprising:

[0006] A data measurement device is installed in the impact hazard zone of the longwall face, including electrodes, measuring lines, and a measurement host. Each electrode is connected in sequence by a measuring line, and the end of the measuring line is connected to the measurement host.

[0007] After selecting the observation device type, the measurement host emits current outward using the power supply electrode, and the measurement electrode receives the current emitted by the power supply electrode. The emission and reception of the current form a covered measurement range, and the measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the difference in the current received by the measurement electrode.

[0008] The apparent resistivity distribution feature data within the measurement range is processed according to the resistivity three-dimensional inversion algorithm to obtain the apparent resistivity three-dimensional distribution result within the measurement range.

[0009] Based on the three-dimensional distribution of apparent resistivity, the impact hazard level within the impact hazard area of ​​the longwall face is obtained using the hazard level calculation formula. The specific steps for determining the impact hazard level within the impact hazard area of ​​the longwall face are as follows:

[0010] Measure the coordinates of the borehole bottom to determine the spatial location of the measurement range; based on the calculated apparent resistivity distribution characteristics within the measurement range, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the hazard level calculation formula Obtain the impact hazard level for each location within the area.

[0011] In the method described in this embodiment of the invention, before setting up data measuring devices on both sides of the impact hazard zone of the longwall face, the method further includes:

[0012] Drill a row of holes on each side wall of the impact hazard zone in the longwall face, place the electrode inside the holes, with the electrode tip exposed: Drilling depth With electrode length The relationship between them is .

[0013] In the method described in this embodiment of the invention, the drilling spacing is set to... meters; the height of the drill hole from the bottom plate is meters; the drilling angle is the same as the horizontal angle. Sloping downwards; the starting point of the borehole is located at a distance from the working face. meters; number of boreholes: The =5, =1, =5°, d=10, =40.

[0014] In the method described in this embodiment of the invention, the starting point of the borehole moves as the working face is mined, and the number of boreholes is adjusted according to the measurement range requirements.

[0015] In the method described in this embodiment of the invention, the observation device is a dipole-dipole device, and the electrodes are arranged at equal intervals in the order of A, B, M, and N.

[0016] In the method described in this embodiment of the invention, during the measurement using the observation device, AB=MN=a, BN=na, and AB, BM, and MN are increased by one electrode spacing point by point to obtain the first oblique sounding profile; then, A, B, M, and N are simultaneously moved by one electrode, and the measurement is repeated to obtain the next profile; this process continues until an inverted trapezoidal profile is obtained; the apparent resistivity of the dipole-dipole device is:

[0017]

[0018] In the formula, The distance between the electrodes. For the number of intervals, Let MN be the potential difference. It represents electric current.

[0019] In the method described in this embodiment of the invention, the three-dimensional resistivity inversion algorithm is the Occam inversion algorithm, and the calculation process is as follows:

[0020] The Occam inversion objective function is:

[0021]

[0022] In the formula, The difference between the measured data and the model forward modeling data. This represents the parameter vector for each node in the model. Here is the Jacobian coefficient matrix. For Lagrange factors, The roughness matrix is ​​represented as follows:

[0023]

[0024] The model parameters are modified by the following formula:

[0025]

[0026] The root mean square error is used to evaluate whether the forward model closely approximates the actual geological conditions. Its expression is:

[0027]

[0028] In the formula, The number of observation data. It is the first Each observation data, to The inversion is stopped when the rate of change is less than 2%.

[0029] In the method described in this embodiment of the invention, the hazard level includes: At that time, there was no risk of impact; At that time, it was a minor impact hazard; At that time, the risk of impact was moderate. At that time, there was a high risk of strong impact.

[0030] On the other hand, embodiments of the present invention also provide a device for detecting impact hazard zones in longwall mining faces based on direct current resistivity methods, comprising:

[0031] A measurement device module is set up to install a data measurement device in the impact hazard zone of the longwall face. The data measurement device includes electrodes, measuring lines, and a measurement host. Each electrode is connected in sequence by a measuring line, and the end of the measuring line is connected to the measurement host.

[0032] The measurement data acquisition module is used to select the observation device type. The measurement host emits current outward using the power supply electrode, and the measurement electrode receives the current emitted by the power supply electrode. The emission and reception of the current form a covered measurement range. The measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the difference in the current received by the measurement electrode.

[0033] The processing module is used to process the acquired apparent resistivity distribution feature data within the measurement range according to the three-dimensional resistivity inversion algorithm to obtain the three-dimensional apparent resistivity distribution result within the measurement range.

[0034] The determination module is used to obtain the impact hazard level within the impact hazard area of ​​the longwall face based on the apparent resistivity three-dimensional distribution results and using the hazard level calculation formula. Specifically, the determination module is used for:

[0035] Measure the coordinates of the borehole bottom to determine the spatial location of the measurement range; based on the calculated apparent resistivity distribution characteristics within the measurement range, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the hazard level calculation formula Obtain the impact hazard level for each location within the area.

[0036] This invention, through the installation of a data measurement device in the impact hazard zone of the longwall face, detects the impact hazard zone based on direct current resistivity and calculates the three-dimensional distribution of apparent resistivity to determine the impact hazard level within the impact hazard zone. This invention offers advantages such as ease of operation, accurate results, and intuitive output.

[0037] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the description, claims, and drawings. Attached Figure Description

[0038] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0039] Figure 1This is a flowchart of a method for detecting impact hazard zones in a longwall mining face based on direct current electrical resistivity, according to an embodiment of the present invention.

[0040] Figure 2 This is a schematic diagram of a method for detecting impact hazard zones in a longwall mining face based on direct current electrical methods, according to an embodiment of the present invention.

[0041] Figure 3 This is a three-dimensional distribution map of apparent resistivity of the method in the embodiments of the present invention;

[0042] Figure 4 This is a horizontal slice of the apparent resistivity along the working surface of the method in this embodiment of the invention;

[0043] Figure 5 This is a vertical slice of the apparent resistivity along the return air duct in the embodiment of the present invention.

[0044] Figure 6 This is a distribution map of the impact hazard level in the impact hazard zone of the mining face in the method of this embodiment of the invention;

[0045] Figure 7 This is a structural diagram of the impact hazard detection device for longwall mining faces based on direct current electrical methods, according to an embodiment of the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0047] The steps illustrated in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in a different order than that presented here.

[0048] Figure 1 This is a flowchart of a method for detecting impact hazard zones in a longwall mining face based on direct current electrical resistivity tomography (DCE) according to an embodiment of the present invention. Figure 1 As shown in the figure, the high-density direct current method (DC method) used in the embodiment of the present invention for detecting the impact hazard zone in the longwall mining face is based on a DC method that has been developed for a long time and is relatively mature. It has been widely used in underground exploration activities such as detecting goaf and water-rich areas. It has advantages such as simple operation, low cost, accurate results, intuitive results, and no damage to the detection object. Furthermore, with the rapid development of resistivity three-dimensional inversion technology, it can accurately obtain the three-dimensional distribution results of apparent resistivity within the detection range, and is suitable for dynamically monitoring the entire process of impact incubation, development, and sudden change in the impact hazard zone of the longwall mining face.

[0049] To achieve the objective of this invention, an embodiment of this invention provides a method for detecting impact hazard zones in a longwall mining face based on direct current resistivity tomography, comprising the following steps:

[0050] Step 100: Set up data measurement devices on both sides of the impact hazard zone of the working face. The data measurement devices include electrodes, measuring lines, and a measuring host. Multiple electrodes are connected in sequence by measuring lines, and the ends of the measuring lines are connected to the measuring host.

[0051] Step 101: Data acquisition is performed to obtain data on the changes in current within the measurement range. The measurement host sequentially supplies power to all electrodes, using the power supply electrodes to emit current, while the other electrodes serve as measurement electrodes to receive the current emitted by the power supply electrodes. The emission and reception of current form a covered measurement range, and the measurement host calculates the data on the changes in current within the measurement range based on the differences in current received by the measurement electrodes.

[0052] Step 102: Perform data processing to obtain the apparent resistivity distribution within the measurement range. Use a mine resistivity three-dimensional inversion program to process the collected current variation data within the measurement range to obtain the apparent resistivity distribution characteristic data within the measurement range.

[0053] Step 103: Determine the impact hazard zone level based on the apparent resistivity distribution characteristic data within the measurement range.

[0054] The invention will now be further described with reference to the accompanying drawings.

[0055] Figure 2 This is a schematic diagram of a method for detecting impact hazard zones in a longwall mining face based on direct current electrical resistivity tomography (DCE) according to an embodiment of the present invention. Figure 2 As shown, 1 represents the working face, 2 represents the detection range, 3 represents the shallow borehole, and 4 represents the coal walls on both sides of the working face.

[0056] like Figure 1 and Figure 2 As shown, a method for detecting rock hazard in a longwall mining face based on high-density direct current resistivity tomography includes the following steps:

[0057] S1. Drill a row of shallow boreholes on each side of the coal face in the impact hazard zone of the longwall face: borehole depth With electrode length The relationship between them is The drilling spacing is meters; the height of the drill hole from the bottom plate is meters; the drilling angle is the same as the horizontal angle. Sloping downwards; the starting point of the borehole is located at a distance from the working face. meters; number of boreholes: The borehole was filled with yellow mud.

[0058] S2. Electrode and measuring line arrangement: Place the electrodes inside the borehole with the electrode ends exposed, and connect all electrodes in sequence with measuring lines. Connect the ends of the measuring lines to the measuring host.

[0059] S3. Data Acquisition: Select the appropriate device type, and the measuring host will supply power to all electrodes in sequence. The electrodes that are supplied with power are called the power supply electrodes. The power supply electrodes emit current, and the remaining electrodes are used as measuring electrodes to receive the current emitted by the power supply electrodes. The emission and reception of current form an approximately semi-circular measuring range. The measuring host calculates the change of current within the measuring range based on the difference in current received by the measuring electrodes.

[0060] S4. Data Processing: The data collected in step S3 is processed using a three-dimensional mine resistivity inversion program to obtain the apparent resistivity distribution within the measurement range;

[0061] S5. Determine the impact hazard zone: Based on the resistivity distribution characteristics within the measurement space obtained in step S4, determine the impact hazard zone level.

[0062] As an optimization, s=5, h=1, α=5°, d=10, n=40, the starting point of the borehole can be flexibly moved as the working face is mined, and the number of boreholes can be adjusted according to the measurement range requirements.

[0063] As an optimization, the device type is a dipole-dipole device, with electrodes arranged equidistantly at intervals of A, B, M, and N. During measurement, AB = MN = a, BN = na, and the electrode spacing is increased point by point along AB, BM, and MN to obtain the first oblique sounding profile. Then, electrodes A, B, M, and N are moved simultaneously, and the measurement is repeated to obtain the next profile. This process continues until an inverted trapezoidal profile is obtained. The apparent resistivity of the dipole-dipole device is:

[0064]

[0065] In the formula, The distance between the electrodes. For the number of intervals, Let MN be the potential difference. It represents electric current.

[0066] As an optimization, the Occam inversion algorithm is used to retrieve the three-dimensional mine resistivity data in step S2. The calculation process is as follows:

[0067] The Occam inversion objective function is:

[0068]

[0069] In the formula, The difference between the measured data and the model forward modeling data. This represents the parameter vector for each node in the model. Here is the Jacobian coefficient matrix. Let T be the Lagrange multiplier, and T denote the transpose of the matrix. The roughness matrix can be represented as:

[0070]

[0071] The model parameters can be modified using the following formula:

[0072]

[0073] Root mean square error (RMSE) is commonly used to evaluate whether a forward model closely approximates actual geological conditions. Its expression is:

[0074]

[0075] In the formula, The number of observation data. It is the first Each observation data, to The inversion is stopped when the rate of change is less than 2%.

[0076] As an optimization, the steps for determining the impact hazard zone level are as follows:

[0077] S11. Measure the coordinates of the bottom of the borehole in step S1 to determine the spatial location of the measurement range.

[0078] S12. Based on the apparent resistivity distribution characteristics within the measurement range obtained in step S3, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the formula The impact hazard level of each location within the assessment area is divided into four levels: no impact hazard, weak impact hazard, moderate impact hazard, and strong impact hazard. The calculated impact hazard level of each point within the area is compared with a preset value to confirm the specific impact hazard level of each point. At that time, there was no risk of impact; At that time, it was a minor impact hazard; At that time, the risk of impact was moderate. At that time, there was a high risk of strong impact.

[0079] Figure 3 This is a three-dimensional distribution map of apparent resistivity of the method in this embodiment of the invention, such as... Figure 3 As shown, after resistivity three-dimensional inversion, the apparent resistivity values ​​at different coordinates in three-dimensional space are obtained. The units of x, y, and z coordinates are meters, and grayscale represents the apparent resistivity values.

[0080] Figure 4 This is a horizontal slice of the apparent resistivity along the working surface of the method in this embodiment of the invention; as shown... Figure 4 As shown, this figure is... Figure 3 The horizontal profile where the working face is located, i.e. at z=337, is sliced ​​to obtain the apparent resistivity values ​​at different coordinates within the horizontal profile where the working face is located after the three-dimensional resistivity inversion. The coordinate unit is meters, and the grayscale represents the apparent resistivity value.

[0081] Figure 5 This is a vertical slice of the apparent resistivity along the return air roadway in an embodiment of the present invention; as shown. Figure 5 As shown, this figure is... Figure 3 The vertical section of the return air roadway in the working face, i.e., at x=890460, is sliced ​​to obtain the apparent resistivity values ​​at different coordinates within the vertical section of the return air roadway after three-dimensional resistivity inversion. The coordinate unit is meters, and the grayscale represents the apparent resistivity value.

[0082] Figure 6 This is a distribution map of the impact hazard level in the impact hazard zone of the longwall mining face according to the method in this embodiment of the invention; as shown. Figure 6 As shown, according to Figure 4 The obtained apparent resistivity is sliced ​​along the horizontal plane of the working surface. Using the impact hazard level classification method described above in this invention, the hazard level values ​​of different coordinates within the horizontal profile of the working surface are obtained. The grayscale represents the magnitude of the hazard level value. By comparing the calculated impact hazard level values ​​of different coordinates with the preset values, the impact hazard level of each location can be determined.

[0083] The design method of this invention has been proven in practice to have good detection effect and accurate test results.

[0084] Therefore, the impact hazard detection method for the impact hazard area of ​​the longwall mining face based on the high-density DC current method has the advantages of simple operation, low cost, accurate results, intuitive results, and no damage to the detection object. It is suitable for use in major coal mines and can also be extended to other similar scenarios.

[0085] Figure 7 This is a structural diagram of the impact hazard detection device for longwall mining faces based on direct current resistivity tomography (DCS) according to an embodiment of the present invention. Figure 7 As shown, the impact hazard detection device for longwall mining faces based on DC electrical resistivity tomography (DCE) in this embodiment of the invention includes:

[0086] A measurement device module 700 is provided for setting up a data measurement device in the impact hazard zone of the longwall face. The data measurement device includes electrodes, measuring lines, and a measurement host. Each electrode is connected in sequence by a measuring line, and the end of the measuring line is connected to the measurement host.

[0087] The measurement data acquisition module 701 is used to select the observation device type. The measurement host emits current outward using the power supply electrode, and the measurement electrode receives the current emitted by the power supply electrode. The emission and reception of the current form a covered measurement range. The measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the difference in the current received by the measurement electrode.

[0088] The processing module 702 is used to process the acquired apparent resistivity distribution feature data within the measurement range according to the three-dimensional resistivity inversion algorithm to obtain the three-dimensional apparent resistivity distribution result within the measurement range.

[0089] The determination module 703 is used to obtain the impact hazard level within the impact hazard area of ​​the longwall face based on the apparent resistivity three-dimensional distribution results and using the hazard level calculation formula. Specifically, the determination module is used for:

[0090] Measure the coordinates of the borehole bottom to determine the spatial location of the measurement range; based on the calculated apparent resistivity distribution characteristics within the measurement range, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the hazard level calculation formula Obtain the impact hazard level for each location within the area.

[0091] This invention utilizes direct current resistivity to detect the impact hazard zone of a longwall face. By calculating the three-dimensional distribution of apparent resistivity, the impact hazard level within the impact hazard zone of the longwall face is determined. This invention offers advantages such as ease of operation, accurate results, and intuitive visualization of the findings.

[0092] While the embodiments disclosed in this invention are as described above, the content is merely for the purpose of facilitating understanding of the invention and is not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and changes to the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection of this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A method for detecting a danger zone of rock burst at a stoping face based on direct current method, characterized in that, include: A data measurement device is installed in the impact hazard zone of the longwall face, including electrodes, measuring lines, and a measurement host. Each electrode is connected in sequence by a measuring line, and the end of the measuring line is connected to the measurement host. After selecting the observation device type, the measurement host emits current outward using the power supply electrode, and the measurement electrode receives the current emitted by the power supply electrode. The emission and reception of the current form a covered measurement range, and the measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the difference in the current received by the measurement electrode. The apparent resistivity distribution feature data within the measurement range is processed according to the resistivity three-dimensional inversion algorithm to obtain the apparent resistivity three-dimensional distribution result within the measurement range. Based on the three-dimensional distribution of apparent resistivity, the impact hazard level within the impact hazard area of ​​the longwall face is obtained using the hazard level calculation formula. The specific steps for determining the impact hazard level within the impact hazard area of ​​the longwall face are as follows: Measure the coordinates of the borehole bottom to determine the spatial location of the measurement range; based on the calculated apparent resistivity distribution characteristics within the measurement range, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the hazard level calculation formula Obtain the impact hazard level for each location within the area.

2. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 1, characterized in that, Before installing data measuring devices on both sides of the impact hazard zone in the longwall mining face, the following is also included: Drill a row of holes on each side wall of the impact hazard zone in the longwall face, place the electrode inside the holes, with the electrode tip exposed: Drilling depth With electrode length The relationship between them is .

3. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography as described in claim 2, characterized in that, Set the drilling spacing to meters; the height of the drill hole from the bottom plate is rice; The drilling angle is the same as the horizontal angle. Sloping downwards; the starting point of the borehole is located at a distance from the working face. meters; number of boreholes: The =5, =1, =5°, d=10, =40.

4. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 3, characterized in that, The starting point of the borehole moves as the working face is mined, and the number of boreholes is adjusted according to the measurement range requirements.

5. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 1, characterized in that, The observation device is a dipole-dipole device, and the electrodes are arranged at equal intervals in the order of A, B, M, and N.

6. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 5, characterized in that, During measurement with the aforementioned observation device, AB=MN=a, BN=na, and AB, BM, and MN are progressively increased by one electrode spacing to obtain the first oblique sounding profile. Then, A, B, M, and N are simultaneously moved by one electrode, and the measurement is repeated to obtain the next profile. This process continues until an inverted trapezoidal profile is obtained. The apparent resistivity of the dipole-dipole device is: In the formula, The distance between the electrodes. For the number of intervals, Let MN be the potential difference. It represents electric current.

7. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 6, characterized in that, The resistivity three-dimensional inversion algorithm is the Occam inversion algorithm, and the calculation process is as follows: The Occam inversion objective function is: In the formula, The difference between the measured data and the model forward modeling data. This represents the parameter vector for each node in the model. Here is the Jacobian coefficient matrix. For Lagrange factors, The roughness matrix is ​​represented as follows: The model parameters are modified by the following formula: The root mean square error is used to evaluate whether the forward model closely approximates the actual geological conditions. Its expression is: In the formula, The number of observation data. It is the first Each observation data, to The inversion is stopped when the rate of change is less than 2%.

8. The method for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography (DCPS) according to claim 1, characterized in that, The hazard levels include: At that time, there was no risk of impact; At that time, it was a minor impact hazard; At that time, the risk of impact was moderate. At that time, there was a high risk of strong impact.

9. A device for detecting rock hazard zones in a longwall mining face based on direct current resistivity tomography, characterized in that, include: A measurement device module is set up to set up a data measurement device in the impact hazard area of ​​the longwall face. The module includes electrodes, measuring lines, and a measurement host. Each electrode is connected in sequence by a measuring line, and the end of the measuring line is connected to the measurement host. The measurement data acquisition module is used to select the observation device type. The measurement host emits current outward using the power supply electrode, and the measurement electrode receives the current emitted by the power supply electrode. The emission and reception of the current form a covered measurement range. The measurement host calculates the apparent resistivity distribution characteristic data within the measurement range based on the difference in the current received by the measurement electrode. The processing module is used to process the acquired apparent resistivity distribution feature data within the measurement range according to the three-dimensional resistivity inversion algorithm to obtain the three-dimensional apparent resistivity distribution result within the measurement range. The determination module is used to obtain the impact hazard level within the impact hazard area of ​​the longwall face based on the apparent resistivity three-dimensional distribution results and using the hazard level calculation formula. Specifically, the determination module is used for: Measure the coordinates of the borehole bottom to determine the spatial location of the measurement range; based on the calculated apparent resistivity distribution characteristics within the measurement range, obtain the apparent resistivity magnitude at each point within the region. and the average apparent resistivity within the region Then use the hazard level calculation formula Obtain the impact hazard level for each location within the area.

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