Top plate water disaster hidden danger detection method based on double-source direct-current resistivity method

Abstract

The invention discloses a roof water disaster hidden danger detection method by a double-source direct-current resistivity method, which is characterized in that emission source electrodes are simultaneously arranged in an earth surface and a mine tunnel to form an up-down coupled current field, so that the permeation of current in a deep stratum is obviously enhanced, and meanwhile, the detection depth is effectively expanded; and meanwhile, the detection precision of water disaster hidden dangers of a deep area, especially a deep roof, can be remarkably improved, and accurate positioning and quantitative evaluation of the hidden dangers are realized. The multi-path response of the geologic structure to the current is fully utilized, so that the collected data contain richer geologic information, and the recognition capability of the deep geologic structure and the water disaster hidden danger can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mine geophysical detection, and in particular relates to a method for detecting roof water hazards using a dual-source direct current resistivity method. Background Art

[0002] With the continuous increase in the depth of coal mining and the continuous expansion of resource mining scope, coal mine roof water hazards, as a major safety hazard, pose a serious threat to mine safety production. Especially under deep mining conditions, complex geological structures, active groundwater activities, and hidden water channels have significantly increased the difficulty of predicting and preventing roof water hazards. Traditional DC electrical detection technology mainly includes surface DC electrical method and mine DC electrical method according to different application scenarios, both of which belong to single-source DC resistivity method. The surface DC resistivity method arranges a single or multiple electrode groups on the surface of the detection area, while the mine DC resistivity method arranges a single or multiple electrode groups near the underground working face. The single-source DC resistivity method uses the potential difference generated when the current flows in the stratum to analyze the distribution of geological bodies, so as to identify potential water-bearing anomalies. The single-source DC resistivity method has been widely used in mine water hazard detection.

[0003] However, due to factors such as current attenuation and environmental interference, this type of method has an obvious lack of detection depth when detecting deep water hazards. Under a single DC source configuration, the current penetration ability is limited. Especially in the case of high-resistance formations, the effective detection depth is difficult to reach the depth where deep roof water hazards are located, and it is often difficult to meet the needs of deep mines for comprehensive and accurate detection of roof water hazards. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method for detecting roof water hazards using a dual-source DC resistivity method, which overcomes the detection depth limitation of traditional methods and improves detection accuracy and reliability through reasonable arrangement of component structures.

[0005] To achieve the above object, the technical solution adopted by the present invention includes:

[0006] A method for detecting roof water hazards using a dual-source DC resistivity method comprises the following steps:

[0007] S1, at least two groups of emission source electrodes are arranged in the detection area, with a gap between two adjacent groups of emission source electrodes, and each group of emission source electrodes includes upper and lower corresponding surface emission electrodes B i and downhole transmitting electrode A i, arrange infinite electrodes G, and connect each transmitting electrode to the infinite electrodes G respectively; arrange survey lines between the surface transmitting electrodes and / or the downhole transmitting electrodes of two adjacent groups of transmitting source electrodes, arrange multiple receiving electrodes on each survey line, and connect each receiving electrode to the infinite electrodes G respectively; wherein i represents the i-th group of transmitting source electrodes;

[0008] S2, injecting current into each group of transmitting source electrodes one by one, and collecting the voltage of all receiving electrodes relative to the infinite electrode G in sequence;

[0009] S3, calculating the abnormal amplitude value of the cth receiving electrode when the i-th group of transmitting source electrodes is injected with current;

[0010] S4, draw the abnormal amplitude diagram of each group of transmitting source electrodes when the current is injected. Specifically, when any group of transmitting source electrodes is injected with current, the receiving electrode with the highest abnormal amplitude value on each measuring line is connected to the surface transmitting electrode B that is currently injected with current. i and downhole transmitting electrode A i Then integrate the abnormal amplitude maps corresponding to all groups, and divide the detection area into grids. The grid with the largest number of passing line segments is the center position of the abnormal body.

[0011] Preferably, in S3, the abnormal amplitude value of the cth receiving electrode when the i-th group of transmitting source electrodes is injected with current is calculated specifically by formula (1);

[0012]

[0013] in, represents the voltage of the cth receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current, represents the voltage of the receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current when there is no abnormal body;

[0014] Preferably, in S1, two groups of emission source electrodes are arranged along the radial direction of the lane in the detection area and two groups of emission source electrodes are arranged along the axial direction of the lane. i Equal height and each well emitter electrode A i The surface transmitting electrode B of each group of transmitting source electrodes is of the same height. i Both are located at the underground transmitting electrode A i Directly above; and arrange 4 survey lines.

[0015] Preferably, the receiving electrodes on each measuring line in S1 are arranged at equal intervals.

[0016] Preferably, 15 receiving electrodes are arranged on each measuring line in S1.

[0017] Preferably, the minimum distance between the infinite electrode G in S1 and the detection area is greater than 1 km.

[0018] Preferably, the injection current intensity of the surface transmitting electrode Bi in S2 is 1A to 10A, and the underground transmitting electrode A i The injection current intensity is 30mA to 100mA.

[0019] Preferably, the grid division in S4 is 100m×100m×100m.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] (1) The dual-source DC resistivity method for detecting roof water hazards of the present invention simultaneously arranges emission source electrodes on the surface and in the mine tunnels to form an upper and lower coupled current field, which significantly enhances the penetration of current in deep strata and effectively expands the detection depth. At the same time, it can significantly improve the detection accuracy of deep areas, especially deep roof water hazards, and realize accurate positioning and quantitative evaluation of hazards.

[0022] (2) The dual-source DC resistivity method for detecting roof water hazards of the present invention flexibly configures receiving electrodes, that is, the receiving electrodes can be arranged on the surface and in the mine tunnel at the same time, or the receiving electrodes can be arranged only on the surface or only in the mine tunnel according to actual conditions. This is conducive to optimizing the detection efficiency and adapting to complex geological environments. At the same time, it is convenient to collect potential difference data at different positions and angles, providing more dimensional information for subsequent data processing and analysis.

[0023] (3) The dual-source DC resistivity method for detecting roof water hazards of the present invention receives signals with both "transmission" and "reflection" properties, which means that the collected data contains both "transmission" information of the current generated by the surface (underground) transmitting source in the stratum and then propagating to the underground (surface), and information of the current generated by the surface (underground) transmitting source being "reflected" to the surface (underground) receiving source when encountering an inhomogeneous medium interface. This composite detection mode makes full use of the multi-path response of the geological structure to the current, so that the collected data contains more abundant geological information, which helps to improve the ability to identify deep geological structures and water hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a schematic diagram of the electrode layout in the detection area.

[0026] Figure 2This is the abnormal amplitude diagram of each measuring line when the A1 B1 dual excitation source is used (the vertical axis represents the abnormal amplitude value).

[0027] Figure 3 This is the abnormal amplitude diagram of each measuring line when the A2B2 dual excitation source is used (the vertical axis represents the abnormal amplitude value).

[0028] Figure 4 This is the abnormal amplitude diagram of each measuring line when the A3B3 dual excitation source is used (the vertical axis represents the abnormal amplitude value).

[0029] Figure 5 This is the abnormal amplitude diagram of each measuring line when the A4B4 dual excitation source is used (the vertical axis represents the abnormal amplitude value).

[0030] Figure 6 It is a plot of each excitation source and the corresponding receiving electrode with the maximum abnormal amplitude.

[0031] Figure 7 yes Figure 6 Detection area grid division diagram. DETAILED DESCRIPTION

[0032] The invention is not limited to the following specific embodiments, and all equivalent changes made on the basis of the technical solution of this application fall within the protection scope of the present invention. All components and devices in the present invention, unless otherwise specified, are all components and devices known in the prior art.

[0033] Example

[0034] S1: Electrode layout

[0035] At least two groups of transmitting source electrodes are arranged in the detection area, and a spacing is left between two adjacent groups of transmitting source electrodes. Each group of transmitting source electrodes includes a corresponding surface transmitting electrode Bi and a downhole transmitting electrode Ai. An infinite electrode G is arranged on the surface, and the minimum distance between the electrode G and the detection area is greater than 1 km. Each transmitting electrode is connected to the infinite electrode G respectively. Survey lines are arranged between the surface transmitting electrodes and the downhole transmitting electrodes of two adjacent groups of transmitting source electrodes along the axial direction of the tunnel. Multiple receiving electrodes are arranged on each survey line, and each receiving electrode is connected to the infinite electrode G respectively.

[0036] Here, i represents the i-th group of emission source electrodes, and the values ​​of i in this embodiment are 1, 2, 3 and 4.

[0037] The schematic diagram of the layout of the detection area electrodes disclosed in this embodiment is as follows Figure 1As shown, two groups of transmitting source electrodes are arranged along the radial direction of the tunnel in the detection area, and two groups of transmitting source electrodes are arranged along the axial direction of the tunnel. The surface transmitting electrodes Bi are of equal height and the underground transmitting electrodes Ai are of equal height. The surface transmitting electrode Bi of each group of transmitting source electrodes is located directly above the underground transmitting electrode Ai, and four survey lines are arranged. The overall structure is a cube; all electrodes are connected to the data acquisition system through cables. 15 receiving electrodes are arranged on each survey line disclosed in this embodiment, and each receiving electrode is arranged at equal intervals. All receiving electrodes form a rectangular observation network to achieve full coverage of the observation area, and all receiving electrodes on the surface and underground are connected to the infinite electrode G respectively.

[0038] S2: Current injection and data acquisition

[0039] Dual-source current injection: Pair and combine the corresponding transmitting electrodes underground and on the surface to form four different dual excitation source systems (i.e., transmitting source electrodes), namely, A1 and B1, A2 and B2, A3 and B3, and A4 and B4. Inject current into each group of transmitting source electrodes one by one, that is, apply a stable current to the transmitting electrodes on the surface and in the tunnel of a group of transmitting systems. The surface current intensity is set to 1A to 10A, and the underground current intensity is set to 30mA to 100mA, which is adjusted according to geological conditions and detection requirements. The current frequency is selected to be low (such as 1Hz) to reduce the skin effect of the formation and ensure that the current can effectively penetrate the deep formation.

[0040] Synchronous data acquisition: Synchronously start all receiving electrodes on the surface and underground to collect potential difference data with the infinite electrode G, collect the voltage of all receiving electrodes relative to the infinite electrode G in turn, and record the voltage of each receiving electrode relative to the infinite electrode G to ensure the synchronization and accuracy of data acquisition. Multiple current injections and data acquisitions can be performed as needed to obtain more observation data and improve the reliability of detection results.

[0041] The current injection and data acquisition schemes are implemented for four different pairs of transmitting electrodes, namely A1 and B1, A2 and B2, A3 and B3, and A4 and B4, respectively.

[0042] S3: Abnormal amplitude calculation

[0043] The abnormal amplitude value of the cth receiving electrode when the i-th group of transmitting source electrodes is injected with current is calculated by formula (1);

[0044]

[0045] in, represents the voltage of the cth receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current, represents the voltage of the receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current when there is no abnormal body;

[0046] According to the above formula, the abnormal amplitudes of all receptions of measuring lines 1, 2, 3 and 4 when the A1 B1 dual excitation source, A2B2 dual excitation source, A3B3 dual excitation source and A4B4 dual excitation source are calculated in turn.

[0047] S4: Explanation of results

[0048] Figure 2 The abnormal amplitude diagram of survey lines 1, 2, 3 and 4 calculated when the dual excitation sources are A1 and B1. Figure 2 In the figure, the position with the maximum anomaly amplitude on line 1 is at the position of receiving electrode No. 5, which indicates that the anomaly passes through the line connecting the dual excitation sources A1 B1 and receiving electrode No. 5 on line 1. Figure 2 In the figure, the position with the maximum anomaly amplitude on line 2 is at the position of receiving electrode 2, which indicates that the anomaly passes through the line connecting the dual excitation sources A1 B1 and receiving electrode 2 on line 2. Figure 2 In the figure, the position with the maximum anomaly amplitude on line 3 is at the position of receiving electrode 4, which indicates that the anomaly passes through the line connecting the dual excitation sources A1 B1 and receiving electrode 4 on line 3. Figure 2 In the figure, the position with the largest anomaly amplitude on line 4 is at the position of receiving electrode No. 3, which indicates that the anomaly passes through the line connecting the A1B1 dual excitation source and the receiving electrode No. 3 on line 4.

[0049] Figure 3 The abnormal amplitude diagram of survey lines 1, 2, 3 and 4 calculated when the dual excitation sources are A2B2. Figure 3 In the figure, the position with the largest anomaly amplitude on line 1 is at the position of receiving electrode No. 4, which indicates that the anomaly passes through the line connecting the A2B2 dual excitation source and the receiving electrode No. 4 on line 1. Figure 3 In the figure, the position with the maximum anomaly amplitude on line 2 is at the position of receiving electrode 3, which indicates that the anomaly passes through the line connecting the A2B2 dual excitation source and the receiving electrode 3 on line 2. Figure 3 In the figure, the position with the maximum anomaly amplitude on line 3 is at the position of receiving electrode No. 6, which indicates that the anomaly passes through the line connecting the A2B2 dual excitation source and the receiving electrode No. 6 on line 3. Figure 3 In the figure, the position with the maximum anomaly amplitude on line 4 is at the position of receiving electrode 4, which indicates that the anomaly passes through the line connecting the A2B2 dual excitation source and the receiving electrode 4 on line 4.

[0050] Figure 4 The abnormal amplitude diagram of survey lines 1, 2, 3 and 4 calculated when the A3B3 dual excitation source is used. Figure 4In the figure, the position with the maximum anomaly amplitude on line 1 is at the position of receiving electrode 2, which indicates that the anomaly passes through the line connecting the A3B3 dual excitation source and the receiving electrode 2 on line 1. Figure 4 In the figure, the position with the maximum anomaly amplitude on line 2 is at the position of receiving electrode 1, which indicates that the anomaly passes through the line connecting the A3B3 dual excitation source and the receiving electrode 1 on line 2. Figure 4 In the figure, the position with the largest anomaly amplitude on line 3 is at the position of receiving electrode No. 1, which indicates that the anomaly passes through the line connecting the A3B3 dual excitation source and the receiving electrode No. 1 on line 3. Figure 4 In the figure, the position with the maximum anomaly amplitude on the No. 4 measuring line is at the position of the No. 4 receiving electrode, which indicates that the anomaly passes through the line connecting the A3B3 dual excitation source and the No. 4 receiving electrode on the No. 4 measuring line.

[0051] Figure 5 The abnormal amplitude diagram of survey lines 1, 2, 3 and 4 calculated when the dual excitation sources are A4B4. Figure 5 In the figure, the position with the maximum anomaly amplitude on line 1 is at the position of receiving electrode 2, which indicates that the anomaly passes through the line connecting the A4B4 dual excitation source and the receiving electrode 2 on line 1. Figure 5 In the figure, the position with the largest anomaly amplitude on line 2 is at the position of receiving electrode No. 4, which indicates that the anomaly passes through the line connecting the A4B4 dual excitation source and the receiving electrode No. 4 on line 2. Figure 5 In the figure, the position with the largest anomaly amplitude on line 3 is at the position of receiving electrode No. 1, which indicates that the anomaly passes through the line connecting the A4B4 dual excitation source and the receiving electrode No. 1 on line 3. Figure 5 In the figure, the position with the maximum anomaly amplitude on line 4 is at the position of receiving electrode 4, which indicates that the anomaly passes through the line connecting the A4B4 dual excitation source and the receiving electrode 4 on line 4.

[0052] Draw the abnormal amplitude diagram of each group of transmitting source electrodes when the current is injected. Specifically, when any group of transmitting source electrodes is injected with current, the receiving electrode with the highest abnormal amplitude value on each measuring line is connected to the surface transmitting electrode B that is currently injected with current. i and downhole transmitting electrode A i Then, integrate the abnormal amplitude diagrams corresponding to all groups, connect all the excitation sources and the corresponding receiving electrodes with the maximum abnormal amplitude to obtain Figure 6 The detection area is divided into grids according to a certain grid size, such as using a 100m×100m×100m grid. Figure 6 Divide and get the result as Figure 7 As shown, Figure 7 The grid with the largest number of line segments passing through it is the area where the line segments intersect densely, which is also the final location of the center of the abnormal body.

[0053] The dual-source DC resistivity method for detecting roof water hazards in this embodiment uses a dual-source (surface and underground) electrode layout to simultaneously lay out the emission source electrodes on the surface and in the mine tunnels to form an upper and lower coupled current field. This dual-source layout breaks through the limitation of the current penetration capability of a single source, significantly enhances the penetration of current in deep strata, and thus effectively expands the detection depth, which is particularly suitable for the detection of roof water hazards in deep mines. It achieves efficient and accurate detection of deep water hazards.

[0054] The above embodiments are only specific application examples of the present invention. In actual operation, corresponding adjustments can be made according to the on-site geological conditions, detection requirements and specific conditions of technical equipment to achieve the best detection effect.

[0055] Through the above steps, a new dual-source DC resistivity method for detecting roof water hazards is realized, which effectively solves the problems existing in the prior art and plays a positive role in promoting coal mine safety production and industry development.

[0056] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0057] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0058] In addition, the various different implementation modes disclosed in this solution may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the content invented by the present disclosure.

Claims

1. A method for detecting roof water hazards using a dual-source DC resistivity method, characterized in that: The following steps are involved: S1, at least two groups of emission source electrodes are arranged in the detection area, with a gap between two adjacent groups of emission source electrodes, and each group of emission source electrodes includes upper and lower corresponding surface emission electrodes B i and downhole transmitting electrode A i , arranging the infinite electrode G, and connecting each transmitting electrode to the infinite electrode G respectively; Survey lines are arranged between the surface transmitting electrodes and / or between the underground transmitting electrodes of two adjacent groups of transmitting source electrodes, a plurality of receiving electrodes are arranged on each survey line, and each receiving electrode is connected to the infinite electrode G respectively; Wherein, i represents the i-th group of emission source electrodes; S2, injecting current into each group of transmitting source electrodes one by one, and collecting the voltage of all receiving electrodes relative to the infinite electrode G in sequence; S3, calculating the abnormal amplitude value of the cth receiving electrode when the i-th group of transmitting source electrodes is injected with current; S4, draw the abnormal amplitude diagram of each group of transmitting source electrodes when the current is injected. Specifically, when any group of transmitting source electrodes is injected with current, the receiving electrode with the highest abnormal amplitude value on each measuring line is connected to the surface transmitting electrode B that is currently injected with current. i and downhole transmitting electrode A i Connection; Then the abnormal amplitude maps corresponding to all groups are integrated, and the detection area is divided into grids. The grid with the largest number of passing line segments is the center position of the abnormal body.

2. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 1, characterized in that: Specifically, in S3, the abnormal amplitude value of the cth receiving electrode when the i-th group of transmitting source electrodes is injected with current is calculated by formula (1); in, represents the voltage of the cth receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current, It represents the voltage of the receiving electrode relative to the infinite electrode G when the i-th group of transmitting source electrodes is injected with current when there is no abnormal body.

3. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 1, characterized in that: In S1, two groups of emission source electrodes are arranged along the radial direction of the lane in the detection area and two groups of emission source electrodes are arranged along the axial direction of the lane. i The same height and each underground transmitting electrode A i The surface transmitting electrode B of each group of transmitting source electrodes is of the same height. i Both are located at the underground transmitting electrode A i Directly above; and arrange 4 survey lines.

4. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 1, characterized in that: The receiving electrodes on each measuring line in S1 are arranged at equal intervals.

5. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 4, characterized in that: In S1, 15 receiving electrodes are arranged on each measuring line.

6. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 1, characterized in that: The minimum distance between the infinite electrode G and the detection area in S1 is greater than 1 km.

7. The method for detecting roof water hazards using a dual-source DC resistivity method according to any one of claims 1 to 6, characterized in that: The injection current intensity of the surface transmitting electrode Bi in S2 is 1A to 10A, and the underground transmitting electrode A i The injection current intensity is 30mA to 100mA.

8. The method for detecting roof water hazards using a dual-source DC resistivity method as claimed in claim 7, characterized in that: The grid division in S4 is 100m×100m×100m.

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