Transient electromagnetic advanced detection method for coal mine heading face

Abstract

The invention discloses a transient electromagnetic advanced detection method for a coal mine heading face, which comprises the following steps of: planning the heading face of a coal mine well, and designing the positions of a transient electromagnetic horizontal detection point and a vertical detection point and a detection wireframe angle according to the planning design principle that the detection points avoid metal objects in a detection range; according to the detection mode, the number of the detection points is reduced, the arrangement mode of the detection points is optimized, the workload is reduced, the working efficiency is improved, and the interference of the metal object on the transient electromagnetic data is effectively reduced, so that the obtained data and result are more appropriate, real and effective, the accuracy and reliability of the detection result are greatly improved, and the detection efficiency is improved. Good popularization prospects are realized.

Description

Technical Field

[0001] The invention relates to a method for transient electromagnetic advance detection of a coal mine excavation face, belonging to the technical field of mine geophysical exploration. Background Art

[0002] In recent years, coal mine underground transient electromagnetic detection technology has played an important role in the field of water hazard prediction and forecasting. However, due to the complexity of the underground detection tunnel environment, the existence of many interference factors seriously restricts the quality of data acquisition, which in turn has a significant impact on the authenticity and reliability of the detection results, especially in the detection process of tunnel excavation face, the problem is particularly prominent, because most underground tunnels use metal objects (such as I-beams, anchor nets, anchor rods, anchor cables, etc.) for support, and these metal objects have a significant interference effect on transient electromagnetic data. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a method for transient electromagnetic advance detection of coal mine excavation faces, so as to at least solve the problem of inaccurate detection results and low precision caused by metal objects on the tunnel walls mentioned in the background technology.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A method for transient electromagnetic advance detection of coal mine excavation face, comprising the following steps:

[0006] s1. According to the coal mine excavation face, the positions and detection wireframe angles of transient electromagnetic horizontal detection points and vertical detection points are planned and designed. The planning and design principle is to make the detection points avoid metal objects within the detection range and reduce the interference of metal objects on transient electromagnetic data;

[0007] s2. Obtain transient electromagnetic data and draw apparent resistivity result diagram;

[0008] s3. According to the apparent resistivity result diagram, the water-rich situation within the detection range is obtained.

[0009] Furthermore, the planning and design of the transient electromagnetic horizontal detection point is to arrange three measurement planes with the excavation face as the reference plane, wherein the measurement line of the first measurement plane points to the roof of the coal mine shaft and forms a 45° angle with the excavation face, the measurement line of the second measurement plane is perpendicular to the excavation face, and the measurement line of the third measurement plane points to the bottom plate of the coal mine shaft and forms a 45° angle with the excavation face. The position of the horizontal detection point and the detection wireframe angle are determined by the following steps:

[0010] a. Align the normal line of the center point of the detection wireframe with the normal line of the center point of the excavation surface;

[0011] b. Select one of the measurement surfaces, adjust the angle of the detection wireframe so that the normal of the detection wireframe is parallel to the measurement line of the measurement surface, take the intersection of the normal of the center point of the detection wireframe and the measurement surface as the reference point, and the positive projection line of the normal of the detection wireframe on the measurement surface is the measurement line;

[0012] c. With the reference point as the circle on the measuring surface, the measuring line is deflected 15°, 30° and 45° to the left and right sides of the excavation face to arrange detection points, respectively, to obtain transient electromagnetic data of the horizontal measuring surface;

[0013] d. Complete the acquisition of transient electromagnetic data for the other two measuring surfaces according to steps b and c.

[0014] Furthermore, for the transient electromagnetic horizontal detection points, the corresponding detection points of each survey line are arranged at a deflection of 15°, 30° and 45° to the left and right sides of the excavation face, respectively, and the interval between adjacent detection points is no more than 15°.

[0015] Furthermore, the position of the vertical detection point and the detection wireframe angle are determined by the following steps:

[0016] a. Take the normal plumb plane of the center point of the excavation face as the vertical measuring plane;

[0017] b. Adjust the angle of the detection wireframe so that the normal line of the detection wireframe is perpendicular to the excavation surface. Take the intersection point of the normal line of the detection wireframe and the excavation surface as the reference point, and the normal line of the detection wireframe as the measuring line;

[0018] c. On the vertical measuring surface, with the reference point as the circle, the measuring line is deflected 15°, 30° and 45° toward the roof and floor of the coal mine respectively to arrange detection points, and obtain transient electromagnetic data of the vertical measuring surface respectively.

[0019] Furthermore, for the transient electromagnetic vertical detection points, the corresponding survey lines are deflected 15°, 30° and 45° to the coal mine roof and coal mine floor respectively to arrange detection points, and the interval between adjacent detection points is no more than 15°.

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

[0021] The present invention plans the excavation face of a coal mine, designs the positions of transient electromagnetic horizontal detection points and vertical detection points and the detection wireframe angles, and the planning and design principle is to make the detection points avoid metal objects within the detection range. This detection method not only reduces the number of detection points, optimizes the arrangement of detection points, reduces workload, and improves work efficiency, but also effectively reduces the interference of metal objects on transient electromagnetic data, so that the acquired data and results are more appropriate, real and effective, greatly improving the accuracy and reliability of the detection results, and has good promotion prospects.

[0022] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which:

[0024] Figure 1 A schematic diagram of the survey line arrangement for the horizontal detection direction of a coal mine excavation face provided in Example 1 of the present invention;

[0025] Figure 2 A schematic diagram of the survey line arrangement in the vertical detection direction of the coal mine excavation face provided in Example 1 of the present invention;

[0026] Figure 3 for Figure 1 Apparent resistivity result diagram of middle measuring line 1;

[0027] Figure 4 for Figure 1 Apparent resistivity result diagram of middle measuring line 2;

[0028] Figure 5 for Figure 1 Apparent resistivity result diagram of middle measuring line 3;

[0029] Figure 6 for Figure 2 Apparent resistivity result diagram of middle measuring line 4;

[0030] Figure 7 A schematic diagram of the survey line arrangement for the horizontal detection direction of a coal mine excavation face provided in Example 2 of the present invention;

[0031] Figure 8 A schematic diagram of the survey line arrangement in the vertical detection direction of a coal mine excavation face provided in Example 2 of the present invention;

[0032] Fig. 9 for Figure 7 Apparent resistivity result diagram of middle measuring line 1;

[0033] Fig.10 for Figure 7 Apparent resistivity result diagram of middle measuring line 2;

[0034] Fig.11 for Figure 7 Apparent resistivity result diagram of middle measuring line 3;

[0035] Fig.12 for Figure 8Apparent resistivity result diagram of middle survey line 4. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] The present invention provides a method for coal mine excavation face transient electromagnetic advance detection, which comprises the following steps:

[0038] s1. Plan the excavation face of the coal mine, design the positions and detection wireframe angles of the transient electromagnetic horizontal and vertical detection points. The planning and design principle is to make the detection points avoid metal objects within the detection range and reduce the interference of metal objects on transient electromagnetic data;

[0039] s2. Obtain transient electromagnetic data and draw apparent resistivity result diagram;

[0040] s3. According to the apparent resistivity result diagram, the water-rich situation within the detection range is obtained.

[0041] The planning and design of transient electromagnetic horizontal detection points is to arrange three horizontal measurement planes with the coal mine excavation face as the reference plane, where the measurement line of the first measurement plane points to the coal mine roof and forms a 45° angle with the excavation face, the measurement line of the second measurement plane is perpendicular to the excavation face, and the measurement line of the third measurement plane points to the coal mine floor and forms a 45° angle with the excavation face. The position of the horizontal detection point and the detection wireframe angle are determined by the following steps:

[0042] a. Align the normal line of the center point of the detection wireframe with the normal line of the center point of the excavation surface;

[0043] b. Select one of the measurement surfaces, adjust the angle of the detection wireframe so that the normal of the detection wireframe is parallel to the measurement line of the measurement surface, take the intersection of the normal of the center point of the detection wireframe and the measurement surface as the reference point, and the positive projection line of the normal of the detection wireframe on the measurement surface is the measurement line;

[0044] c. With the reference point as the circle on the measuring surface, the measuring line is deflected 15°, 30° and 45° to the left and right sides of the excavation face to arrange detection points, respectively, to obtain transient electromagnetic data of the horizontal measuring surface;

[0045] d. Complete the acquisition of transient electromagnetic data for the other two measuring surfaces according to steps b and c.

[0046] The position of the vertical detection point and the detection wireframe angle are determined by the following steps:

[0047] a. Take the normal plumb plane of the center point of the excavation face as the vertical measuring plane;

[0048] b. Adjust the angle of the detection wireframe so that the normal line of the detection wireframe is perpendicular to the excavation surface. Take the intersection point of the normal line of the detection wireframe and the excavation surface as the reference point, and the normal line of the detection wireframe as the measuring line;

[0049] c. On the vertical measuring surface, with the reference point as the circle, the measuring line is deflected 15°, 30° and 45° toward the roof and floor of the coal mine respectively to arrange detection points, and obtain transient electromagnetic data of the vertical measuring surface respectively.

[0050] Among them, for the transient electromagnetic horizontal detection points, each corresponding survey line is arranged with detection points deflected 15°, 30° and 45° to the left and right sides of the excavation face, and the interval between adjacent detection points is not greater than 15°. For the transient electromagnetic vertical detection points, the corresponding survey lines are arranged with detection points deflected 15°, 30° and 45° to the coal mine roof and coal mine floor, and the interval between adjacent detection points is not greater than 15°. Furthermore, the arrangement intervals of the horizontal detection points and the vertical detection points can be the same or different.

[0051] Take the case of detection of the excavation face of a tunnel in a mine as an example:

[0052] 1. Detection time: 10:00, November 24, 2023;

[0053] 2. Detection location: the head of a certain lane (50m from a certain wire detection point);

[0054] 3. Detection purpose: To detect the water-rich situation within 100m in front of a tunnel in a mine;

[0055] 4. Hydrogeological conditions: The front section of the tunnel is mainly coal seam;

[0056] 5. Site conditions: The power supply has been cut off in the tunnel, and it is supported by anchor spraying. There is a coal seam at the head, and there is water accumulation on the right side of the head. The left and right sides are supported by metal I-beams, anchor rods, anchor cables, and anchor nets, which have a great impact on the detection signal.

[0057] Example 1

[0058] Use existing detection methods to detect

[0059] The arrangement of survey lines and detection points is generally as follows: Figure 1 , three survey lines are arranged in the horizontal detection direction of the excavation face, including survey line 1: 45° above the top plate, survey line 2: 0° along the layer, and survey line 3: -45° below the bottom plate. The detection points of each survey line are arranged in a 180° semicircular area from the left side to the right side of the tunnel excavation face every 15°, and the detection points are numbered 1#-13#. Figure 2, arrange the survey line 4 in the longitudinal section direction of the tunnel centerline: arrange a detection point every 15° in the longitudinal section direction from 90° to -90° on the top plate to the bottom plate, and the detection points are numbered a#-m# for detection. Among them, the apparent resistivity result of survey line 1 is as follows Figure 3 The apparent resistivity result of line 2 is as follows: Figure 4 The apparent resistivity result of measuring line 3 is as follows: Figure 5 The apparent resistivity result of measuring line 4 is as follows: Figure 6 .

[0060] Detection conclusion of Example 1: Figure 3-Figure 6 This is a pseudo-section diagram of the apparent resistivity of a certain tunnel head-on transient electromagnetic advance detection, including line 1 (45° above the top plate), line 2 (0° along the layer), line 3 (-45° below the bottom plate), and line 4 (90° to -90° of the top plate in the longitudinal section):

[0061] 1) The detection results of survey line 1 show that the apparent resistivity value is high and the possibility of the existence of water-rich areas is low.

[0062] 2) The detection results of survey line 2 show that there are two low-resistance anomaly areas, namely YC1 and YC2; YC1 is 10-40m away from the left bank and 60-100m deep; YC2 is 40-100m away from the right bank and 0-30m deep. Analysis shows that there is a certain possibility of water-rich in the two anomaly areas, and the low-resistance anomaly on the right bank is affected by the on-site metal interference;

[0063] 3) The detection results of survey line 3 show that there are two abnormal areas, namely YC3 and YC4; YC3 is 0-35m away from the left bank and 40-100m deep; YC4 is 20-40m away from the right bank and 30-60m deep. Analysis shows that there is a certain possibility of water abundance in the two abnormal areas;

[0064] 4) The detection results of survey line 4 show that there are two abnormal areas, namely YC5 and YC6; YC5 is 0-20m away from the top plate and 40-100m deep; YC6 is 40-100m away from the bottom plate and 12-76m deep. Analysis shows that there is a certain possibility of water-rich in the two abnormal areas, and the low-resistance anomaly of the top plate is affected by the on-site metal interference.

[0065] Example 2

[0066] The present invention provides a detection method for detecting

[0067] The arrangement of survey lines and detection points is generally as follows: Figure 7, three survey lines are arranged in the horizontal detection direction of the excavation face, including survey line 1: 45° above the top plate, survey line 2: 0° along the layer, and survey line 3: -45° below the bottom plate. The detection points of each survey line are in the 135°-45° fan-shaped area from the left side to the right side of the tunnel excavation face, and one detection point is arranged every 15°. The detection points are numbered 1#-7#. Figure 8 , arrange the survey line 4 in the longitudinal section direction of the tunnel centerline: arrange a detection point every 15° in the longitudinal section direction from 45° to -45° on the top plate, and the detection points are numbered a#-g# for detection. The apparent resistivity result of survey line 1 is as follows Fig. 9 The apparent resistivity result of line 2 is as follows: Fig.10 The apparent resistivity result of measuring line 3 is as follows: Fig.11 The apparent resistivity result of measuring line 4 is as follows: Fig.12 :

[0068] Example 2 Detection conclusion: Figure 9-12 This is a pseudo-section diagram of the apparent resistivity of a certain tunnel head-on transient electromagnetic advance detection, including four directions: line 1 (45° direction of the top plate), line 2 (0° direction along the layer), line 3 (45° direction of the bottom plate), and line 4 (longitudinal section direction of the tunnel):

[0069] 1) The detection results of survey line 1 show that the apparent resistivity value of the left bank is 0-30m and the depth is 0-30m, which is low, and the apparent resistivity value of the right bank is 0-30m and the depth is 0-30m, which is low, and the possibility of the existence of water-rich areas is high;

[0070] 2) The detection results of survey line 2 show that the apparent resistivity value of the left bank is 0-30m and the depth is 0-30m, which is low, and the apparent resistivity value of the right bank is 0-30m and the depth is 0-30m, which is low, and the possibility of the existence of water-rich areas is high;

[0071] 3) The detection results of survey line 3 show that the apparent resistivity value of the left bank is 0-30m and the depth is 0-30m, which is low, and the apparent resistivity value of the right bank is 0-30m and the depth is 0-30m, which is low, and the possibility of the existence of water-rich areas is high;

[0072] 4) The detection results of survey line 4 show that the apparent resistivity value is low from the top plate to the bottom plate at a depth of 0-30m, and there is a high possibility of the existence of water-rich areas.

[0073] Comparison of the results of Example 1 and Example 2

[0074]

[0075] in conclusion:

[0076] The detection method provided by the present invention is used for detection, which not only reduces the overall number of detection points by 24, optimizes the arrangement of detection points, reduces workload, improves work efficiency, but also can reduce the interference of metal objects supporting the left and right sides of the tunnel, effectively improving the accuracy and reliability of detection.

[0077] The above description is only a preferred embodiment of the present invention and does not constitute any form of confidentiality restriction on the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for transient electromagnetic advance detection of coal mine excavation face, characterized in that: The following steps are involved: s1. Plan the excavation face of the coal mine, design the positions and detection wireframe angles of the transient electromagnetic horizontal and vertical detection points. The planning and design principle is to make the detection points avoid metal objects within the detection range and reduce the interference of metal objects on transient electromagnetic data; s2. Obtain transient electromagnetic data and draw apparent resistivity result diagram; s3. According to the apparent resistivity result diagram, the water-rich situation within the detection range is obtained.

2. The coal mine excavation face transient electromagnetic advance detection method according to claim 1 is characterized in that: The planning and design of transient electromagnetic horizontal detection points is to arrange three measurement surfaces with the coal mine excavation face as the reference plane, where the measurement line of the first measurement surface points to the coal mine roof and forms a 45° angle with the excavation face, the measurement line of the second measurement surface is perpendicular to the excavation face, and the measurement line of the third measurement surface points to the coal mine floor and forms a 45° angle with the excavation face. The position of the horizontal detection point and the detection wireframe angle are determined by the following steps: a. Align the normal line of the center point of the detection wireframe with the normal line of the center point of the excavation surface; b. Select one of the measurement surfaces, adjust the angle of the detection wireframe so that the center point normal of the detection wireframe is parallel to the center measurement line of the measurement surface, take the intersection of the center point normal of the detection wireframe and the measurement surface as the reference point, and the positive projection line of the detection wireframe normal on the measurement surface is the measurement line; c. With the reference point as the circle on the measuring surface, the measuring line is deflected 15°, 30° and 45° to the left and right sides of the excavation face to arrange detection points, respectively, to obtain transient electromagnetic data of the horizontal measuring surface; d. Complete the acquisition of transient electromagnetic data for the other two measuring surfaces according to steps b and c.

3. The method for coal mine excavation face transient electromagnetic advance detection according to claim 2 is characterized in that: For transient electromagnetic horizontal detection points, the corresponding detection points of each survey line are arranged at a deflection of 15°, 30° and 45° to the left and right sides of the excavation face respectively, and the interval between adjacent detection points is no more than 15°.

4. The coal mine excavation face transient electromagnetic advance detection method according to claim 1 is characterized in that: The position of the vertical detection point and the detection wireframe angle are determined by the following steps: a. Take the normal plumb plane of the center point of the excavation face as the vertical measuring plane; b. Adjust the angle of the detection wireframe so that the normal line of the detection wireframe is perpendicular to the excavation surface. Take the intersection point of the normal line of the detection wireframe and the excavation surface as the reference point, and the normal line of the detection wireframe as the measuring line; c. On the vertical measuring surface, with the reference point as the circle, the measuring line is deflected 15°, 30° and 45° toward the roof and floor of the coal mine respectively to arrange detection points, and obtain transient electromagnetic data of the vertical measuring surface respectively.

5. The coal mine excavation face transient electromagnetic advance detection method according to claim 3 is characterized in that: For the transient electromagnetic vertical detection points, the corresponding survey lines are deflected 15°, 30° and 45° to the coal mine roof and coal mine floor respectively to arrange detection points, and the interval between adjacent detection points is no more than 15°.

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