Exploration method for mining roof water flowing fissure zone and bottom plate damage zone of coal mine working face

Abstract

The invention discloses a method for probing a coal mine working face mining roof water flowing fissure zone and a bottom plate damage zone. The method specifically comprises the steps that 1, the height of the working face mining roof water flowing fissure zone and the depth of the bottom plate damage zone are predicted; 2, according to the height, predicted in the step 1, of the water flowing fractured zone, a top plate water flowing fractured zone ground directional exploration drill hole is designed; 3, ground directional exploration drilling of the top plate water flowing fractured zone is constructed, and the height and form of the top plate water flowing fractured zone are determined according to drilling slurry consumption; 4, according to the top plate water flowing fissure zone ground directional exploration drill hole in the step 2 and the working face mining bottom plate damage zone depth, a bottom plate damage zone depth exploration branch drill hole is designed; and step 5, constructing a bottom plate damaged zone depth exploration branch drill hole, and determining the depth of the bottom plate damaged zone according to the drilling slurry consumption. The method can accurately judge the height of the top plate water flowing fissure zone and the depth of the bottom plate damage zone, determines the form of the top plate water flowing fissure zone, and provides data support for coal mine water prevention and control work.

Description

Technical Field

[0001] The invention belongs to the technical field of mine water hazard prevention and control methods, and relates to a method for detecting a water-conducting fracture zone of a roof and a damaged zone of a bottom plate of a coal mine working face. Background Art

[0002] After the coal seam is mined, due to the redistribution of ground stress, a rock fracture zone of a certain height will be formed on the roof, which has good water conductivity, called the water-conducting fracture zone. The height and shape of the water-conducting fracture zone are controlled by mining and geological conditions. The current status of the water-conducting fracture zone is mainly divided into saddle type and arch type; the coal seam floor is sheared to form a rock damage zone of a certain depth, called the floor damage zone. The water-conducting fracture zone and the floor damage zone are the basic data for coal mine water prevention and control work, and their accuracy determines the safety of coal mine water prevention and control work. Therefore, mines threatened by roof and floor water hazards need to carry out actual measurement of the height of the roof water-conducting fracture zone and the depth of the floor damage zone.

[0003] At present, the existing measurement methods of roof water-conducting fracture zones include constructing straight holes on the ground, observing mud consumption, and conducting in-hole observation, or constructing upward holes underground, conducting water pressure tests, in-hole observation, electrical detection, etc. The detection of floor damage zones mainly relies on constructing underground drilling holes, conducting water pressure tests, in-hole observation, electrical detection, etc. The above methods require the construction of multiple boreholes, especially the construction of ground straight holes, which results in a large amount of ineffective engineering and high costs. In addition, there are certain safety risks in underground drilling, and the construction progress is slow. Moreover, after the overlying coal seam is mined to form a goaf area, it is impossible to construct an exploration borehole through the goaf to determine the roof water-conducting fracture zone or the floor damage zone, which affects the implementation of mine water prevention and control work and mine safety.

[0004] After searching, the Chinese patent "A method for detecting water-conducting fracture zones based on directional drilling detection technology" (application number: CN202410978707.3, publication date: 2024.11.29) includes determining the single coal seam water-conducting fracture zone exploration area, the multi-coal seam water-conducting fracture zone exploration area and the single coal seam directional horizontal drilling area and the multi-coal seam directional horizontal drilling area, and selecting the first surface drilling position and the second surface drilling position; drilling from the first surface drilling position and the second surface drilling position, setting a branch inclination point, and drilling to the multi-coal seam water-conducting fracture zone exploration area for exploration; continuing to drill from the first surface drilling position and the second surface drilling position, setting a branch inclination point, and drilling from the branch inclination point to the single coal seam water-conducting fracture zone exploration area for exploration; obtaining the fracture zone development conditions of the single coal seam water-conducting fracture zone exploration area and the multi-coal seam water-conducting fracture zone exploration area.

[0005] The problems with the above scheme are: no design requirements for directional drilling, no requirements for directional drilling and sealing, and it cannot be applied in practice. It is not clear to conduct exploration at different locations of the working face, the exploration results are not universal, and the exploration results cannot determine the morphology of the water-conducting fracture zone, which is not conducive to the promotion of the exploration results. Summary of the invention

[0006] The purpose of the present invention is to provide a method for detecting the water-conducting fracture zone and the bottom plate damage zone of the mining roof of a coal mine working face. By giving the design requirements of directional drilling, the drilling and sealing requirements of directional drilling and the detection position at the working face, and utilizing the mud consumption during the ground directional drilling construction, the height of the water-conducting fracture zone of the roof and the depth of the bottom plate damage zone can be accurately judged, and the shape of the water-conducting fracture zone of the roof can be determined, thereby providing data support for the water prevention and control work of the coal mine.

[0007] The technical solution adopted by the present invention is a method for detecting the water-conducting fracture zone of the roof and the damaged zone of the floor of a coal mine working face, which is specifically implemented according to the following steps: Step 1: estimate the height of the water-conducting fracture zone in the top plate and the depth of the damaged zone in the bottom plate of the working face; Step 2, designing a surface directional exploration borehole for the roof water-conducting fracture zone according to the height of the water-conducting fracture zone estimated in step 1; Step 3: construct a directional exploration drill hole on the roof water-conducting fracture zone, and determine the height and shape of the roof water-conducting fracture zone according to the drilling mud consumption; Step 4, designing the branch drilling for the depth exploration of the bottom plate damage zone according to the ground directional exploration drilling of the roof water-conducting fracture zone in step 2 and the depth of the bottom plate damage zone of the mining face; Step 5: construct branch boreholes to detect the depth of the bottom plate damage zone and determine the depth of the bottom plate damage zone based on the drilling mud consumption.

[0008] Preferably, the height of the water-conducting fracture zone of the mining roof of the working face estimated in step 1 is specifically: referring to the "Specifications for Coal Pillar Retention and Compression Coal Mining in Buildings, Water Bodies, Railways and Main Shafts and Lanes", and using a statistical formula to calculate the height H of the water-conducting fracture zone of the working face.

[0009] Preferably, the estimated depth of the working face mining floor damage zone in step 1 is specifically: refer to the "Specifications for Coal Pillar Retention and Compression Mining in Buildings, Water Bodies, Railways and Main Shafts and Tunnels", use statistical formulas and theoretical formulas to calculate the depth of the floor damage zone respectively, and take the maximum value as the estimated value M of the floor damage zone depth.

[0010] Preferably, the conditions for determining the position of the ground directional exploration drilling hole in the roof water-conducting fracture zone in step 2 are as follows: Determine the ground directional exploration drilling holes in the roof water-conducting fracture zone. The location of the ground directional exploration drilling holes in the roof water-conducting fracture zone is not within the lateral influence range of the water-conducting fracture zone and the distance between the ground directional exploration drilling holes in the roof water-conducting fracture zone and the lateral influence boundary of the water-conducting fracture zone is 50-200m. In addition, the distance between the ground directional exploration drilling holes in the roof water-conducting fracture zone and the cut eye is greater than the working face width L. According to the position determination conditions, the position of the first ground directional exploration drill hole T1 in the roof water-conducting fracture zone is first determined, and then the second ground directional exploration drill hole T2 in the roof water-conducting fracture zone is arranged at a different position of the working face. The plane distance between T2 and T1 holes is not less than 200m, and the position determination conditions are met.

[0011] Preferably, the ground directional exploration drilling structure of the roof water-conducting fracture zone is two-level, the first level is a straight hole section, the second level is a branch hole of the bare hole section, and each ground directional exploration drilling hole of the roof water-conducting fracture zone includes 3 branch holes, among which the end point of the first branch hole is 0.9H away from the coal seam, and the spacing from the working face tunnel is 0.5L; the end point of the second branch hole is 0.8H away from the coal seam, and the spacing from the working face tunnel is 30m; the end point of the third branch hole is 0.6H away from the coal seam, and the spacing from the working face tunnel is 10m; and the angle between the drilling trajectory at the end point of each branch hole of each roof water-conducting fracture zone ground directional exploration drilling hole and the horizontal plane is not less than 20°.

[0012] Preferably, the construction of the directional exploration drilling of the water-conducting fracture zone of the roof in step 3 is specifically as follows: One month after the coal seam mining at the detection position was completed, a ground directional exploration drilling hole was constructed in the water-conducting fracture zone of the roof. The specific construction process was as follows: two ground directional exploration drilling holes in the water-conducting fracture zone of the roof were constructed in sequence. When constructing each ground directional exploration drilling hole in the water-conducting fracture zone of the roof, the first level was constructed as a straight hole section, specifically: the casing was lowered to 10m into the intact bedrock, and then the first branch hole, the second branch hole, and the third branch hole were constructed in sequence.

[0013] Preferably, in step 3, the height and shape of the roof water-conducting fracture zone are determined according to the drilling mud consumption as follows: During the drilling of the corresponding branch holes, solid-free mud is used. If the mud consumption increases to the point of total loss, it is determined that the water-conducting fracture zone has been entered and drilling is stopped; otherwise, drilling is continued to the designed end point; after the construction is completed, the branch holes are sealed, and a roof water-conducting fracture zone position is obtained for each branch hole. Based on the water-conducting fracture zone positions obtained by the ground directional exploration drilling of two roof water-conducting fracture zones, a total of 6 branch holes, the maximum water-conducting fracture zone height is obtained and the shape of the water-conducting fracture zone is determined; Among them, for each branch hole, if all leakage occurs during drilling, the height corresponding to the position where all leakage occurs is the height of the water-conducting fracture zone; if all leakage does not occur during drilling, the height corresponding to the position of the end hole point is the height of the water-conducting fracture zone; According to the three branch holes of the ground directional exploration drilling hole of the same roof water-conducting fracture zone, the morphology of the water-conducting fracture zone at the corresponding position is determined as follows: If the height of the water-conducting fracture zone obtained by the first branch hole of the ground directional exploration drilling corresponding to the water-conducting fracture zone is greater than the height of the water-conducting fracture zone obtained by the other two branch holes, then the water-conducting fracture zone is arch-shaped, otherwise it is saddle-shaped.

[0014] Preferably, step 4 is specifically: A bottom plate damage zone depth exploration branch hole is set at each top plate water-conducting fracture zone ground directional exploration drill hole. The starting point of the bottom plate damage zone depth exploration branch hole is the end point of the straight hole section. The specific position confirmation conditions are as follows: The branch drilling trajectory for deep exploration of the bottom plate damage zone does not enter the development range of the water-conducting fracture zone. The end point of the branch drilling for deep exploration of the bottom plate damage zone is 1.3M away from the coal seam. In the vertical direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone is located below the bottom plate of the coal seam, with a vertical distance of 1.3M from the bottom plate of the coal seam. In the horizontal direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone passes through the tunnel and enters 30~50m inside the projection range of the working face.

[0015] The branch drilling holes for deep exploration of the bottom plate damage zone are not within the development range of the water-conducting fracture zone, that is, if the roof water-conducting fracture zone is arched, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the mining range of the working face; if the roof water-conducting fracture zone is saddle-shaped, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the lateral influence range of the water-conducting fracture zone.

[0016] Preferably, step 5 is specifically: After the three branch holes of the ground directional exploration drilling hole in each roof water-conducting fracture zone are sealed, the corresponding bottom plate damage zone depth exploration branch drilling hole is constructed. Solid-free mud is used during the drilling of the bottom plate damage zone depth exploration branch drilling hole. If the mud consumption increases to more than twice the original consumption at a certain time point, it is judged that the bottom plate damage zone has been entered, and the top leakage construction is continued until the mud consumption returns to the level before the bottom plate damage zone, which means that the complete rock layer under the bottom plate damage zone has been entered. At this time, the depth corresponding to the position where the mud consumption returns to the level before the bottom plate damage zone is considered to be the depth of the bottom plate damage zone. Otherwise, drilling continues to the designed end hole point, and the depth corresponding to the end hole position is considered to be the depth of the bottom plate damage zone. After construction, the borehole is fully sealed; The maximum value of the bottom plate damage zone depths obtained by directional exploration of the two bottom plate damage zone branch holes is taken as the final bottom plate damage zone depth.

[0017] Preferably, the sealing material in step 3 and step 5 is cement-water glass double liquid slurry.

[0018] The beneficial effects of the present invention are: The method for detecting the water-conducting fracture zone and the bottom plate damage zone of the mining roof of the coal mine working face of the present invention provides the design requirements of directional drilling, the drilling and sealing requirements of directional drilling, and clearly specifies the different positions of the working face for detection. Since the engineering volume of the conventional hole before entering the water-conducting fracture zone is invalid, the directional hole can share the invalid engineering volume, and the underground construction environment is complex and the construction risk is high, the present invention can save the drilling engineering volume of the conventional hole, avoid the safety risks of underground construction drilling, and realize the accurate detection of the water-conducting fracture zone and the bottom plate damage zone under the goaf. With the help of the rock stratum fracture conditions reflected by the mud consumption during the ground directional drilling, the height and shape of the water-conducting fracture zone and the depth of the bottom plate damage zone can be accurately judged, which is of great significance to improving the technical level of coal mine water hazard prevention and control. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flow chart of the method for detecting the water-conducting fracture zone of the roof and the damaged zone of the floor of the coal mine working face of the present invention; Figure 2 It is a cross-sectional diagram of a drilling hole for detecting a water-conducting fracture zone in a roof and a damaged zone in a coal mine working face in the present invention; Figure 3 It is a plan view of drilling holes for detecting water-conducting fracture zones in roof and damaged zones in bottom plate of a coal mine working face in the present invention. DETAILED DESCRIPTION

[0020] The following is a detailed description in conjunction with specific implementation methods.

[0021] Example 1 The present invention provides a method for detecting water-conducting fracture zones in the roof of a coal mine working face and damage zones in the floor, and the process thereof is as follows: Figure 1 As shown, the specific steps are as follows: Step 1: estimate the height of the water-conducting fracture zone in the top plate and the depth of the damaged zone in the bottom plate of the working face; Step 2, designing a surface directional exploration borehole for the roof water-conducting fracture zone according to the height of the water-conducting fracture zone estimated in step 1; Step 3: construct a directional exploration drill hole on the roof water-conducting fracture zone, and determine the height and shape of the roof water-conducting fracture zone according to the drilling mud consumption; Step 4, designing the branch drilling for the depth exploration of the bottom plate damage zone according to the ground directional exploration drilling of the roof water-conducting fracture zone in step 2 and the depth of the bottom plate damage zone of the mining face; Step 5: construct branch boreholes to detect the depth of the bottom plate damage zone and determine the depth of the bottom plate damage zone based on the drilling mud consumption.

[0022] Example 2 Based on Example 1, the height of the water-conducting fracture zone of the working face mining roof is estimated in step 1 as follows: referring to the "Specifications for Coal Pillar Retention and Compression Coal Mining in Buildings, Water Bodies, Railways and Main Shafts and Lanes", a statistical formula is used to calculate the height H of the water-conducting fracture zone of the working face.

[0023] The estimated depth of the working face mining floor damage zone in step 1 is as follows: refer to the "Specifications for Coal Pillar Retention and Coal Compression Mining in Buildings, Water Bodies, Railways and Main Shafts and Tunnels", use statistical formulas and theoretical formulas to calculate the depth of the floor damage zone respectively, and take the maximum value as the estimated value M of the floor damage zone depth.

[0024] Example 3 Based on Example 2, the conditions for determining the position of the ground directional exploration drilling hole in the roof water-conducting fracture zone in step 2 are as follows: Determine the water-conducting fracture zone of the roof and drill holes for ground directional exploration, such as Figure 2 and 3 As shown in the figure, the position of the ground directional exploration drilling hole in the roof water-conducting fracture zone is not within the lateral influence range of the water-conducting fracture zone and the distance between it and the lateral influence boundary of the water-conducting fracture zone is 50-200m, and the distance between the ground directional exploration drilling hole in the roof water-conducting fracture zone and the cut eye is greater than the working face width L; According to the position determination conditions, the position of the first ground directional exploration drill hole T1 in the roof water-conducting fracture zone is first determined, and then the second ground directional exploration drill hole T2 in the roof water-conducting fracture zone is arranged at a different position of the working face. The plane distance between T2 and T1 holes is not less than 200m, and the position determination conditions are met.

[0025] Example 4 On the basis of Example 3, the ground directional exploration drilling structure of the roof water-conducting fracture zone is 2 levels, the first level is a straight hole section, the second level is a branch hole of the bare hole section, and each ground directional exploration drilling hole of the roof water-conducting fracture zone includes 3 branch holes, among which the vertical distance between the end point of the first branch hole and the coal seam is 0.9H, and the spacing between the end point and the working face tunnel is 0.5L; the vertical distance between the end point of the second branch hole and the coal seam is 0.8H, and the spacing between the end point and the working face tunnel is 30m; the vertical distance between the end point of the third branch hole and the coal seam is 0.6H, and the spacing between the end point and the working face tunnel is 10m; and the angle between the drilling trajectory at the end point of each branch hole of the ground directional exploration drilling hole of the roof water-conducting fracture zone and the horizontal plane is not less than 20°, such as Figure 2 and Figure 3 As shown, in this embodiment, the three branch holes of the directional exploration drilling hole T1 in the roof water-conducting fracture zone are T1-1, T1-2, and T1-3, and the three branch holes of the directional exploration drilling hole T2 in the roof water-conducting fracture zone are T2-1, T2-2, and T2-3; The specific steps of constructing the ground directional exploration drilling holes in the water-conducting fracture zone of the roof in step 3 are as follows: One month after the coal seam mining at the detection position was completed, a ground directional exploration drilling hole was constructed in the water-conducting fracture zone of the roof. The specific construction process was as follows: two ground directional exploration drilling holes in the water-conducting fracture zone of the roof were constructed in sequence. When constructing each ground directional exploration drilling hole in the water-conducting fracture zone of the roof, the first level was constructed as a straight hole section, specifically: the casing was lowered to 10m into the intact bedrock, and then the first branch hole, the second branch hole, and the third branch hole were constructed in sequence.

[0026] Example 5 On the basis of Example 4, the height and shape of the water-conducting fracture zone of the roof are determined according to the drilling mud consumption in step 3 as follows: During the drilling of the corresponding branch holes, solid-free mud is used. If the mud consumption increases to the point of total loss, it is determined that the water-conducting fracture zone has been entered and drilling is stopped; otherwise, drilling is continued to the designed end point; after the construction is completed, the branch holes are sealed with cement-water-glass double-liquid slurry. Each branch hole obtains a roof water-conducting fracture zone position. Based on the water-conducting fracture zone positions obtained by ground directional exploration drilling of two roof water-conducting fracture zones, a total of 6 branch holes, the maximum water-conducting fracture zone height is obtained and the shape of the water-conducting fracture zone is determined; Among them, for each branch hole, if all leakage occurs during drilling, the height corresponding to the position where all leakage occurs is the height of the water-conducting fracture zone; if all leakage does not occur during drilling, the height corresponding to the position of the end hole point is the height of the water-conducting fracture zone; According to the three branch holes of the ground directional exploration drilling hole of the same roof water-conducting fracture zone, the morphology of the water-conducting fracture zone at the corresponding position is determined as follows: If the height of the water-conducting fracture zone obtained by the first branch hole of the ground directional exploration drilling corresponding to the water-conducting fracture zone is greater than the height of the water-conducting fracture zone obtained by the other two branch holes, then the water-conducting fracture zone is arch-shaped, otherwise it is saddle-shaped.

[0027] Example 6 Based on Example 5, step 4 is specifically as follows: A branch hole for deep exploration of the bottom plate damage zone is set at each directional exploration hole on the ground of the roof water-conducting fracture zone. The starting point of the branch hole for deep exploration of the bottom plate damage zone is the end point of the straight hole section. The specific position confirmation conditions are as follows: The branch drilling trajectory for deep exploration of the bottom plate damage zone does not enter the development range of the water-conducting fracture zone. The end point of the branch drilling for deep exploration of the bottom plate damage zone is 1.3M away from the coal seam. In the vertical direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone is located below the bottom plate of the coal seam, with a vertical distance of 1.3M from the bottom plate of the coal seam. In the horizontal direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone passes through the tunnel and enters 30~50m inside the projection range of the working face.

[0028] The branch drilling holes for deep exploration of the bottom plate damage zone are not within the development range of the water-conducting fracture zone, that is, if the roof water-conducting fracture zone is arched, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the mining range of the working face; if the roof water-conducting fracture zone is saddle-shaped, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the lateral influence range of the water-conducting fracture zone.

[0029] After the three branch holes of the ground directional exploration drilling hole in each roof water-conducting fracture zone are sealed, the corresponding bottom plate damage zone depth exploration branch drilling hole is constructed. During the drilling of the bottom plate damage zone depth exploration branch drilling hole, solid-free mud is used. If the mud consumption increases to more than twice the original consumption at a certain time point, it is judged that the bottom plate damage zone has been entered, and the top leakage construction is continued until the mud consumption returns to the level before the bottom plate damage zone, which means that the complete rock layer under the bottom plate damage zone has been entered. At this time, the depth corresponding to the position where the mud consumption returns to the level before the bottom plate damage zone is considered to be the depth of the bottom plate damage zone. Otherwise, continue to drill to the designed end hole point. If the end hole point is reached, the depth corresponding to the end hole position is considered to be the depth of the bottom plate damage zone. After construction, the borehole is fully sealed, and the sealing material is cement-water-glass double liquid slurry; The maximum value of the bottom plate damage zone depths obtained by directional exploration of the two bottom plate damage zone branch holes is taken as the final bottom plate damage zone depth.

Claims

1. A method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face, characterized in that: The specific steps are as follows: Step 1: estimate the height of the water-conducting fracture zone in the top plate and the depth of the damaged zone in the bottom plate of the working face; Step 2, designing a surface directional exploration borehole for the roof water-conducting fracture zone according to the height of the water-conducting fracture zone estimated in step 1; Step 3: construct a directional exploration drill hole on the roof water-conducting fracture zone, and determine the height and shape of the roof water-conducting fracture zone according to the drilling mud consumption; Step 4, designing the branch drilling for the depth exploration of the bottom plate damage zone according to the ground directional exploration drilling of the roof water-conducting fracture zone in step 2 and the depth of the bottom plate damage zone of the mining face; Step 5: construct branch boreholes to detect the depth of the bottom plate damage zone and determine the depth of the bottom plate damage zone based on the drilling mud consumption.

2. The method for detecting water-conducting fracture zones and floor damage zones of coal mine working faces according to claim 1, characterized in that: The height of the water-conducting fracture zone of the mining roof of the working face estimated in step 1 is specifically as follows: referring to the "Specifications for the Installation of Coal Pillars and Compressed Coal Mining in Buildings, Water Bodies, Railways and Main Shafts and Lanes", the height H of the water-conducting fracture zone of the working face is calculated using a statistical formula.

3. The method for detecting water-conducting fracture zones and floor damage zones of coal mine working faces according to claim 2, characterized in that: The estimated depth of the working face mining floor damage zone in step 1 is specifically as follows: referring to the "Specifications for Coal Pillar Retention and Compression Mining for Buildings, Water Bodies, Railways and Main Shafts and Tunnels", the depth of the floor damage zone is calculated using statistical formulas and theoretical formulas respectively, and the maximum value is taken as the estimated value M of the floor damage zone depth.

4. The method for detecting water-conducting fracture zones and floor damage zones of coal mine working faces according to claim 3, characterized in that: The conditions for determining the position of the ground directional exploration drilling hole in the roof water-conducting fracture zone in step 2 are as follows: Determine the ground directional exploration drilling holes in the roof water-conducting fracture zone. The location of the ground directional exploration drilling holes in the roof water-conducting fracture zone is not within the lateral influence range of the water-conducting fracture zone and the distance between the ground directional exploration drilling holes in the roof water-conducting fracture zone and the lateral influence boundary of the water-conducting fracture zone is 50-200m. In addition, the distance between the ground directional exploration drilling holes in the roof water-conducting fracture zone and the cut eye is greater than the working face width L. According to the position determination conditions, the position of the first ground directional exploration drill hole T1 in the roof water-conducting fracture zone is first determined, and then the second ground directional exploration drill hole T2 in the roof water-conducting fracture zone is arranged at a different position of the working face. The plane distance between T2 and T1 is not less than 200m, and the position determination conditions are met.

5. The method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face according to claim 4, characterized in that: The ground directional exploration drilling structure of the roof water-conducting fracture zone is two-level, the first level is the straight hole section, the second level is the open hole section branch hole, each roof water-conducting fracture zone ground directional exploration drilling hole includes 3 branch holes, among which the end point of the first branch hole is 0.9H away from the coal seam, and the spacing from the working face tunnel is 0.5L; the end point of the second branch hole is 0.8H away from the coal seam, and the spacing from the working face tunnel is 30m; the end point of the third branch hole is 0.6H away from the coal seam, and the spacing from the working face tunnel is 10m; and the angle between the drilling trajectory at the end point of each branch hole of each roof water-conducting fracture zone ground directional exploration drilling hole and the horizontal plane is not less than 20°.

6. The method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face according to claim 5, characterized in that: The specific steps of constructing the ground directional exploration drilling holes in the water-conducting fracture zone of the roof in step 3 are as follows: One month after the coal seam mining at the detection position was completed, a ground directional exploration drilling hole was constructed in the water-conducting fracture zone of the roof. The specific construction process was as follows: two ground directional exploration drilling holes in the water-conducting fracture zone of the roof were constructed in sequence. When constructing each ground directional exploration drilling hole in the water-conducting fracture zone of the roof, the first level was constructed as a straight hole section, specifically: the casing was lowered to 10m into the intact bedrock, and then the first branch hole, the second branch hole, and the third branch hole were constructed in sequence.

7. The method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face according to claim 6, characterized in that: In step 3, the height and shape of the water-conducting fracture zone of the roof are determined according to the drilling mud consumption: During the drilling of the corresponding branch holes, solid-free mud is used. If the mud consumption increases to the point of total loss, it is determined that the water-conducting fracture zone has been entered and drilling is stopped; otherwise, drilling is continued to the designed end point; after the construction is completed, the branch holes are sealed, and a roof water-conducting fracture zone position is obtained for each branch hole. Based on the water-conducting fracture zone positions obtained by the ground directional exploration drilling of two roof water-conducting fracture zones, a total of 6 branch holes, the maximum water-conducting fracture zone height is obtained and the shape of the water-conducting fracture zone is determined; Among them, for each branch hole, if all leakage occurs during drilling, the height corresponding to the position where all leakage occurs is the height of the water-conducting fracture zone; if all leakage does not occur during drilling, the height corresponding to the position of the end hole point is the height of the water-conducting fracture zone; According to the three branch holes of the ground directional exploration drilling hole in the same roof water-conducting fracture zone, the morphology of the water-conducting fracture zone at the corresponding position is determined as follows: If the height of the water-conducting fracture zone obtained by the first branch hole of the ground directional exploration drilling corresponding to the water-conducting fracture zone is greater than the height of the water-conducting fracture zone obtained by the other two branch holes, then the water-conducting fracture zone is arch-shaped, otherwise it is saddle-shaped.

8. The method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face according to claim 7, characterized in that: The step 4 is specifically as follows: A bottom plate damage zone depth exploration branch hole is set at each top plate water-conducting fracture zone ground directional exploration drill hole. The starting point of the bottom plate damage zone depth exploration branch hole is the end point of the straight hole section. The specific position confirmation conditions are as follows: The branch drilling trajectory for deep exploration of the bottom plate damage zone does not enter the development range of the water-conducting fracture zone. The end point of the branch drilling for deep exploration of the bottom plate damage zone is 1.3M away from the coal seam. In the vertical direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone is located below the bottom plate of the coal seam, with a vertical distance of 1.3M from the bottom plate of the coal seam. In the horizontal direction, the end point of the branch drilling for deep exploration of the bottom plate damage zone passes through the tunnel and enters 30~50m inside the projection range of the working face. The branch drilling holes for deep exploration of the bottom plate damage zone are not within the development range of the water-conducting fracture zone, that is, if the roof water-conducting fracture zone is arched, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the mining range of the working face; if the roof water-conducting fracture zone is saddle-shaped, the branch drilling trajectory for deep exploration of the bottom plate damage zone is not within the lateral influence range of the water-conducting fracture zone.

9. The method for detecting water-conducting fracture zones and floor damage zones of coal mine working faces according to claim 8, characterized in that: The step 5 is specifically as follows: After the three branch holes of the ground directional exploration drilling hole in each roof water-conducting fracture zone are sealed, the corresponding bottom plate damage zone depth exploration branch drilling hole is constructed. Solid-free mud is used during the drilling of the bottom plate damage zone depth exploration branch drilling hole. If the mud consumption increases to more than twice the original consumption at a certain time point, it is judged that the bottom plate damage zone has been entered, and the top leakage construction is continued until the mud consumption returns to the level before the bottom plate damage zone, which means that the complete rock layer under the bottom plate damage zone has been entered. At this time, the depth corresponding to the position where the mud consumption returns to the level before the bottom plate damage zone is considered to be the depth of the bottom plate damage zone. Otherwise, drilling continues to the designed end hole point, and the depth corresponding to the end hole position is considered to be the depth of the bottom plate damage zone. After construction, the borehole is fully sealed; The maximum value of the bottom plate damage zone depths obtained by directional exploration of the two bottom plate damage zone branch holes is taken as the final bottom plate damage zone depth.

10. The method for detecting water-conducting fracture zones in the roof and damaged zones in the floor of a coal mine working face according to claim 9, characterized in that: The sealing material in step 3 and step 5 is cement-water glass double liquid slurry.

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