Method for determining grout diffusion path of coal mine water disaster ground area grouting engineering

Abstract

The coal mine water disaster ground area grouting engineering slurry diffusion path determination method disclosed by the application has the specific steps of: 1. constructing a long distance directional drilling hole, 2. forming a drilled hole track, 3. arranging two first electric method geophysical prospecting lines on the two sides of the drilled hole track at equal intervals, 4. carrying out a primary electric method geophysical prospecting operation before grouting, 5. adding a high conductivity indicator into the grouting slurry and injecting the grouting slurry into the stratum to form a designed slurry diffusion range, 6. carrying out a secondary geophysical prospecting operation, and circumscribing an electric method geophysical prospecting low resistance area on the surface of the treatment area, 7. comparing and analyzing the designed slurry diffusion range and the electric method geophysical prospecting low resistance area, judging whether there is a slurry diffusion coverage blind area or a slurry abnormal diffusion area, and taking corresponding measures to obtain a final slurry diffusion area and a slurry diffusion path. The application realizes the purpose of determining the slurry diffusion path by adding a high conductivity indicator into the grouting slurry and timely carrying out electric method geophysical prospecting.

Description

Technical Field

[0001] This invention belongs to the technical field of monitoring methods for the diffusion range of grout in borehole grouting in coal mine operation areas, and relates to a method for determining the diffusion path of grout in grouting projects in ground areas of coal mines with water hazards. Background Technology

[0002] Mine water hazards are one of the main threats to coal mine safety. In recent years, with the continuous improvement of the performance of long-distance directional drilling grouting equipment, advanced regional grouting for coal mine water hazard control has gradually become the main means of water prevention and control in coal mines. The promotion and implementation of this method has ensured the safe production of mines. Ideally, after the borehole is completed according to the designed trajectory, the grout will move along the borehole and fill the rock fissures, thereby eliminating the water hazard by sealing the water-conducting channels. However, because regional grouting is a hidden project and the actual strata are heterogeneous, the actual movement path of the grout is difficult to control under the high pressure at the borehole opening. If problems such as borehole collapse occur in the middle, a blocked section will be formed, and grout cannot enter the blocked section. If underground caverns, fault zones, karst collapse columns, or other channels exist near the borehole, the grout may diffuse endlessly along these channels, leading to ineffective grout consumption, wasted grouting materials, increased construction time and costs, and potential large-scale groundwater pollution. Some areas may also have blind spots for remediation, compromising the effectiveness of grouting treatment. Therefore, understanding the actual diffusion path of the grout is crucial for optimizing and adjusting the treatment plan and ensuring the effectiveness of the remediation. Currently, there is no mature method for monitoring and analyzing the grout diffusion path. Previously, the diffusion range of grout was often inferred indirectly by observing grout inclusions and other debris returned from cuttings logging during adjacent borehole drilling after grouting. However, this method can only determine whether the grout has diffused to the borehole's location, not the diffusion boundary. Furthermore, in actual observation, the number of grout inclusions is very small compared to other cuttings, making accurate identification difficult in cuttings logging. Grout transport channels such as karst channels are also difficult to detect through borehole cuttings. Therefore, it is necessary to explore and study methods that can accurately detect the diffusion range of slurry. Summary of the Invention

[0003] The purpose of this invention is to provide a method for determining the grout diffusion path in grouting projects in ground areas of coal mines with water hazards, thereby solving the problem that the grout diffusion boundary cannot be determined in the prior art.

[0004] The technical solution adopted in this invention is a method for determining the diffusion path of grout in surface grouting projects for coal mine water hazards, comprising the following steps:

[0005] Step 1: Construct long-distance directional boreholes using long-distance directional drilling and grouting equipment within the strata between the coal seam and the target aquifer;

[0006] Step 2: Project the trajectory of the long-distance directional drilling onto the surface of the treatment area to form the trajectory of the completed drilling.

[0007] Step 3: On both sides of the completed borehole trajectory, two first electrical geophysical exploration lines are arranged at equal intervals; the initial electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data;

[0008] Step 4: After adding a highly conductive indicator to the grout, inject it into the formation through a long-distance directional borehole. The grout will spread evenly in the isotropic homogeneous formation to form the designed grout diffusion range.

[0009] Step 5: After grouting is completed, another geophysical exploration operation will be carried out. Based on the original stratigraphic background data, the low resistivity zone of the electrical geophysical exploration will be delineated on the surface of the treatment area.

[0010] Step 6: Compare and analyze the designed slurry diffusion range and the low resistivity zone of the electrical geophysical exploration to determine whether there is a slurry diffusion coverage blind zone or an abnormal slurry diffusion zone, and then obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone or the boundary of the abnormal slurry diffusion zone.

[0011] Step 7: Determine the grout diffusion path for the grouting project.

[0012] The invention is further characterized by:

[0013] Method for determining the grout diffusion path in grouting projects in ground areas of coal mine water hazards: Step 3: Arrange two first electrical resistivity tomography detection lines at equal intervals, with an interval of 30m to 50m.

[0014] Method for determining the grout diffusion path in grouting projects in ground areas of coal mine water hazards, with carbon fiber as the high conductivity indicator in step 4.

[0015] The method for determining the grout diffusion path in grouting projects in surface areas of coal mine water hazards, specifically step 6, involves judging whether there are blind spots or abnormal grout diffusion zones.

[0016] The area where the low resistivity zone of the electrical geophysical exploration does not cover the designed slurry diffusion range is called the slurry diffusion coverage blind zone; the area where the low resistivity zone of the electrical geophysical exploration exceeds the designed slurry diffusion range is called the slurry abnormal diffusion zone.

[0017] The method for determining the grout diffusion path in grouting projects in surface areas of coal mine water hazards, specifically step 6, involves obtaining the supplementary grout diffusion boundary of the grout diffusion coverage blind zone or the boundary of the abnormal grout diffusion zone as follows:

[0018] If there is a grout diffusion blind zone, then conduct additional long-distance directional drilling and repeat steps 2-5 to obtain the supplementary grout diffusion boundary of the grout diffusion blind zone.

[0019] If an abnormal slurry diffusion zone exists, the trajectory of the abnormal slurry diffusion zone will be projected onto the surface of the treatment area, and a second electrical resistivity tomography (EDT) probe will be deployed for another geophysical exploration. Based on the exploration results, the position of the second EDT probe will be continuously adjusted until the boundary of the abnormal slurry diffusion zone is delineated.

[0020] The method for determining the grout diffusion path in grouting projects in surface areas of coal mine water hazards, step 7, is as follows:

[0021] The area enclosed by the boundary of the low-resistivity zone in electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone, and the boundary of the abnormal slurry diffusion zone is the final slurry diffusion area; the slurry diffusion path of the grouting project is the distance from the borehole opening of the long-distance directional drilling to the boundary of the final slurry diffusion area.

[0022] The beneficial effects of this invention are:

[0023] 1. Previously, there was a lack of dynamic analysis and monitoring methods for grout diffusion. The cuttings logging method after grouting was completed only provided a single-hole view and could not determine the planar diffusion range. By deploying a first electrical resistivity tomography (EDT) probe line on the ground and conducting timely geophysical exploration based on grout consumption during the grouting process, and then optimizing and adjusting the grouting plan based on the exploration results, the efficiency of grouting treatment can be improved and blind spots in the treatment can be eliminated.

[0024] 2. By comparing the results before and after ground geophysical exploration, the influence of potential low-resistivity zones in the primary strata is eliminated, allowing for a more direct determination of the planar diffusion range of the slurry. Compared to rock cuttings identification, the method is simpler and less difficult to identify.

[0025] 3. Ground-based electrical geophysical exploration has a wide coverage area, which is well adapted to the characteristics of a wide exploration coverage area during regional governance, and facilitates the analysis of the location of abnormal slurry consumption points.

[0026] 4. By adding carbon fiber material with strong conductivity to the grout, the resistivity of the formation within the grout diffusion range is reduced. The operation method is relatively simple and the construction difficulty is small.

[0027] 5. Ground-based electrical geophysical exploration does not interfere with drilling and grouting operations. Geophysical exploration can be carried out during grouting or after grouting has stopped, without waiting for the grout to solidify, making it highly effective.

[0028] 6. Carbon fiber materials have high strength. After solidifying together with the grouting slurry, they can improve the strength of the grout-formed rock mass, which is beneficial to improving the ability to withstand rock loads and resist mining disturbances. Attached Figure Description

[0029] Figure 1This is a schematic diagram of the grouting treatment and the arrangement of the first ground electrical resistivity tomography (OTT) detection line of the present invention;

[0030] Figure 2 This is a planar schematic diagram of the drilling trajectory and the arrangement of the first electrical resistivity tomography (OTT) probe lines of the present invention;

[0031] Figure 3 This is a comparative schematic diagram of the slurry diffusion range and the low resistivity zone of the electrical geophysical exploration method designed in this invention;

[0032] Figure 4 This is a schematic diagram showing the location of the second electrical resistivity detection line and the low-resistivity region of the electrical resistivity detection method in this invention.

[0033] In the figure: 1. Coal seam, 2. Target aquifer, 3. Long-distance directional borehole, 4. Completed borehole trajectory, 5. First electrical resistivity detection line, 6. Designed slurry diffusion range, 7. Low resistivity zone of electrical resistivity detection, 8. Blind zone of slurry diffusion coverage, 9. Abnormal slurry diffusion zone, 10. Second electrical resistivity detection line. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] The method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines provided by this invention specifically includes the following steps:

[0036] Step 1: As Figure 1 As shown, a long-distance directional drilling grouting equipment is used to construct a long-distance directional borehole 3 in the stratum between coal seam 1 and target aquifer 2;

[0037] Step 2: Based on the drilling measurement data recorded during the drilling process, project the trajectory of the long-distance directional borehole 3 onto the surface of the treatment area to form the completed borehole trajectory 4;

[0038] Step 3: As Figure 2 As shown, on both sides of the completed borehole trajectory 4, two first electrical geophysical exploration lines 5 are arranged at equal intervals of 30m to 50m; the initial electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data.

[0039] Step 4: After adding carbon fiber high-conductivity indicator to the grout, inject it into the formation along a long-distance directional borehole 3. The grout will uniformly diffuse in the isotropic homogeneous formation to form the designed grout diffusion range 6, such as... Figure 3 As shown;

[0040] Step 5: After grouting is completed, another geophysical exploration operation will be conducted. Based on the original geological background data, a low-resistivity zone 7 will be delineated on the surface of the treatment area using electrical resistivity geophysical methods. Figure 3 As shown;

[0041] Step 6: Compare and analyze the designed slurry diffusion range 6 and the low resistivity zone 7 of electrical geophysical exploration to determine whether there is a slurry diffusion coverage blind zone 8 or an abnormal slurry diffusion zone 9. The determination method is as follows: Figure 3 and Figure 4 As shown, the area where the low resistivity zone 7 of the electrical geophysical exploration does not cover the designed slurry diffusion range 6 is the slurry diffusion coverage blind zone 8; the area where the low resistivity zone 7 of the electrical geophysical exploration exceeds the designed slurry diffusion range 6 is the slurry abnormal diffusion zone 9.

[0042] The method for obtaining the supplementary slurry diffusion boundary or the boundary of the abnormal slurry diffusion zone 9 for the slurry diffusion coverage blind zone 8 is as follows: Figure 4 As shown, if there is a slurry diffusion coverage blind zone 8, then a long-distance directional borehole 3 is drilled to supplement the construction, and steps 2-5 are repeated to obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8; if there is an abnormal slurry diffusion zone 9, then the trajectory of the abnormal slurry diffusion zone 9 is projected onto the surface of the treatment area, and a second electrical resistivity tomography detection line 10 is set up to conduct geophysical exploration again. Based on the exploration results, the position of the second electrical resistivity tomography detection line 10 is continuously adjusted until the boundary of the abnormal slurry diffusion zone 9 is delineated.

[0043] Step 7: Determine the grout diffusion path for the grouting project, as follows:

[0044] The area enclosed by the boundary of the low-resistivity zone 7 in the electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8, and the boundary of the abnormal slurry diffusion zone 9 is the final slurry diffusion area; the slurry diffusion path of the grouting project is from the borehole position of the long-distance directional borehole 3 to the boundary position of the final slurry diffusion area.

[0045] The slurry diffusion path is generally also the main water-conducting channel, and is the main target area for grouting treatment. Based on the final slurry diffusion area and slurry diffusion path, the coal mine water hazard treatment plan is adjusted and optimized. By deploying the second electrical resistivity tomography detection line 10, adjusting the grout concentration and grouting pump volume, etc., the abnormal slurry diffusion area 9 is treated in a key manner, and the main water-conducting channel is blocked, thereby eliminating the coal mine water hazard.

[0046] Example 1

[0047] This invention provides a method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines. The specific steps are as follows:

[0048] Step 1: As Figure 1 As shown, a long-distance directional drilling grouting equipment is used to construct a long-distance directional borehole 3 in the stratum between coal seam 1 and target aquifer 2;

[0049] Step 2: Based on the drilling measurement data recorded during the drilling process, project the trajectory of the long-distance directional borehole 3 onto the surface of the treatment area to form the completed borehole trajectory 4;

[0050] Step 3: As Figure 2 As shown, on both sides of the completed borehole trajectory 4, two first electrical geophysical exploration lines 5 are arranged at equal intervals of 30m; the initial electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data.

[0051] Step 4: After adding carbon fiber high-conductivity indicator to the grout, inject it into the formation along a long-distance directional borehole 3. The grout will uniformly diffuse in the isotropic homogeneous formation to form the designed grout diffusion range 6, such as... Figure 3 As shown;

[0052] Step 5: After grouting is completed, another geophysical exploration operation will be conducted. Based on the original geological background data, a low-resistivity zone 7 will be delineated on the surface of the treatment area using electrical resistivity geophysical methods. Figure 3 As shown;

[0053] Step 6: Compare and analyze the designed slurry diffusion range 6 and the low resistivity zone 7 of electrical geophysical exploration to determine whether there is a slurry diffusion coverage blind zone 8 or an abnormal slurry diffusion zone 9. The determination method is as follows: Figure 3 and Figure 4 As shown, the area where the low resistivity zone 7 of the electrical geophysical exploration does not cover the designed slurry diffusion range 6 is the slurry diffusion coverage blind zone 8; the area where the low resistivity zone 7 of the electrical geophysical exploration exceeds the designed slurry diffusion range 6 is the slurry abnormal diffusion zone 9.

[0054] The method for obtaining the supplementary slurry diffusion boundary or the boundary of the abnormal slurry diffusion zone 9 for the slurry diffusion coverage blind zone 8 is as follows: Figure 4 As shown, if there is a slurry diffusion coverage blind zone 8, then a long-distance directional borehole 3 is drilled to supplement the construction, and steps 2-5 are repeated to obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8; if there is an abnormal slurry diffusion zone 9, then the trajectory of the abnormal slurry diffusion zone 9 is projected onto the surface of the treatment area, and a second electrical resistivity tomography detection line 10 is set up to conduct geophysical exploration again. Based on the exploration results, the position of the second electrical resistivity tomography detection line 10 is continuously adjusted until the boundary of the abnormal slurry diffusion zone 9 is delineated.

[0055] Step 7: Determine the grout diffusion path for the grouting project, as follows:

[0056] The area enclosed by the boundary of the low-resistivity zone 7 in the electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8, and the boundary of the abnormal slurry diffusion zone 9 is the final slurry diffusion area; the slurry diffusion path of the grouting project is from the borehole position of the long-distance directional borehole 3 to the boundary position of the final slurry diffusion area.

[0057] Example 2

[0058] This invention provides a method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines. The specific steps are as follows:

[0059] Step 1: As Figure 1 As shown, a long-distance directional drilling grouting equipment is used to construct a long-distance directional borehole 3 in the stratum between coal seam 1 and target aquifer 2;

[0060] Step 2: Based on the drilling measurement data recorded during the drilling process, project the trajectory of the long-distance directional borehole 3 onto the surface of the treatment area to form the completed borehole trajectory 4;

[0061] Step 3: As Figure 2 As shown, on both sides of the completed borehole trajectory 4, two first electrical geophysical exploration lines 5 are arranged at equal intervals of 40m; the initial electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data.

[0062] Step 4: After adding carbon fiber high-conductivity indicator to the grout, inject it into the formation along a long-distance directional borehole 3. The grout will uniformly diffuse in the isotropic homogeneous formation to form the designed grout diffusion range 6, such as... Figure 3 As shown;

[0063] Step 5: After grouting is completed, another geophysical exploration operation will be conducted. Based on the original geological background data, a low-resistivity zone 7 will be delineated on the surface of the treatment area using electrical resistivity geophysical methods. Figure 3 As shown;

[0064] Step 6: Compare and analyze the designed slurry diffusion range 6 and the low resistivity zone 7 of electrical geophysical exploration to determine whether there is a slurry diffusion coverage blind zone 8 or an abnormal slurry diffusion zone 9. The determination method is as follows: Figure 3 and Figure 4 As shown, the area where the low resistivity zone 7 of the electrical geophysical exploration does not cover the designed slurry diffusion range 6 is the slurry diffusion coverage blind zone 8; the area where the low resistivity zone 7 of the electrical geophysical exploration exceeds the designed slurry diffusion range 6 is the slurry abnormal diffusion zone 9.

[0065] The method for obtaining the supplementary slurry diffusion boundary or the boundary of the abnormal slurry diffusion zone 9 for the slurry diffusion coverage blind zone 8 is as follows: Figure 4 As shown, if there is a slurry diffusion coverage blind zone 8, then a long-distance directional borehole 3 is drilled to supplement the construction, and steps 2-5 are repeated to obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8; if there is an abnormal slurry diffusion zone 9, then the trajectory of the abnormal slurry diffusion zone 9 is projected onto the surface of the treatment area, and a second electrical resistivity tomography detection line 10 is set up to conduct geophysical exploration again. Based on the exploration results, the position of the second electrical resistivity tomography detection line 10 is continuously adjusted until the boundary of the abnormal slurry diffusion zone 9 is delineated.

[0066] Step 7: Determine the grout diffusion path for the grouting project, as follows:

[0067] The area enclosed by the boundary of the low-resistivity zone 7 in the electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8, and the boundary of the abnormal slurry diffusion zone 9 is the final slurry diffusion area; the slurry diffusion path of the grouting project is from the borehole position of the long-distance directional borehole 3 to the boundary position of the final slurry diffusion area.

[0068] Example 3

[0069] This invention provides a method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines. The specific steps are as follows:

[0070] Step 1: As Figure 1 As shown, a long-distance directional drilling grouting equipment is used to construct a long-distance directional borehole 3 in the stratum between coal seam 1 and target aquifer 2;

[0071] Step 2: Based on the drilling measurement data recorded during the drilling process, project the trajectory of the long-distance directional borehole 3 onto the surface of the treatment area to form the completed borehole trajectory 4;

[0072] Step 3: As Figure 2 As shown, on both sides of the completed borehole trajectory 4, two first electrical geophysical exploration lines 5 are arranged at equal intervals of 50m; the initial electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data.

[0073] Step 4: After adding carbon fiber high-conductivity indicator to the grout, inject it into the formation along a long-distance directional borehole 3. The grout will uniformly diffuse in the isotropic homogeneous formation to form the designed grout diffusion range 6, such as... Figure 3 As shown;

[0074] Step 5: After grouting is completed, another geophysical exploration operation will be conducted. Based on the original geological background data, a low-resistivity zone 7 will be delineated on the surface of the treatment area using electrical resistivity geophysical methods. Figure 3 As shown;

[0075] Step 6: Compare and analyze the designed slurry diffusion range 6 and the low resistivity zone 7 of electrical geophysical exploration to determine whether there is a slurry diffusion coverage blind zone 8 or an abnormal slurry diffusion zone 9. The determination method is as follows: Figure 3 and Figure 4 As shown, the area where the low resistivity zone 7 of the electrical geophysical exploration does not cover the designed slurry diffusion range 6 is the slurry diffusion coverage blind zone 8; the area where the low resistivity zone 7 of the electrical geophysical exploration exceeds the designed slurry diffusion range 6 is the slurry abnormal diffusion zone 9.

[0076] The method for obtaining the supplementary slurry diffusion boundary or the boundary of the abnormal slurry diffusion zone 9 for the slurry diffusion coverage blind zone 8 is as follows: Figure 4 As shown, if there is a slurry diffusion coverage blind zone 8, then a long-distance directional borehole 3 is drilled to supplement the construction, and steps 2-5 are repeated to obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8; if there is an abnormal slurry diffusion zone 9, then the trajectory of the abnormal slurry diffusion zone 9 is projected onto the surface of the treatment area, and a second electrical resistivity tomography detection line 10 is set up to conduct geophysical exploration again. Based on the exploration results, the position of the second electrical resistivity tomography detection line 10 is continuously adjusted until the boundary of the abnormal slurry diffusion zone 9 is delineated.

[0077] Step 7: Determine the grout diffusion path for the grouting project, as follows:

[0078] The area enclosed by the boundary of the low-resistivity zone 7 in the electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone 8, and the boundary of the abnormal slurry diffusion zone 9 is the final slurry diffusion area; the slurry diffusion path of the grouting project is from the borehole position of the long-distance directional borehole 3 to the boundary position of the final slurry diffusion area.

Claims

1. A method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines, characterized in that, Includes the following steps: Step 1: In the strata between the coal seam (1) and the target aquifer (2), a long-distance directional drilling grouting equipment is used to construct a long-distance directional borehole (3). Step 2: Project the trajectory of the long-distance directional borehole (3) onto the surface of the treatment area to form the trajectory of the completed borehole (4). Step 3: On both sides of the completed borehole trajectory (4), two first electrical geophysical exploration lines (5) are arranged at equal intervals. The first electrical geophysical exploration operation is carried out before grouting, and the geophysical exploration results are used as the original stratigraphic background data. Step 4: After adding a high conductivity indicator to the grout, inject it into the formation along a long-distance directional borehole (3). The grout will diffuse uniformly in the isotropic homogeneous formation to form the designed grout diffusion range (6). The high conductivity indicator is carbon fiber. Step 5: After grouting is completed, another geophysical exploration operation is carried out. Combined with the original stratigraphic background data, the low resistivity zone of electrical geophysical exploration is delineated on the surface of the treatment area (7). Step 6: Compare and analyze the designed slurry diffusion range (6) and the low resistivity zone of the electrical geophysical exploration (7) to determine whether there is a slurry diffusion coverage blind zone (8) or an abnormal slurry diffusion zone (9), and then obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone (8) or the boundary of the abnormal slurry diffusion zone (9). The method for determining whether there is a slurry diffusion coverage blind zone (8) or an abnormal slurry diffusion zone (9) in step 6 is as follows: The area where the low resistivity zone (7) of the electrical geophysical exploration does not cover the designed slurry diffusion range (6) is the slurry diffusion coverage blind zone (8), and the area where the low resistivity zone (7) of the electrical geophysical exploration exceeds the designed slurry diffusion range (6) is the slurry abnormal diffusion zone (9). The method for obtaining the supplementary slurry diffusion boundary or the boundary of the abnormal slurry diffusion zone (9) of the slurry diffusion coverage blind zone (8) is as follows: If there is a slurry diffusion coverage blind zone (8), then supplement the construction with long-distance directional drilling (3), repeat steps 2-5, and obtain the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone (8); If an abnormal slurry diffusion zone (9) exists, the trajectory of the abnormal slurry diffusion zone (9) is projected onto the surface of the treatment area, and a second electrical resistivity tomography probe (10) is deployed for geophysical exploration. Based on the exploration results, the position of the second electrical resistivity tomography probe (10) is continuously adjusted until the boundary of the abnormal slurry diffusion zone (9) is delineated. Step 7: Determine the grout diffusion path for the grouting project. The method for determining the grout diffusion path for the grouting project is as follows: The area enclosed by the boundary of the low-resistivity zone (7) of the electrical geophysical exploration, the supplementary slurry diffusion boundary of the slurry diffusion coverage blind zone (8), and the boundary of the abnormal slurry diffusion zone (9) is the final slurry diffusion area. The slurry diffusion path of the grouting project is from the borehole position of the long-distance directional borehole (3) to the boundary position of the final slurry diffusion area.

2. The method for determining the grout diffusion path in grouting projects for surface areas affected by water hazards in coal mines according to claim 1, characterized in that, In step 3, two first electrical resistivity detection lines (5) are arranged at equal intervals, with an interval of 30m to 50m.

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