Method for determining diffusion range of underground roadway drilling grouting slurry

Abstract

The invention discloses a method for determining the diffusion range of underground roadway drilling grouting slurry. The method comprises the following steps: (1) completing construction of all grouting drilling holes; (2) a probe of a transient electromagnetic detection instrument is placed in the grouting drill hole, and in-hole transient electromagnetic detection and recording are carried out once; (3) after grouting is completed in the constructed grouting drill hole, secondary in-hole transient electromagnetic detection is carried out, and recording is carried out; 4) comparing detection information of two times of in-hole transient electromagnetic detection, determining a diffusion range of the grouting slurry, and completing grouping; (5) a water pressure test is conducted, the unit permeable rate of each grouting hole is tested, and secondary grouping is completed; the invention belongs to the technical field of coal mine grouting slurry diffusion detection, and is suitable in diffusion range determination mode, small in detection interference and high in precision. The method comprises the steps of (1) determining a slurry diffusion range, (2) determining a slurry diffusion range, (3) determining a slurry diffusion range, (4) determining a slurry diffusion range, (5) determining a slurry diffusion range, (6) dividing a slurry non-coverage blind area possibility grade, obtaining slurry diffusion sufficiency subareas, and delineating a slurry non-coverage blind area, and (6) supplementing and treating until the slurry covers all treatment areas.

Description

Technical Field

[0001] This invention belongs to the field of coal mine grout diffusion detection technology, and relates to a method for determining the diffusion range of grout in underground roadway boreholes. Background Technology

[0002] When underground coal mine roadways are excavated along the coal seam, the original strata are disturbed, disrupting the stratum balance and creating fissures. If aquifers exist in the roof and floor of the coal seam within the disturbance area of ​​the roadway excavation, water from the aquifers will enter the roadway along the fissures, affecting safe production in the coal mine. Therefore, it is necessary to prevent water hazards to the roof and floor of the roadway during the roadway excavation process. One method of roadway water hazard prevention is to reinforce the roof and floor within the disturbance area by drilling. Due to the heterogeneity of the stratum structure, the diffusion path of the grout in the aquifer is uncertain, and there may be blind spots in the grouting area. In the past, the conventional transient electromagnetic method used to determine the diffusion range of the grout was often carried out in the underground roadway, which is in a complex environment with significant signal interference.

[0003] Therefore, there is an urgent need to develop a low-interference, high-precision method to determine the diffusion range of slurry in the aquifer in a timely manner. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the diffusion range of grout in underground roadways, which solves the problems of unsuitable methods for determining the diffusion range of grout in underground boreholes in aquifers, large detection interference, and low accuracy in the existing technology.

[0005] The technical solution adopted in this invention is a method for determining the diffusion range of grout in underground roadway drilling, which is implemented according to the following steps: Step 1: Complete the construction of all grouting boreholes; Step 2: Place the probe of the transient electromagnetic detection instrument into the grouting borehole to conduct the first transient electromagnetic detection in the borehole and record the detection information. Step 3: After grouting is completed in the grouting borehole, a second transient electromagnetic detection is performed inside the borehole, and the secondary detection information is recorded. Step 4: Compare the detection information from the two transient electromagnetic probes inside the borehole to determine the diffusion range of the grouting slurry and complete the grouping. Step 5: Conduct a water pressure test to determine the unit permeability of each grouting hole and complete the secondary grouping. Step 6: Based on the two grouping results, classify the probability levels of the slurry-uncovered blind areas to obtain the slurry diffusion sufficiency zones and delineate the slurry-uncovered blind areas. Step 7: Supplement treatment. Repeat steps 3 and 4 until the slurry covers the entire treated area.

[0006] The beneficial effect of this invention is that when an aquifer exists within the disturbance range of the tunnel roof and floor, affecting the safe excavation of the tunnel, grouting is required to seal the aquifer within this disturbance range. Due to the heterogeneity of the geological structure, the diffusion path of the grout in the aquifer is uncertain, and blind zones may exist within the grouting area. This invention, after the grout has diffused, determines the diffusion range of the grout by analyzing the changes in apparent resistivity and permeability of the formation before and after grouting using the difference in apparent resistivity and permeability detected by transient electromagnetic methods before and after grouting. This solves the problems of conventional transient electromagnetic methods for determining the grout diffusion range, where the detection instrument is located in the underground tunnel, resulting in significant signal interference and low accuracy. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the trend profile of the slurry diffusion range and the detection results of the transient electromagnetic detection zone in the method of the present invention; Figure 2 This is a schematic diagram of the transient electromagnetic detection inside the hole using the method of the present invention. Detailed Implementation

[0008] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0009] The method for determining the diffusion range of grout in underground roadway drilling of the present invention is implemented according to the following steps: Step 1: Complete the construction of all grouting boreholes for the target aquifers that require grouting in the roof and floor of the underground roadway; Specifically, based on the geological and hydrogeological conditions of the coal mine, the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam is obtained, the grouting range of the roadway is determined, and the construction of all grouting boreholes is completed.

[0010] Step 2: Place the probe of the transient electromagnetic detection instrument into the grouting borehole completed in Step 1, perform the first transient electromagnetic detection in the borehole in the area that needs to be grouted, and record the detection information. Before detection, it is necessary to remove equipment that interferes with the detection signal to avoid "low-resistance pollution" from underground conveyor belts, tunneling machines, drilling rigs, scraper machines, and other machinery.

[0011] In-hole transient electromagnetic detection involves placing a transmitting frame outside the grouting borehole and inserting a receiving probe into the borehole for detection. The process involves moving the receiving probe within the borehole to measure point by point. The spacing between measurement points can be determined based on the required detection accuracy. The detection range of each measurement point is a sector in plan view, and multiple measurement points are superimposed to form multiple sector-shaped advanced detection areas. The superposition and processing of multiple sets of data not only increases the detection range but also enhances anomaly display and improves interpretation accuracy.

[0012] Due to the limitations of the underground exploration environment, the size of the measuring coil of the borehole transient electromagnetic detection instrument is limited, and the detection range of the borehole transient electromagnetic detection in underground roadways is within 120m ahead of the measuring point.

[0013] Step 3: After grouting is completed in the grouting borehole, a second transient electromagnetic detection is performed on the grouting area, and the detection information is recorded. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from underground conveyor belts, tunneling machines, drilling rigs, scraper machines, and other equipment. Step 4: Compare the detection information from the two transient electromagnetic probes inside the borehole to determine the diffusion range of the grouting fluid and complete one grouping. The process of determining the diffusion range of the grout is as follows: interpret the detection information of the transient electromagnetic detection in the hole before and after grouting to obtain the apparent resistivity distribution map, compare and analyze the difference between the apparent resistivity distribution maps before and after grouting, divide the area where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is in the range of 0~20Ω·m into one group, and divide the area where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is greater than 20Ω·m into another group.

[0014] Step 5: Conduct a water pressure test to determine the unit permeability of each grouting hole, and complete the secondary grouping. A water pressure test was conducted on each grouting hole to measure the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). The unit permeability of each grouting hole was compared, and a permeability contour map was drawn. The area with a unit permeability greater than 0.01 Lu was divided into one group, and the area with a unit permeability less than 0.01 Lu was divided into another group.

[0015] Step 6: Combining the grouping results from Step 4 and Step 5, classify the probability levels of slurry-uncovered blind spots to obtain slurry diffusion adequacy zones and delineate slurry-uncovered blind spots.

[0016] The specific classification criteria are shown in Table 1.

[0017] Table 1. Criteria for Delineating Blind Zones Not Covered by Grout

[0018] The above-mentioned criteria for judging the difference in apparent resistivity and unit permeability before and after grouting can be adjusted adaptively according to the actual conditions of the mine.

[0019] Step 7: Supplement treatment. Repeat steps 3 to 6 until the slurry covers the entire treated area.

[0020] For blind areas not covered by slurry in the treatment area, secondary supplementary grouting is carried out. The density of supplementary grouting boreholes is designed to be different for blind areas with different probabilities of not being covered by slurry. The density of blind areas with a high probability of not being covered by slurry needs to be higher than that of blind areas with a low probability of not being covered by slurry. The specific borehole density is designed according to the actual situation of the mine. After the slurry has completely diffused and solidified, perform transient electromagnetic detection and water pressure test in the borehole again and analyze to determine the blind area not covered by the slurry. Steps 3 and 4 can be repeated multiple times until the slurry covers the entire treatment area.

[0021] Example 1 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, determine the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all conventional grouting boreholes. The borehole diameter for the first borehole is Ф133mm, and the borehole diameter for the second borehole is Ф89mm. Figure 1 The borehole length is 300m.

[0022] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 100m. Figure 2 A total of three detections were conducted. The first transient electromagnetic detection was carried out in the borehole for the area that needed grouting. Before detection, the equipment that interfered with the detection signal on site had to be removed to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines.

[0023] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is carried out in the grouting area. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before and after grouting is in the range of 0~20Ω·m into one group, and divide the region where the difference between the apparent resistivity before and after grouting is greater than 20Ω·m into another group.

[0024] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.01Lu into one group, and divide the area with unit permeability less than 0.01Lu into another group.

[0025] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of the slurry-uncovered blind zone, obtain the slurry diffusion sufficiency zoning, and delineate the slurry-uncovered blind zone.

[0026] The specific classification criteria are as follows:

[0027] Step 7: Based on Step 6, the blind spots that are likely not covered by the slurry were delineated. Figure 1 (Detecting grout blind areas) No blind areas were found to be uncovered by grout. Assuming a drilling density of one borehole every 20m, a second grouting was performed on the blind areas. After repeating steps 3 to 6, no blind areas were found in the grouting area again, confirming that the grout covered the entire area.

[0028] Example 2 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, obtain the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all conventional grouting boreholes with a borehole length of 260m.

[0029] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 80m for a total of 3 times. The last detection range is 100m. Perform the first transient electromagnetic detection in the borehole for the area that needs grouting. Before detection, remove any equipment that may interfere with the detection signal to avoid "low-resistance contamination" from equipment such as conveyor belts, tunneling machines, drilling rigs, and scraper machines in the well.

[0030] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is carried out in the grouting area. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is in the range of 0~10Ω·m into one group, and divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is greater than 10Ω·m into another group.

[0031] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.01Lu into one group, and divide the area with unit permeability less than 0.01Lu into another group.

[0032] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of the slurry-uncovered blind zone, obtain the slurry diffusion sufficiency zoning, and delineate the slurry-uncovered blind zone.

[0033] Step 7: Perform secondary grouting in the blind areas not covered by the grout in the treatment area. For blind areas where the grout is likely not covered, the additional drilling density is one hole every 30m. For blind areas where the grout is unlikely to cover, the additional drilling density is one hole every 50m. After performing secondary grouting in the blind areas, repeat steps 3 to 6. If no blind areas are found in the grouting area again, it is confirmed that the grout covers the entire area.

[0034] Example 3 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, obtain the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all grouting directional boreholes. The borehole diameter is Ф133mm for the first borehole and Ф89mm for the second borehole, with a borehole length of 360m.

[0035] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 90m for a total of 4 times. Perform the first transient electromagnetic detection in the borehole for the area that needs grouting. Before detection, remove any equipment that may interfere with the detection signal to avoid "low-resistance contamination" from equipment such as conveyor belts, tunneling machines, drilling rigs, and scraper machines in the well.

[0036] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is carried out in the grouting area. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is in the range of 0~10Ω·m into one group, and divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is greater than 10Ω·m into another group.

[0037] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.02Lu into one group, and divide the area with unit permeability less than 0.02Lu into another group.

[0038] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of the slurry-uncovered blind zone, obtain the slurry diffusion sufficiency zoning, and delineate the slurry-uncovered blind zone.

[0039] Step 7: Perform secondary grouting in the blind areas not covered by the grout in the treatment area. For blind areas where the grout is likely not covered, the additional drilling density is one hole every 25m. For blind areas where the grout is unlikely to cover, the additional drilling density is one hole every 50m. After performing secondary grouting in the blind areas, repeat steps 3 to 6. If no blind areas are found in the grouting area again, it is confirmed that the grout covers the entire area.

[0040] Example 4 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, obtain the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all conventional grouting boreholes. The borehole diameter is Ф127mm for the first borehole and Ф85mm for the second borehole, with a borehole length of 160m.

[0041] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 50m for a total of 3 times. The last detection range is 60m. Perform the first transient electromagnetic detection in the borehole for the area that needs grouting. Before detection, remove any equipment that may interfere with the detection signal to avoid "low-resistance contamination" from equipment such as conveyor belts, tunneling machines, drilling rigs, and scraper machines in the well.

[0042] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is carried out in the grouting area. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before and after grouting is in the range of 0~20Ω·m into one group, and divide the region where the difference between the apparent resistivity before and after grouting is greater than 20Ω·m into another group.

[0043] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.015Lu into one group, and divide the area with unit permeability less than 0.015Lu into another group.

[0044] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of slurry-covered blind spots to obtain slurry diffusion adequacy zones. No slurry-covered blind spots were found, confirming that the slurry covers the entire area.

[0045] Example 5 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, obtain the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all directional grouting boreholes with a borehole length of 540m.

[0046] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 90m for a total of 6 detections. Set up 6 signal receiving points in each borehole. Perform the first transient electromagnetic detection in the borehole for the area that needs grouting. Before detection, remove any equipment that may interfere with the detection signal to avoid "low-resistance contamination" from equipment such as conveyor belts, tunneling machines, drilling rigs, and scraper machines in the well.

[0047] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is carried out in the grouting area. Before detection, it is also necessary to remove equipment that interferes with the detection signal to avoid "low-resistance contamination" from equipment such as underground conveyor belts, tunneling machines, drilling rigs, and scraper machines. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is in the range of 0~10Ω·m into one group, and divide the region where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is greater than 10Ω·m into another group.

[0048] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.01Lu into one group, and divide the area with unit permeability less than 0.01Lu into another group.

[0049] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of slurry-covered blind spots to obtain slurry diffusion adequacy zones. No slurry-covered blind spots were found, confirming that the slurry covers the entire area.

[0050] Example 6 Following the steps described above in this invention, the following specific operations are performed: Step 1: Based on the geological and hydrogeological conditions of the coal mine, obtain the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam, determine the grouting range of the roadway, and construct all conventional grouting boreholes with a borehole length of 100m.

[0051] Step 2: Place the probe from the transient electromagnetic detection instrument into the borehole and perform a detection every 100m interval for a total of 1 detection. Perform the first transient electromagnetic detection in the borehole for the area that needs grouting. Before detection, remove any equipment that may interfere with the detection signal.

[0052] Step 3: After grouting is completed in the drilled borehole, a second transient electromagnetic detection is performed in the grouting area. Before detection, equipment that interferes with the detection signal must be removed from the site. Step 4: Interpret the data from the transient electromagnetic detection in the borehole before and after grouting to obtain the apparent resistivity distribution map. Divide the region where the difference between the apparent resistivity before and after grouting is in the range of 0~20Ω·m into one group, and divide the region where the difference between the apparent resistivity before and after grouting is greater than 20Ω·m into another group.

[0053] Step 5: Conduct a water pressure test on each grouting hole to test the unit permeability of each grouting hole (the unit permeability needs to be stabilized for more than 30 minutes). Compare the unit permeability of each grouting hole, draw a permeability contour map, divide the area with unit permeability greater than 0.01Lu into one group, and divide the area with unit permeability less than 0.01Lu into another group.

[0054] Step 6: Combining the grouping from Step 4 and Step 5, classify the probability levels of slurry-covered blind spots to obtain slurry diffusion adequacy zones. No slurry-covered blind spots were found, confirming that the slurry covers the entire area.

Claims

1. A method for determining the diffusion range of grout in underground roadways, characterized in that, Follow these steps: Step 1: Complete the construction of all grouting boreholes; Step 2: Place the probe of the transient electromagnetic detection instrument into the grouting borehole to conduct the first transient electromagnetic detection in the borehole and record the detection information. Step 3: After grouting is completed in the grouting borehole, a second transient electromagnetic detection is performed inside the borehole, and the secondary detection information is recorded. Step 4: Compare the detection information from the two transient electromagnetic probes inside the borehole to determine the diffusion range of the grouting slurry and complete the grouping. Step 5: Conduct a water pressure test to determine the unit permeability of each grouting hole and complete the secondary grouping. Step 6: Based on the two grouping results, classify the probability levels of the slurry-uncovered blind areas to obtain the slurry diffusion sufficiency zones and delineate the slurry-uncovered blind areas. Step 7: Supplement treatment. Repeat steps 3 to 6 until the slurry covers the entire treated area.

2. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, In step 1, the specific process is as follows: Based on the geological and hydrogeological conditions of the coal mine, the spatial distribution of the aquifer and aquitard in the roadway and the roof of the coal seam is obtained, the grouting range of the roadway is determined, and the construction of all grouting boreholes is completed.

3. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, In step 2, the transient electromagnetic detection inside the borehole involves placing the transmitting wire frame outside the grouting borehole and placing the receiving probe inside the grouting borehole for detection. The specific process is as follows: by moving the receiving probe in the grouting borehole, it can measure point by point in the grouting borehole. The spacing between the measuring points can be determined according to the detection accuracy requirements. The detection range of each measuring point is a fan-shaped area when viewed from the plane. Multiple measuring points are superimposed to finally form multiple fan-shaped advanced detection areas.

4. The method for determining the diffusion range of grout in underground roadway drilling according to claim 2 or 3, characterized in that, Before detection, it is necessary to remove any equipment that may interfere with the detection signal to avoid "low-resistance contamination" of downhole instruments.

5. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, Step 4, the specific process is as follows: The process of determining the diffusion range of the grout is as follows: interpret the detection information of the transient electromagnetic detection in the hole before and after grouting to obtain the apparent resistivity distribution map, compare and analyze the difference between the apparent resistivity distribution maps before and after grouting, divide the area where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is in the range of 0~20Ω·m into one group, and divide the area where the difference between the apparent resistivity before grouting and the apparent resistivity after grouting is greater than 20Ω·m into another group.

6. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, Step 5, the specific process is as follows: A water pressure test was conducted on each grouting hole to measure the unit permeability of each grouting hole. The unit permeability of each grouting hole was compared, and a permeability contour map was drawn. The area with a unit permeability greater than 0.01 Lu was divided into one group, and the area with a unit permeability less than 0.01 Lu was divided into another group.

7. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, In step 6, the specific criteria for classification are as follows: 。 8. The method for determining the diffusion range of grout in underground roadway drilling according to claim 1, characterized in that, Step 7 involves the following steps: For blind spots not covered by grout in the treatment area, secondary grouting is carried out. The density of the supplementary grouting boreholes is designed to be different for blind spots with different probabilities of not being covered. The density of blind spots with a high probability of not being covered by grout needs to be higher than that of blind spots with a low probability of not being covered by grout. After the slurry has completely diffused and solidified, the transient electromagnetic detection and water pressure test in the borehole are carried out again, and the blind areas not covered by the slurry are analyzed and determined. Steps 3 to 6 are repeated multiple times until the slurry covers the entire treatment area.

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