A method for evaluating the prevention and control effect of karst water hazards in deep mining

Abstract

The present invention proposes a method for evaluating the prevention and control effect of karst water disasters in deep mining. Based on traditional geophysical exploration techniques and the data interpolation and masking processing technology of the MapGIS system, sequence fusion is carried out to verify the prevention and control effect. First, a qualitative evaluation is carried out on the aquifer after ground directional near-horizontal drilling and grouting transformation based on physical quantities such as the permeability coefficient and water permeability rate of the target layer to be transformed. Secondly, the MapGIS system is used to analyze and process the grouting parameters of each coordinate point to obtain the "Special Evaluation Map of Grouting Effect Zoning". At the same time, based on the "Evaluation Map of Apparent Resistivity Low-Resistance Abnormal Zone" obtained from mine electrical prospecting, double-map data masking processing is carried out to obtain the "Superimposed Analysis and Evaluation Map of Abnormal Zones". Finally, the "Comprehensive Evaluation Map of the Prevention and Control Effect of Karst Water Disasters in Deep Mining" is obtained and specific steps for eliminating abnormal zones before mining are proposed. The present invention can provide a scientific theoretical basis for the prevention and control of karst water disasters in deep coal resource mining and can effectively avoid the occurrence of water inrush disasters in deep mining.

Description

Technical Field

[0001] The present invention belongs to the field of coalfield geology, and particularly relates to a method for evaluating the prevention and control effect of karst water disasters in deep mining. Background Art

[0002] In China, the shallow coal resources in the central and eastern regions are becoming increasingly depleted. Although the coal resources in the western regions are rich, the ecological and environmental resources are relatively fragile and the industrial infrastructure conditions are not yet complete. At present, it is still difficult to relocate the coal industry on a large scale to the west. Therefore, while developing the western resources, it is also necessary to strengthen the development and utilization of the deep resources in the central and eastern mining areas, improve the energy self-sufficiency rate in the central and eastern regions, and reduce the dependence on external energy. During the national energy structure adjustment stage, in order to ensure national energy security, the central and eastern mining areas still need to maintain a stable coal production period of about 20 years. The coal mining depth in the central and eastern regions of China is increasing at a rate of 8 - 12 m per year. The resulting "three highs and one disturbance" pose a huge challenge to the safe mining of deep mining, especially the threat of confined water disasters is particularly serious. China has taken the lead in the world in the technology of mine water disaster prevention and control. At present, the main measures are comprehensive treatment of ground directional near-horizontal drilling and underground supplementary grouting. However, with the increase of mining depth, water inrush disasters still occur in the mined faces after treatment, mainly because there is a lack of a scientific and effective post-treatment effect evaluation system. However, so far, there is no special and specific comprehensive prevention and control effect evaluation specification at home and abroad. The disaster of water inrush caused by mining in deep coal seams is a very complex engineering geological disaster. At present, a scientific and effective mine water disaster prevention and control effect evaluation system is urgently needed in the process of treating confined water disasters in deep coal seams in the central and eastern regions. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for evaluating the prevention and control effect of karst water disasters in deep mining, which can scientifically and effectively evaluate the prevention and control effect of the mining area after comprehensive treatment of confined water disasters in deep mining by ground directional near-horizontal drilling and underground supplementary grouting, and then realize safe mining. To achieve the above purpose, the present invention adopts the following technical solutions:

[0004] A method for evaluating the prevention and control effect of karst water disasters in deep mining, comprising the following steps:

[0005] (1) Calculate the permeability coefficient K and the water permeability q of the grouting target layer after transformation to qualitatively evaluate and determine the grouting transformation effect of the target layer; if the grouting transformation effect meets the standard, proceed to step (2), otherwise, continue to grout and transform the target layer;

[0006] (2) Based on the MapGIS system, generate a thematic zoning evaluation map of the grouting effect to quantitatively evaluate the grouting target layer;

[0007] (3) Based on the on-site investigation of mine electrical method and the MapGIS system, generate an evaluation map of the low-resistivity anomaly area of the apparent resistivity of the water-resisting layer after grouting modification to quantitatively evaluate the grouting target layer;

[0008] (4) Based on the MapGIS system, mask and extract the anomaly areas from the grouting effect thematic zoning evaluation map in step (2) and the low-resistivity anomaly area evaluation map in step (3) to form an overlay analysis evaluation map of the anomaly areas;

[0009] (5) Through the design of dense boreholes underground, investigate the grouting target layer and mark the water inflow of each borehole, and finally obtain the water inflow map of the dense boreholes underground to verify the overlay analysis evaluation map of the anomaly areas in step (4);

[0010] (6) Based on the overlay analysis of the water inflow map of the dense boreholes underground in step (5) and the overlay analysis evaluation map of the anomaly areas in step (4), obtain a comprehensive evaluation map of the prevention and control effect of karst water disasters in deep mining;

[0011] (7) Carry out supplementary grouting on the non-compliant areas in the comprehensive evaluation map of the prevention and control effect of karst water disasters in deep mining through the method of underground supplementary grouting.

[0012] Preferably, step (1) specifically includes:

[0013] (11) Set up a water pressure test to obtain the pressure value and water flow value during the stable water injection period;

[0014] (12) Calculate the unit water absorption ω:

[0015]

[0016] where ω is the unit water absorption, L / min·m·m;

[0017] Q is the injected flow value at stable water pressure, L / min;

[0018] L is the length of the test section, m;

[0019] H is the head height converted from the test pressure, m.

[0020] (13) Calculate the permeability coefficient K of the target layer and the water permeability q of the target layer:

[0021] where r is the radius of the water pressure borehole, m.

[0022] where P is the water pressure value, MPa;

[0023] (14) When the permeability coefficient K or the water permeability q meets the following conditions, it can be qualitatively determined as compliant; otherwise, it is qualitatively determined as non-compliant:

[0024] 10 -6 1 ≤ k ≤ 10 -5 ; 0.1 ≤ q ≤ 1

[0025] Preferably, between step (1) and step (2), there is also a step of qualitatively evaluating the water-blocking performance of the grouting target layer, specifically:

[0026] S1. Establish a mechanical model of the diffusion radius:

[0027]

[0028] Where, △P - the difference between the water injection pressure and the hydrostatic pressure;

[0029] b - the total width of the rock layer fissures;

[0030] Q - the stable water pressure value;

[0031] μ - the kinematic viscosity coefficient of the fluid;

[0032] t - the water temperature;

[0033] R - the water injection diffusion radius;

[0034] r c - the water injection borehole radius;

[0035] S2. Calculate the maximum water-blocking coefficient Z of the grouting target layer max :

[0036]

[0037] p c - the water injection pressure;

[0038] R - the water injection diffusion radius;

[0039] S3. Judge the water inrush situation of the coal mining face floor:

[0040] First, calculate the critical water inrush coefficient T 0 and the conventional water inrush coefficient T s , if T S > T 0 , then it is in the state of water inrush during mining, and continue to grout and transform the target layer; otherwise, it is in the state of no water inrush during mining, and enter step (2);

[0041] Where, T 0 = Z max ;

[0042] M - the thickness of the water-resisting layer, m;

[0043] C - The maximum depth value of the floor failure caused by mining, m;

[0044] p - The water pressure borne by the floor water - resistant layer, MPa.

[0045] Preferably, step (2) specifically includes the following steps:

[0046] (21) Obtain the grouting database: According to the grouting points of the nearly horizontal branch boreholes for statistics, form a grouting database including grouting coordinates, final grouting volume, and grouting final pressure factor;

[0047] (22) Generate a special evaluation effect diagram of grouting pressure:

[0048] First, import the data of the grouting database into the Surfer system, calculate the area delineated after the grouting transformation based on the KRIGING interpolation calculation to form a data map, and then import the data map into the MapGIS system;

[0049] After that, divide the evaluation area and set the final pressure threshold range: According to the final pressure of the ground - oriented nearly horizontal grouting, the grouting effect can be divided into three levels: the up - to - standard area, the qualified area, and the relatively weak area; among them, the threshold range of the up - to - standard area: final pressure ≥ 10 MPa; the threshold range of the qualified area: 8 MPa ≤ final pressure < 10 MPa; the threshold range of the relatively weak area: final pressure < 8 MPa;

[0050] Finally, based on the MapGIS system, conduct a zonal evaluation of the pressure in each of the above - mentioned evaluation areas to obtain a special evaluation effect diagram of grouting pressure;

[0051] (23) Generate a special evaluation effect diagram of grouting volume:

[0052] First, based on the KRIGING interpolation calculation, calculate the area delineated after the grouting transformation to form a data map, and then import the data map into the MapGIS system;

[0053] After that, divide the evaluation area and set the final pressure threshold range: Based on the median M and the maximum value Q of the grouting volume at each grouting point of the nearly horizontal hole branch holes zmax conduct a gradient division into three grades, namely the fracture zone, the pore zone, and the normal zone;

[0054] Finally, based on the MapGIS system, conduct a zonal evaluation of the grouting volume in each of the above - mentioned evaluation areas to obtain a special evaluation effect diagram of grouting volume;

[0055] (24) Delineate the comprehensive evaluation map of the dangerous area:

[0056] Overlay and analyze the special evaluation effect diagram of grouting volume and the special evaluation effect diagram of grouting pressure based on the MapGIS system to obtain a special zonal evaluation map of grouting effect.

[0057] Preferably, step (3) specifically includes the following steps:

[0058] (31) Conduct on-site exploration of mine electrical methods according to industry standards to obtain the contour slice map of the low-resistivity anomaly area of the bedding apparent resistivity after ground-controlled directional drilling and grouting transformation;

[0059] (32) Based on the MapGIS system, extract the contour slice map of the low-resistivity anomaly area of the bedding apparent resistivity to form an evaluation map of the low-resistivity anomaly area of the water-resisting layer apparent resistivity.

[0060] Preferably, in step (5), according to the design principles of underground exploration boreholes, conduct exploration on the grouting target layer after ground directional drilling transformation in the mining face area; among them, the design principles of underground exploration boreholes include:

[0061] The final hole spacing of the borehole shall not be greater than 60 m, and it is necessary to cover the entire mining area of the working face;

[0062] The water inflow per single hole shall not be greater than 5 m 3 / h, which is regarded as qualified;

[0063] Conduct key exploration on the anomaly areas in the anomaly area superposition analysis and evaluation map in step (4), and the final hole spacing of the borehole shall not be greater than 35 m.

[0064] Compared with the prior art, the advantages of the present invention are: it can scientifically and effectively evaluate the prevention and control effect of karst water disasters in deep coal seam mining, can improve the special evaluation standard for the prevention and control effect of karst water disasters in deep mining in China, provide a scientific theoretical basis for the prevention and control of karst water disasters in deep coal resource mining, and can effectively avoid the occurrence of water inrush disasters in deep mining. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 It is a flow chart of the method for evaluating the prevention and control effect of karst water disasters in deep mining according to an embodiment of the present invention;

[0066] Figure 2 It is a mechanical model diagram of the water injection diffusion radius. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0067] The present invention will be described in more detail below with reference to the schematic diagrams, in which the preferred embodiments of the present invention are shown. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the present invention.

[0068] As Figures 1 - 2, a method for evaluating the prevention and control effect of karst water hazards in deep mining, which is based on traditional geophysical exploration techniques and MapGIS system data interpolation masking processing techniques to perform sequence fusion verification of the prevention and control effect, including the following steps (1) to (9). Among them, geophysical exploration techniques include mine electrical methods, water pressure tests, and dense boreholes, etc.

[0069] The steps of this method are mainly aimed at evaluating the prevention and control effect of water hazards in the coal seam floor. When evaluating the prevention and control effect of the aquifer in the coal seam roof, only steps (2)-(9) are required.

[0070] (1) Calculate the permeability coefficient K and the water permeability q of the grouting target layer after transformation to qualitatively evaluate and determine the grouting transformation effect of the target layer (aquifer); if the grouting transformation effect meets the standard, proceed to step (2), otherwise, continue to grout and transform the target layer.

[0071] Step (1) specifically includes:

[0072] (11) Set up a water pressure test to obtain the pressure value and water flow value during the stable water injection period.

[0073] That is, conduct an in-situ water pressure test, among which, this test is an existing technology.

[0074] ① Construct a water pressure borehole from the safety chamber in the return airway of the mining face that has been arranged to the grouting transformation target layer (the borehole spacing is not less than 50m, and the test boreholes are not less than 3, evenly distributed along the working face strike).

[0075] ② Install a casing in the section 1-2m from the orifice to the top boundary of the target layer, seal it with cement (P.S.A 32.5) slurry, and after consolidation, conduct a sealing effect test using 1.5 times the hydrostatic pressure of the transformation target layer, with the test time being stable for no less than 30min.

[0076] ③ Continue to construct boreholes in the target layer (generally not less than 3-5m), and reserve the protection thickness of the target layer (greater than 1.5m).

[0077] ④ Install a self-made enhanced water injection sealing device with a length of 3000mm at the lower part of the drill pipe. The A end is the water pressure inlet end, the B end is the closed end, the length of the middle water pressure section is 1000mm, and the sealing length of the B end is 1000mm.

[0078] ⑤ Install a pressure gauge and a flowmeter on the water pressure pipe, connect one end of the water supply pipe to the grouting pump, and inject water into the borehole under high pressure for testing.

[0079] ⑥ When conducting the water pressure test, the second gear of the grouting pump should be used to maintain a stable pressure for no less than 30min.

[0080] ⑦ Record the pressure value and water flow value during the stable water injection period.

[0081] (12) Calculate the unit water absorption ω.

[0082]

[0083] Among them, ω is the unit water absorption, L / min·m·m;

[0084] Q is the injected flow value at stable water pressure, L / min;

[0085] L is the length of the test section, m;

[0086] H is the head height converted from the test pressure, m.

[0087] (13) Calculate the permeability coefficient K of the target layer and the water permeability q of the target layer.

[0088] Among them, r is the radius of the water injection borehole, m.

[0089] Among them, P is the water pressure value, MPa.

[0090] (14) According to the national standard of "Code for Geological Investigation of Water Resources and Hydropower Projects", when the permeability coefficient K or the water permeability q meets the following conditions, it can be qualitatively judged as qualified, that is, the grouting target layer has been transformed into a slightly permeable grade, and the grouting transformation effect can be judged to be good; otherwise, it is qualitatively judged as unqualified.

[0091] 10 -6 ≤k≤10 -5 ; 0.1≤q≤1.

[0092] Case A:

[0093] Set the water pressure test parameters of the water - resisting layer at the floor of the F1101 working face according to ① - ⑦ in step (1) as shown in Table 1:

[0094] Table 1 Water pressure test data after grouting transformation of the coal seam floor

[0095]

[0096] Calculate the parameters such as the unit water absorption, permeability coefficient, and water permeability of the limestone grouting transformation at the floor of the F1101 working face in Case A according to steps (12) and (13) as shown in Table 2:

[0097] Table 2 Calculation table of unit water absorption, water permeability and permeability coefficient of the test section after grouting transformation of the coal seam floor

[0098]

[0099] Conduct qualitative judgment according to step (14):

[0100] As shown in Table 2, the permeability coefficient of the limestone floor grouting transformation in the F1101 working face in Case A is between 2.88×10 -6 ~5.22×10 -6 cm / s; according to the grading standard of the permeability performance of rock and soil masses, as shown in the "Code for Geological Investigation of Water Resources and Hydropower Projects", when the permeability grade is slightly permeable, the permeability coefficient needs to meet the requirement of being between 10 -6 cm / s~10 -5 cm / s; therefore, it shows that the floor of the F1101 working face has been transformed into a slightly permeable rock mass and has a certain water-blocking ability.

[0101] Furthermore, between step (1) and step (2), there is also a step of qualitatively evaluating the water-blocking performance of the grouting target layer after transformation, specifically:

[0102] S1. Establish a mechanical model of the diffusion radius.

[0103]

[0104] Among them, △P - the difference between the injection pressure and the hydrostatic pressure;

[0105] b - the total width of rock fractures, that is, the thickness of the fractured rock layer in the water pressure section * the fracture rate in the water pressure section;

[0106] Q - the stable water pressure flow value;

[0107] μ - the kinematic viscosity coefficient of the fluid;

[0108] t - the water temperature;

[0109] R - the injection diffusion radius;

[0110] r c - the radius of the injection borehole.

[0111] S2. Calculate the maximum water-blocking coefficient Z of the grouting target layer max .

[0112]

[0113] Among them, the water-blocking coefficient, that is, the water-blocking pressure value per unit thickness of the rock mass;

[0114] p c - the injection pressure;

[0115] R - the injection diffusion radius.

[0116] S3. Judge the water inrush situation of the floor of the coal mining face.

[0117] First, calculate the critical water inrush coefficient T 0 and the conventional water inrush coefficient T s , if TS >T 0 , it is in the state of water inrush during mining, then continue to grout and transform the target layer; otherwise, it is in the state of no water inrush during mining, and enter step (2).

[0118] Among them, T 0 =Z max ;

[0119] M - thickness of the water - resisting layer, m;

[0120] C - maximum depth value of the mined floor damage, m;

[0121] p - water pressure borne by the water - resisting layer of the floor, MPa.

[0122] Finally, according to the above analysis and judgment principles, a qualitative analysis conclusion is formed.

[0123] (2) Based on the MapGIS system, generate a special - area evaluation map of grouting effect to quantitatively evaluate the grouting target layer.

[0124] Specifically, it includes the following steps:

[0125] (21) Obtain the grouting database: According to the grouting points of nearly horizontal branch boreholes for statistics, form a grouting database including grouting coordinates, grouting volume, and grouting final - pressure factors.

[0126] (22) Generate a special - evaluation effect diagram of grouting pressure.

[0127] First, import the data of the grouting database into the Surfer system. Based on KRIGING interpolation calculation, calculate the area delineated after grouting transformation to form a data map, and then import the data map into the MapGIS system.

[0128] After that, divide the evaluation area and set the range of final - pressure thresholds: According to the final pressure of nearly horizontal ground - directed grouting, the grouting effect can be divided into three levels: up - to - standard area, qualified area, and relatively weak area; among them, the threshold range of the up - to - standard area: final pressure ≥ 10 MPa; the threshold range of the qualified area: 8 MPa ≤ final pressure < 10 MPa; the threshold range of the relatively weak area: final pressure < 8 MPa.

[0129] Finally, based on the MapGIS system, conduct a zonal evaluation of the pressure in each of the above - mentioned evaluation areas to obtain a special - evaluation effect diagram of grouting pressure.

[0130] (23) Generate a special - evaluation effect diagram of grouting volume.

[0131] First, based on KRIGING interpolation calculation, calculate the area delineated after grouting transformation to form a data map, and then import the data map into the MapGIS system.

[0132] After that, divide the evaluation area and set the final pressure threshold range: Based on the median M and the maximum value Q of the grouting volume at each grouting point of the nearly horizontal hole branch holes (single holes). zmax Perform gradient division into three levels between them, namely crack area I, pore area II, and normal area III.

[0133] Among them, I: M; II: III:

[0134] Finally, based on the MapGIS system, conduct zonal evaluation on the grouting volume of each above-mentioned evaluation area to obtain the special evaluation effect diagram of the grouting volume.

[0135] (24) Draw the comprehensive evaluation map of the dangerous area: Superimpose and analyze the special evaluation effect diagram of the grouting volume and the special evaluation effect diagram of the grouting pressure based on the MapGIS system to obtain the special zonal evaluation map of the grouting effect.

[0136] (3) Based on the on-site investigation of mine electrical method and the MapGIS system, generate the evaluation map of the low-resistivity anomaly area of the apparent resistivity of the water-resisting layer after grouting transformation to quantitatively evaluate the grouting target layer.

[0137] Specifically, it includes the following steps:

[0138] (31) Conduct on-site investigation of mine electrical method according to the national energy industry standard NB / T 10550-2021 "Coupled Monitoring and Early Warning Method of Microseismic and Electrical Methods for Water Inrush from the Floor of Complex Mines" to obtain the contour slice map of the low-resistivity anomaly area of the apparent resistivity along the bedding after ground controlled directional drilling grouting transformation. Among them, along the bedding means that the direction of the grouting borehole is drilled along the dip of the rock stratum.

[0139] (32) Based on the MapGIS system, extract the contour slice map of the low-resistivity anomaly area of the apparent resistivity along the bedding to form the evaluation map of the low-resistivity anomaly area of the apparent resistivity of the water-resisting layer.

[0140] (4) Based on the MapGIS system, perform mask extraction of the anomaly areas on the special zonal evaluation map of the grouting effect in step (2) and the evaluation map of the low-resistivity anomaly area of the apparent resistivity in step (3) to form the evaluation map of the superposition analysis of the anomaly areas.

[0141] (5) Through the design of dense boreholes underground, investigate the grouting target layer and mark the water inflow of each borehole. Finally, obtain the map of the water inflow of the dense boreholes underground to verify the evaluation map of the superposition analysis of the anomaly areas in step (4). Among them, a mining area contains multiple mining faces (mining face areas).

[0142] Specifically, according to the design principles of underground exploration boreholes, the grouting target layer after the ground directional drilling transformation in the coal mining face area (mining face area) is explored; among them, the design principles of underground exploration boreholes include:

[0143] The final hole spacing of the boreholes shall not be greater than 60 m, and the entire mining area of the working face needs to be covered. Among them, the final hole spacing of the boreholes refers to the terminal distance between two underground exploration boreholes.

[0144] The water inflow of a single hole not exceeding 5 m3 / h is regarded as qualified.

[0145] The abnormal areas in the abnormal area superposition analysis and evaluation map in step (4) are key explored, and the final hole spacing of the boreholes shall not be greater than 35 m.

[0146] (6) Based on the superposition analysis of the underground intensive borehole water inflow map in step (5) and the abnormal area superposition analysis and evaluation map in step (4), a comprehensive evaluation map of the prevention and control effect of deep mining karst water disasters is obtained.

[0147] (7) Methods and specifications for eliminating the areas with unqualified evaluations.

[0148] The unqualified areas (abnormal areas) in the comprehensive evaluation map of the prevention and control effect of deep mining karst water disasters are supplemented with grouting through underground supplementary grouting.

[0149] The specific implementation is as follows:

[0150] ① When the water inflow of a single hole is greater than 5 m 3 / h, underground supplementary grouting is required. The grouting pressure is controlled at 2 times the hydrostatic pressure value. After the grouting is completed, the hole needs to be reamed again to test the water inflow (or a new inspection borehole is constructed within 5 m near the original detection borehole) until the water inflow of a single hole is less than 5 m 3 / h, which can be regarded as qualified.

[0151] ② Repeat step ①, and conduct underground supplementary grouting on the unqualified areas in the whole mining face area to completely eliminate the abnormal areas.

[0152] (8) Other factors threatening safe mining.

[0153] After the grouting transformation, the properties of the roof rock strata in the mining face also need to be considered. The empty roof distance of the goaf roof should be controlled to eliminate the risk of sharp increase in the concentrated stress in the mining face.

[0154] (9) Safe mining of the trial mining face.

[0155] After the industry experts demonstrate the pre-mining grouting transformation effect evaluation report (the pre-mining evaluation report made based on this evaluation method) and all are qualified, the trial mining face can be mined.

[0156] The above are only the preferred embodiments of the present invention and do not impose any restrictive effect on the present invention. Any person skilled in the art, within the scope of the technical solution of the present invention, makes any form of equivalent substitution or modification and other changes to the technical solution and technical content disclosed by the present invention, which are all within the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A method for evaluating the prevention and control effect of karst water hazards in deep mining, characterized in that, it includes the following steps: (1)Calculate the permeability coefficient of the grouting target layer after transformation and the water permeability rate q to qualitatively evaluate and determine the grouting transformation effect of the target layer; if the grouting transformation effect meets the standard, proceed to step (2), otherwise, continue to grout and transform the target layer; (2) Based on the MapGIS system, generate a special evaluation map for grouting effect zoning to quantitatively evaluate the grouting target layer; (3) Based on the on-site exploration of mine electrical method and the MapGIS system, generate an evaluation map for the low-resistivity anomaly area of the apparent resistivity of the aquifuge after grouting transformation to quantitatively evaluate the grouting target layer; (4) Based on the MapGIS system, mask and extract the abnormal areas from the special evaluation map for grouting effect zoning in step (2) and the evaluation map for the low-resistivity anomaly area in step (3) to form an overlay analysis evaluation map of abnormal areas; (5) Through the design of dense boreholes underground, explore the grouting target layer and mark the water inflow of each borehole. Finally, obtain the underground dense borehole water inflow map to verify the overlay analysis evaluation map of abnormal areas in step (4); (6) Based on the overlay analysis of the underground dense borehole water inflow map in step (5) and the overlay analysis evaluation map of abnormal areas in step (4), obtain a comprehensive evaluation map of the prevention and control effect of karst water hazards in deep mining; (7) Carry out supplementary grouting on the non-compliant areas in the comprehensive evaluation map of the prevention and control effect of karst water hazards in deep mining through the method of underground supplementary grouting; Finally, the test mining face is safely mined; Step (2) specifically includes the following steps: (21) Obtain the grouting database: According to the grouting points of nearly horizontal branch boreholes, make statistics to form a grouting database including grouting coordinates, grouting volume, and grouting final pressure factors; (22) Generate a special evaluation effect diagram for grouting pressure: First, import the data of the grouting database into the Surfer system. Based on the KRIGING interpolation calculation, calculate the defined range after grouting transformation to form a data map, and import the data map into the MapGIS system; Then divide the evaluation area and set the final pressure threshold range: According to the final pressure of the ground-directed nearly horizontal grouting, the grouting effect can be divided into three levels: the up-to-standard area, the qualified area, and the relatively weak area; among them, the threshold range of the up-to-standard area: final pressure ≥ 10 MPa; the threshold range of the qualified area: 8 MPa ≤ final pressure < 10 MPa; the threshold range of the relatively weak area: final pressure < 8 MPa; Finally, based on the MapGIS system, conduct a zonal evaluation of the pressure in each of the above evaluation areas to obtain a special evaluation effect diagram for grouting pressure; (23) Generate a special evaluation effect diagram for grouting volume: First, based on the KRIGING interpolation calculation, calculate the defined range after grouting transformation to form a data map, and import the data map into the MapGIS system; After that, divide the evaluation area and set the final pressure threshold range: Based on the median M and the maximum value of the grouting volume at each grouting point of the nearly horizontal hole branch holes Q zmax Perform gradient division into three grades, namely the crack area, the pore area, and the normal area; Finally, based on the MapGIS system, conduct a zonal evaluation of the grouting volume in each of the above evaluation areas to obtain a special evaluation effect diagram for grouting volume; (24) Define the comprehensive evaluation map of the dangerous area: The special evaluation effect diagram for grouting volume and the special evaluation effect diagram for grouting pressure are subjected to overlay analysis based on the MapGIS system to obtain a special evaluation map for grouting effect zoning.

2. The method for evaluating the prevention and control effect of karst water hazards in deep mining according to claim 1, characterized in that, Step (1) specifically includes: (11)Set up a water pressure test to obtain the pressure value and water flow value during the stable water injection period; (12)Calculate the unit water absorption ω: ； Among them, ω - Unit water absorption, L / (min·m²); Q - Pressing flow rate value when water pressure is stable, L / min; L - Length of the test section, m; H - Head height for test pressure conversion, m; (13) Calculate the permeability coefficient of the target layer K and the water permeability rate of the target layer q : ; where, r - radius of the pressure-relief borehole, m; ; wherein, P - Water pressure value, MPa; (14) When the permeability coefficient K or the water permeability q meets the following conditions, it can be qualitatively determined as meeting the standard; otherwise, it is qualitatively determined as not meeting the standard: ； 。 3. The method for evaluating the prevention and control effect of karst water disaster in deep mining according to claim 2, characterized in that, between step (1) and step (2), it further includes a step of qualitatively evaluating the water-blocking performance of the grouting target layer after transformation, specifically: S1. Establish a mechanical model of the diffusion radius: ； ； Among them, △ P - Pressure difference between water injection pressure and hydrostatic pressure; b - Total width of fractures in rock strata; Q - The press-in flow rate value when the water pressure is stable; μ - Kinematic viscosity of the fluid; t - Water temperature; R - Water injection diffusion radius; - Injection borehole radius; S2. Calculate the maximum water resistance coefficient of the grouting target layer : ； p c - Water injection pressure; R - Water injection diffusion radius; S3. Judge the water inrush situation of the coal mining face floor: First, calculate the critical water inrush coefficient T 0 and the conventional water inrush coefficient T s , if , then it is in the state of water inrush during mining, and grouting modification of the target layer will continue; otherwise, it is in the state of no water inrush during mining, and proceed to step (2); Among them, ; ; M - Thickness of the aquitard, m; C - Maximum depth value of floor failure caused by mining, m; p- Water pressure borne by the floor water-resisting layer, MPa.

4. The method for evaluating the prevention and control effect of karst water disaster in deep mining according to claim 1, characterized in that, step (3) specifically includes the following steps: (31)Conduct on-site exploration of mine electrical method according to industry standards to obtain the contour slice map of the low-resistivity anomaly area of the bedding apparent resistivity after ground controlled directional drilling grouting transformation; (32)Based on the MapGIS system, extract the contour slice map of the low-resistivity anomaly area of the bedding apparent resistivity to form an evaluation map of the low-resistivity anomaly area of the water-resisting layer apparent resistivity.

5. The method for evaluating the prevention and control effect of karst water disaster in deep mining according to claim 1, characterized in that, in step (5), according to the design principle of underground exploration boreholes, explore the grouting target layer after ground directional drilling transformation in the mining face area; among them, the design principle of underground exploration boreholes includes: The final hole spacing of the borehole is not greater than 60 m, and the entire mining area of the working face needs to be covered; The water inflow per single hole is not more than 5 m 3 / h, which is regarded as qualified; Focus on exploring the anomaly area in the anomaly area superposition analysis evaluation map in step (4), and the final hole spacing of the borehole is not greater than 35 m.

Images