Mine goaf water disaster prevention and control method

Abstract

The invention discloses a mine goaf water disaster prevention and control method, and belongs to the technical field of water disaster prevention and control. S2, analyzing a water burst rule of each mining area of the mine; s3, performing partition isolation feasibility research on the first mining area; and S4, comprehensive water prevention and control technical measures and countermeasures of the mine. Starting from multiple aspects of coal mining overlying strata failure law research, mine water gushing law analysis, one-mining-area partition isolation feasibility research, mine comprehensive water prevention and control technical measures and countermeasures and the like, a set of complete mine flood disease comprehensive prevention and control system is formed, flood disease occurrence can be controlled from the source, and the mine flood disease prevention and control method is suitable for popularization and application. According to the method, the systematicness and comprehensiveness of mine flood prevention and control are improved, personalized water prevention and control technical measures and countermeasures are formulated according to the differences of hydrogeological conditions, mining technical conditions and the like of different mines, the personalized requirements of the different mines can be met, and the pertinence and effectiveness of mine flood prevention and control are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of water hazard prevention and control, and specifically relates to a method for preventing and controlling water hazard in a mine goaf. Background Art

[0002] Coal, as a vital energy source, holds a crucial position. However, during coal mining, mine flooding remains a major threat to mine safety and production, resulting in significant economic losses and casualties for coal mining companies. The causes of mine flooding are complex and diverse, primarily including water from underground aquifers, surface water, old goaf water, and water accumulation in goafs. Under the influence of geological structures, mining activities, and other factors, these water sources can flow into mines through channels such as water-conducting fractures, faults, and fissures, causing mine water inrush and even water inrush accidents.

[0003] Mine flood prevention and control has long been a top priority for coal mine safety. To effectively prevent and control mine floods, scholars and engineers at home and abroad have conducted extensive research and practice, developing a variety of mine flood prevention and control technologies, such as waterproof coal pillars, grouting to block water, dewatering and pressure reduction, and water exploration and drainage. These technologies have significantly improved mine flood prevention and control capabilities and ensured safe mine production. However, with the continuous increase in coal mining depth and intensity, mine hydrogeological conditions have become increasingly complex, posing even more severe challenges to mine flood prevention and control.

[0004] Existing mine flood prevention and control technologies often focus on the application of single technical means, lacking systematic research on the formation mechanisms of mine floods and the establishment of a comprehensive prevention and control system. This makes it difficult to control floods at their source, resulting in less than ideal prevention and control results. Due to the differences in hydrogeological conditions and mining techniques among different mines, existing mine flood prevention and control technologies lack specificity and are unable to meet the individual needs of different mines. This can significantly reduce prevention and control effectiveness in practice. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preventing and controlling water hazards in mine goaf areas to solve the problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: S1. Study on the damage law of overburden during coal seam mining. Drill holes before and after mining are constructed in two zones on the surface of the working face. Flushing fluid loss is observed, borehole peeks are made, and well logging is performed to explore the height of the caving zone and the water-conducting fracture zone after mining on the working face. Numerical simulation and similar material simulation are performed to study the damage law of overburden during mining on the working face. The S1. Study on the damage law of overburden during coal seam mining includes analysis of factors affecting the height of the water-conducting fracture zone, on-site measurement analysis of the height of the water-conducting fracture zone, numerical simulation analysis of the development characteristics of the water-conducting fracture zone, physical simulation analysis of the development characteristics of the water-conducting fracture zone, comprehensive analysis of the height of the water-conducting fracture zone, and study of the distribution characteristics of the height of the water-conducting fracture zone in each mining area. S2. Analysis of water inflow patterns in each mining area of ​​the mine, including the distribution characteristics and hydrogeological parameters of the surface water system, aquifers (water barriers), the patterns and sources of mine water inflow, and prediction of the amount of mine water inflow when mining subsequent coal seams using the large well method and hydrogeological analogy method. The S2 analysis of water inflow patterns in each mining area of ​​the mine includes analysis of the distribution characteristics of aquifers (water barriers) and analysis of the patterns of mine water inflow; S3. Feasibility study on zoning and isolation of a mining area. This study examines various factors that affect the stability of the coal pillar, including mining depth, mining thickness, mining width, and the mechanical properties of the coal seam and overlying strata. It particularly emphasizes the impact of the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure form of the coal pillar, and whether there are long-term or periodic power sources in and near the reserved working face on the stability of the coal pillar. The S3. Feasibility study on zoning and isolation of a mining area includes analysis of factors affecting coal pillar stability, determination of the reasonable width of the waterproof coal pillar, calculation of the waterproof isolation coal pillar in the mining area, and feasibility analysis of zoning and isolation of the mining area. S4. Comprehensive technical measures and countermeasures for mine water prevention and control. First, determine the spatial location, possible water volume, and water pressure of the waterlogged area. Mark the lowest point of the waterlogged area and the elevation of the outer edge of the waterlogged area on the mining engineering plan. Based on this, formulate a water exploration and drainage design and select an appropriate and safe coal mining method. The S4. Comprehensive technical measures and countermeasures for mine water prevention and control include prediction and forecasting of waterlogging in goafs, three prevention measures during the rainy season, and prevention and control of old goaf water. As a further optimization of this technical solution: in the analysis of factors affecting the development height of the water-conducting fracture zone, the influence of overburden lithology and its combination characteristics, coal seam mining conditions, geological structure, coal mining methods and roof management, time process, repeated mining and other factors on the development height of the water-conducting fracture zone is studied; in the on-site measurement analysis of the development height of the water-conducting fracture zone, the borehole flushing fluid loss observation, core engineering geological recording, geophysical logging and three-dimensional imaging logging methods are used to measure the development height of the water-conducting fracture zone on-site; the numerical simulation analysis of the development characteristics of the water-conducting fracture zone is carried out to design a reasonable numerical simulation scheme, and numerical simulations such as FLAC3D are used to analyze the development height of the water-conducting fracture zone. The simulation software simulates the coal seam mining process, analyzes the damage of the roof overburden, and calculates the development height of the water-conducting fracture zone. The physical simulation analysis of the development characteristics of the water-conducting fracture zone is based on similarity theory to determine similar conditions and lay a simulation test model of similar materials. The comprehensive analysis of the development height of the water-conducting fracture zone integrates field measurements, numerical simulation and physical simulation results to conduct a comprehensive analysis of the development height of the water-conducting fracture zone and draw more accurate and reliable conclusions. The study on the distribution characteristics of the development height of the water-conducting fracture zone in each mining area studies the distribution characteristics of the development height of the water-conducting fracture zone in multiple mining areas respectively, providing a basis for formulating targeted water prevention and control measures for each mining area; As a further preferred embodiment of the present technical solution: the analysis of the distribution characteristics of the aquifer (water barrier) comprises studying the distribution characteristics of the aquifer (water barrier) in the first mining area, the second mining area and the third mining area, including the lithology, thickness and water-richness of the aquifer, and the lithology, thickness and water-blocking performance of the aquiclude; and the analysis of the mine water inrush pattern comprises collecting data related to mine water inrush, including the location of the water outlet, water volume and water quality, and establishing a mine water inrush database; As a further preferred embodiment of the present technical solution: the analysis of factors affecting the stability of the coal pillar includes analyzing the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure form of the coal pillar, whether there is a long-term or periodic power source in the reserved working face and its vicinity, and other factors affecting the stability of the coal pillar; in determining the reasonable width of the waterproof coal pillar, a limit equilibrium zone model is established to analyze the stress state and failure form of the coal pillar; in calculating the waterproof isolation coal pillar of a mining area, the elastic core zone width and the theoretical coal pillar width of the mining area are calculated based on the relevant design parameters of the waterproof coal pillar; in the feasibility analysis of zoning isolation of a mining area, two zoning isolation schemes for a mining area are proposed, namely, completely sealing the water accumulated in the goaf of a mining area and setting a sealed wall to allow the water accumulated in the goaf to flow to the central water tank by gravity; As a further preferred embodiment of the present technical solution: the prediction and forecast of water accumulation in the goaf adopts a variety of methods such as data analysis, on-site investigation, drilling, geophysical exploration, analytical calculation, etc. to conduct a comprehensive prediction and forecast of water accumulation in the goaf, providing a basis for mine water prevention and control work; the three-prevention measures in the rainy season are formulated, including flood control, drainage prevention, lightning protection, etc., to ensure the safety of the mine during the flood season; the location of the water exploration starting point is determined in the prevention and control of old goaf water, the water exploration drilling holes are reasonably arranged, and the advanced water exploration and discharge drilling construction technology is adopted to ensure the safety and efficiency of the water exploration operation; As a further preferred embodiment of the present technical solution: in the on-site measurement analysis of the development height of the water-conducting fracture zone, the drilling position, depth and inclination are reasonably designed to ensure the accuracy and representativeness of the measured data; in the numerical simulation analysis of the development characteristics of the water-conducting fracture zone, the numerical simulation results are compared and analyzed with the on-site measurement results to verify the accuracy and reliability of the numerical simulation; in the physical simulation analysis of the development characteristics of the water-conducting fracture zone, monitoring points are arranged in the model, and advanced monitoring means are used to monitor the model excavation process in real time, recording data such as overburden collapse and fracture development height; As a further preferred embodiment of the present technical solution: the analysis of the distribution characteristics of the aquifer (water barrier) in different mining areas analyzes the differences in the distribution characteristics of the aquifer (water barrier) in different mining areas to provide basic data for the analysis of mine water inrush patterns. The analysis of the mine water inrush patterns includes analyzing the composition of water samples of the mine water inrush to understand the source and supply path of the mine water inrush, and focusing on analyzing the mine water inrush patterns in a mining area, including the water inrush characteristics of the working face, the main water outlet points and the water volume statistics; As a further preferred embodiment of the present technical solution: the reasonable width of the waterproof coal pillar is determined by theoretical calculation and analysis to ensure the stability of the coal pillar; the width of the waterproof isolation coal pillar in the mining area is calculated by using a standard formula, and compared with the theoretical calculation result to determine the final width of the waterproof isolation coal pillar; the feasibility analysis of the zoning isolation in the mining area is carried out on two schemes, and a comprehensive evaluation is conducted from the aspects of technical feasibility, economic rationality, safety and reliability to select the optimal scheme; As a further optimization of this technical solution: the three preventions in the rainy season are regularly inspected and maintained on flood control facilities, drainage systems, and lightning protection facilities to ensure their normal operation; the prevention and control of old empty water strengthens the safety management during the exploration and discharge of water, closely observes the water discharge of the drilling holes, and if any abnormal situation is found, immediately take emergency measures to check the discharge effect and ensure that there is no water accumulation in the old empty area before mining operations can be carried out.

[0007] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention starts from multiple aspects such as the study of overburden destruction laws in coal seam mining, analysis of mine water gushing laws, feasibility study of zoning and isolation of a mining area, and comprehensive technical measures and countermeasures for mine water prevention and control, to form a complete system for comprehensive mine flood prevention and control. This helps to control the occurrence of floods at the source and improve the systematic and comprehensive nature of mine flood prevention and control. In view of the differences in hydrogeological conditions, mining technical conditions, etc. of different mines, personalized technical measures and countermeasures for water prevention and control are formulated, which helps to meet the personalized needs of different mines and improve the pertinence and effectiveness of mine flood prevention and control.

[0008] 2. The present invention adopts multiple methods to comprehensively predict and forecast the water accumulation in the goaf, which improves the precision and accuracy of the prediction. This helps to provide a more scientific and reliable basis for mine water prevention and control work, and realize early prediction, early prevention and early control of mine water disasters. It not only proposes emergency treatment measures after the occurrence of floods, but also formulates prevention and control measures before the occurrence of floods. This helps to advance the prevention and control of mine water disasters, from passive response to active prevention, and effectively control the occurrence and development of water disasters. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a flow chart of a method for preventing and controlling water hazards in a mine goaf area according to the present invention; Figure 2 The present invention is a framework of a mine goaf water hazard prevention method Figure 1 ; Figure 3 The present invention is a framework of a mine goaf water hazard prevention method Figure 2 . DETAILED DESCRIPTION

[0010] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0011] Example See also Figure 1-Figure 3As shown, the present invention provides a technical solution: including: S1, research on the law of overburden destruction in coal seam mining, constructing two zones of exploration drilling holes before mining and after mining on the surface of the working face, observing the amount of flushing fluid loss, drilling peek, logging, etc., and exploring the development height of the caving zone and the water-conducting fracture zone after the working face is mined; performing numerical simulation and similar material simulation to study the law of overburden destruction in the process of working face mining, S1, research on the law of overburden destruction in coal seam mining includes analysis of factors affecting the development height of the water-conducting fracture zone, on-site measurement analysis of the development height of the water-conducting fracture zone, numerical simulation analysis of the development characteristics of the water-conducting fracture zone, physical simulation analysis of the development characteristics of the water-conducting fracture zone, comprehensive analysis of the development height of the water-conducting fracture zone and research on the distribution characteristics of the development height of the water-conducting fracture zone in each mining area; S2. Analysis of water inflow patterns in each mining area of ​​the mine, including the distribution characteristics of surface water systems, aquifers (water barriers) and their hydrogeological parameters, the patterns and sources of water inflow in the mine, and the prediction of the amount of water inflow in the mine when mining subsequent coal seams using the large well method and hydrogeological analogy method. S2. Analysis of water inflow patterns in each mining area of ​​the mine, including the distribution characteristics of aquifers (water barriers) and the analysis of water inflow patterns in the mine; S3. Feasibility study of zoning isolation in the first mining area. This study examines various factors that affect the stability of the coal pillar, including mining depth, mining thickness, mining width, and the mechanical properties of the coal seam and overlying strata. It particularly emphasizes the impact of the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure form of the coal pillar, and whether there are long-term or periodic power sources in and near the reserved working face on the stability of the coal pillar. The S3. Feasibility study of zoning isolation in the first mining area includes analysis of factors affecting coal pillar stability, determination of the reasonable width of the waterproof coal pillar, calculation of the waterproof isolation coal pillar in the first mining area, and feasibility analysis of zoning isolation in the first mining area. S4. Comprehensive technical measures and countermeasures for mine water prevention and control. First, determine the spatial location, possible water volume, and water pressure of the waterlogged area. Mark the lowest point of the waterlogged area and the elevation of the outer edge of the waterlogged area on the mining project plan. Based on this, formulate a water exploration and drainage design and select an appropriate and safe coal mining method. S4. Comprehensive technical measures and countermeasures for mine water prevention and control include prediction and forecasting of waterlogging in goafs, three prevention measures during the rainy season, and prevention and control of old goaf water. In this embodiment, specifically: in the analysis of factors affecting the development height of the water-conducting fracture zone, the influence of overburden lithology and its combination characteristics, coal seam mining conditions, geological structure, coal mining methods and roof management, time process, repeated mining and other factors on the development height of the water-conducting fracture zone are studied; in the on-site measurement analysis of the development height of the water-conducting fracture zone, the borehole flushing fluid loss observation, core engineering geological recording, geophysical logging and three-dimensional imaging logging are used to measure the development height of the water-conducting fracture zone on-site; in the numerical simulation analysis of the development characteristics of the water-conducting fracture zone, a reasonable numerical simulation scheme is designed; the numerical simulation software such as FLAC3D is used to simulate the coal seam mining process, analyze the damage of the roof overburden, calculate the development height of the water-conducting fracture zone, and in the physical simulation analysis of the development characteristics of the water-conducting fracture zone, the phase Similar theory, determine similar conditions, lay similar material simulation test model, comprehensive analysis of the development height of water-conducting fracture zone, comprehensive field measurement, numerical simulation and physical simulation results, comprehensive analysis of the development height of water-conducting fracture zone, draw more accurate and reliable conclusions, the distribution characteristics of the development height of water-conducting fracture zone in each mining area are studied respectively, and the distribution characteristics of the development height of water-conducting fracture zone in multiple mining areas are studied to provide a basis for formulating targeted water prevention and control measures in each mining area. The development height of water-conducting fracture zone in the mining process of working face is studied and analyzed through the actual measurement of the development height of "two belts", and the mining-induced overburden damage characteristics under the same mining height conditions are analyzed by means of similar material simulation and numerical simulation. By collecting the measured data of water-conducting fracture zone in the region, it is verified that the measured results are consistent with the regional characteristics. In this embodiment, specifically: the distribution characteristics of the aquifer (water-blocking) layers in the first, second, and third mining areas are analyzed, including the lithology, thickness, and water-richness of the aquifer, and the lithology, thickness, and water-blocking performance of the water-blocking layer. The mine water inrush pattern analysis collects data related to mine water inrush, including the location of the water outlet, water volume, and water quality, to establish a mine water inrush database. The large well method treats the entire tunnel system of the mining area as a large water collection well, and adopts the submersible formula and the pressure-contained to unpressure formula, namely: ,in is the mine water inflow (m3 / h), is the permeability coefficient (m / d), is the height of the water column (m), is the thickness of the aquifer (m), is the water level drop (m), is the reference influence radius (m), is the reference radius (m); the hydrogeological analogy method is to predict the water inflow of a new mine with similar hydrogeological conditions and the same mining method based on the known mine water richness coefficient. The calculation formula is: ,in Water inflow of new mine (m3 / h), is the known old well water yield (m3 / h), is the known mined-out area of ​​the old mine (km2), and F is the designed new mine area (km2); In this embodiment, specifically: the analysis of factors influencing coal pillar stability analyzes the influence of factors such as the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure mode of the coal pillar, and whether there are long-term or periodic power sources in the reserved working face and its vicinity on the stability of the coal pillar. A limit equilibrium zone model is established to determine the reasonable width of the waterproof coal pillar and analyze the stress state and failure mode of the coal pillar. The calculation of the waterproof isolation coal pillar in a mining area calculates the width of the elastic core zone and the theoretical coal pillar width of the mining area based on the relevant design parameters of the waterproof coal pillar. The feasibility analysis of zoned isolation in a mining area proposes two zoned isolation schemes for a mining area: completely sealing the water accumulation in the goaf of the mining area and setting up a sealed wall to allow the water accumulation in the goaf to flow to the central water tank. A mechanical model of coal pillar stability is established based on geological survey data and coal seam occurrence conditions. The model divides the coal pillar into a limit equilibrium zone, an elastic core zone, and a hydraulic failure zone. Each zone has its own specific mechanical behavior and failure mode. By assuming the coal pillar as a uniform and continuous elastic body and considering the fixed end constraints at both ends of the coal pillar and the stress state in different zones, a foundation is laid for the quantitative analysis of coal pillar stability. In this embodiment, specifically: in the prediction and forecast of water accumulation in goaf, multiple methods such as data analysis method, on-site investigation, drilling method, geophysical prospecting method, analytical calculation method, etc. are adopted to comprehensively predict and forecast the water accumulation in goaf, so as to provide a basis for mine water prevention and control work; in the three-prevention measures in rainy season, three-prevention measures in rainy season are formulated, including flood control, drainage prevention, lightning protection, etc., to ensure the safety of mines during the flood season; in the prevention and control of old goaf water, the position of the water exploration starting point is determined, the water exploration drilling holes are reasonably arranged, and the advanced water exploration and discharge drilling construction technology is adopted to ensure the safety and efficiency of water exploration operations; the mining space method is applicable to when the water accumulation height H in the old goaf is large, especially when the entire mining working area is flooded, and the water accumulation amount in the goaf is estimated more accurately; the water accumulation space law is applicable to the range of maximum water head height H<5m, that is, the water head height is more accurately predicted within the caving zone; In this embodiment, specifically: in the on-site measurement analysis of the development height of the water-conducting fracture zone, the drilling position, depth and inclination are reasonably designed to ensure the accuracy and representativeness of the measured data; in the numerical simulation analysis of the development characteristics of the water-conducting fracture zone, the numerical simulation results are compared and analyzed with the on-site measurement results to verify the accuracy and reliability of the numerical simulation; in the physical simulation analysis of the development characteristics of the water-conducting fracture zone, monitoring points are arranged in the model, and advanced monitoring methods are used to monitor the model excavation process in real time, recording data such as overburden collapse and fracture development height. Through on-site measurement and analysis, The method includes observation of borehole flushing fluid loss, core engineering geological logging, geophysical logging and three-dimensional imaging logging. Combined with numerical simulation and physical simulation analysis, it comprehensively determines the development height of water-conducting fracture zones and caving zones. The lithology and structure of the overburden, coal seam mining conditions, geological structure, time factors and repeated mining, etc., jointly affect the development of water-conducting fracture zones. As the working face advances, the height of the caving zone and water-conducting fracture zone gradually increases. As the goaf expands, the subsidence of the overburden changes significantly, and the subsidence characteristics vary at different locations. In this embodiment, specifically: the distribution characteristics of aquifers (water barriers) are analyzed, and the differences in the distribution characteristics of aquifers (water barriers) in different mining areas are analyzed to provide basic data for the analysis of mine water inrush patterns. The analysis of mine water inrush patterns analyzes the composition of water samples from mine water inrush to understand the source and recharge path of mine water inrush. The analysis focuses on the mine water inrush patterns in one mining area, including the characteristics of water inrush from the working face, the main water outlet points, and water volume statistics. The differences in the distribution characteristics of aquifers and aquitards in different mining areas are mainly reflected in the changes in the thickness of the aquifers (water barriers) and the water richness. In this embodiment, specifically: the reasonable width of the waterproof coal pillar is determined through theoretical calculation and analysis to ensure the stability of the coal pillar. The standard formula is used to calculate the width of the waterproof isolation coal pillar in a mining area, and the width is compared and analyzed with the theoretical calculation results to determine the final width of the waterproof isolation coal pillar. The feasibility analysis of the zoning isolation in a mining area is to conduct a feasibility analysis on the two schemes, and a comprehensive evaluation is conducted from the aspects of technical feasibility, economic rationality, safety and reliability to select the optimal scheme. When calculating the width of the waterproof coal pillar of the theoretical model, in addition to the coal pillar height, coal seam burial depth, average bulk density of the overlying rock layer, water head pressure in the old empty area, and the bonding strength of the coal pillar top and bottom plates, which can be obtained from relevant exploration reports, the tensile and compressive strength of the coal rock, the plastic rheological strength of the coal rock, the lateral pressure coefficient, the core area load concentration coefficient, and the pore weakening coefficient need to be obtained through relevant experiments and theories. In this embodiment, specifically: in the rainy season, the flood control facilities, drainage systems, and lightning protection facilities are regularly inspected and maintained to ensure their normal operation. The geodetic survey team is responsible for collecting meteorological information and hydrological data. In case of heavy to torrential rain or ground flooding, it is necessary to report to the mine dispatch room in a timely manner and notify the flood control and rescue team in a timely manner to make preparations for flood control and rescue. At the same time, the water inflow at each level in the mine is monitored. When the water inflow changes, it is necessary to carefully analyze and report to the rescue leadership group. The professional rescue team and rescue reserve team under the rescue leadership group are in place during the rainy season. During this period, the supply group must ensure that emergency materials are in place, establish a flood control reserve warehouse, and make it easy to use at any time. In case of thunderstorms, the Mechanical and Electrical Department must assign special personnel to guard areas where the power supply lines are complex and prone to failure to prevent lightning from breaking through and breaking the power cables and injuring people. In the rainy season, water accumulates in low-lying areas of the ground, and drainage ditches must be cleared in time. Water accumulated in important production sites must be pumped out in time. Repair and blocking measures must be taken for leaking houses and water ingress. Dangerous houses must be renovated or personnel must be evacuated before it is expected to arrive. Professionals from the mining company will cooperate with various units to carry out temporary For key places where the ground elevation is lower than the highest flood level in previous years, drainage ditches should be dug before the rainy season, and flood control soil and woven bags should be prepared. In case of heavy rain, flood control soil and woven bags should be prepared at the wellhead to prevent rainwater from flowing back into the well. Flood control and rescue personnel and wellhead staff should be mobilized in time to deal with the cofferdam at the wellhead water inlet. For the prevention and control of old empty water, safety management should be strengthened during the exploration and discharge of water. The water discharge of the drilling hole should be closely observed. If any abnormal situation is found, emergency measures should be taken immediately to test the discharge effect. Only after ensuring that there is no water accumulation in the old empty area can mining operations be carried out. On the basis of the old goaf water hazard forecast, for some projects that may cause major accidents, such as cutting holes in the mountains to penetrate old lanes, etc., an old goaf water hazard notice should be issued 5 to 10 days in advance to increase vigilance, check the implementation of waterproofing measures, and ensure safety. The main measure to prevent and control old goaf water is to conduct strict exploration and drainage. The spatial location of the waterlogged area, the possible amount of water and water pressure must be found out first, and the lowest point of the waterlogged area and the elevation of the outer edge of the waterlogged area must be marked on the plan of the mining project. On this basis, the exploration and drainage design can be compiled to select an appropriate and safe coal mining method. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations that come within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates. In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preventing and controlling water hazards in a mine goaf, characterized in that: include: S1. Study on the damage law of overburden during coal seam mining. Drill holes before and after mining are constructed in two zones on the surface of the working face. Flushing fluid loss is observed, borehole peeks are made, and well logging is performed to explore the height of the caving zone and the water-conducting fracture zone after mining on the working face. Numerical simulation and similar material simulation are performed to study the damage law of overburden during mining on the working face. The S1. Study on the damage law of overburden during coal seam mining includes analysis of factors affecting the height of the water-conducting fracture zone, on-site measurement analysis of the height of the water-conducting fracture zone, numerical simulation analysis of the development characteristics of the water-conducting fracture zone, physical simulation analysis of the development characteristics of the water-conducting fracture zone, comprehensive analysis of the height of the water-conducting fracture zone, and study of the distribution characteristics of the height of the water-conducting fracture zone in each mining area. S2. Analysis of water inflow patterns in each mining area of ​​the mine, including the distribution characteristics and hydrogeological parameters of the surface water system, aquifers (water barriers), the patterns and sources of mine water inflow, and prediction of the amount of mine water inflow when mining subsequent coal seams using the large well method and hydrogeological analogy method. The S2 analysis of water inflow patterns in each mining area of ​​the mine includes analysis of the distribution characteristics of aquifers (water barriers) and analysis of the patterns of mine water inflow; S3. Feasibility study on zoning and isolation of a mining area. This study examines various factors that affect the stability of the coal pillar, including mining depth, mining thickness, mining width, and the mechanical properties of the coal seam and overlying strata. It particularly emphasizes the impact of the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure form of the coal pillar, and whether there are long-term or periodic power sources in and near the reserved working face on the stability of the coal pillar. The S3. Feasibility study on zoning and isolation of a mining area includes analysis of factors affecting coal pillar stability, determination of the reasonable width of the waterproof coal pillar, calculation of the waterproof isolation coal pillar in the mining area, and feasibility analysis of zoning and isolation of the mining area. S4. Comprehensive technical measures and countermeasures for water prevention and control in mines. First, find out the spatial location of the waterlogged area, the possible amount of water and the water pressure, and mark the position of the lowest point of the waterlogged area and the elevation of the outer edge of the waterlogged area on the mining project plan. On this basis, prepare the water exploration and discharge design and select the applicable and safe coal mining method. The said S4. Comprehensive technical measures and countermeasures for water prevention and control in mines include the prediction and forecast of waterlogging in goaf, the three preventions in rainy season and the prevention and control of old goaf water.

2. A method for preventing and controlling water hazards in a mine goaf according to claim 1, characterized in that: The analysis of factors influencing the development height of the water-conducting fracture zone is conducted to study the influence of overburden lithology and its combination characteristics, coal seam mining conditions, geological structure, coal mining methods and roof management, time process, repeated mining and other factors on the development height of the water-conducting fracture zone. The field measurement analysis of the development height of the water-conducting fracture zone adopts the methods of drilling fluid loss observation, core engineering geological recording, geophysical logging and three-dimensional imaging logging to measure the development height of the water-conducting fracture zone on site. The numerical simulation analysis of the development characteristics of the water-conducting fracture zone is conducted to design a reasonable numerical simulation scheme, and use numerical simulation software such as FLAC3D to simulate the coal seam development. During the mining process of the layer, the damage of the roof overburden is analyzed, and the development height of the water-conducting fracture zone is calculated. In the physical simulation analysis of the development characteristics of the water-conducting fracture zone, similar conditions are determined based on similarity theory, and a simulation test model of similar materials is laid. In the comprehensive analysis of the development height of the water-conducting fracture zone, the results of field measurements, numerical simulation and physical simulation are integrated to conduct a comprehensive analysis of the development height of the water-conducting fracture zone, and a more accurate and reliable conclusion is obtained. In the study on the distribution characteristics of the development height of the water-conducting fracture zone in each mining area, the distribution characteristics of the development height of the water-conducting fracture zone in multiple mining areas are studied respectively, providing a basis for formulating targeted water prevention and control measures for each mining area.

3. A method for preventing and controlling water hazards in a mine goaf according to claim 2, characterized in that: The analysis of the distribution characteristics of aquifers (water-blocking layers) is to study the distribution characteristics of aquifers (water-blocking layers) in the first, second and third mining areas, including the lithology, thickness, water-richness, etc. of the aquifers, and the lithology, thickness, water-blocking performance, etc. of the water-blocking layers. The analysis of the mine water inrush patterns is to collect data related to mine water inrush, including the location of the water outlet, water volume, water quality, etc., to establish a mine water inrush database.

4. A method for preventing and controlling water hazards in a mine goaf according to claim 3, characterized in that: The analysis of factors affecting coal pillar stability includes analysis of the internal structure of the coal body, the contact properties at both ends of the coal pillar, the stress state and failure form of the coal pillar, whether there is a long-term or periodic power source in the reserved working face and its vicinity, and other factors affecting the stability of the coal pillar. In determining the reasonable width of the waterproof coal pillar, a limit equilibrium zone model is established to analyze the stress state and failure form of the coal pillar. In calculating the waterproof isolation coal pillar in a mining area, the width of the elastic core zone and the theoretical coal pillar width of the mining area are calculated based on the relevant design parameters of the waterproof coal pillar. In the feasibility analysis of zoning isolation in a mining area, two zoning isolation schemes for a mining area are proposed, namely, completely sealing the water in the goaf of a mining area and setting up a closed wall to allow the water in the goaf to flow to the central water tank.

5. A method for preventing and controlling water hazards in a mine goaf according to claim 4, characterized in that: In the prediction and forecast of water accumulation in goaf, multiple methods such as data analysis, on-site investigation, drilling, geophysical exploration, analytical calculation and so on are used to make a comprehensive prediction and forecast of water accumulation in goaf, so as to provide a basis for mine water prevention and control. In the three-prevention in rainy season, three-prevention measures in rainy season are formulated, including flood prevention, drainage prevention, lightning protection, etc., to ensure the safety of mine during the flood season. In the prevention and control of old goaf water, the location of the water exploration starting point is determined, the water exploration drilling holes are reasonably arranged, and the advanced water exploration and discharge drilling construction technology is adopted to ensure the safety and efficiency of water exploration operations.

6. A method for preventing and controlling water hazards in a mine goaf according to claim 5, characterized in that: In the field measurement analysis of the development height of the water-conducting fracture zone, the drilling position, depth and inclination are reasonably designed to ensure the accuracy and representativeness of the measured data. In the numerical simulation analysis of the development characteristics of the water-conducting fracture zone, the numerical simulation results are compared and analyzed with the field measurement results to verify the accuracy and reliability of the numerical simulation. In the physical simulation analysis of the development characteristics of the water-conducting fracture zone, monitoring points are arranged in the model, and advanced monitoring methods are used to monitor the model excavation process in real time, and record data such as overburden collapse and fracture development height.

7. A method for preventing and controlling water hazards in a mine goaf according to claim 6, characterized in that: The analysis of the distribution characteristics of the aquifer (water-blocking layer) mentioned above analyzes the differences in the distribution characteristics of the aquifer (water-blocking layer) in different mining areas, and provides basic data for the analysis of mine water inrush patterns. The analysis of the mine water inrush patterns analyzes the composition of water samples of mine water inrush, understands the source and replenishment path of mine water inrush, and focuses on analyzing the mine water inrush patterns of a mining area, including the water inrush characteristics of the working face, the main water outlet points and water volume statistics.

8. A method for preventing and controlling water hazards in a mine goaf according to claim 7, characterized in that: The reasonable width of the waterproof coal pillar is determined through theoretical calculation and analysis to ensure the stability of the coal pillar. The standard formula is used to calculate the width of the waterproof isolation coal pillar in the mining area, and the calculation is compared with the theoretical calculation results to determine the final width of the waterproof isolation coal pillar. The feasibility analysis of the zoning isolation of the mining area conducts a feasibility analysis on the two schemes, conducts a comprehensive evaluation from the aspects of technical feasibility, economic rationality, safety and reliability, and selects the optimal scheme.

9. A method for preventing and controlling water hazards in a mine goaf according to claim 8, characterized in that: The three prevention measures in the rainy season include regular inspection and maintenance of flood control facilities, drainage systems, and lightning protection facilities to ensure their normal operation. The prevention and control of old empty water strengthens safety management during the exploration and release of water, closely observes the water output of the drilling holes, and immediately takes emergency measures if any abnormal situation is found to check the effect of water release. Only after ensuring that there is no water accumulation in the old empty area can mining operations be carried out.

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