Prevention and control method for side goaf water damage of coal mining working face

Abstract

The invention discloses a method for preventing and treating lateral goaf water disasters of a coal mining working face, which is suitable for preventing and treating accumulated water in a near-side goaf of an inclined structure area. A roadway which is far away from the goaf and cannot be threatened by the safety of the accumulated water in the goaf is utilized to carry out drainage operation of the accumulated water in the goaf; by means of the method, the safety of the crossheading roadway on the small coal pillar side in the tunneling process can be guaranteed, the adverse effect of the accumulated water drainage work of the goaf on the tunneling progress of the roadway can be reduced to the maximum degree, and it is guaranteed that the overall mining work is efficiently and safely promoted.

Description

Technical Field

[0001] The invention relates to the technical field of water hazard prevention and control in goaf areas, and in particular to a method for preventing and controlling water hazard in goaf areas facing the side of coal mining work. Background Art

[0002] Water accumulation in goafs poses a significant safety threat to underground mining operations. In actual mining operations, water seepage accidents often occur due to a combination of factors, including insufficiently detailed and accurate geological data, a vague understanding of goaf conditions, and the failure to strictly implement water exploration and drainage measures. Water seepage in goafs is often accompanied by powerful and powerful water pressure. Once it erupts, it can instantly engulf everything, causing immeasurable casualties and property losses.

[0003] In recent years, the overall number of coal mine water disasters has shown a significant downward trend, and other types of water disasters have also decreased significantly. However, what is worrying is that the proportion of water disasters in goaf areas remains high. Major and even serious water seepage accidents in goaf areas still appear in the news from time to time, dealing a heavy blow to the coal industry's production safety and seriously restricting the industry's healthy development.

[0004] In coal mining operations, if the mining face is adjacent to a waterlogged goaf, the two main methods currently used to prevent and control water damage in the goaf are preserving a water-blocking coal pillar and preemptively draining the accumulated water. When the amount of water in the goaf is substantial and the water pressure is high, a wider coal pillar is often required to mitigate the potential threat of water damage. However, this practice inevitably results in a significant waste of coal resources, which is undesirable from the perspective of resource efficiency. Preemptive drainage, by contrast, offers significant advantages. By applying this method scientifically and rationally, it can effectively drain accumulated water from adjacent goafs, significantly reducing the required coal pillar width. This not only significantly reduces the waste of coal resources but also improves resource recovery while ensuring the safety of coal mining operations, providing strong support for the sustainable development of the coal industry.

[0005] According to the "Detailed Rules for Coal Mine Water Prevention and Control," when a small coal pillar is left between a newly designed working face and an existing goaf, the head pressure exerted by accumulated water in the goaf on the new working face must be reduced to below 0.01 MPa, and dynamic replenishment water must be continuously released from the goaf during the working face recovery process. Currently, the most common drainage measure involves simultaneous drainage, evaluation, and excavation in the new working face drift. However, this approach faces significant challenges in the geological conditions of syncline structures. In syncline areas, the working face typically exhibits high ends and a low center. Therefore, the new working face drift must be constructed downwards first, which increases the difficulty and slows down the drainage of accumulated water in the adjacent goaf. This often necessitates pausing drift excavation to allow the goaf to be drained for a period of time before continuing. However, since the water head pressure must be reduced to below 0.01MPa, excavation has to be stopped again for drainage after a short distance. This method has seriously restricted the excavation progress of the drift tunnel. There is an urgent need for a method for preventing and controlling side goaf water hazards in coal mining work that can solve the above problems. Summary of the Invention

[0006] In view of the above-mentioned technical deficiencies, the purpose of the present invention is to provide a method for preventing and controlling water hazards in side goafs during coal mining operations.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for preventing and controlling water hazards in side goafs of coal mining working faces, comprising the following steps:

[0009] S1. Collect data on adjacent goafs, test and obtain water level data in the goafs, and predict the amount of water accumulated in the goafs;

[0010] S2. Collect the layout data of the drift roadway of the newly designed working face and the width data of the coal pillar between the newly designed working face and the goaf;

[0011] S3, carry out construction of new working face drift away from goaf;

[0012] S4. After the drift is constructed to the lowest point, a special drainage tunnel is constructed vertically toward the goaf, and the excavation is stopped at a position 30-50m away from the goaf;

[0013] S5. Construct water tank and drainage system at the stop excavation location;

[0014] S6. Construct several drainage holes in the goaf;

[0015] S7. Drain water from the goaf and monitor the water output from the drainage holes and the water level in the goaf in real time;

[0016] S8. Analyze the drainage effect in real time and draw the location of the water accumulation line;

[0017] S9. Excavate the tunnel near the goaf, and the excavation head should always be outside the waterlogging line;

[0018] S10. When the tunnel near the goaf reaches the lowest point, a drainage borehole is constructed directly into the goaf to continuously drain the dynamic replenishment water from the goaf.

[0019] Preferably, in step S1, the data of the adjacent goaf include: specifications and dimensions of the adjacent goaf, roadway layout, mining time, mining method, coal mining thickness and water inflow during mining.

[0020] Preferably, the special drainage tunnel in step S4 is a temporary tunnel.

[0021] Preferably, in step S4, the construction stop position is 40m away from the goaf.

[0022] Preferably, in step S6, the sparse drilling holes are arranged in a fan shape on a plane.

[0023] Preferably, the position where the drainage borehole enters the goaf is 2-4 m higher than the bottom plate.

[0024] Preferably, the position where the drainage borehole enters the goaf is 3m higher than the bottom plate.

[0025] Preferably, in step S5, the size of the water tank and the rated drainage capacity of the drainage system are determined according to the predicted amount of water accumulated in the goaf and the drainage duration requirement.

[0026] The beneficial effects of the present invention are:

[0027] The method of the present invention comprehensively considers the unique structural characteristics of the syncline structural area, the complex characteristics of water accumulation in the goaf, and the specific layout of the new working face drift tunnel. The principle is simple and easy to understand. While ensuring the prevention and control effect, it minimizes the impact on the working face construction progress and has high safety. It provides a practical and effective solution to the problem of lateral goaf water hazards facing coal mining workers. The present invention is more suitable for goaf water hazard prevention and control under complex working conditions such as small coal pillars and large-scale water accumulation in single-sided goaf areas in syncline structural areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 This is a schematic diagram of mining planning according to an embodiment of the present invention. DETAILED DESCRIPTION

[0030] 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. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] Example:

[0032] This embodiment provides a method for preventing and controlling water hazards in side goafs of coal mining work, comprising the following steps:

[0033] S1. Collect data on adjacent goafs, obtain goaf water level data through testing, and predict the amount of water accumulated in the goafs; specifically, collect data on the specifications and dimensions of the adjacent goafs, roadway layout, mining time, mining method, coal thickness, and water inflow during mining; obtain goaf water level data through professional testing familiar to those skilled in the art; and, based on this, use methods familiar to those skilled in the art to predict the amount of water accumulated in the goafs and the amount of dynamic water replenishment;

[0034] S2. Collecting layout data of the drifts of the newly designed working face and data on the width of the coal pillars between the newly designed working face and the goaf, and analyzing the spatial relationship between the newly designed working face and the adjacent goaf using existing methods known to those skilled in the art;

[0035] S3. Construction of the new working face drift away from the goaf. According to the design plan, construction of the new working face drift away from the goaf will be carried out first. Since this drift is far away from the goaf, it is less affected by water damage in the goaf and can ensure construction safety.

[0036] S4. After the drift reaches its lowest point, a dedicated drainage tunnel is constructed perpendicularly toward the goaf. Excavation is stopped at a distance of 30-50m from the goaf. When the drift tunnel away from the goaf reaches its lowest point, the tunnel turns perpendicularly toward the goaf to construct a dedicated drainage tunnel. This dedicated drainage tunnel is a temporary tunnel with simplified support to meet temporary use. When the dedicated drainage tunnel is constructed 30-50m from the goaf, excavation is stopped, and the construction of the dedicated drainage tunnel is completed.

[0037] S5. Construct a water tank and drainage system at the stop-excavation location. The size of the water tank and the rated drainage capacity of the drainage system shall be determined based on the predicted amount of water accumulated in the goaf and the drainage duration requirements, and shall comply with the relevant requirements of the "Detailed Rules for Coal Mine Water Prevention and Control";

[0038] S6. Construct several drainage holes into the goaf. The drainage holes are arranged in a fan shape on the plane. The position where the drainage holes enter the goaf is 2-4 meters above the floor.

[0039] S7. Drain water from the goaf, monitor the water output from the drainage holes and the water level in the goaf in real time, calculate the total water output and the total drainage volume, and closely monitor the real-time water level in the goaf;

[0040] S8. Analyze the drainage effect in real time and draw the location of the water accumulation line. Based on the real-time water level data of the goaf and the elevation of the coal mining floor in the goaf, analyze the drainage effect and draw the real-time location of the water accumulation line in the goaf.

[0041] S9. Excavate the drift roadway near the goaf, ensuring that the excavation head is always outside the water accumulation line. While draining water, excavate the drift roadway near the goaf according to the real-time drawn position of the water accumulation line. During the excavation process, ensure that the excavation head is always outside the water accumulation line to ensure the safety of the roadway excavation.

[0042] S10. When the tunnel near the goaf reaches the lowest point, drainage holes are constructed directly into the goaf to continuously drain the dynamic replenishment water from the goaf, further reducing the risk of water damage in the goaf.

[0043] Preferably, in step S4, the construction stop position is 40m away from the goaf.

[0044] Preferably, in step S6, the position where the drainage borehole enters the goaf is 3m higher than the bottom plate.

[0045] The contents not introduced in detail in this example, such as collecting data, testing water level data, predicting water accumulation, calculating total water flow and total water discharge, analyzing discharge effects, and drawing water accumulation line positions, can all be obtained by those skilled in the art using existing methods familiar to those skilled in the art.

[0046] The tunnel excavation, tunnel construction, water tank and drainage system construction, drawing of water accumulation lines, drainage drilling construction and other construction not described in detail in this embodiment are all carried out using existing methods or methods well known to those skilled in the art.

[0047] like Figure 1The figure below shows the mine's mining plan. The newly designed 4082 working face is located adjacent to the 215 goaf. The geological structure of the area is generally syncline-shaped, and the designed coal pillar thickness between the 4082 working face's haulage drift and the 215 working face is only 8 meters. The 4082 working face mines the 4-2# coal seam, which has a thickness ranging from 8 to 12 meters. The working face is 950 meters long and 88 meters wide. The 215 goaf is flooded at an elevation of +1007 meters. The working faces below the water level and hydraulically connected to the 215 goaf have accumulated a total of 750,000 cubic meters of water, posing a potential challenge to the safety and efficiency of subsequent mining operations at the 4082 working face.

[0048] Using the method in this example, construction began first in the return tunnel, away from the 215 goaf. When construction reached the lowest point in the tunnel, the tunnel turned perpendicular to the 215 goaf and began construction of a dedicated drainage tunnel. When excavation reached 40 meters from the 215 goaf, excavation ceased, and work began on constructing a temporary water tank and installing a drainage system. Subsequently, 10 drainage boreholes were drilled at the head of the tunnel, officially beginning the work of draining the accumulated water from the goaf.

[0049] During the drainage process, a dedicated person is arranged to record the water output of the drainage borehole and the water level changes in the goaf in real time, so as to evaluate the drainage effect in a timely and accurate manner; once the elevation of the head of the transport chute, that is, the transport tunnel, is higher than the water accumulation elevation in the goaf, the excavation operation of the transport tunnel will be started immediately.

[0050] During the excavation of Yunshun Tunnel, water drainage work was carried out continuously, and the drainage effect evaluation was carried out continuously to ensure that the excavation head of Yunshun Tunnel was always higher than the water accumulation elevation of the goaf; when the Yunshun Tunnel was excavated to its lowest point, a drainage borehole was constructed directly at the head towards the 215 goaf to drain the dynamic replenishment water of the 215 goaf and ensure the safe and orderly progress of the mining operation.

[0051] The method of this embodiment comprehensively considers the unique structural characteristics of the syncline structural area, the complex characteristics of water accumulation in the goaf, and the specific layout of the new working face drift tunnel. The principle is simple and easy to understand. While ensuring the prevention and control effect, it minimizes the impact on the working face construction progress and has high safety. It provides a practical and effective solution to the problem of lateral goaf water hazards facing coal mining workers. The present invention is more suitable for goaf water hazard prevention and control under complex working conditions such as small coal pillars and large-scale water accumulation in single-sided goaf areas in syncline structural areas.

[0052] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preventing and controlling water hazards in side goafs of coal mining working faces, characterized in that: The following steps are involved: S1. Collect data on adjacent goafs, test and obtain water level data in the goafs, and predict the amount of water accumulated in the goafs; S2. Collect the layout data of the drift roadway of the newly designed working face and the width data of the coal pillar between the newly designed working face and the goaf; S3, carry out construction of new working face drift away from goaf; S4. After the drift is constructed to the lowest point, a special drainage tunnel is constructed vertically toward the goaf, and the excavation is stopped at a position 30-50m away from the goaf; S5. Construct water tank and drainage system at the stop excavation location; S6. Construct several drainage holes in the goaf; S7. Drain water from the goaf and monitor the water output from the drainage holes and the water level in the goaf in real time; S8. Analyze the drainage effect in real time and draw the location of the water accumulation line; S9. Excavate the tunnel near the goaf, and the excavation head should always be outside the waterlogging line; S10. When the tunnel near the goaf reaches the lowest point, a drainage borehole is constructed directly into the goaf to continuously drain the dynamic replenishment water from the goaf.

2. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 1, characterized in that: In step S1 , the data of the adjacent goaf include: the specifications and dimensions of the adjacent goaf, the layout of the roadway, the mining time, the mining method, the mining thickness and the water inflow during mining.

3. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 1, characterized in that: The special drainage tunnel in step S4 is a temporary tunnel.

4. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 1, characterized in that: In step S4, the construction stop position is 40m away from the goaf.

5. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 1, characterized in that: In step S6, the sparse drilling holes are arranged in a fan shape on a plane.

6. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 5, characterized in that: The position where the drainage borehole enters the goaf is 2-4m higher than the bottom plate.

7. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 6, characterized in that: The position where the drainage borehole enters the goaf is 3m higher than the bottom plate.

8. A method for preventing and controlling water hazards on the side of coal mining working faces according to claim 1, characterized in that: In step S5, the size of the water tank and the rated drainage capacity of the drainage system are determined according to the predicted amount of water accumulated in the goaf and the drainage duration requirement.

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