Thick and hard top plate roof-cutting roadway-forming gangue side buffer control method

Abstract

The invention provides a thick and hard top plate roof-cutting roadway-forming gangue side buffering control method, and belongs to the technical field of roof-cutting pressure-relief coal-pillar-free self-roadway-forming mining. The method comprises the following steps: step 1, mounting a first gangue retaining support device on one side, close to a working face, of a roadway; 2, a flexible buffer wall is arranged on the side, away from the mining working face, of the first gangue blocking supporting device; 3, a second gangue blocking supporting device is arranged on the side, away from the first gangue blocking supporting device, of the flexible buffering wall; 4, roof cutting and pressure relief are conducted after the working face is mined; the method is used for solving the technical problems that in the mining process of an existing roof-cutting pressure-relief coal-pillar-free self-roadway-forming technology, under the geological condition of a thick and hard roof, large caving gangue behind a working face can generate strong impact load on a gangue blocking support, and large-range deformation and failure of a hydraulic gangue blocking support are prone to occurring in the mining process of the existing roof-cutting pressure-relief coal-pillar-free self-roadway-forming technology.

Description

Technical Field

[0001] The invention belongs to the technical field of top cutting, pressure relief, non-coal pillar and self-forming laneway mining, and in particular relates to a gangue wall buffering control method for top cutting and laneway forming of thick hard roof. Background Art

[0002] Common underground coal mines mainly use traditional longwall mining methods, that is, to recover a working face, two recovery tunnels need to be excavated first, and then the working face is recovered. A section coal pillar (generally 20-50 meters wide) needs to be retained between two adjacent recovery working faces to protect the adjacent working face's empty tunnel from being disturbed by the gangue falling from the goaf of the previous working face. However, due to the existence of the section protection coal pillar, a large amount of coal resources in the mine will be lost, resulting in a low recovery rate of coal resources in the working face. In order to improve the recovery rate of coal resources in the working face, a mining technology of self-forming lanes with top cutting and pressure relief without coal pillars is currently proposed. This technology realizes automatic lane formation by pre-splitting and top cutting, makes full use of the crushing and expansion characteristics of the roof rock mass, and eliminates the filling body in the goaf-retained lane. This technology weakens the structural transmission between the roof of the goaf and the roof of the lane by pre-splitting and top cutting, improves the stress environment of the lane, and realizes coal pillar-free mining.

[0003] However, the current technology of top cutting and pressure relief without coal pillars and self-forming lanes cannot be applied to mines with all geological conditions. Especially when the technology of top cutting and pressure relief without coal pillars and self-forming lanes is used in the working face with thick hard roof, a large number of large blocks of gangue will gradually collapse in the goaf behind the working face. These large collapsed gangue will form a large impact disturbance. In particular, it will cause a large impact load on the hydraulic gangue retaining support of the top cutting lane behind the working face, which will cause a large range of deformation and failure of the gangue retaining support, and even a series of problems such as large-scale instability and dumping.

[0004] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a gangue buffering control method for cutting off the thick hard roof to form a laneway, so as to solve the technical problem that in the existing top cutting and pressure relief technology for self-forming lanes without coal pillars, when encountering the geological conditions of thick hard roof during mining, large pieces of collapsed gangue behind the working face will produce strong impact loads on the gangue retaining support, which is easy to cause large-scale deformation and failure of the hydraulic gangue retaining support.

[0006] In order to achieve the above-mentioned purpose, the thick hard roof cutting and gangue side buffer control method of the present invention provides the following technical solutions: A method for controlling the buffering of gangue walls during the cutting of thick hard roof slabs into laneways comprises the following steps: Step 1: Install a first rock retaining support device on the side of the tunnel close to the working face; Step 2, setting a flexible buffer wall on the side of the first gangue retaining support device away from the working face being mined; Step 3, a second rock retaining support device is provided on a side of the flexible buffer wall away from the first rock retaining support device; Step 4: Cut the top and release the pressure after the working face is mined.

[0007] As a further optimized technical solution, the first rock retaining support device includes: First vertical support structures, which are evenly spaced along the mining direction of the working face, and the distance between any two adjacent first vertical support structures is L1; A first transverse connecting structure, wherein a plurality of the first transverse connecting structures are arranged at intervals along the height direction of the first vertical supporting structures and are used to transversely connect all the first vertical supporting structures; The first buffer net is fixedly arranged on the framework formed by all the first vertical supporting structures and the first transverse connecting structures, and is used to prevent gangue from passing through.

[0008] As a further optimized technical solution, the second rock retaining support device includes: Second vertical support structures, the second vertical support structures are evenly spaced along the mining direction of the working face, and the distance between any two adjacent second vertical support structures is L2; A second transverse connecting structure, wherein a plurality of the second transverse connecting structures are arranged at intervals along the height direction of the second vertical supporting structures and are used to transversely connect all the second vertical supporting structures; A second buffer net is fixedly arranged on a framework formed by all the second vertical supporting structures and the second transverse connecting structures.

[0009] As a further optimized technical solution, the first buffer net is arranged on the side of the first gangue retaining support device facing the working face.

[0010] As a further optimized technical solution, the distance L1 between any two adjacent first vertical support structures is greater than the distance L2 between any two adjacent second vertical support structures.

[0011] As a further optimized technical solution, the second buffer net is arranged on the side of the second rock retaining support device facing away from the working face.

[0012] As a further optimized technical solution, the first vertical supporting structure is a U-shaped steel, each of the first vertical supporting structures includes a plurality of the U-shaped steels, the plurality of the U-shaped steels are overlapped in the length extension direction, and the plurality of the U-shaped steels are fixedly connected.

[0013] As a further optimized technical solution, the second vertical support structure is a U-shaped steel, each of the second vertical support structures includes a plurality of the U-shaped steels, the plurality of the U-shaped steels are overlapped in the length extension direction, and the plurality of the U-shaped steels are slidably connected.

[0014] As a further optimized technical solution, the first transverse connecting structure includes a card cable and a connecting plate. The card cable is fixedly arranged on the first vertical supporting structure, and the card cable fixes and presses a plurality of U-shaped steels on the first vertical supporting structure. The connecting plate is arranged between any two adjacent card cables, and both ends are fixedly connected to the card cables respectively.

[0015] As a further optimized technical solution, the second transverse connecting structure includes a card cable and a connecting plate. The card cable is fixedly arranged on the second vertical supporting structure, and the card cable is fixedly sleeved on multiple U-shaped steels on the second vertical supporting structure. The connecting plate is arranged between two adjacent cards, and the two ends are fixedly connected to the card cables respectively.

[0016] Beneficial effects: (1) Improvement of tunnel stability. In the case of thick and hard roof, the traditional technology of cutting the roof to relieve pressure and forming a tunnel without coal pillars is prone to large deformation of the tunnel due to the impact of collapsed gangue, which affects subsequent use and maintenance. The present invention effectively buffers the impact load and greatly reduces the overall deformation of the tunnel by setting up two layers of gangue retaining support devices and flexible buffer walls. This means that the shape and size of the tunnel can remain relatively stable, reducing the support and repair work caused by deformation and reducing the maintenance cost of the tunnel. In addition, since the deformation of the tunnel is effectively controlled, the damage to the tunnel structure caused by impact damage is reduced, thereby extending the service life of the tunnel. This is of great significance to the long-term mining planning of the mine, reducing the need for frequent new tunnel construction and improving the overall efficiency and economy of mine mining.

[0017] (2) Guarantee of mining safety During the mining process of thick hard roof, the impact of collapsed gangue on the gangue retaining support may cause the support to fail, and then cause safety accidents such as roof falls, threatening the lives of underground workers. The buffer control method of the present invention can effectively absorb the impact energy, reduce the risk of failure of the gangue retaining support, create a safer working environment for underground workers, and ensure the safe production of the mine. In addition, the application of this method makes the top cutting and unloading coal pillar-free self-forming lane technology more stably implemented under thick hard roof conditions, optimizing the entire mining process. The effective control of the impact of gangue during the mining process enables subsequent transportation, excavation and other work to be carried out more smoothly, improving the coordination and overall efficiency between various mining links.

[0018] (3) Contribution to resource utilization and environmental protection. The technology of cutting the roof to relieve pressure and forming a self-forming tunnel without coal pillars itself helps to improve the recovery rate of coal resources and reduce the loss of coal pillars in sections. The present invention further expands the application of this technology under thick and hard roof conditions, making it possible to effectively mine more coal resources that were originally difficult to mine due to geological conditions, thereby improving the overall utilization rate of coal resources and reducing resource waste. By effectively buffering and controlling the collapsed gangue, the damage caused by gangue to the tunnel and the surrounding environment is reduced, and dust pollution during gangue discharge and transportation is reduced. At the same time, since the demand for new tunnels is reduced, the amount of gangue generated during excavation is also indirectly reduced, which has positive significance for environmental protection.

[0019] (4) The promotion of industry technology development. This invention solves the application problem of the top-cutting pressure-relieving, non-coal-pillar self-forming tunneling technology under thick and hard roof conditions, expands the scope of application of the technology, and provides a feasible technical solution for mine mining under similar geological conditions. This helps to promote the entire coal mining industry to develop in a more efficient, environmentally friendly and safe direction; the proposal of this method provides new ideas and references for technological innovation in related fields, inspires more technical personnel in this field to conduct in-depth research and improvement on mine mining technology, and promotes the continuous improvement of the technical level of the entire industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them: Figure 1 A schematic diagram of self-forming laneway mining with top cutting and pressure relief without coal pillars according to an embodiment of the present invention; Figure 2 for Figure 1 The enlarged schematic diagram of part D in the middle; Figure 3 for Figure 2 A schematic cross-sectional view along the AA direction in FIG. Figure 4 for Figure 2 A cross-sectional schematic diagram along the BB direction; Figure 5 for Figure 2 A cross-sectional schematic diagram along the CC direction in FIG. Figure 6 This is a schematic structural diagram of a first rock retaining support device according to an embodiment of the present invention; Figure 7 The figure is a schematic structural diagram of a second rock retaining support device according to an embodiment of the present invention.

[0021] In the figure: 1. working face; 2. first rock-blocking support device; 201. first vertical support structure; 202. first transverse connecting structure; 203. first buffer net; 3. flexible buffer wall; 4. second rock-blocking support device; 401. second vertical support structure; 402. second transverse connecting structure; 403. second buffer net; 5. goaf; 6. tunnel; 7. cable clamp; 8. connecting plate. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. 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 belong to the scope of protection of the present invention.

[0023] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0024] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0025] The present invention provides a gangue buffering control method for cutting off the top of a thick hard roof into a laneway. Two layers of gangue retaining support devices are installed on one side of the laneway close to the working face, and a flexible buffer wall is arranged between the two layers of gangue retaining support devices. The two layers of gangue retaining support devices and the flexible buffer wall are used to buffer the impact load when large pieces of collapsed gangue fall behind the working face of the thick hard roof, thereby reducing the damage of the thick hard roof to the hydraulic gangue retaining support during the collapse process, thereby ensuring the safe use of the laneway.

[0026] Example 1 A method for controlling the buffering of gangue walls during the cutting of thick hard roof slabs into laneways comprises the following steps: Step 1: Install a first rock retaining support device 2 on the side of the tunnel 6 close to the working face 1.

[0027] like Figure 1 , Figure 2 , Figure 3 , Figure 6As shown, the first rock retaining support device 2 includes a first vertical support structure 201 , a first transverse connecting structure 202 and a first buffer net 203 .

[0028] The first vertical support structure 201 is along the mining direction of the working face 1 ( Figure 1 The first vertical support structures 201 are evenly spaced (in the direction indicated by the arrow in the middle), and the distance between any two adjacent first vertical support structures 201 is L1. The top and bottom ends of the first vertical support structures 201 are fixedly connected to the top and bottom of the tunnel 6 respectively. In this embodiment, the first vertical support structures 201 are made of U-shaped steel. In order to increase the anti-deformation ability of the first vertical support structures 201, each first vertical support structure 201 includes a plurality of vertically arranged U-shaped steels, and the plurality of vertically arranged U-shaped steels are overlapped in the length extension direction, and the plurality of U-shaped steels are fixedly connected to ensure the anti-deformation ability of the first vertical support structures 201.

[0029] A plurality of first transverse connecting structures 202 are arranged at intervals along the height direction of the first vertical supporting structures 201 , and are used to transversely connect all the first vertical supporting structures 201 , so that the first vertical supporting structures 201 and the first transverse connecting structures 202 form a mesh skeleton.

[0030] The first buffer net 203 is fixedly arranged on the framework formed by all the first vertical supporting structures 201 and the first transverse connecting structures 202, and is used to block the passage of gangue, prevent the gangue from falling into the tunnel 6, blocking the tunnel, and affecting the ventilation of the tunnel and the safety of pedestrians and transported materials.

[0031] Step 2, a flexible buffer wall 3 is provided on the side of the first gangue retaining support device 2 away from the working face 1 being mined.

[0032] like Figure 2 , Figure 4 As shown, the flexible buffer wall 3 is made of common energy-absorbing material. By setting the flexible buffer wall 3, sufficient deformation space is reserved for the first gangue retaining support device 2 to achieve the effect of buffering and absorbing impact energy.

[0033] Step 3, a second rock retaining support device 4 is arranged on the side of the flexible buffer wall 3 away from the first rock retaining support device 2, and the second rock retaining support device 4 is directly opposite to the hydraulic rock retaining support device, that is, the first rock retaining support device 2, the flexible buffer wall 3 and the second rock retaining support device 4 in the present invention are arranged on the inner side of the hydraulic rock retaining support, so that after the working face 1 is mined out to become the goaf 5, during the top cutting and pressure relief process, the two layers of rock retaining support devices and the flexible buffer wall 3 are used together to absorb the impact energy of the collapsed rock and reduce the deformation of the hydraulic rock retaining support.

[0034] like Figure 1 , Figure 2 , Figure 5 , Figure 7 As shown, the second rock retaining support device 4 includes a second vertical support structure 401 , a second transverse connection structure 402 and a second buffer net 403 .

[0035] The second vertical support structure 401 is along the mining direction of the working face 1 ( Figure 1 The second vertical support structures 401 are evenly spaced (in the direction indicated by the arrow in the middle), and the distance between any two adjacent second vertical support structures 401 is L2. The top and bottom ends of the second vertical support structures 401 are fixedly connected to the top and bottom of the lane 6 respectively. In this embodiment, the second vertical support structures 401 are made of U-shaped steel. In order to increase the deformation resistance of the second vertical support structures 401, each second vertical support structure 401 includes a plurality of U-shaped steels, which are overlapped in the length extension direction and are slidably connected. That is, Figure 5 In the state shown, when the goaf 5 is undergoing top cutting and pressure relief, the rightward horizontal impact force generated during the falling of the thick hard roof continues to act on the second vertical support structure 401 after being absorbed and buffered by the first gangue retaining support device 2 and the flexible buffer wall 3. If the impact force is too large, the second vertical support structure 401 as a whole will undergo an arc deformation to the left. During the arc deformation process, a certain amount of mutual sliding will occur between the multiple overlapping U-shaped steels, which will increase the length of the second vertical support structure 401 as a whole, thereby preventing the gangue from further deforming toward the direction of the tunnel 6.

[0036] A plurality of second transverse connecting structures 402 are arranged at intervals along the height direction of the second vertical supporting structures 401 , and are used to transversely connect all the second vertical supporting structures 401 , so that the second vertical supporting structures 401 and the second transverse connecting structures 402 form a mesh skeleton.

[0037] The second buffer net 403 is fixedly arranged on the framework formed by all the second vertical support structures 401 and the second horizontal connection structure 402, and is used to separate the goaf 5 and the tunnel 6 of the working face 1. That is, the second rock retaining support device 4 is on the side facing away from the working face 1, and is used to cooperate with the first rock retaining support device 2 and the flexible buffer wall 3 to further prevent the collapse of the thick hard roof from impacting and deforming.

[0038] By arranging the first rock retaining support device 2, the flexible buffer wall 3 and the second rock retaining support device 4 on the side of the hydraulic rock retaining support facing the working surface, the damage to the hydraulic rock retaining support caused by the thick hard roof during the collapse process can be reduced, thereby ensuring the safe use of the tunnel 6.

[0039] Step 4, after mining at working face 1, top cutting and pressure relief are performed.

[0040] Furthermore, the distance L1 between any two adjacent first vertical support structures 201 is greater than the distance L2 between any two adjacent second vertical support structures 401. In this way, when the gangue first impacts the first gangue retaining support device 2, sufficient movement space can be reserved for large pieces of collapsed gangue to achieve a buffering effect. The second gangue retaining support device 4 is to prevent the gangue from further deforming, that is, the first gangue retaining support device 2 and the flexible buffer wall 3 do not directly resist the huge horizontal impact force, but buffer each other through deformation to avoid the huge impact force from further damaging the tunnel 6. The huge impact force of large pieces of gangue is buffered and absorbed by the first gangue retaining support device 2 and the flexible buffer wall 3, and then blocked by the second gangue retaining support device 4, thereby achieving the effect of reducing the adverse effects of the impact energy of large pieces of gangue on the tunnel 6.

[0041] Furthermore, in order to fully support the buffering effect of the first gangue retaining support device 2, the first buffer net 203 is arranged on the side of the first gangue retaining support device 2 facing the working surface 1. At this time, the gangue will first contact and impact the easily deformed first buffer net 203 during the falling process.

[0042] Furthermore, in order to fully support the anti-deformation capability of the second rock retaining support device 4 , the second buffer net 403 is arranged on the side of the second rock retaining support device 4 facing away from the working face 1 .

[0043] Furthermore, the first transverse connecting structure 202 includes a cable 7 and a connecting plate 8, the cable 7 is fixedly arranged on the first vertical supporting structure 201, and the cable 7 is fixedly pressed against a plurality of U-shaped steels on the first vertical supporting structure 201, so that the first vertical supporting structure 201 is a supporting structure that is not easily deformed, so as to provide sufficient supporting force for the deformation of the first buffer net 203, so that the first gangue retaining support device 2 can play the role of buffering gangue. The connecting plate 8 is arranged between any two adjacent cables 7, and the two ends are fixedly connected to the cables 7 respectively.

[0044] Furthermore, the second transverse connecting structure 402 includes a cable 7 and a connecting plate 8. The cable 7 is fixedly arranged on the second vertical supporting structure 401, and the cable 7 is fixedly sleeved on multiple U-shaped steels on the second vertical supporting structure 401. The connecting plate 8 is arranged between two adjacent cables 7, and the two ends are fixedly connected to the cables 7 respectively.

[0045] In summary, the gangue buffering control method for cutting off the thick hard roof provided by the present invention can reduce the huge impact of large pieces of gangue falling on the tunnel 6 during the cutting and pressure relief process, thereby reducing the overall deformation of the tunnel 6, making the cutting and pressure relief technology of forming a tunnel without coal pillars more applicable.

[0046] It should be understood that the above description is merely exemplary and the embodiments of the present application do not limit this.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are within the scope of protection of the pending claims of the present invention.

Claims

1. A method for controlling the buffering of gangue sidewalls in a roadway formed by cutting off a thick hard roof, characterized in that: The steps include: Step 1, installing a first rock retaining support device (2) on a side of the tunnel (6) close to the working surface (1); Step 2, providing a flexible buffer wall (3) on the side of the first gangue retaining support device (2) away from the mining working surface (1); Step 3, a second rock retaining support device (4) is provided on a side of the flexible buffer wall (3) away from the first rock retaining support device (2); Step 4, after mining at the working face (1), the top is cut to release the pressure.

2. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 1 is characterized in that: The first rock retaining and supporting device (2) comprises: First vertical support structures (201), the first vertical support structures (201) being evenly spaced along the mining direction of the working face (1), and the distance between any two adjacent first vertical support structures (201) is L1; A first transverse connecting structure (202), wherein a plurality of the first transverse connecting structures (202) are arranged at intervals along the height direction of the first vertical supporting structures (201) and are used to transversely connect all the first vertical supporting structures (201); A first buffer net (203), the first buffer net (203) is fixedly arranged on a framework formed by all the first vertical support structures (201) and the first transverse connection structure (202), and is used to prevent gangue from passing through.

3. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 2 is characterized in that: The second rock retaining support device (4) comprises: Second vertical support structures (401), the second vertical support structures (401) being evenly spaced along the mining direction of the working face (1), and the distance between any two adjacent second vertical support structures (401) being L2; A second transverse connecting structure (402), wherein a plurality of the second transverse connecting structures (402) are arranged at intervals along the height direction of the second vertical supporting structures (401) and are used to transversely connect all the second vertical supporting structures (401); A second buffer net (403), the second buffer net (403) is fixedly arranged on a framework formed by all the second vertical supporting structures (401) and the second transverse connecting structures (402).

4. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 2 is characterized in that: The first buffer net (203) is arranged on a side of the first rock retaining support device (2) facing the working surface (1).

5. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 3 is characterized in that: The distance L1 between any two adjacent first vertical support structures (201) is greater than the distance L2 between any two adjacent second vertical support structures (401).

6. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 3 is characterized in that: The second buffer net (403) is arranged on a side of the second rock retaining support device (4) facing away from the working surface (1).

7. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 3 is characterized in that: The first vertical support structure (201) is a U-shaped steel, and each of the first vertical support structures (201) comprises a plurality of the U-shaped steels, the plurality of the U-shaped steels are overlapped in a length extension direction, and the plurality of the U-shaped steels are fixedly connected.

8. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 3 is characterized in that: The second vertical support structure (401) is a U-shaped steel, and each of the second vertical support structures (401) comprises a plurality of the U-shaped steels, the plurality of the U-shaped steels are overlapped in a length extension direction, and the plurality of the U-shaped steels are slidably connected.

9. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 7, characterized in that: The first transverse connection structure (202) comprises a card cable (7) and a connection plate (8); the card cable (7) is fixedly arranged on the first vertical support structure (201), and the card cable (7) is fixedly pressed against a plurality of U-shaped steels on the first vertical support structure (201); the connection plate (8) is arranged between any two adjacent card cables (7), and both ends are fixedly connected to the card cables (7).

10. The method for controlling the buffering of gangue side of thick hard roof cutting into laneway according to claim 8, characterized in that: The second transverse connecting structure (402) comprises a card cable (7) and a connecting plate (8); the card cable (7) is fixedly arranged on the second vertical supporting structure (401), and the card cable (7) is fixedly sleeved on a plurality of U-shaped steels on the second vertical supporting structure (401); the connecting plate (8) is arranged between two adjacent card cables (7), and both ends are fixedly connected to the card cables (7).

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