Method of retaining entry along gob in inclined coal seam working face

Abstract

The present invention relates to the technical field of coal mining, and discloses a method for retaining a lane along the goaf of a fully-mechanized mining working face in an inclined coal seam. The method for retaining a lane along the goaf of an inclined coal seam working face disclosed by the present invention comprises the following steps: drilling a blasting hole in the roof below the first working face support at the lower end of the working face; setting a first gangue retaining support structure below the blasting hole; as the working face advances, the first working face support at the lower end of the working face moves forward, and then blasting the drilled blasting hole is carried out to make the gangue blasted fall and fill the first gangue retaining support structure. Compared with the existing method for retaining a lane along the goaf of an inclined coal seam working face, the method for retaining a lane along the goaf of an inclined coal seam working face of the present application can effectively reduce the amount of engineering work, reduce the operation time, reduce the impact of retaining a lane along the goaf on coal mining production, and can also reduce safety risks and ensure the safety of personnel.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, in particular to a gob-side lane retaining method for a fully-mechanized mining working face in an inclined coal seam. Background Art

[0002] Gob-side entry retention refers to maintaining the original mining roadway along the edge of the goaf after the coal mining working face, re-supporting the drift of the previous section and leaving it for use in the next section. Gob-side entry retention can maximize resource recovery and avoid coal loss.

[0003] The patent application with publication number CN104453994A discloses a method for filling the side of the goaf with top coal caving. During the working face advancement process, this method directly uses a top coal caving support to lower the gangue above the goaf and transport it to the end of the working face. After simple crushing, reprinting and return transportation, the processed gangue is piled up and filled in the goaf on the side of the goaf, forming a gangue wall to serve as the side support. The working face hydraulic support at the side filling position is required to be provided with a rear top beam to facilitate the installation of the gangue return device and to achieve a sufficient height of gangue accumulation. At the same time, during the gangue accumulation process or after the gangue accumulation, the side support of the goaf is sealed and reinforced by spraying a cementing filling material on the gangue accumulation area. This method is mainly used in horizontal or nearly horizontal coal seams. It is necessary to lower the gangue above the goaf and transport it to the end of the working face for filling.

[0004] The patent application with publication number CN108979638A discloses a method for retaining lanes along the goaf in a coal mining tunnel using a composite wedge-shaped regeneration wall and a single-leg shed beam. In this method, after the coal seam is cut during coal mining, the advance gap is connected to the coal mining working face to form a wedge-shaped gap. A concrete block wall is built below the formed wedge-shaped gap. The gangue that collapses in the goaf naturally accumulates downward to fill the wedge-shaped gap to form a filling body. Concrete is sprayed into the filling body in the wedge-shaped gap to complete the lane retention along the goaf. This method makes full use of the characteristic that gangue automatically slides down after the roof of the inclined coal mining working face collapses. By pre-densely supporting the gangue and then concentrating it downward, a dense filling body is naturally formed. Obviously, compared with the aforementioned method, this method utilizes the filling body formed by the natural downward accumulation of gangue that collapses in the goaf. There is no need to transport the gangue. Compared with the aforementioned method, this method can greatly reduce the amount of engineering work and is more suitable for inclined coal seam working faces. However, this method still has certain defects. Opening an advance gap still requires a large amount of engineering work, usually requiring blasting. In addition, spalling problems are prone to occur above the working point of the advance gap, so it poses a greater safety risk. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for retaining a lane along the goaf of an inclined coal seam working face, thereby reducing the engineering workload and lowering the safety risk.

[0006] The method for retaining a lane along a gob in an inclined coal seam working face disclosed in the present invention comprises the following steps:

[0007] Drill blasting holes in the top plate below the first working face support at the lower end of the working face;

[0008] A first rock retaining support structure is set below the blasting hole;

[0009] As the working face advances, the first working face support at the lower end of the working face moves forward, and then the blasting holes are blasted, so that the blasted gangue falls and fills the first gangue support structure.

[0010] Preferably, after the first rock retaining support structure is provided, a second rock retaining support structure is provided below the first rock retaining support structure, and a filler is provided between the first rock retaining support structure and the second rock retaining support structure.

[0011] Preferably, before the first working face support at the lower end of the working face moves forward, a supplementary anchoring structure is set up for advance support of the lower tunnel, and the supplementary anchoring structure is located between two adjacent anchoring structures of the original lower tunnel.

[0012] Preferably, before the first working face support at the lower end of the working face moves forward, a hysteresis support is set in the lower tunnel, and the hysteresis support is removed after blasting and the tunnel section corresponding to the blasting is stabilized.

[0013] Preferably, before the first working face support at the lower end of the working face moves forward, the bottom of the upper wall of the lower tunnel is reinforced by a reinforcement structure.

[0014] Preferably, the first rock retaining support structure comprises a first support frame and a first covering member, and the first covering member is arranged on the first support frame;

[0015] The first support frame includes a first frame member and a second frame member arranged parallel to the working face top plate along the coal mining direction, a third frame member and a fourth frame member arranged parallel to the working face bottom plate along the coal mining direction, and a fifth frame member arranged horizontally between the working face top plate and the bottom plate. The first frame member and the second frame member are fixed to the working face top plate by anchors, the third frame member and the fourth frame member are fixed to the working face bottom plate by anchors, and the two ends of the fifth frame member are respectively clamped between the first frame member and the second frame member and between the third frame member and the fourth frame member.

[0016] Preferably, the first covering member includes a first bottom covering member and a buffer covering member, the first bottom covering member is laid on the first supporting frame, and the buffer covering member is laid on the first bottom covering member.

[0017] Preferably, the second gangue retaining support structure includes a second support frame and a second cover member, the second cover member is arranged on the second support frame, the second support frame includes a sixth frame member arranged on the working face top plate along the coal mining direction and a seventh frame member arranged laterally between the working face top plate and the upper wall of the lower tunnel, the sixth frame member is fixed to the working face top plate by an anchor member, the upper end of the seventh frame member is mounted on the sixth frame member, and the lower end of the seventh frame member is anchored to the upper wall of the lower tunnel.

[0018] Preferably, the second covering member includes a second bottom covering member, a sealing covering member and a protective covering member, the second bottom covering member is laid on the second supporting frame, the sealing covering member is laid on the second bottom covering member, and the protective covering member is laid on the sealing covering member.

[0019] Preferably, the distance between the blasting eye and the tail beam of the first working face support at the lower end of the tunnel is less than 1.0m, and the distance between the blasting eye and the first rock retaining support structure is greater than or equal to 0.8m, and the distance between the first rock retaining support structure and the upper wall of the tunnel below is greater than or equal to 0.5mm.

[0020] The beneficial effects of the present invention are: compared with the existing method of retaining lanes along the goaf in the inclined coal seam working face, the method of retaining lanes along the goaf in the inclined coal seam working face of the present application can effectively reduce the amount of engineering work, reduce the operation time, reduce the impact of retaining lanes along the goaf on coal mining production, and can reduce safety risks and ensure personnel safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a top view schematic diagram of this application;

[0022] Figure 2 It is a schematic cross-sectional view after blasting and filling of the present application.

[0023] Figure numerals: working face 1, lower tunnel 2, working face support 3, end support 4, blasting hole 5, first gangue retaining support structure 6, first skeleton member 61, second skeleton member 62, third skeleton member 63, fourth skeleton member 64, fifth skeleton member 65, first covering member 66, second gangue retaining support structure 7, sixth skeleton member 71, seventh skeleton member 72, second covering member 73, supplementary anchoring structure 8, original anchoring structure 81, lagging pillar 9. DETAILED DESCRIPTION

[0024] The present invention is further described below.

[0025] The method for retaining a lane along a gob in an inclined coal seam working face disclosed in the present invention comprises the following steps:

[0026] A blasting hole 5 is drilled in the top plate below the first working face support 3 at the lower end of the working face 1;

[0027] A first rock retaining support structure 6 is provided below the blasting hole 5;

[0028] As the working face 1 advances, the first working face support 3 at the lower end of the working face 1 moves forward, and then the blasting holes 5 are blasted, so that the blasted gangue falls and fills the first gangue support structure 6.

[0029] like Figure 1 and 2 As shown, the inclined coal seam working face 1 is set up at an angle, and tunnels are set up at both ends of the working face 1. Usually, the upper tunnel is the return air tunnel, and the lower tunnel 2 is the transport tunnel. Different from the prior art of filling the advance gap with waste rock, this application places the construction preparation work of the broken roof below the first working face support 3, that is, Figure 1 The work is completed below the 1# support of the middle working face 1, and then the first working face support 3 is moved before blasting, so that the blasted waste rock falls and fills the first waste rock support structure 6, forming a stable goaf-side tunnel. The construction preparation work mainly includes setting blasting holes 5 and setting supports, both of which are carried out between the first working face support 3 at the lower end of the working face 1 and the tunnel 2 below. During the support operation, the protection of the working face support 3 and the end support 4 can effectively improve safety. The blasting is carried out after the frame is moved, which can also minimize the risk of blasting.

[0030] Providing only a single-layer slag retaining support structure is obviously relatively weak. Therefore, in a preferred embodiment of the present application, after the first slag retaining support structure 6 is provided, a second slag retaining support structure 7 is provided below the first slag retaining support structure 6, and a filler is provided between the first slag retaining support structure 6 and the second slag retaining support structure 7. Providing the first slag retaining support structure 6 and the second slag retaining support structure 7 and providing a filler between them can significantly improve the load-bearing performance, effectively resist the impact of blasting, and withstand the compression of falling slag. The filler can be made of readily available materials such as slag contained in woven bags and cement backing boards.

[0031] Although there is protection from hydraulic supports, in order to improve the safety of construction and coal mining operations, in a preferred embodiment of the present application, before the first working face support 3 at the lower end of the working face 1 moves forward, a supplementary anchoring structure 8 is set up for advance support of the lower tunnel 2, and the supplementary anchoring structure 8 is located between the two adjacent original anchoring structures 81 of the lower tunnel 2. In general, the tunnel's support requirements only need to meet its usage conditions, but because this application requires construction operations and subsequent blasting, reinforcement is carried out on the basis of the original anchoring structure 81 of the tunnel. The specific method is to set the supplementary anchoring structure 8 between the two adjacent original anchoring structures 81 of the original lower tunnel 2, so as to maximize coordination with the original anchoring structure and ensure the stability of the tunnel. The supplementary anchoring structure 8 can adopt existing conventional reinforcement structures such as anchor rods or anchor cables. Figure 1 In the embodiment shown, anchor cables are used for reinforcement, and the original anchoring structure 81 of the tunnel is also an anchor cable. The dotted anchor cables in the figure represent the supplementary anchoring structure 8, and the solid anchor cables represent the original anchoring structure 81.

[0032] In order to further prevent the impact of blasting, in a preferred embodiment of the present application, before the first working face support 3 at the lower end of the working face 1 moves forward, a lagging support 9 is set in the lower tunnel 2. After the blasting and the tunnel section corresponding to the blasting are stabilized, the lagging support 9 is removed. The lagging support 9 usually adopts a single hydraulic support, which can be removed after the tunnel has been completely stabilized and placed in the front for reuse. It is usually necessary to recover the lagging support 9 after lagging the working face for 50m, and attention should be paid to ventilation during the recovery process. The number of rows of lagging supports 9 can be determined according to the specific situation, and usually 2 rows are sufficient.

[0033] In order to prevent the lower tunnel 2 from being unstable, the present application also reinforces the bottom of the upper wall of the lower tunnel 2 with a reinforcement structure before the first working face support 3 at the lower end of the working face 1 moves forward. In conjunction with the aforementioned supplementary anchoring structure 8 and lagging support 9, the stability of the lower tunnel 2 can be guaranteed to the greatest extent possible, and the construction is relatively simple conventional construction. The reinforcement of the upper wall of the lower tunnel 2 can be carried out before the construction of the second rock retaining support structure 7, so that the lower end of the second rock retaining support structure 7 can be fixed to the reinforced upper wall position, which not only prevents the second rock retaining support structure 7 from affecting the structure, but also improves the stability of the upper wall.

[0034] The first gangue retaining support structure 6 and the second gangue retaining support structure 7 can be arranged according to the existing support structure. However, in a preferred embodiment of the present application, the first gangue retaining support structure 6 includes a first support frame and a first cover member 66, and the first cover member 66 is arranged on the first support frame; the first support frame includes a first frame member 61 and a second frame member 62 arranged on the top plate of the working face 1 parallel to the coal mining direction, a third frame member 63 and a fourth frame member 64 arranged on the bottom plate of the working face 1 parallel to the coal mining direction, and a fifth frame member 65 arranged horizontally between the top plate and the bottom plate of the working face 1, the first frame member 61 and the second frame member 62 are fixed to the top plate of the working face 1 by anchors, the third frame member 63 and the fourth frame member 64 are fixed to the bottom plate of the working face 1 by anchors, and the two ends of the fifth frame member 65 are respectively clamped between the first frame member 61 and the second frame member 62 and between the third frame member 63 and the fourth frame member 64.

[0035] The main function of the first support frame is to provide structural strength, and the first cover member 66 can better play the role of retaining gangue. The first gangue retaining support structure 6 needs to bear the impact caused by blasting, so its strength is very important. In the first support frame of this application, the first frame member 61, the second frame and the third frame member 63, the fourth frame member 64 respectively clamp the two ends of the fifth frame member 65 to form a frame, and the first frame member 61, the second frame, the third frame member 63, and the fourth frame are all stably anchored on the top and bottom plates of the working face 1 along the coal mining direction. Not only is the stability of the frame itself high, but it can also protect the top and bottom plates there, improve its ability to withstand impact, and ensure the stability of the later tunnel. In addition, by clamping and fixing the fifth frame member 65, it can withstand the forces on both sides. The upper side can withstand the impact of blasting and the falling squeezing pressure of gangue, and the lower side can bear the pressure formed by the filler between the first gangue retaining support structure 6 and the second gangue retaining support structure 7.

[0036] Although common materials such as metal mesh and half-logs can be used for the first cover 66, in a preferred embodiment of the present application, the first cover 66 includes a first bottom cover and a buffer cover. The first bottom cover is laid on the first support frame, and the buffer cover is laid on the first bottom cover. The first bottom cover mainly covers the first support frame, facilitating the installation of the buffer cover, which can better withstand the impact of blasting and falling gangue, reducing the impact on the first support frame. The first bottom cover can be made of metal mesh, while the buffer cover can be made of waste belts that are easily available in the transport lane. Of course, other materials can also be used as long as they meet the buffering requirements.

[0037] Similar to the first gangue retaining support structure 6, the second gangue retaining support structure 7 includes a second support frame and a second cover member 73. The second cover member 73 is arranged on the second support frame. However, since the second gangue retaining support structure 7 does not need to bear the force from bottom to top, in a preferred embodiment of the present application, the second support frame includes a sixth frame member 71 arranged on the top plate of the working face 1 along the coal mining direction and a seventh frame member 72 arranged laterally between the top plate of the working face 1 and the upper wall of the lower tunnel 2. The sixth frame member 71 is fixed to the top plate of the working face 1 by an anchor, the upper end of the seventh frame member 72 is mounted on the sixth frame member 71, and the lower end of the seventh frame member 72 is anchored to the upper wall of the lower tunnel 2. The sixth frame member 71 is securely fixed to the top plate of the working surface 1, and the seventh frame member 72 is placed on top of it to bear the downward force. The lower end of the seventh frame member 72 is anchored to the upper wall of the lower tunnel 2. In addition to strengthening the stability of the upper wall of the lower tunnel 2, it also forms a wedge-shaped gap at the bottom of the working surface 1, similar to the wedge-shaped gap described in the background art. After filling, it can better ensure the density. The first frame member 61, the second frame member, the third frame member 63, the fourth frame member 64, the fifth frame member 65, the sixth frame member 71, and the seventh frame member 72 can all be made of various types of existing steel, among which I-beams are the most preferred, and other profiles such as U-shaped steel can also be used.

[0038] The most basic function of the second cover 73 is to block, but the function of the second rock retaining support structure 7 is different from that of the first rock retaining support structure 6, so the second cover 73 is also different. In the preferred embodiment of the present application, the second cover 73 includes a second bottom cover, a sealing cover and a protective cover. The second bottom cover is laid on the second support frame, the sealing cover is laid on the second bottom cover, and the protective cover is laid on the sealing cover. Among them, the second bottom cover has a similar function to the first bottom cover mentioned above, and both can be made of metal mesh, while the main function of the sealing cover is to prevent air leakage during the next stage of mining. After the sealing cover is set, there is no need to carry out spraying operations, which can reduce the amount of work and there is no need to wait for the spraying to solidify. The sealing cover can be made of materials with windproof and airtight effects such as wind tube cloth, and the protective cover mainly plays the role of protecting the sealing cover, usually half a log.

[0039] The function of the blasting hole 5 is to place explosives for blasting. Pre-splitting blasting is preferably used for blasting, so a pre-splitting blasting hole 5 should be set. In order to minimize the impact of blasting on the rock retaining support structure, in a preferred embodiment of the present application, the distance between the blasting hole 5 and the tail beam of the first working face support 3 at the lower end of the tunnel is less than 1.0m, and the distance between the blasting hole 5 and the first rock retaining support structure 6 is greater than or equal to 0.8m. Of course, the distance between the blasting hole 5 and the tail beam of the first working face support 3 at the lower end cannot be too small, otherwise it will increase the difficulty of construction. In addition, sufficient space is also required between the first rock retaining support structure 6 and the second rock retaining support structure 7 to better exert the overall rock retaining support effect. Therefore, the distance between the first rock retaining support structure 6 and the upper wall of the lower tunnel 2 is greater than or equal to 0.5mm. As for the specific arrangement of the blasting hole 5, in one embodiment of the present application, the blasting holes 5 are spaced 400mm apart, and the blasthole depth is not less than 5.0m.

Claims

1. A method for retaining gob-side entry in an inclined coal seam working face, characterized in that: The steps include: A blasting hole (5) is drilled in the top plate below the first working face support (3) at the lower end of the working face (1); A first rock retaining support structure (6) is provided below the blasting hole (5); As the working face (1) advances, the first working face support (3) at the lower end of the working face (1) moves forward, and then the blasting holes (5) are blasted, so that the blasted waste rock falls and fills the first waste rock support structure (6); After the first rock retaining support structure (6) is provided, a second rock retaining support structure (7) is provided below the first rock retaining support structure (6), and a filler is provided between the first rock retaining support structure (6) and the second rock retaining support structure (7); The first rock retaining support structure (6) comprises a first support frame and a first covering member (66), wherein the first covering member (66) is arranged on the first support frame; The first support frame comprises a first frame member (61) and a second frame member (62) arranged parallel to the coal mining direction on the top plate of the working face (1), a third frame member (63) and a fourth frame member (64) arranged parallel to the coal mining direction on the bottom plate of the working face (1), and a fifth frame member (65) arranged transversely between the top plate and the bottom plate of the working face (1), the first frame member (61) and the second frame member (62) are fixed to the top plate of the working face (1) by anchoring members, the third frame member (63) and the fourth frame member (64) are fixed to the bottom plate of the working face (1) by anchoring members, and two ends of the fifth frame member (65) are respectively clamped between the first frame member (61) and the second frame member (62) and between the third frame member (63) and the fourth frame member (64); The first covering member (66) comprises a first bottom covering member and a buffer covering member, wherein the first bottom covering member is laid on the first supporting frame, and the buffer covering member is laid on the first bottom covering member; The second gangue retaining support structure (7) includes a second support frame and a second covering member (73), the second covering member (73) is arranged on the second support frame, the second support frame includes a sixth frame member (71) arranged on the top plate of the working face (1) along the coal mining direction and a seventh frame member (72) arranged transversely between the top plate of the working face (1) and the upper wall of the lower tunnel (2), the sixth frame member (71) is fixed to the top plate of the working face (1) by an anchor member, the upper end of the seventh frame member (72) is mounted on the sixth frame member (71), and the lower end of the seventh frame member (72) is anchored to the upper wall of the lower tunnel (2).

2. The method for retaining gob-side entry in an inclined coal seam working face according to claim 1, characterized in that: Before the first working face support (3) at the lower end of the working face (1) moves forward, a supplementary anchoring structure (8) is set up for advance support of the lower tunnel (2), and the supplementary anchoring structure (8) is located between two adjacent original anchoring structures (81) of the lower tunnel (2).

3. The method for retaining gob-side entry in an inclined coal seam working face according to claim 1, wherein: Before the first working face support (3) at the lower end of the working face (1) moves forward, a hysteresis support (9) is set in the lower tunnel (2). After blasting and the tunnel section corresponding to the blasting is stabilized, the hysteresis support (9) is removed.

4. The method for retaining gob-side entry in an inclined coal seam working face according to claim 1, wherein: Before the first working face support (3) at the lower end of the working face (1) moves forward, the upper bottom of the lower tunnel (2) is reinforced by a reinforcement structure.

5. The method for retaining gob-side entry in an inclined coal seam working face according to claim 4, characterized in that: The second covering member (73) comprises a second bottom covering member, a sealing covering member and a protective covering member, wherein the second bottom covering member is laid on the second supporting frame, the sealing covering member is laid on the second bottom covering member, and the protective covering member is laid on the sealing covering member.

6. The method for retaining gob-side entry in an inclined coal seam working face according to claim 1, characterized in that: The distance between the blasting hole (5) and the tail beam of the first working face support (3) at the lower end of the tunnel is less than 1.0m, and the distance between the blasting hole (5) and the first rock retaining support structure (6) is greater than or equal to 0.8m, and the distance between the first rock retaining support structure (6) and the upper wall of the lower tunnel (2) is greater than or equal to 0.5mm.

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