Roof-cutting roadway-forming gangue side deformation control method

Abstract

The invention belongs to the technical field of roadway excavation, and particularly provides a roof-cutting roadway-forming gangue side deformation control method which comprises the following steps: S1, propelling a coal face; a goaf is formed behind the working face; the side edge of the goaf forms a roof-cutting roadway; s2, a gangue blocking structure is arranged between the side position of the roof-cutting roadway and gangue on the edge of the goaf; the gangue blocking structure is axially arranged along the roadway; the gangue blocking structure comprises two layers of gangue blocking structures, wherein the first layer of gangue blocking structure is laid along the side of the roadway; the second layer of gangue blocking structure is laid on gangue on the edge of the goaf and is laid in the axial direction of the roadway; the second U-shaped steel is connected with the first-layer waste rock blocking structure and the second-layer waste rock blocking structure; s3, the gangue continues to fall into the gangue blocking structure; and S4, the waste rock blocking structure is filled with slurry, and a waste rock blocking wall is formed. The defect that in the prior art, a gangue blocking structure is insufficient in roadway gangue side deformation control effect is overcome.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel excavation, and in particular to a method for controlling deformation of gangue walls in a tunnel cut into a roof. Background Art

[0002] Coal resources play an important role in the energy structure, and safe mining is an important guarantee for energy security. Roof directional pre-splitting blasting technology is widely used in coal mine roof cutting and tunneling technology, which can effectively reduce the impact of mine pressure on the surrounding rock of the working face tunnel. In the roof cutting and tunneling method, after the roof is directional pre-splitting and top cutting, the roof collapses during the mining process of the working face. Due to the characteristics of rock mass expansion and mine pressure, the gangue is easy to flow into the tunnel from the side of the tunnel adjacent to the goaf, increasing the deformation of the tunnel side, causing the tunnel space to decrease, and affecting the normal use of the tunnel. Under the current roof cutting and tunneling process system, the gangue retaining method of fixing the single-layer mesh structure formed by U-shaped steel, metal mesh, callan, and connecting rod on the gangue side is generally used to control the deformation of the gangue side of the tunnel. This method has relatively low strength under strong mine pressure and dynamic load, and the gangue retaining structure has limited control effect on the deformation of the gangue side of the tunnel.

[0003] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome the defect that the gangue retaining structure used in the above-mentioned prior art has insufficient control effect on the deformation of the gangue side of the roadway, and provide the following technical solutions: A method for controlling deformation of gangue sidewalls in a roadway cut-off process, the improvement of which is that the method comprises the following steps: Step S1, advancing the coal mining working face; forming a goaf behind the working face; forming a tunnel 2 at the side edge of the goaf; Step S2, setting a gangue retaining structure between the side position of the tunnel 2 and the gangue at the edge of the goaf; the gangue retaining structure is set along the axial direction of the tunnel; The rock retaining structure includes a double-layer rock retaining structure: the first layer of the rock retaining structure is laid along the side of the roadway; the second layer of the rock retaining structure is laid on the rock at the edge of the goaf and is laid along the axial direction of the roadway; the second U-shaped steel 3-2 connects the first layer of the rock retaining structure with the second layer of the rock retaining structure; Step S3, the gangue continues to fall into the gangue retaining structure; Step S4, filling the rock retaining structure with slurry to form a rock retaining wall 7.

[0005] Preferably, the first layer of the rock retaining structure and the second layer of the rock retaining structure both include: The first U-shaped steel 3-1 includes two U-shaped steels overlapped in an upper and lower manner; the first U-shaped steel 3-1 is arranged perpendicular to the ground and evenly added along the axial direction of the tunnel; the first U-shaped steel 3-1 of the first layer of the rock retaining structure is arranged opposite to the first U-shaped steel 3-1 of the second layer of the rock retaining structure; A U-shaped steel connecting rod 8, comprising a rod-shaped object, is arranged parallel to the ground, and the U-shaped steel connecting rod 8 is arranged on two adjacent first U-shaped steels 3-1; Callan 4 is arranged parallel to the ground and connects two U-shaped steel bars overlapped one above the other. A callan 4 is arranged on the upper and lower sides of the U-shaped steel connecting rod. The metal mesh 5 is arranged along the axial direction of the tunnel and laid on the surface of the first U-shaped steel; The sealing cloth 6 is attached to the surface of the metal mesh 5 .

[0006] Preferably, the second U-shaped steel 3-2 is arranged on the ground, connects the two first U-shaped steels arranged opposite to each other, and is evenly added along the axial direction of the tunnel.

[0007] Preferably, step S4, filling the slurry in the rock retaining structure, comprises: Step S4-1, setting grouting holes; drilling holes in the side of the tunnel 2; and cutting the metal mesh 5 and the closed cloth 6 located at the side of the tunnel 2 as grouting holes; Step S4-2, setting a grouting pipe 9; passing the grouting pipe 9 from the outside of the tunnel 2 through the closed cloth 6 to the inside of the rock retaining structure; Step S4-3, when the slurry injected into the rock retaining structure leaks outward from the grouting port, it is confirmed that the slurry inside the rock retaining structure has been filled, and the grouting is stopped; Step S4-5, waiting for the slurry to solidify to form a rock retaining wall 7.

[0008] Preferably, step S4, filling slurry in the rock retaining structure, includes: grouting holes are set beside each first U-shaped steel in the side of the tunnel, and the grouting holes are located at the uppermost end of the metal mesh 5; the diameter of the grouting holes matches the aperture of the grouting pipe.

[0009] Preferably, the width of the rock retaining structure is 0.5m-1m; the length of the rock retaining structure increases as the working face advances.

[0010] Preferably, one side of the first U-shaped steel having an opening is in contact with the metal mesh; the spacing between two adjacent first U-shaped steels is 500 mm-600 mm; and the metal mesh is made of steel bars with a diameter of 3.5 mm to 6.5 mm.

[0011] Preferably, the range of the filling slurry is 60m behind the working face and expands as the working face advances.

[0012] Beneficial effects: The present invention provides a method for controlling the deformation of the gangue wall of the top-cutting laneway. Behind the coal mining face, the gangue wall of the top-cutting laneway is constructed with a gangue retaining structure composed of two layers of U-shaped steel, metal mesh, callan, and connecting rods, which are fixed so as to leave a certain space between the gangue retaining structures. A layer of closed cloth is laid on each of the metal meshes inside the space formed by the two layers of the gangue retaining structure to prevent the slurry from flowing out. Slurry is filled between the two gangue retaining structures and solidified to form a gangue retaining wall to play a gangue retaining role. This scheme increases the strength of the gangue wall by adjusting the gangue retaining structure, thereby achieving the purpose of controlling the deformation of the gangue wall of the top-cutting laneway under strong mine pressure and dynamic load, and improving the lane forming effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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 It is a schematic diagram of a process flow involved in the present invention; Figure 2 It is a structural schematic diagram of a tunnel section involved in the present invention; Figure 3 It is a structural schematic diagram of the side of the laneway involved in the present invention; In the figure: 1. Goaf; 2. Tunnel; 3-1. First U-shaped steel; 3-2. Second U-shaped steel; 4. Callan; 5. Metal mesh; 6. Sealing cloth; 7. Gangue retaining wall; 8. U-shaped steel connecting rod; 9. Grouting pipe. DETAILED DESCRIPTION

[0014] 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.

[0015] 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.

[0016] 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.

[0017] like Figure 1 As shown, a method for controlling deformation of gangue side in a roadway cut into a top is improved in that the control method comprises the following steps: Step S1, advance the coal mining working face; a goaf 1 is formed behind the working face; a cut-top laneway 2 is formed at the side edge of the goaf. Specifically, as the coal mining working face advances, a goaf 1 is formed behind the working face, and a laneway 2 is formed at the side edge of the goaf, i.e., a cut-top laneway is formed. Among them, the side of the goaf refers to the corresponding surface perpendicular to the goaf and the working face, i.e., it can be understood that the cut-top laneway is set on the side of the goaf 1 and is perpendicular to the working face at the same time. The lanes 2 involved in the following text of this application are all cut-top laneways.

[0018] Step S2, a rock retaining structure is arranged between the side of the tunnel 2 and the edge of the goaf 1; the rock retaining structure is arranged along the axial direction of the tunnel. Specifically, the side of the tunnel 2 is the side part of the tunnel, that is, the side wall of the tunnel.

[0019] Step S3, the gangue continues to fall into the gangue retaining structure; Step S4, filling the rock retaining structure with slurry to form a rock retaining wall 7.

[0020] Preferably, the rock retaining structure includes a double-layer rock retaining structure: the first layer of the rock retaining structure is laid along the side of the tunnel; the second layer of the rock retaining structure is laid on the edge of the goaf and axially along the tunnel; the second U-shaped steel 3-2 connects the first layer of the rock retaining structure with the second layer of the rock retaining structure.

[0021] Preferably, each layer of the rock retaining structure comprises: The first U-shaped steel 3-1 includes two U-shaped steels overlapped at the top and bottom. The first U-shaped steel 3-1 is set perpendicular to the ground and evenly added along the axial direction of the tunnel. It is set at the side of the tunnel and also correspondingly set on the edge of the goaf. The first U-shaped steel 3-1 of the first layer of the rock retaining structure is set opposite to the first U-shaped steel 3-1 of the second layer of the rock retaining structure.

[0022] A U-shaped steel connecting rod 8, comprising a rod-shaped object, is arranged parallel to the ground, and the U-shaped steel connecting rod 8 is arranged on two adjacent first U-shaped steels 3-1; Callan 4 is arranged parallel to the ground and is used to connect two U-shaped steel bars overlapped one above the other. A callan 4 is arranged on the upper side and the lower side of the U-shaped steel connecting rod. The metal mesh 5 is arranged along the axial direction of the tunnel and laid on the surface of the first U-shaped steel; The sealing cloth 6 is in contact with the surface of the metal mesh 5 .

[0023] Preferably, the second U-shaped steel 3-2 is arranged on the ground, that is, on the bottom plate of the tunnel, connecting the two first U-shaped steels arranged opposite to each other, and is evenly added along the axial direction of the tunnel; Specifically, the rock-retaining structure can be understood as a double-layer rock-retaining structure. Each layer of the rock-retaining structure includes a first U-shaped steel 3-1, a U-shaped steel connecting rod 8, and a callan 4. At the same time, in order to ensure the stability of the double-layer rock-retaining structure, it is necessary to set the first U-shaped steel 3-1 set on the side of the tunnel and the first U-shaped steel 3-1 set on the edge of the goaf. Among them, the first U-shaped steel 3-1 includes two U-shaped steels overlapped up and down, and the overlapping part is connected by a callan 4.

[0024] The U-shaped steel connecting rod 8 connects two adjacent first U-shaped steels 3-1. The length of the U-shaped steel connecting rod 8 is longer than the distance between the two first U-shaped steels.

[0025] The calliper 4 is used to enhance the connection strength of the upper and lower overlapping U-shaped steels. It also enhances the connection strength of the U-shaped steel connecting rod 8. A calliper 4 is provided on the upper and lower sides of the U-shaped steel connecting rod. Specifically, the calliper includes a group of relatively connected annular steels, which can fix the overlapping parts of the U-shaped steels, and adopts the bolt-type calliper commonly used in engineering operations, that is, the contact parts of the relatively connected annular steels are bolted.

[0026] The metal mesh 5 is laid on the surface of the first U-shaped steel. Specifically, the metal mesh 5 is laid on the surface of the first U-shaped steel used for the first layer of the rock retaining structure of the tunnel side; the metal mesh 5 is also laid on the surface of the first U-shaped steel used for the second layer of the rock retaining structure of the edge of the goaf.

[0027] A layer of sealed cloth 6 is also required to be provided on the surface of the metal mesh 5 as a waterproof layer.

[0028] After the rock retaining structure is set, the edge of the goaf will continue to collapse into the rock retaining structure. When the rock fills the rock retaining structure, step S4 is performed to fill the rock retaining structure with slurry to form a rock retaining wall 7. Step S4 includes: Step S4-1, setting grouting holes; drilling holes in the side of the tunnel 2; and cutting the metal mesh 5 and the sealing cloth 6 located at the side of the tunnel 2 as grouting holes. Preferably, the grouting holes are set beside each first U-shaped steel at the side of the tunnel, and the grouting holes are located at the uppermost end of the metal mesh 5; the diameter of the grouting holes matches the aperture of the grouting pipe.

[0029] Step S4-2, setting a grouting pipe 9; passing the grouting pipe 9 from the outside of the tunnel 2 through the closed cloth 6 to the inside of the rock retaining structure; Step S4-3, when the slurry injected into the rock retaining structure leaks outward from the grouting port, it is confirmed that the slurry inside the rock retaining structure has been filled, and the grouting is stopped; Step S4-5, waiting for the slurry to solidify to form a rock retaining wall 7.

[0030] Specifically, first use pliers to cut the metal mesh 5 of the first layer of the gangue retaining structure of the tunnel side, that is, the metal mesh outside the first U-shaped steel, wherein the cutting position is located at the top of the metal mesh, and the size of the cut hole is preferably large enough to be plugged into the grouting pipe, that is, R 剪开的孔洞 =R 注浆管 , and then use scissors to cut the sealing cloth on the outside of the first U-shaped steel to facilitate the insertion of the grouting pipe to fill the slurry into the rock retaining structure.

[0031] After cutting the metal mesh and sealing cloth on the outside of the first U-shaped steel, the grouting pipe is set in the rock retaining structure and filled with slurry. The grouting pipe only needs to be inserted into the metal mesh and sealing cloth on the outside of the first U-shaped steel to perform grouting. Since the rock fall in the goaf behind the working face has filled the rock retaining structure, the length of the grouting pipe inserted into the rock retaining structure is only enough to complete the grouting inside the rock retaining structure. It is not necessary to insert the grouting pipe into the rock retaining structure too long to prevent the rock fall and compaction process inside the rock retaining structure from damaging the grouting pipe.

[0032] During grouting, when the slurry injected into the rock retaining structure leaks out from the grouting port, the slurry inside the rock retaining structure is considered to be full. This is because the grouting position in the rock retaining structure is located at the top of the metal mesh and sealing cloth outside the first U-shaped steel. When the slurry leaks out from the grouting position, it can be considered that the slurry in the rock retaining structure is full. When the slurry solidifies to form a rock retaining wall, the strength of the rock wall is increased, and the purpose of controlling the deformation of the rock wall in the roadway under strong mine pressure and dynamic load cutting can be achieved, thereby improving the roadway formation effect.

[0033] Preferably, the width of the double-layer rock retaining structure is 0.5m-1m; the length of the rock retaining structure is extended as the working face advances. Specifically, under normal circumstances, the width of the double-layer rock retaining structure, that is, the length of the second U-shaped steel used for the double-layer rock retaining, is 0.5m-1m. The double-layer rock retaining structure involved in the present application can be regarded as a temporary concrete rock retaining structure. The rock wall formed by injecting slurry into the collapsed rock inside the double-layer U-shaped steel is only used to serve the mining of the current working face and the next working face. After the mining of the coal mining working face adjacent to the temporary concrete rock retaining structure is completed, the overlying rock strata in the goaf will all collapse, and the temporary concrete rock retaining structure will be buried in the goaf together. Furthermore, the top cutting cuts off the strong dynamic pressure disturbance of the gangue falling from the goaf to the roof of the retained lane. Therefore, the double-layered gangue retaining structure only plays the role of retaining gangue to prevent the gangue falling from the goaf from entering the retained lane. There is no need to support the roof of the retained lane. Therefore, the width of the double-layered gangue retaining structure does not need to be too wide, only 0.5m-1m is enough. When the double-layered gangue retaining structure is actually arranged on site, it is also necessary to make timely adjustments according to the thickness of the coal seam and the intensity of the mine pressure.

[0034] Preferably, the first U-shaped steel has an open side that is in contact with the metal mesh; the spacing between two adjacent first U-shaped steels is 500 mm-600 mm. Specifically, the U-shaped steel can be a commonly used U-shaped steel, and the open side of the first U-shaped steel is facing the metal mesh, that is, the closed side of the first U-shaped steel 3-1 set on the side of the tunnel is in contact with the side of the tunnel; the closed surface of the first U-shaped steel 3-1 set on the edge of the goaf is in contact with the edge of the goaf. Because the non-open surface of the first U-shaped steel, that is, the closed surface, is mainly used to withstand the horizontal thrust of the collapsed gangue. Therefore, placing the metal mesh inside the first U-shaped steel makes it easier to utilize the supporting force of the U-shaped steel. The function of the metal mesh is mainly to prevent the injected slurry between the two layers of the first U-shaped steel from flowing into the interior of the goaf, and to help the collapsed gangue inside the double-layer gangue retaining structure to form a gangue wall by grouting. Therefore, placing the metal mesh inside the first U-shaped steel is more conducive to the U-shaped steel auxiliary supporting the metal mesh, and is more conducive to supporting the grouting of collapsed gangue between the two layers of the first U-shaped steel.

[0035] Among them, the size between adjacent first U-shaped steels is generally 500-600 mm. Specifically, the size between adjacent first U-shaped steels is mainly related to the thickness of the working face coal seam and the inclination of the working face coal seam. The greater the thickness of the working face coal seam and the inclination of the coal seam, the smaller the spacing between adjacent first U-shaped steels. The model of U-shaped steel is generally selected from five models such as 18U, 25U, 29U, 36U and 40U according to the thickness of the working face coal seam and the inclination of the coal seam. Specifically, the greater the thickness of the working face coal seam and the greater the inclination of the coal seam, the greater the mine pressure disturbance that the U-shaped steel needs to resist, and the larger the size of the U-shaped steel required. In actual design, it is also necessary to refer to engineering experience to finally select and determine the appropriate U-shaped steel model. Furthermore, the steel bar type used in the metal mesh also needs to be selected according to the thickness of the coal seam at the working face and the inclination of the coal seam. Generally, steel bars with a diameter of 3.5mm to 6.5mm are selected. This is mainly because as the thickness and inclination of the coal seam increase, the lateral pressure of the gangue collapsed in the goaf area on the double-layer retaining structure increases. Therefore, when the thickness and inclination of the coal seam at the working face increase, a metal mesh with a larger steel bar diameter needs to be selected. In actual design, it is also necessary to refer to engineering experience to finally select and determine the appropriate steel bar diameter.

[0036] Preferably, the grouting range is outside 60m behind the working face, and gradually expands as the working face advances. Specifically, the range outside 60m behind the working face is the area where the gangue in the goaf gradually collapses, so a grouting pipe can be set outside 60m behind the working face and grouting can be performed in the gangue retaining structure in the goaf, and the grouting area can be gradually expanded in the direction of the working face as the working face advances, so as to improve the strength of the collapsed gangue in the gangue retaining structure.

[0037] 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 deformation of gangue side in a roadway cut, characterized in that: The method comprises the following steps: Step S1, advancing the coal mining working face; a goaf (1) is formed behind the working face; and a tunnel (2) is formed at the side edge of the goaf (1); Step S2, arranging a rock retaining structure between the side of the tunnel (2) and the edge of the gangue of the goaf (1); the rock retaining structure is arranged along the axial direction of the tunnel; The rock retaining structure comprises a double-layer rock retaining structure: a first layer of the rock retaining structure is laid along the side of the tunnel; a second layer of the rock retaining structure is laid on the edge of the goaf (1) and is laid along the axial direction of the tunnel; a second U-shaped steel (3-2) connects the first layer of the rock retaining structure and the second layer of the rock retaining structure; Step S3, the gangue continues to fall into the gangue retaining structure; Step S4, filling the rock retaining structure with slurry to form a rock retaining wall (7).

2. The method for controlling deformation of gangue side in a roadway cut-off according to claim 1, characterized in that: The first layer of the rock retaining structure and the second layer of the rock retaining structure both include: The first U-shaped steel (3-1) comprises two U-shaped steels overlapped in an upper and lower manner; the first U-shaped steel (3-1) is arranged perpendicular to the ground and evenly added along the axial direction of the tunnel; the first U-shaped steel (3-1) of the first layer of the rock retaining structure is arranged opposite to the first U-shaped steel (3-1) of the second layer of the rock retaining structure; A U-shaped steel connecting rod (8), comprising a rod-shaped object, arranged parallel to the ground, and the U-shaped steel connecting rod (8) is arranged on two adjacent first U-shaped steels (3-1); A calliper (4) is arranged parallel to the ground and connects the two U-shaped steels overlapped one above the other; one calliper (4) is arranged on the upper side and the lower side of the U-shaped steel connecting rod; A metal mesh (5) is arranged along the axial direction of the tunnel and laid on the surface of the first U-shaped steel; A sealed cloth (6), the sealed cloth being in contact with the surface of the metal mesh (5).

3. The method for controlling deformation of gangue side in cutting top lane as claimed in claim 2, characterized in that: The second U-shaped steel (3-2) is arranged on the ground, connects the two first U-shaped steels arranged opposite to each other, and is evenly added along the axial direction of the tunnel.

4. The method for controlling deformation of gangue side in top cutting laneway as claimed in claim 2, characterized in that: Step S4, filling slurry in the rock retaining structure, comprises: Step S4-1, setting grouting holes; drilling holes in the side of the tunnel (2); and cutting the metal mesh (5) and the sealing cloth (6) located in the side of the tunnel (2) to serve as grouting holes; Step S4-2, setting a grouting pipe (9); passing the grouting pipe (9) from the outside of the tunnel (2) through the sealing cloth (6) to reach the inside of the rock retaining structure; Step S4-3, when the slurry injected into the rock retaining structure leaks outward from the grouting port, it is confirmed that the slurry inside the rock retaining structure has been filled, and the grouting is stopped; Step S4-5, waiting for the slurry to solidify to form a rock retaining wall (7).

5. The method for controlling deformation of gangue side in top cutting laneway as claimed in claim 4, characterized in that: Step S4, filling slurry in the rock retaining structure, comprising: the grouting holes are arranged beside each first U-shaped steel in the side of the tunnel, and the grouting holes are located at the uppermost end of the metal mesh (5); the diameter of the grouting holes matches the aperture of the grouting pipe.

6. The method for controlling deformation of gangue side in top cutting laneway as claimed in claim 1, characterized in that: The width of the rock retaining structure is 0.5m-1m; the length of the rock retaining structure is extended as the working face advances.

7. The method for controlling deformation of gangue side in top cutting laneway as claimed in claim 2, characterized in that: The first U-shaped steel has an open side in contact with the metal mesh; the spacing between two adjacent first U-shaped steels is 500 mm to 600 mm; and the metal mesh is made of steel bars with a diameter of 3.5 mm to 6.5 mm.

8. The method for controlling deformation of gangue side in top cutting laneway as claimed in claim 1, characterized in that: The range of the filling slurry is 60m behind the working face and expands as the working face advances.

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