Self-flowing type filling mining method supported by staggered pier studs

Abstract

The invention belongs to the technical field of coal mine filling mining, and relates to a staggered pier column supporting self-flowing type filling mining method which comprises the following steps: pre-burying a filling pipeline; preparing filling material slurry and storing for later use; a transverse concrete retaining wall and a longitudinal concrete retaining wall are poured; a plurality of concrete pier columns are poured, and a concrete sealing wall is poured; and the filling material slurry and the stoping of the next section of filling area are synchronously carried out. The transverse concrete retaining wall, the longitudinal concrete retaining wall, the concrete sealing wall and the plurality of concrete pier studs are arranged on the working face of the coal mine, so that a sealed environment can be formed in the subsection filling area, the situation that filling material slurry affects stoping of the next subsection filling area is avoided, stoping and filling can be conducted synchronously, and the working efficiency is improved. The goaf filling is prevented from influencing normal stoping, the production efficiency of the working face is improved, the coal yield is guaranteed, meanwhile, gangue accumulated on the ground surface can be consumed, ground surface subsidence is relieved, and the ecological environment is protected.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine filling mining, and relates to a self-flowing filling mining method supported by a staggered pier. Background Art

[0002] After coal is mined from underground, the overlying rock layers in the goaf gradually break and collapse, easily causing severe surface subsidence, damage to structures, and disruption to groundwater systems. Furthermore, coal mining produces a large amount of solid waste—gangue—which accumulates on the surface, forming gangue heaps. Weathered gangue dust seriously affects air quality in mining areas. Heavy metals contained in the heaps enter groundwater after rain, polluting water resources. Furthermore, gangue heaps are prone to heat and spontaneous combustion, releasing harmful gases. Backfill mining technology, which injects materials such as gangue and fly ash into the goaf, achieves this goal by supporting the roof, reducing surface subsidence, and protecting the ecological environment.

[0003] However, due to the mutual interference between filling and mining in time and space, the existing filling technology generally requires preparation for filling to begin after mining is completed, and filling to begin after the preparation is completed. After filling, the slurry must be allowed to solidify before mining can be carried out again. The repeated and complicated cycle operations and the waiting after grouting directly lengthen the entire mining cycle, resulting in reduced production efficiency of the working face and affecting coal production. Summary of the Invention

[0004] The purpose of the present invention is to provide a self-flowing filling mining method supported by staggered piers, which can take into account both filling and mining, avoid filling affecting normal mining, and improve the production efficiency of the working face.

[0005] To achieve the above-mentioned purpose, the present invention provides a specific technical solution for a self-flowing filling mining method supported by staggered piers as follows: A self-flowing filling mining method supported by staggered piers comprises the following steps: The coal mine working face is divided into multiple filling areas along its advancing direction, and holes are drilled at the surface positions corresponding to the multiple filling areas, and each drill hole is connected to the corresponding filling area, and a filling pipeline is pre-buried in each drill hole; Prepare the gangue accumulated on the surface into filling material slurry; The first transport tunnel and the second transport tunnel are respectively set on both sides of the width direction of the coal mine working face. After the mining of the first filling area is completed, a transverse concrete retaining wall is cast in the first filling area, and a longitudinal concrete retaining wall is cast in the first transport tunnel to connect the transverse concrete retaining wall with the longitudinal concrete retaining wall. In the first transport lane, multiple concrete piers are cast along the advancing direction of the coal mine working face, and in the second transport lane, a concrete closed wall is cast near the coal mine working face to connect the concrete closed wall with the transverse concrete retaining wall; The filling material slurry is injected into the filling pipeline, and the filling material slurry flows into the first filling area through the filling pipeline to complete the filling of the first filling area. While filling the first filling area, the next filling area is mined simultaneously, and the above steps are repeated to fill each filling area in turn.

[0006] The present invention is also characterized in that: When pouring a transverse concrete retaining wall, a filling bracket is set up along the width direction of the coal mine working face in the first filling area near the second filling area, and a flexible mold filling bag is hung behind the filling bracket, and then concrete is injected into the flexible mold filling bag for filling to obtain a transverse concrete retaining wall.

[0007] The upper end of each concrete pier is provided with a flexible cushion layer.

[0008] A steel wire mesh is fixedly arranged between two adjacent concrete piers.

[0009] Among them, multiple concrete piers are arranged in two rows, and the two rows of concrete piers are staggered.

[0010] The distance between two adjacent concrete piers in the advancing direction of the coal mine working face is determined by the following formula: .

[0011] Among them, L is the distance between two adjacent concrete piers in the advancing direction of the coal mine working face, d is the diameter of the concrete pier, P is the compressive strength of concrete, [δ] is the load per meter of the roadside support, and K is the safety factor, which is taken as 1.5.

[0012] The spacing between two adjacent concrete piers in the width direction of the coal mine working face is determined by the following formula: .

[0013] Among them, S is the distance between two adjacent concrete piers in the width direction of the coal mine working face, and d is the diameter of the concrete pier.

[0014] While the filling material slurry is filling the first filling area, a gelling material is injected into the first filling area through the filling pipeline. The gelling material and the filling material slurry are mixed to form a filling body to fill the first filling area.

[0015] The dislocated pier support gravity filling mining method of the present invention has the following advantages: First, by setting up horizontal concrete retaining walls, longitudinal concrete retaining walls, concrete sealed walls and multiple concrete piers on the coal mine working face, a sealed environment can be formed in the current segment filling area, avoiding the filling material slurry from affecting the mining of the next segment filling area during the solidification process, so that mining and filling can be carried out simultaneously, avoiding the filling of the goaf affecting normal mining, improving the production efficiency of the working face, and ensuring coal production.

[0016] Second, by preparing a filling slurry with gangue, fly ash, cement and other materials and filling it into the goaf, it plays a role in supporting the roof of the goaf after solidification, effectively controlling the fracture and collapse of the overburden in the goaf, thereby alleviating the damage to the surface caused by coal mining. At the same time, it can also consume the gangue accumulated on the surface and protect the ecological environment.

[0017] Third, by setting up multiple concrete piers in a staggered arrangement to support the tunnel roof, the first transport tunnel is retained as the tunnel for the next working face mining, which improves the succession efficiency of the working face mining, reduces the number of coal pillars left, and improves the resource recovery rate of the mining area. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall top view structure of the coal mine working face in the present invention.

[0019] Figure 2 It is a schematic diagram of the overall left-side structure of the coal mine working face of the present invention.

[0020] Figure 3 It is a structural schematic diagram of the concrete pier column in the present invention.

[0021] Reference numerals: 1. Filling area, 2. First transport lane, 3. Second transport lane, 4. Horizontal concrete retaining wall, 5. Longitudinal concrete retaining wall, 6. Concrete sealed wall, 7. Concrete pier, 8. Steel wire mesh, 9. Filling support, 10. Filling pump station, 11. Mobile pump station, 12. First grouting pipe, 13. Second grouting pipe, 14. Filling pipeline, 15. Flexible cushion, 16. Filling body. DETAILED DESCRIPTION

[0022] The technical solutions in this application will be described clearly and in detail below in conjunction with the accompanying drawings. In the description of the embodiments of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, such as A and / or B, which can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" refers to two or more than two. The following terms "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0023] like Figure 1 、 Figure 2 、 Figure 3 As shown, the present invention provides a self-flowing filling mining method supported by staggered piers, comprising the following steps: The coal mine working face is divided into multiple filling areas 1 along its advancing direction, and holes are drilled at the surface positions corresponding to the multiple filling areas 1. Each borehole is connected to the corresponding filling area, and a filling pipeline 14 is pre-buried in each borehole.

[0024] The gangue accumulated on the surface is crushed, screened, ball-milled in sequence, and then mixed with fly ash and cement in proportion to prepare filling material slurry, which is then stored for future use.

[0025] A first transport tunnel 2 and a second transport tunnel 3 are respectively set on both sides of the width direction of the coal mine working face. When the mining of the first filling area is completed, a transverse concrete retaining wall 4 is cast in the first filling area along the width direction of the coal mine working face. The position of the transverse concrete retaining wall 4 is close to the next filling area, that is, the transverse concrete retaining wall 4 is located in the first filling area and is close to the second filling area. A longitudinal concrete retaining wall 5 is cast in the position of the first transport tunnel 2 near the first filling area along the advancing direction of the coal mine working face, and the transverse concrete retaining wall 4 is connected to the longitudinal concrete retaining wall 5.

[0026] A plurality of concrete piers 7 are cast in the first transport tunnel 2 near the longitudinal concrete retaining wall 5 along the advancing direction of the coal mine working face, and a concrete closed wall 6 is cast in the second transport tunnel 3 near the transverse concrete retaining wall 4 along the width direction of the coal mine working face, and the concrete closed wall 6 is connected to the transverse concrete retaining wall 4.

[0027] The stored filling material slurry to be used is injected into the filling pipeline 14. The filling material slurry flows into the first filling area through the filling pipeline 14 under the action of gravity, and the entire first filling area is filled. While filling the first filling area, the next filling area is mined simultaneously, and the above steps are repeated to fill each filling area in turn.

[0028] In summary, the filling material slurry is a high-concentration filling slurry. Through the cooperation of the horizontal concrete retaining wall 4, the longitudinal concrete retaining wall 5, the concrete closed wall 6 and the multiple concrete piers 7, a sealed environment can be formed in this section of the filling area, so as to avoid the filling material slurry affecting the mining of the next section of the filling area during the filling process, so that the mining and filling can be carried out simultaneously, avoiding the filling of the goaf affecting the normal mining, improving the production efficiency of the working face, and ensuring the output of coal. At the same time, multiple concrete piers 7 serve as the side support materials of the first transport tunnel 2 to support the roof, retain a tunnel, and realize the tunnel along the goaf. In addition, the filling material slurry is allowed to flow freely after entering the first section of the filling area, and gravity filling is carried out, so as to better adapt to different geological conditions and improve the resource recovery rate.

[0029] like Figure 1 As shown, when pouring the transverse concrete retaining wall 4, a filling bracket 9 is set along the width direction of the coal mine working face in the first filling area near the second filling area, and the flexible mold filling bag is hung behind the filling bracket 9, and then concrete is injected into the flexible mold filling bag for filling to obtain a transverse concrete retaining wall. The flexible mold filling bag facilitates the rapid pouring of the transverse concrete retaining wall.

[0030] like Figure 1 、 Figure 2 As shown, when pouring the transverse concrete retaining wall 4, a filling pump station 10 and a first grouting pipe 12 are set in the first transport tunnel 2, and the concrete slurry is injected into the flexible mold filling bag through the first grouting pipe 12 by the filling pump station 10. At the same time, when pouring the longitudinal concrete retaining wall 5 and multiple concrete piers 7, the concrete slurry is transported thereto through the filling pump station 10.

[0031] like Figure 2 As shown, a flexible cushion layer 15 is provided at the upper end of each concrete pier 7. The flexible cushion layer 15 is made of wood material. The flexible cushion layer 15 has a buffering effect and can absorb and disperse stress concentration to a certain extent to relieve the pressure on the top plate, avoid local excessive stress causing the top plate to fall, and ensure that filling and mining can proceed normally.

[0032] like Figure 1 、 Figure 3As shown, a steel wire mesh 8 is fixedly installed between two adjacent concrete piers 7. The steel wire mesh 8 can prevent the concrete piers 7 from tilting, avoid the top plate from falling, and further ensure that filling and mining can be carried out normally.

[0033] like Figure 1 As shown, multiple concrete piers 7 are arranged in two rows, and the two rows of concrete piers are staggered, so that two adjacent concrete piers 7 are staggered, thereby adapting to coal mining areas with complex geological structures and uneven roof pressure. The staggered arrangement can flexibly adjust the pier position according to actual conditions, better adapt to different geological conditions, and maximize the recovery of coal resources.

[0034] like Figure 1 As shown, the distance between two adjacent concrete piers in the advancing direction of the coal mine working face is determined by the following formula: .

[0035] Among them, L is the distance between two adjacent concrete piers in the advancing direction of the coal mine working face, d is the diameter of the concrete pier, P is the compressive strength of concrete, [δ] is the load per meter of the roadside support, and K is the safety factor, which is taken as 1.5.

[0036] The distance between two adjacent concrete piers in the width direction of the coal mine working face is determined by the following formula: .

[0037] Among them, S is the distance between two adjacent concrete piers in the width direction of the coal mine working face, and d is the diameter of the concrete pier.

[0038] According to field experience, the value of d is generally φ0.8m~φ1m for piers, the spacing S between two adjacent concrete piers in the width direction of the coal mine working face is 0.4m~0.5m, and the spacing L between two adjacent concrete piers in the width direction of the coal mine working face is 1.1m~1.3m.

[0039] like Figure 2 、 Figure 3 As shown, while the filling material slurry is filling the first filling area, cementitious material is injected into the first filling area through the first grouting pipe 12. The cementitious material is mixed with the filling material slurry to form a filling body 16 to fill the first filling area. The mixing of the cementitious material and the filling material slurry can make the formed filling body 16 have higher strength, which is convenient for supporting the filling area after filling, so that the next filling area can be safely and smoothly mined.

[0040] like Figure 1 、 Figure 2As shown, when pouring the concrete closed wall 6, a mobile pump station 11 and a second grouting pipe 13 are set in the second transport tunnel 3. The mobile pump station 11 transports the concrete slurry to the designated position through the second grouting pipe 13 to pour the concrete closed wall 6.

[0041] Working principle: During coal mining, the coal mine working face is first divided into multiple filling areas 1 along its advancing direction, and holes are drilled at positions near the multiple filling areas 1 on the surface, and each borehole is connected to the corresponding filling area. A filling pipeline 14 is pre-buried in each borehole, and then the gangue accumulated on the surface is crushed, screened, and ball-milled in turn, and then a high-concentration filling material slurry is prepared in proportion with fly ash and cement. The filling material slurry is then stored for standby use, and then a first transport lane 2 and a second transport lane 3 are respectively set on both sides of the width direction of the coal mine working face. When the first filling area is mined, a horizontal concrete retaining wall 4 is cast along the width direction of the coal mine working face at a position near the second filling area in the first filling area, and a longitudinal concrete retaining wall is cast along the advancing direction of the coal mine working face at a position near the first filling area in the first transport lane 2. Concrete retaining wall 5, and connect the horizontal concrete retaining wall 4 with the longitudinal concrete retaining wall 5, and then cast multiple concrete piers 7 along the advancement direction of the coal mine working face at the position of the first transport tunnel 2 near the longitudinal concrete retaining wall 5, and cast a concrete closed wall 6 along the width direction of the coal mine working face at the position of the second transport tunnel 3 near the horizontal concrete retaining wall 4, and make the concrete closed wall 6 connected to the horizontal concrete retaining wall 4 and tightly sealed to prevent the filling material slurry from flowing out, and finally inject the filling material slurry stored for use into the filling pipeline 14, and the filling material slurry flows into the first filling area through the filling pipeline 14 under the action of gravity, and the entire first filling area is filled. While filling the first filling area, the next filling area is mined simultaneously, and the above steps are repeated to fill each filling area in turn.

[0042] It will be understood that the present invention is described by way of some embodiments, and it will be appreciated by those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. A self-flowing filling mining method supported by staggered piers, characterized in that: The following steps are involved: The coal mine working face is divided into multiple filling areas along its advancing direction, and holes are drilled at the surface positions corresponding to the multiple filling areas, and each drill hole is connected to the corresponding filling area, and a filling pipeline is pre-buried in each drill hole; Prepare the gangue accumulated on the surface into filling material slurry; The first transport tunnel and the second transport tunnel are respectively set on both sides of the width direction of the coal mine working face. After the mining of the first filling area is completed, a transverse concrete retaining wall is cast in the first filling area, and a longitudinal concrete retaining wall is cast in the first transport tunnel to connect the transverse concrete retaining wall with the longitudinal concrete retaining wall. In the first transport lane, multiple concrete piers are cast along the advancing direction of the coal mine working face, and in the second transport lane, a concrete closed wall is cast near the coal mine working face to connect the concrete closed wall with the transverse concrete retaining wall; The filling material slurry is injected into the filling pipeline, and the filling material slurry flows into the first filling area through the filling pipeline to complete the filling of the first filling area. While filling the first filling area, the next filling area is mined simultaneously, and the above steps are repeated to fill each filling area in turn.

2. The staggered pier support gravity filling mining method according to claim 1, characterized in that: When pouring a transverse concrete retaining wall, a filling bracket is set up along the width direction of the coal mine working face in the first filling area near the second filling area, and a flexible mold filling bag is hung behind the filling bracket. Then, concrete is poured into the flexible mold filling bag for filling to obtain a transverse concrete retaining wall.

3. The staggered pier support gravity filling mining method according to claim 1, characterized in that: The upper end of each concrete pier is provided with a flexible cushion layer.

4. The staggered pier support gravity filling mining method according to claim 1, characterized in that: A steel wire mesh is fixedly arranged between two adjacent concrete piers.

5. The staggered pier support gravity filling mining method according to claim 1, characterized in that: The plurality of concrete piers are arranged in two rows, and the two rows of concrete piers are staggered.

6. The staggered pier support gravity filling mining method according to claim 5, characterized in that: The distance between two adjacent concrete piers in the advancing direction of the coal mine working face is determined by the following formula: ， Among them, L is the distance between two adjacent concrete piers in the advancing direction of the coal mine working face, d is the diameter of the concrete pier, P is the compressive strength of concrete, [δ] is the load per meter of the roadside support, and K is the safety factor, which is taken as 1.

5.

7. The staggered pier support gravity filling mining method according to claim 5, characterized in that: The distance between two adjacent concrete piers in the width direction of the coal mine working face is determined by the following formula: ， Among them, S is the distance between two adjacent concrete piers in the width direction of the coal mine working face, and d is the diameter of the concrete pier.

8. The staggered pier support gravity filling mining method according to claim 1, characterized in that: While the filling material slurry is filling the first filling area, a gelling material is injected into the first filling area through the filling pipeline. The gelling material and the filling material slurry are mixed to form a filling body to fill the first filling area.

Images