Coal mine underground closed wall and construction method thereof

Abstract

This invention discloses a sealed wall for underground coal mines and its construction method, relating to the field of coal mining. The sealed wall includes an outer wall and an inner wall. The outer wall and inner wall are sequentially arranged in the underground roadway from the side furthest from the goaf to the side closest to the goaf. The outer wall is adjacent to the inner wall, and the inner side of the outer wall connects to the outer side of the inner wall. The outer wall is a cement mortar-filled wall, and its entire internal cross-section is reinforced with a steel cage. The inner wall is a precast block masonry wall. The construction method of this sealed wall for underground coal mines is also disclosed. The advantages of this invention are: the structure of the outer and inner walls enhances the compressive strength of the sealed wall, ensuring that the wall is not damaged or leaks air under pressure, thus guaranteeing the safety of methane gas outside the sealed wall.

Description

Technical Field

[0001] The invention relates to the field of coal mining, and in particular to an underground closed wall of a coal mine and a construction method thereof. Background Art

[0002] The closed wall in the coal mine is connected to the goaf and plays a sealing role. With the increase of the mining depth of the mine, the corresponding tunnel surrounding rock stress gradually increases, especially the construction tunnel excavated along the goaf, the stress is more concentrated, resulting in the reduction of coal pillar hardness, soft coal wall, more and larger cracks, and increased pressure in the closed tunnel, which is easy to cause the closed wall to be crushed. The existing closed walls generally use prefabricated block walls, which have weak compressive resistance and are easily damaged by pressure. The wall surface slurry is easy to fall off, which is easy to cause air leakage in the goaf, leading to safety accidents such as gas gushing in the tunnel, spontaneous combustion in the goaf, and leakage of toxic and harmful gases, and it is difficult to maintain in the later stage. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a coal mine underground closed wall with strong compression resistance and a construction method thereof.

[0004] The present invention solves the above-mentioned technical problems through the following technical means: an underground closed wall of a coal mine, comprising an outer wall (1) and an inner wall (2); the outer wall (1) and the inner wall (2) are arranged in sequence in the underground tunnel from the side far from the goaf to the side close to the goaf, the outer wall (1) is adjacent to the inner wall (2), and the inner side surface of the outer wall (1) is connected to the outer side surface of the inner wall (2); the outer wall (1) is a cement mortar filling wall, and the entire internal section of the outer wall (1) is provided with a steel cage; the inner wall (2) is a prefabricated block masonry wall.

[0005] As an optimized technical solution, the coal mine underground enclosed wall also includes an explosion-proof wall (3), which is arranged on a side close to the goaf relative to the inner wall (2), and is spaced a predetermined distance from the inner wall (2). The explosion-proof wall (3) is a sandbag wall.

[0006] As an optimized technical solution, the coal mine underground enclosed wall also includes an extraction pipe (4), which passes through the outer wall (1), the inner wall (2), and the explosion-proof wall (3). One end of the extraction pipe (4) passes through the outside of the outer wall (1) and is provided with a valve, and the other end passes through the inside of the explosion-proof wall (3).

[0007] As an optimized technical solution, the coal mine underground enclosed wall also includes a fireproof pipe (5), which runs through the outer wall (1), the inner wall (2), and the explosion-proof wall (3), and one end of the fireproof pipe (5) passes through the outer side of the outer wall (1), and the other end passes through the inner side of the explosion-proof wall (3).

[0008] As an optimized technical solution, the coal mine underground enclosed wall further comprises a first drainage pipe (6) and a second drainage pipe (8); the first drainage pipe (6) passes through the outer wall (1), the inner wall (2) and the explosion-proof wall (3), one end of the first drainage pipe (6) passes through the outer side of the outer wall (1), and the other end passes through the inner side of the explosion-proof wall (3); the second drainage pipe (8) passes through the outer wall (1) and the inner wall (2), one end of the second drainage pipe (8) passes through the outer side of the outer wall (1), and the other end passes through the inner side of the inner wall (2) and is located between the inner wall (2) and the explosion-proof wall (3).

[0009] As an optimized technical solution, the coal mine underground closed wall also includes a first observation tube (7) and a second observation tube (9); the first observation tube (7) passes through the outer wall (1), the inner wall (2), and the explosion-proof wall (3), one end of the first observation tube (7) passes through the outer side of the outer wall (1), and the other end passes through the inner side of the explosion-proof wall (3); the second observation tube (9) passes through the outer wall (1) and the inner wall (2), one end of the second observation tube (9) passes through the outer side of the outer wall (1), and the other end passes through the inner side of the inner wall (2) and is located between the inner wall (2) and the explosion-proof wall (3).

[0010] As an optimized technical solution, the thickness of the outer wall (1) is 2800 mm, and the steel cage is a cube with a side length of 300 mm.

[0011] As an optimized technical solution, the steel cage is formed by anchor rods and tied with iron wires.

[0012] The method for constructing a closed wall in an underground coal mine comprises the following steps:

[0013] Step A, using sandbags to build an explosion-proof wall (3), and reserving holes for an extraction pipe (4), a fireproof pipe (5), a first water discharge pipe (6), and a first observation pipe (7) on the explosion-proof wall (3);

[0014] Step B, using prefabricated blocks to build an inner wall (2) at a predetermined distance from the explosion-proof wall (3) outside the explosion-proof wall (3), and reserving holes for an extraction pipe (4), a fire prevention pipe (5), a first drainage pipe (6), a first observation pipe (7), a second drainage pipe (8), and a second observation pipe (9) on the inner wall (2);

[0015] Step C, installing the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), the first observation pipe (7), the second drain pipe (8), and the second observation pipe (9), passing one end of the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), the first observation pipe (7), the second drain pipe (8), and the second observation pipe (9) out of the outside of the location of the outer wall (1), passing the other end of the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), and the first observation pipe (7) out of the inside of the explosion-proof wall (3), and passing the other end of the second drain pipe (8) and the second observation pipe (9) out of the inside of the inner wall (2) and located between the inner wall (2) and the explosion-proof wall (3);

[0016] Step D: integrally casting the outer wall (1) on the outer side of the inner wall (2) and adjacent to the inner wall (2).

[0017] As an optimized technical solution, in step D, the casting method of the outer wall (1) is to first erect a formwork, then place a steel cage in the filling area with the entire section, then fill it with cement mortar, and finally compact it with a vibrating rod and maintain it.

[0018] The advantages of the present invention are that the structure of the outer wall and the inner wall enhances the compression resistance of the closed wall in the coal mine, the wall is not damaged or leaks when under pressure, and the gas outside the closed wall is guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the main view of the closed wall in an underground coal mine according to an embodiment of the present invention.

[0020] Figure 2 It is a side view schematic diagram of a closed wall in an underground coal mine according to an embodiment of the present invention.

[0021] Figure 3 It is a top view schematic diagram of a closed wall in an underground coal mine according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figures 1 to 3 As shown, the closed wall in an underground coal mine includes an outer wall 1, an inner wall 2, an explosion-proof wall 3, an extraction pipe 4, a fire-proof pipe 5, a first drainage pipe 6, a first observation pipe 7, a second drainage pipe 8, and a second observation pipe 9.

[0024] An outer wall 1, an inner wall 2 and an explosion-proof wall 3 are arranged in sequence in the underground tunnel from the side far from the goaf to the side close to the goaf. The outer wall 1 is adjacent to the inner wall 2, the inner side surface of the outer wall 1 is connected to the outer side surface of the inner wall 2, and the explosion-proof wall 3 is separated from the inner wall 2 by a predetermined distance.

[0025] The outer wall 1 is a cement mortar filled wall, the cement used is 325 cement, and the thickness is 2800mm; the entire internal section of the outer wall 1 is provided with a steel cage, which is a cube with a side length of 300mm, tied with waste anchor rods with a diameter of 22mm, and firmly tied with 14# iron wire.

[0026] The inner wall 2 is a prefabricated block masonry wall with a thickness of 800 mm.

[0027] The explosion-proof wall 3 is a sandbag wall with a thickness of 4200 mm.

[0028] The extraction pipe 4 passes through the outer wall 1 , the inner wall 2 , and the explosion-proof wall 3 . One end of the extraction pipe 4 passes through the outer side of the outer wall 1 and is provided with a valve, and the other end passes through the inner side of the explosion-proof wall 3 .

[0029] The fireproof pipe 5 is arranged above the extraction pipe 4, and the fireproof pipe 5 passes through the outer wall 1, the inner wall 2, and the explosion-proof wall 3. One end of the fireproof pipe 5 passes through the outside of the outer wall 1 and is provided with a valve, and the other end passes through the inside of the explosion-proof wall 3.

[0030] The first drain pipe 6 is arranged below the extraction pipe 4 , and passes through the outer wall 1 , the inner wall 2 , and the explosion-proof wall 3 . One end of the first drain pipe 6 passes through the outer side of the outer wall 1 and is provided with a U-shaped water seal and a valve, and the other end passes through the inner side of the explosion-proof wall 3 .

[0031] The first observation tube 7 is arranged above the fireproof tube 5 , and the first observation tube 7 passes through the outer wall 1 , the inner wall 2 , and the explosion-proof wall 3 . One end of the first observation tube 7 passes through the outer side of the outer wall 1 , and the other end passes through the inner side of the explosion-proof wall 3 .

[0032] The second drain pipe 8 is arranged below the extraction pipe 4. The second drain pipe 8 passes through the outer wall 1 and the inner wall 2. One end of the second drain pipe 8 passes through the outside of the outer wall 1 and is provided with a valve, and the other end passes through the inside of the inner wall 2 and is located between the inner wall 2 and the explosion-proof wall 3.

[0033] The second observation tube 9 is arranged above the fireproof tube 5. The second observation tube 9 passes through the outer wall 1 and the inner wall 2. One end of the second observation tube 9 passes through the outer side of the outer wall 1, and the other end passes through the inner side of the inner wall 2 and is located between the inner wall 2 and the explosion-proof wall 3.

[0034] The method for constructing a closed wall in an underground coal mine comprises the following steps:

[0035] Step A, using sandbags to build an explosion-proof wall 3, the thickness of the explosion-proof wall 3 is 4200 mm, and holes for the extraction pipe 4, the fireproof pipe 5, the first drainage pipe 6, and the first observation pipe 7 are reserved on the explosion-proof wall 3;

[0036] Step B, building an inner wall 2 with prefabricated blocks at a predetermined distance from the explosion-proof wall 3 on the outside of the explosion-proof wall 3, the thickness of the inner wall 2 is 800 mm, and pipe holes for the extraction pipe 4, the fireproof pipe 5, the first drainage pipe 6, the first observation pipe 7, the second drainage pipe 8, and the second observation pipe 9 are reserved on the inner wall 2;

[0037] Step C, installing the extraction pipe 4, the fireproof pipe 5, the first drain pipe 6, the first observation pipe 7, the second drain pipe 8, and the second observation pipe 9, passing one end of the extraction pipe 4, the fireproof pipe 5, the first drain pipe 6, the first observation pipe 7, the second drain pipe 8, and the second observation pipe 9 through the outside of the position of the outer wall 1, passing the other end of the extraction pipe 4, the fireproof pipe 5, the first drain pipe 6, and the first observation pipe 7 through the inside of the explosion-proof wall 3, passing the other end of the second drain pipe 8 and the second observation pipe 9 through the inside of the inner wall 2 and being located between the inner wall 2 and the explosion-proof wall 3;

[0038] Step D, integrally pouring the outer wall 1 on the outer side of the inner wall 2 adjacent to the inner wall 2; the pouring method is to first erect a formwork, and then place a steel cage in the filling area with the entire section. The steel cage is a cube with a side length of 300 mm, which is made of waste anchor rods with a diameter of 22 mm and is firmly tied with 14# iron wire, and then filled with cement mortar, the cement used is 325 cement, and finally vibrated with a vibrating rod for maintenance; the thickness of the outer wall 1 is 2800 mm.

[0039] After the construction of the underground closed wall of the coal mine was completed, after more than six months of continuous observation, the closed wall was intact, the gas concentration outside the wall did not reach 0.2% or above, and no carbon monoxide was detected inside the wall, outside the wall and within 20m around it. Actual measurement results verified that this closed wall construction technology has obvious effect on the closed control of coal (rock) bodies in the closed area of ​​the goaf, and the technical conditions are mature.

[0040] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A closed wall in an underground coal mine, characterized in that: The invention comprises an outer wall (1), an inner wall (2), an explosion-proof wall (3), an extraction pipe (4), a fire-proof pipe (5), a first drainage pipe (6) and a second drainage pipe (8); the outer wall (1), the inner wall (2) and the explosion-proof wall (3) are arranged in sequence in the underground tunnel from the side far from the goaf to the side close to the goaf; the outer wall (1) is adjacent to the inner wall (2), and the inner side surface of the outer wall (1) is connected to the outer side surface of the inner wall (2); the outer wall (1) is a cement mortar filled wall, the entire internal section of the outer wall (1) is provided with a steel cage; the inner wall (2) is a prefabricated block masonry wall; the explosion-proof wall (3) is arranged on a side close to the goaf relative to the inner wall (2), the explosion-proof wall (3) is spaced a predetermined distance from the inner wall (2), and the explosion-proof wall (3) is a sandbag wall; the extraction pipe (4) passes through the outer wall (1), the inner wall (2), and the explosion-proof wall (3), and the extraction pipe One end of the fireproof pipe (4) passes through the outside of the outer wall (1) and is provided with a valve, and the other end passes through the inside of the explosion-proof wall (3); the fireproof pipe (5) passes through the outer wall (1), the inner wall (2), and the explosion-proof wall (3); one end of the fireproof pipe (5) passes through the outside of the outer wall (1), and the other end passes through the inside of the explosion-proof wall (3); the first drain pipe (6) passes through the outer wall (1), the inner wall (2), and the explosion-proof wall (3); One end of the first drain pipe (6) passes through the outside of the outer wall (1), and the other end passes through the inside of the explosion-proof wall (3); the second drain pipe (8) passes through the outer wall (1) and the inner wall (2); one end of the second drain pipe (8) passes through the outside of the outer wall (1), and the other end passes through the inside of the inner wall (2) and is located between the inner wall (2) and the explosion-proof wall (3); the steel cage is formed by anchor rods and tied with iron wire.

2. The closed wall for underground coal mine according to claim 1, characterized in that: The coal mine underground sealed wall further comprises a first observation tube (7) and a second observation tube (9); the first observation tube (7) passes through the outer wall (1), the inner wall (2) and the explosion-proof wall (3); one end of the first observation tube (7) passes through the outer side of the outer wall (1) and the other end passes through the inner side of the explosion-proof wall (3); the second observation tube (9) passes through the outer wall (1) and the inner wall (2); one end of the second observation tube (9) passes through the outer side of the outer wall (1) and the other end passes through the inner side of the inner wall (2) and is located between the inner wall (2) and the explosion-proof wall (3).

3. The closed wall of an underground coal mine as claimed in claim 2, characterized in that: The thickness of the outer wall (1) is 2800 mm, and the steel cage is a cube with a side length of 300 mm.

4. A method for constructing a closed wall in an underground coal mine as claimed in claim 2, characterized in that: The following steps are involved: Step A, using sandbags to build an explosion-proof wall (3), and reserving holes for an extraction pipe (4), a fireproof pipe (5), a first drain pipe (6), and a first observation pipe (7) on the explosion-proof wall (3); Step B, using prefabricated blocks to build an inner wall (2) at a predetermined distance from the explosion-proof wall (3) outside the explosion-proof wall (3), and reserving holes for an extraction pipe (4), a fire prevention pipe (5), a first drainage pipe (6), a first observation pipe (7), a second drainage pipe (8), and a second observation pipe (9) on the inner wall (2); Step C, installing the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), the first observation pipe (7), the second drain pipe (8), and the second observation pipe (9), passing one end of the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), the first observation pipe (7), the second drain pipe (8), and the second observation pipe (9) out of the outside of the location of the outer wall (1), passing the other end of the extraction pipe (4), the fireproof pipe (5), the first drain pipe (6), and the first observation pipe (7) out of the inside of the explosion-proof wall (3), and passing the other end of the second drain pipe (8) and the second observation pipe (9) out of the inside of the inner wall (2) and positioned between the inner wall (2) and the explosion-proof wall (3); Step D: integrally casting the outer wall (1) on the outer side of the inner wall (2) and adjacent to the inner wall (2).

5. The method for constructing a closed wall in an underground coal mine according to claim 4, characterized in that: In step D, the casting method of the outer wall (1) is to first erect a formwork, then place a steel cage in the full section of the filling area, then fill it with cement mortar, and finally vibrate it with a vibrating rod and maintain it.

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