Closed wall air leakage plugging grouting process

Abstract

The invention discloses a closed wall air leakage plugging grouting process, and relates to the technical field of mine closed walls. Surrounding rocks around the sealing wall are grouted, filled and blocked to block air leakage cracks, and finally the purpose of blocking the periphery of the sealing wall is achieved; a plastic plugging material is selected as a grouting material; and then grouting, filling and plugging are conducted on the inner space of the two wall bodies of the closed wall, and finally the purposes of reinforcing the closed wall body and plugging cracks of the closed wall body are achieved. And an inorganic efficient filling material is selected as a grouting material. Through the treatment thought of surrounding rock crack filling reinforcement and internal grouting filling top formation, an air leakage channel is effectively blocked, and roadway deformation is restrained.

Description

Technical Field

[0001] The invention relates to the technical field of mine closed walls, and in particular to a closed wall air leakage plugging grouting process. Background Art

[0002] Sealed wall is a key technology for controlling ventilation in coal mines. It is used in underground tunnel excavation, face layout and all production operations where ventilation control or gas management is required. When the coal seam is explosive, operators usually build a sealed wall in the tunnel leading to the goaf to seal the goaf and prevent fresh air from entering the goaf.

[0003] When the working face of multiple mineable coal seams in the coal mining area is mined, these areas after mining become relatively closed goaf groups. Affected by the mining of the working face, the sealing effect of the closed wall will be reduced accordingly, resulting in air leakage from the closed wall to the goaf group. When the goaf group leaks, it will directly threaten the safe production of the coal mine. Therefore, how to effectively control the problem of cracking and air leakage of the closed wall during post-mining is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The purpose of the invention is to provide a grouting process for plugging air leakage in a closed wall, which can effectively plug the closed wall for a long time.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: a closed wall air leakage plugging grouting process, comprising the following steps:

[0006] Step 1: First, grout the surrounding rock around the closed wall to seal the air leakage cracks, and finally achieve the purpose of sealing the surrounding of the closed wall; the grouting material is selected as plastic sealing material;

[0007] Step 2: Grouting and filling the inner spaces of the two walls of the closed wall to seal them, so as to achieve the purpose of reinforcing the closed wall and sealing the cracks of the closed wall; the grouting material is selected from inorganic high-efficiency filling materials;

[0008] Preferably, in the first step, the rock filling and plugging of the drilled holes around the closed wall is arranged with a hole depth of 3.0m, a spacing between adjacent drilled holes of no more than 2m, and the side extending 2m outside the wall.

[0009] Preferably, in the second step, two drilling holes are arranged to fill the internal space of the closed wall, with the opening position 1m away from the tunnel roof, the hole spacing 2m, the drilling inclination angle 18-22°, and the final hole at the tunnel roof.

[0010] Preferably, the grouting pipe is made of 6-point galvanized steel pipe.

[0011] Furthermore, in order to make it easier to insert the grouting pipe into the drill hole and prevent blockage, two rows of eyelets are arranged at the front end of the grouting pipe, with 8 to 10 holes in each row, 100 mm apart, and the diameter of the eyelets is not less than 8 mm.

[0012] Compared with the prior art, the present invention effectively blocks air leakage channels and inhibits tunnel deformation through the management idea of ​​filling and reinforcing the surrounding rock cracks and filling and capping the interior with grouting. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view schematic diagram of the arrangement of the surrounding rock filling and plugging boreholes;

[0014] Figure 2 It is a side view schematic diagram of the arrangement of the surrounding rock filling and plugging boreholes;

[0015] Figure 3 It is a front view schematic diagram of the filling drill hole inside the closed wall;

[0016] Figure 4 It is a schematic side view of the filling drill hole inside the closed wall. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below with reference to specific embodiments.

[0018] A certain working face was withdrawn and closed in June 2024. After investigation, it was found that the surrounding rocks of the three closed walls associated with the working face all had air leakage. On the one hand, there is a hidden danger of toxic and harmful gas overflow from the closed wall; on the other hand, when the air pressure inside and outside the closed wall changes, oxygen may be supplied to the goaf through the air leakage cracks, posing a risk of spontaneous combustion of the coal seam in the goaf. In order to eliminate the hidden danger of air leakage in the closed wall, filling and sealing control measures need to be taken.

[0019] Step 1: First, grouting is used to fill the surrounding rock of the closed wall to seal the air leakage cracks; considering the effective thickness of the coal rock mass and the diffusion performance of the material, the surrounding rock of the closed wall is filled and sealed with a hole depth of 3.0m, the distance between adjacent holes is no more than 2m, and the side extends 2m outside the wall. The diameter of the hole is 42mm, and a 2.5m casing is installed. The sealing position is about 1m away from the hole mouth. See the schematic diagram of the drilling arrangement. Figure 1 , Figure 2 As shown; the ultimate goal is to form a blocking wall with a thickness of about 2-3m around the enclosed area.

[0020] The grouting pipe is made of 6-point galvanized steel pipe. In order to make it easier to insert the grouting pipe into the drill hole and prevent blockage, the front end needs to be flattened and sharpened, and two rows of eyelets are arranged, with 8 to 10 in each row, 100mm apart, and the diameter of the eyelets is not less than 8mm.

[0021] In order to prevent and control the cracks in the surrounding rock of the closed wall, the plastic plugging material (FSD-II) produced by Xuzhou Ji'an Mining Technology Co., Ltd. was selected. The material consists of two components, material A and material B. Material A is a gelling agent, and material B is an initiator. After material A and material B are mixed, the gelling substance in material A produces electrostatic repulsion and hydration in the molecules under the action of material B. The macromolecular structure gradually stretches from the curled state, a large number of water molecules around are adsorbed, free water is reduced, and the viscosity increases, eventually forming a spatial network structure. When the spatial network structure reaches a certain size, the repulsion and attraction within the molecules reach a certain balance, and the spatial network structure no longer increases further. At this time, the viscosity formed by the material can ensure both effective plugging of the cracks and plastic flow and effective diffusion. The material is not easy to decompose and change, and can maintain a lasting plugging effect.

[0022] Step 2: Fill and seal the inner spaces of the two walls of the closed wall with grouting;

[0023] Two holes are arranged for filling the internal space of the closed wall. The opening position is 1m away from the tunnel roof, the hole spacing is 2m, the drilling angle is about 20°, and the final hole is at the tunnel roof. After it is in place, the drill rod is pulled out, and a 6-point galvanized steel pipe is inserted and fixed. See the schematic diagram of the drilling arrangement Figure 3 , Figure 4 As shown;

[0024] For the internal filling and plugging of the closed wall, the inorganic high-efficiency filling material (JCT-I) specially made for the closed wall produced by Xuzhou Ji'an Mining Technology Co., Ltd. was selected. The material consists of two powder components, A material and B material. According to the site requirements, the two powders are mixed with water at a water-cement ratio of 6 to form a premixed liquid, which is fully mixed by a slurry mixing device to form an inorganic solid material. After the mixed slurry is poured into the permanent closed wall cavity, on the one hand, it has a good penetration and plugging function for the broken holes and cracks in the surrounding rock, and on the other hand, it can form a complete top connection effect. During the grouting process, the pressure grouting method is used to make the material close to the top, and diffuse and penetrate into the surrounding rock cracks, effectively blocking the air leakage channel and inhibiting the deformation of the roadway.

[0025] By filling and sealing the enclosed wall, the hidden danger of air leakage in the enclosed wall is eliminated and the safe production of the mine is guaranteed.

[0026] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A grouting process for sealing air leakage in a closed wall, characterized in that: The following steps are involved: Step 1: First, grout the surrounding rock around the closed wall to seal the air leakage cracks, and finally achieve the purpose of sealing the surrounding of the closed wall; the grouting material is selected as plastic sealing material; The second step: fill and seal the internal space of the two walls of the closed wall with grouting, so as to finally achieve the purpose of reinforcing the closed wall and sealing the cracks of the closed wall; inorganic high-efficiency filling material is selected as the grouting material.

2. A grouting process for blocking air leakage in a closed wall according to claim 1, characterized in that: In the first step, the surrounding rock of the closed wall is filled and the drilled holes are sealed with a depth of 3.0m. The distance between adjacent drilled holes is not more than 2m, and the side extends 2m outside the wall.

3. A grouting process for sealing air leakage in a closed wall according to claim 1, characterized in that: In the second step, two drilling holes are arranged to fill the internal space of the closed wall. The opening position is 1m away from the top plate of the tunnel, the hole spacing is 2m, the drilling inclination angle is 18-22°, and the final hole is at the top plate of the tunnel.

4. A grouting process for blocking air leakage in a closed wall according to any one of claims 1 to 3, characterized in that: The grouting pipe is made of 6-point galvanized steel pipe.

5. A grouting process for blocking air leakage in a closed wall according to claim 4, characterized in that: Two rows of eyelets are arranged at the front end of the grouting pipe, with 8 to 10 eyelets in each row, an interval of 100 mm, and an eyelet diameter of not less than 8 mm.

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