Narrow coal pillar reinforcing structure based on double-pull anchor cable

Abstract

The utility model discloses a narrow coal pillar reinforcing structure based on double-pull anchor cables, which is specifically characterized in that steel wire meshes are arranged on the wall surfaces of a roadway A and a roadway B, and a plurality of U-shaped shed supports are uniformly arranged on the wall surfaces of the roadway A and the roadway B and on the steel wire meshes at intervals; a plurality of through holes are evenly distributed in the position, away from the U-shaped shed support, of the rock mass of the narrow coal pillar in the transverse direction and the longitudinal direction, and the through holes are anchor cable installation holes. An anchor cable is arranged in each mounting hole in a penetrating mode, and the two ends of each anchor cable extend out of the wall face A and the wall face B correspondingly. Tensioning auxiliary tools are arranged at the two ends of the anchor cable. The tensioning auxiliary tool is used for being matched with the tensioning device to conduct tensioning and pre-tightening on the two ends of the anchor cable. The pre-tightened anchor cable is used for achieving bidirectional reinforcing and supporting of the narrow coal pillar. The problems that an existing narrow coal pillar is insufficient in supporting strength and poor in stability are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of coal mine support, and particularly relates to a narrow coal pillar reinforcement structure based on double tension anchor cables.

Background Art

[0002] In existing mines, narrow coal pillars are set between adjacent mining faces. A narrow coal pillar in a mine refers to a coal pillar isolated from the goaf in driving along the goaf, and its main function is to maintain the stability of the surrounding rock of the roadway in driving along the goaf. During the coal mining process, the narrow coal pillar will be affected by the overlying stress, generating fine cracks and stabilizing within a certain range. These cracks may form air leakage channels, affecting the safety and production efficiency of the mine. Moreover, under conventional support, the narrow coal pillar shows strong mine pressure and serious deformation, affecting its safe use. It is urgent to strengthen the support strength of the narrow coal pillar to ensure the normal continuation of the mining face.

Content of the Utility Model

[0003] The purpose of the utility model is to provide a narrow coal pillar reinforcement structure based on double tension anchor cables to solve the problems of insufficient support strength and poor stability of existing narrow coal pillars.

[0004] The utility model adopts the following technical solutions: A narrow coal pillar reinforcement structure based on double tension anchor cables, based on a narrow coal pillar located between roadway A and roadway B. The wall surface of the narrow coal pillar on the side of roadway A is wall surface A, and the wall surface on the side of roadway B is wall surface B;

[0005] The reinforcement structure is specifically as follows:

[0006] Steel wire meshes are arranged on the wall surfaces of roadway A and roadway B, and a plurality of U-shaped shed supports are evenly and spacedly arranged on the wall surfaces of roadway A and roadway B and above the steel wire meshes;

[0007] A plurality of through holes are horizontally and vertically evenly arranged on the rock mass of the narrow coal pillar at positions avoiding the U-shaped shed supports. The through holes are installation holes for anchor cables; an anchor cable is penetrated through each installation hole, and both ends of each anchor cable extend beyond wall surface A and wall surface B respectively;

[0008] Tensioning auxiliary tools are provided at both ends of the anchor cable. Each tensioning auxiliary tool is a tray and a locking device sequentially sleeved on the end of the anchor cable. The tray is fixed on wall surface A or wall surface B, and the locking device is used to lock the anchor cable. The bottom of the locking device contacts the tray;

[0009] Among them, the tensioning auxiliary tool is used to cooperate with the tensioner to perform tension pre-tightening on both ends of the anchor cable; the pre-tightened anchor cable is used to realize the two-way reinforcement support for the narrow coal pillar.

[0010] Furthermore, at least two collars are spacedly arranged at the middle section of each anchor cable.

[0011] Further, the spacing distance between multiple mounting holes in the horizontal direction is 400 mm, and the spacing distance in the vertical direction is 800 mm.

[0012] Further, the end of each cable bolt extends at least 0.5 m beyond wall surface A or wall surface B.

[0013] The beneficial effects of the present utility model are as follows: By arranging a wire mesh and a U-shaped shed support on a narrow coal pillar, and horizontally and vertically and uniformly arranging multiple cable bolts on the rock mass of the narrow coal pillar and avoiding the position of the U-shaped shed support, trays and locks are installed on both sides of the cable bolts, and the two ends of the cable bolts are pre-tightened by a tensioning tool, realizing two-way reinforcement support, improving the support strength of the narrow coal pillar, solving the problem of tight mining and excavation connection in the mine, and avoiding the formation of an isolated panel due to skip mining in the mining area.

Description of the Drawings

[0014] Figure 1 It is a schematic structural view of a narrow coal pillar reinforcement structure based on double-tension cable bolts of the present invention from the longitudinal sectional view along the narrow coal pillar;

[0015] Figure 2 is Figure 1 a schematic structural view from view A;

[0016] Figure 3 It is an installation schematic view of a prefabricated cable bolt located in a narrow coal pillar from the longitudinal sectional view along the narrow coal pillar in the present invention.

[0017] Wherein, 1. Cable bolt, 2. Sleeve, 3. Ferrule, 4. Lock, 5. Tray, 6. U-shaped shed support, 7. Narrow coal pillar, 8. Wire mesh.

Specific Embodiments

[0018] The present utility model will be described in detail below in conjunction with the drawings and specific embodiments.

[0019] The present utility model provides a narrow coal pillar reinforcement structure based on double-tension cable bolts. As Figure 1 shown, based on the narrow coal pillar 7 located between roadway A and roadway B, the wall surface of the narrow coal pillar 7 on the side of roadway A is wall surface A, and the wall surface on the side of roadway B is wall surface B;

[0020] The reinforcement structure is specifically:

[0021] As Figure 2 shown, a wire mesh is arranged on the wall surfaces of roadway A and roadway B, and multiple U-shaped shed supports 6 are evenly and spacedly arranged on the wall surfaces of roadway A and roadway B and above the wire mesh;

[0022] A plurality of through holes are uniformly arranged horizontally and vertically on the rock mass of the narrow coal pillar 7, avoiding the position of the U-shaped shed support 6. The through holes are installation holes for anchor cables; an anchor cable 1 is penetrated in each installation hole, and both ends of each anchor cable 1 extend beyond the wall surface A and the wall surface B respectively;

[0023] Tensioning auxiliary tools are provided at both ends of the anchor cable 1. Each tensioning auxiliary tool is a tray 5 and a locking device 4 sleeved on the end of the anchor cable 1 in sequence. The tray 5 is fixed on the wall surface A or the wall surface B, and the locking device 4 is used to lock the anchor cable 1. The bottom of the locking device 4 contacts the tray 5;

[0024] Among them, the tensioning auxiliary tool is used to cooperate with the tensioner to tension and pre-tighten both ends of the anchor cable 1; the pre-tightened anchor cable 1 is used to realize the two-way reinforcement support of the narrow coal pillar 7.

[0025] In some embodiments, at least two collars 3 are arranged at intervals in the middle section of each anchor cable 1. The collar 3 can be a high-strength extrusion threaded collar. A high-strength extrusion threaded collar is installed every certain distance in the length direction of the anchor cable 1 to increase the friction with the grouting anchoring material and effectively prevent the internal deformation of the coal pillar body.

[0026] In some embodiments, the interval distance of the plurality of installation holes in the horizontal direction is 400 mm, and the interval distance in the vertical direction is 800 mm. The anchor cables are arranged with a uniform density, which can achieve the maximum reinforcement effect within a limited space at the optimal cost.

[0027] In some embodiments, the distance that the end of each anchor cable 1 extends out of the wall surface A or the wall surface B is at least 0.5 m. The extension length of the anchor cable 1 should not only ensure convenient cooperation with tensioning but also ensure that it does not affect passage.

[0028] The present utility model also provides an installation method for a narrow coal pillar reinforcement structure based on a double-tensioned anchor cable. Based on a prefabricated anchor cable, as Figure 3 shown, the prefabricated anchor cable is a sleeve 2 sleeved on one end of the anchor cable 1, and the sleeve 2 is fixed with a collar 3.

[0029] The installation method includes the following steps:

[0030] S1. When driving the roadway A, drill through holes from one side of the roadway A into the rock mass of the narrow coal pillar 7, which are the installation holes for the prefabricated anchor cables. The installation holes are a plurality of uniformly arranged ones. Preparation work such as marking can be carried out in advance at the position where the anchor cable 1 is preset, and then the installation holes are drilled. The diameter of the installation holes can be, for example, 28 mm.

[0031] Insert the prefabricated anchor cables into each of the said installation holes; and ensure that both ends of the prefabricated anchor cables pass through both sides of the narrow coal pillar 7; and ensure that the end of the prefabricated anchor cable with the casing 2 extends to one side of the roadway B. Among them, before grouting, first stir the grouting material with water to an appropriate ratio, and then add auxiliary materials such as quick-setting agent and mix evenly. A ZBQ35 / 6 type grouting pump can be used. Connect the grouting pump to the grouting pipe. During the grouting process, observe the orifice of the installation hole. If a small amount of slurry oozes out, immediately stop grouting. At this time, it can ensure sufficient grouting.

[0032] Use a foaming agent to pre-seal each installation hole to prevent slurry leakage of the grout plug. Then use a grouting pump to grout and reinforce the gap between each prefabricated anchor cable and its corresponding installation hole through the grouting pipe;

[0033] After the grouting is completed, tie the grouting pipe with a strapping band or wire to prevent the cement slurry from flowing out. Then, successively put on the tray 5 and the locking device 4 on the end of the anchor cable 1 on one side of the roadway A and fix them; after the slurry quickly solidifies, then use a tensioning device to apply a pre-tightening force to realize the pre-tightening reinforcement of the anchor cable on one side of the narrow coal pillar 7 in the roadway A.

[0034] S2. When tunneling to the roadway B, as the tunneling progresses, the ends of the prefabricated anchor cables will be exposed one by one. On the premise of ensuring that the ends of the prefabricated anchor cables exceed the wall surface of the narrow coal pillar 7, cut off the excess length of the anchor cable 1, remove the anti-static casing 2, and then successively install the tray 5 and the locking device 4 on the end of the anchor cable 1 on one side of the roadway B.

[0035] According to this method, successively cut and install the tensioning auxiliary tools for each prefabricated anchor cable on one side of the roadway B.

[0036] Finally, tension and pre-tighten each anchor cable 1 on one side of the roadway B to realize the two-way reinforcement support for the narrow coal pillar 7.

[0037] In some embodiments, in S1, before inserting the anchor cable 1 into the installation hole, first fixedly install a grouting pipe in parallel on the anchor cable 1, and a grout plug is sleeved on the anchor cable 1 and adjacent to the outer walls on both sides of the narrow coal pillar 7. For example, two grout plugs are sleeved at 1 m and 0.5 m from the end of the anchor cable 1 respectively, and are tied and fixed with a flame-retardant tape. At the same time, the grouting pipe is tied to the anchor cable and exposed 1 m.

[0038] The utility model realizes two-way reinforcement support by arranging a wire mesh and a U-shaped shed support on the narrow coal pillar, horizontally and vertically and evenly arranging multiple anchor cables on the rock mass of the narrow coal pillar and avoiding the U-shaped shed support, installing trays and locking devices on both sides of the anchor cables, and pre-tightening both ends of the anchor cables through a tensioning tool, improves the support strength of the narrow coal pillar, solves the problem of tight mining and tunneling connection in the mine, and can avoid the formation of an isolated panel due to skip mining in the mining area.

Claims

1. A narrow coal pillar reinforcement structure based on double-pull anchor cables, characterized in that: Based on a narrow coal pillar (7) located between tunnel A and tunnel B, the wall surface of the narrow coal pillar (7) located on the tunnel A side is wall surface A, and the wall surface of the narrow coal pillar (7) located on the tunnel B side is wall surface B; The reinforcement structure is specifically: Steel wire mesh is arranged on the wall surface of the lane A and the lane B, and a plurality of U-shaped shed brackets (6) are evenly and spacedly arranged on the wall surface of the lane A and the lane B and on the steel wire mesh; A plurality of through holes are evenly arranged horizontally and vertically on the rock mass of the narrow coal pillar (7) at a position avoiding the U-shaped shed support (6), the through holes being mounting holes for anchor cables; an anchor cable (1) is arranged through each mounting hole, and the two ends of each anchor cable (1) extend to the outside of the wall surface A and the wall surface B respectively; Both ends of the anchor cable (1) are provided with tensioning auxiliary tools, each of which is a tray (5) and a lock (4) which are sequentially sleeved on the ends of the anchor cable (1), the tray (5) being fixed on the wall surface A or the wall surface B, the lock (4) being used to lock the anchor cable (1), and the bottom of the lock (4) being in contact with the tray (5); The tensioning auxiliary tool is used to cooperate with the tensioner to tension and pre-tighten the two ends of the anchor cable (1); the pre-tightened anchor cable (1) is used to achieve bidirectional reinforcement support for the narrow coal pillar (7).

2. A narrow coal pillar reinforcement structure based on double-pull anchor cables as claimed in claim 1, characterized in that: At least two hoops (3) are arranged at intervals in the middle section of each anchor cable (1).

3. A narrow coal pillar reinforcement structure based on double-pull anchor cables as claimed in claim 1, characterized in that: The spacing distance between the plurality of mounting holes in the horizontal direction is 400 mm, and the spacing distance in the vertical direction is 800 mm.

4. A narrow coal pillar reinforcement structure based on double-pull anchor cables as claimed in claim 1, characterized in that: The end of each anchor cable (1) protrudes from the wall surface A or the wall surface B by at least 0.5 m.

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