Pre-grouting reinforcement method suitable for surrounding rock of fully-mechanized face support removing channel

Abstract

The invention discloses a surrounding rock pre-grouting reinforcement method suitable for a fully mechanized face support removing channel, and belongs to the technical field of surrounding rock stability control. Grouting holes are formed in a working face through a working face haulage roadway and an air return roadway, and the grouting holes in each side are divided into shallow holes, medium-length holes and deep holes; superfine cement grout is injected into the working face through the shallow holes, the medium-deep holes and the deep holes, and full permeation of the coal and rock mass is achieved; the shallow holes, the deep holes and the medium-length holes are drilled in a crossed mode and grouted; after grouting is completed, a corresponding reinforcing structure is formed, and after the coal mining support reaches a mining stopping line and forms a support removing channel, the coal wall and the top plate are both pre-reinforced coal and rock masses; on the basis of pre-grouting reinforcement, proper anchor rods and anchor cables are arranged on the coal wall and the top plate of the support removing channel. According to the method, through advanced pre-grouting, the coal and rock mass in the frame removing channel area is reinforced in advance, the strength and bearing capacity of the coal and rock mass in the stopping line area are improved, and safety guarantee is provided for follow-up safe frame removing.

Description

Technical Field

[0001] The invention belongs to the technical field of surrounding rock stability control, and in particular relates to a surrounding rock pre-grouting reinforcement method suitable for a fully mechanized mining face support withdrawal channel. Background Art

[0002] In the production of coal mining working faces, the handover of working faces is an inevitable part and a key step for the mine to achieve safe and efficient production. The length of time for the equipment to be withdrawn from the working face restricts the production efficiency of the mine to a certain extent. The technology of withdrawing the channel without pre-excavation has problems such as unstable space for withdrawing the frame, easy collapse of the working face roof, and easy spalling of the coal wall. Especially in the environment of broken surrounding rock, the safety of moving and reversing the equipment using this technology does not meet the standards, and safety accidents are very likely to occur.

[0003] In engineering practice, the research on the stability control of the surrounding rock of the withdrawal channel without pre-excavation is still incomplete, and the production safety during the withdrawal of the support cannot be guaranteed by relying solely on traditional simple support. Therefore, targeted control measures need to be taken to effectively solve the problem of the stability control of the surrounding rock of the withdrawal channel without pre-excavation and ensure the basic stability of the surrounding rock in the area of ​​the stop mining line. Summary of the invention

[0004] In view of this, the present invention provides a method for pre-grouting reinforcement of surrounding rocks of a fully mechanized mining face support withdrawal channel, which is used to solve the above-mentioned problem.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A method for pre-grouting reinforcement of surrounding rock in a fully mechanized mining face support withdrawal channel, comprising:

[0007] a: Grouting holes are arranged from the transport tunnel and return air tunnel of the working face into the working face. The grouting holes on each side are divided into shallow holes, medium-deep holes and deep holes. The reinforcement range of shallow holes is 1 / 7 to 1 / 5 of the width of the working face, the reinforcement range of medium-deep holes is 1 / 4 to 1 / 2 of the width of the working face, and the reinforcement range of deep holes is 2 / 5 to 3 / 5 of the width of the working face;

[0008] b: Inject ultrafine cement slurry into the working face through shallow holes, medium-deep holes and deep holes to achieve full penetration into the coal and rock mass;

[0009] c: After the grouting is completed, the corresponding pre-grouting reinforcement structure is formed. After the coal mining support reaches the stop line and forms a support withdrawal channel, the coal wall and the roof are both pre-reinforced coal rock mass;

[0010] d: On the basis of pre-grouting reinforcement, appropriate anchor rods and cables are arranged on the coal wall and roof of the channel for removing the support frame to further ensure the stability of the channel surrounding rock during the process of removing the support frame.

[0011] Furthermore, in a, adjust the angles of shallow holes, medium-deep holes and deep holes to ensure that the final hole position falls 2.5m to 3.0m above the mining height of the working face, so as to ensure the reinforcement effect on the subsequent formation of the roof of the withdrawal channel.

[0012] Furthermore, in a, the grouting holes of the shallow holes, medium-deep holes and deep holes are arranged in a plum blossom shape, the shallow holes and the deep holes are on the same vertical line, and the medium-deep holes are located between the two rows of shallow holes and deep holes.

[0013] Furthermore, the order of grouting and drilling in a and b is: shallow hole drilling, shallow hole grouting, deep hole drilling, deep hole grouting, medium-deep hole drilling, medium-deep hole grouting.

[0014] Furthermore, in b, the water-cement ratio of the ultrafine cement slurry is controlled at 0.8-1.0, and the grouting pressure is adjusted according to the reinforcement depth of shallow holes, medium-deep holes and deep holes. The grouting pressure of shallow holes is controlled at 5-8 MPa, the grouting pressure of medium-deep holes is controlled at 8-10 MPa, and the grouting pressure of deep holes is controlled at 10-12 MPa.

[0015] The beneficial effects of the present invention are:

[0016] The present invention reinforces the surrounding rock of the stop mining line area by grouting in the transport tunnels and return air tunnels on both sides of the working face. On the one hand, it can fill and repair the broken coal rock mass under the influence of advanced stress, improve the integrity and bearing capacity of the coal rock mass, and basically meet the needs of the withdrawal channel layout; on the other hand, due to the pre-reinforcement of the coal rock mass, it can create conditions for the subsequent support work of the withdrawal channel and reduce the support cost. The present invention has a good effect on the stability control of the surrounding rock of the withdrawal channel under conditions such as severe mining and soft coal seam mining, and is simple to operate and reasonably designed, with extremely high promotion and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 It is a grouting reinforcement cross-sectional view of "a method for pre-grouting reinforcement of surrounding rock of a support withdrawal channel of a fully mechanized mining face" of the present invention.

[0019] Figure 2 It is a plan view of the grouting hole of the present invention "a method for pre-grouting reinforcement of surrounding rock of the support withdrawal channel suitable for comprehensive mining face".

[0020] Figure 3It is a top view of grouting reinforcement of "a method for pre-grouting reinforcement of surrounding rock of a support withdrawal channel of a fully mechanized mining face" of the present invention.

[0021] Figure 4 This is a pre-grouting reinforcement effect diagram of the present invention "a method for pre-grouting reinforcement of surrounding rocks of a fully mechanized mining face support withdrawal channel".

[0022] Figure 5 This is a diagram showing the effect of the support withdrawal channel being formed in the present invention, "a method for pre-grouting reinforcement of surrounding rocks of the support withdrawal channel applicable to comprehensive mining face".

[0023] Among them, in the figure:

[0024] 1- transport tunnel; 2- return air tunnel; 3- shallow hole grouting hole; 4- medium and deep hole grouting hole; 5- deep hole grouting hole; 6- coal seam roof; 7- mining coal seam; 8- coal seam floor; 9- pre-grouting reinforcement structure; 10- stop mining line; 11- coal mining support; 12- support withdrawal channel; 13- anchor rod; 14- anchor cable. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0026] See attached Figure 1-5 As shown, the present invention provides a method for pre-grouting reinforcement of surrounding rocks of a fully mechanized mining face support withdrawal channel, comprising:

[0027] a: Grouting holes are arranged in the working face from the working face transport tunnel 1 and the return air tunnel 2. The grouting holes on each side are divided into shallow holes 3, medium-deep holes 4, and deep holes 5. The reinforcement range of shallow holes 3 is 1 / 7 to 1 / 5 of the working face width, and the preferred value is 1 / 6 of the working face width; the reinforcement range of medium-deep holes 4 is 1 / 4 to 1 / 2 of the working face width, and the preferred value is 1 / 3 of the working face width; the reinforcement range of deep holes 5 is 2 / 5 to 3 / 5 of the working face width, and the preferred value is 1 / 2 of the working face width; adjust the angles of shallow holes 3, medium-deep holes 4, and deep holes 5 to ensure that the final hole position falls 2.5m to 3.0m above the mining height of the working face, so as to ensure the reinforcement effect on the subsequent formation of the roof of the withdrawal channel;

[0028] b: Inject ultrafine cement slurry into the working face through shallow hole 3, medium-deep hole 4, and deep hole 5 to achieve full penetration into the coal and rock mass;

[0029] c: After the grouting is completed, a corresponding pre-grouting reinforcement structure 9 is formed between the coal seam roof 6, the mined coal seam 7 and the coal seam floor 8, such as Figure 1; After the coal mining support 11 reaches the stop mining line 10 and forms the support withdrawal channel 12, the coal wall and the roof are both pre-reinforced coal rock mass;

[0030] d: On the basis of pre-grouting reinforcement, appropriate anchor rods 13 and anchor cables 14 are arranged on the coal wall and roof of the support removal channel 12 to further ensure the stability of the channel surrounding rock during the support removal process, such as Figure 5 .

[0031] The grouting holes of the shallow hole 3, the medium-depth hole 4 and the deep hole 5 are arranged in a plum blossom shape, such as Figure 2 ; The shallow holes 3 and the deep holes 5 are in the same vertical line, and the medium-deep holes 4 are located between the two rows of shallow holes 3 and deep holes 5, such as Figure 3 ; The order of grouting and drilling is: shallow hole drilling, shallow hole grouting, deep hole drilling, deep hole grouting, medium-deep hole drilling, medium-deep hole grouting; the main purpose of this arrangement is to test and supplement the effect of the previous group of grouting by drilling and grouting after replacing the grouting holes; at the same time, grouting the shallow holes first to achieve reinforcement of the shallow surrounding rock, so as to apply greater grouting pressure to the medium-deep holes and deep holes.

[0032] The water-cement ratio of the ultrafine cement slurry is controlled at 0.8-1.0. The grouting pressure is adjusted according to the reinforcement depth of the shallow hole 3, the medium-deep hole 4, and the deep hole 5. The grouting pressure of the shallow hole 3 is controlled at 5-8MPa, the grouting pressure of the medium-deep hole 4 is controlled at 8-10MPa, and the grouting pressure of the deep hole 5 is controlled at 10-12MPa.

[0033] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0034] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for pre-grouting reinforcement of surrounding rock in fully mechanized mining face support removal channel, characterized in that: include: a: Grouting holes are arranged inside the working face from the working face transport tunnel (1) and the return air tunnel (2). The grouting holes on each side are divided into shallow holes (3), medium-deep holes (4), and deep holes (5). The reinforcement range of the shallow holes (3) is 1 / 7 to 1 / 5 of the width of the working face, the reinforcement range of the medium-deep holes (4) is 1 / 4 to 1 / 2 of the width of the working face, and the reinforcement range of the deep holes (5) is 2 / 5 to 3 / 5 of the width of the working face; b: injecting ultrafine cement slurry into the working face through shallow holes (3), medium-deep holes (4), and deep holes (5) to achieve full penetration into the coal and rock mass; c: After the grouting is completed, the corresponding pre-grouting reinforcement structure (9) is formed, and after the coal mining support (11) reaches the stop mining line (10) and forms a support withdrawal channel (12), the coal wall and the roof are both pre-reinforced coal rock mass; d: On the basis of pre-grouting reinforcement, appropriate anchor rods (13) and anchor cables (14) are arranged on the coal wall and roof of the support removal channel (12) to further ensure the stability of the channel surrounding rock during the support removal process.

2. The method for pre-grouting reinforcement of surrounding rock in the fully mechanized mining face support removal channel according to claim 1, characterized in that: In a, the angles of the shallow hole (3), the medium-deep hole (4), and the deep hole (5) are adjusted to ensure that the final hole position falls 2.5m to 3.0m above the mining height of the working face, so as to ensure the reinforcement effect on the top plate of the subsequent channel for removing the support.

3. The method for pre-grouting reinforcement of surrounding rock in the fully mechanized mining face support removal passage according to claim 1 is characterized in that: In a, the grouting holes of the shallow holes (3), the medium-depth holes (4) and the deep holes (5) are arranged in a plum blossom shape, the shallow holes (3) and the deep holes (5) are on the same vertical line, and the medium-depth holes (4) are located between two rows of shallow holes (3) and deep holes (5).

4. The method for pre-grouting reinforcement of surrounding rock in the fully mechanized mining face support removal passage according to claim 1 is characterized in that: The order of grouting and drilling in a and b is: shallow hole drilling, shallow hole grouting, deep hole drilling, deep hole grouting, medium-deep hole drilling, medium-deep hole grouting.

5. The method for pre-grouting reinforcement of surrounding rock in the channel for removing support from a fully mechanized mining face according to claim 1 is characterized in that: In b, the water-cement ratio of the ultrafine cement slurry is controlled at 0.8-1.0, and the grouting pressure is adjusted according to the reinforcement depth of the shallow hole (3), the medium-deep hole (4), and the deep hole (5). The grouting pressure of the shallow hole (3) is controlled at 5-8 MPa, the grouting pressure of the medium-deep hole (4) is controlled at 8-10 MPa, and the grouting pressure of the deep hole (5) is controlled at 10-12 MPa.

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