CN109681248B - A kind of advance support method of grouting anchor cable - Google Patents

Abstract

The invention relates to a grouting anchor cable advance support method, belongs to the advance support field, and solves the problems of insufficient support strength, slow support speed, broken roof and high labor intensity of workers caused by repeated support in the prior art. The advance support method of the present invention comprises the following steps: step 1, determining the mining roadway (1) to be supported in the current mining working face (3); step 2, according to the advance support pressure distribution law of the mining roadway (1) and the engineering According to the geological conditions, determine the advance support distance L; step 3, install grouting anchor cable advance support on the roof of the mining roadway (1) to form a roof support structure; during coal mining, the mining face (3) moves forward At the same time, the advance support of the grouting anchor cable is continuously added along the advancing direction, so that the advance support distance is maintained within a safe range. The advanced support method of the grouting anchor cable of the invention improves the support strength and support efficiency and reduces the manual labor intensity while ensuring safe mining.

Description

A kind of advance support method of grouting anchor cable

technical field

The invention relates to the technical field of advance support, in particular to a method for advance support of grouting anchor cables.

Background technique

The stability of the surrounding rock of the roadway has an important impact on the safe production of the mine. The instability of the surrounding rock of the roadway causes a large number of casualties and property losses. Therefore, strengthening the control of the surrounding rock of the roadway is of great significance to the safe production of the mine. The main purpose of the roadway advanced support is to prevent the deformation, movement and damage of the surrounding rock of the roadway due to the superposition of the advanced support pressure and the support pressure along the inclined direction in the working face. At this stage, the use of comprehensive mechanized equipment for coal resource mining will cause a lot of pressure. If active and effective support methods cannot be adopted, it will have a certain impact on the mining efficiency of the fully mechanized mining face, and may also bring about Certain safety risks will bury certain safety hazards for the follow-up coal mining work.

The traditional advanced support method is a single hydraulic prop combined with a π-shaped steel (large slab) shed to support the advance support, which has certain limitations in the use process. When the coal seam pressure is high, the traditional advanced support cannot reach the required strength, and the roof at the exit of the fully mechanized mining face is very likely to sink. It is more difficult to deal with, especially in the area with intensive roof cutting at the rear of the fully mechanized mining face, there is a greater possibility of potential safety hazards; 2) The support speed is slow, the traditional advanced support produces a slow support effect, and the pillar returns. The speed of retraction is also slow, which will affect the overall advancement speed of the working face and reduce the efficiency and output of coal mining; 3) The labor intensity is high, and in the process of traditional advanced support, frequent support and retraction are required. Greatly increased labor intensity. In addition, the advance support hydraulic support has the following defects: 1) The roof will be repeatedly supported in the process of moving the frame, causing the roof to be broken, which is not conducive to the safe management and maintenance of the roof, and poses a threat to the life and equipment of underground tunnel workers; 2 ) When moving forward, there will be severe sliding friction between the roof and the roof beam, causing certain damage to the roadway roof, affecting its life, reducing the stability and reliability of its work, and threatening the safety of workers; 3) When installing, maintaining and dismantling such a bracket, the labor intensity of the staff is very high.

SUMMARY OF THE INVENTION

In view of the above analysis, the present invention aims to provide a method for advance support of grouting anchor cables, which is used to solve the problem of insufficient support strength of advance support in the prior art, slow support speed, and roof broken due to repeated support, which affects the strength of the roof. And the problem of high labor intensity of workers.

The object of the present invention is mainly achieved through the following technical solutions:

A grouting anchor cable advance support method, comprising the following steps: step 1, determining a mining roadway to be supported in a current mining face; step 2, determining the advance support pressure distribution law of the mining roadway and engineering geological conditions. Support distance L; Step 3, add grouting anchor cable advance support to the roof of the mining roadway to form a roof support structure; during coal mining, while the mining face is pushed forward, grouting anchors are continuously added along the advancing direction Cable advance support, so that the advance support distance L is maintained within a safe range.

Further, in step 3, the step of adding grouting anchor cable advance support includes: S1. Drilling an anchor cable hole on the roof of the mining roadway; S2. Sending the grouting anchor cable into the anchor cable hole, waiting for the grouting anchor cable After feeding to the bottom of the anchor cable hole, install the grouting plug, tray and anchor in sequence; S3. Grouting the grouting anchor cable through the grouting pipe, the slurry is injected along the grouting pipe, and flows into the grouting from the grouting outlet Anchoring section; S4. After the grouting and anchoring section is grouted and completely solidified, the grouting anchor cable is tensioned and pre-tightened by the anchor.

Further, the advance support distance L is,

L=L ₁ +L ₂ ,

In the formula, L is the advance support distance, m; L ₁ is the shortest safe support distance, m; L ₂ is the insurance support distance, m.

Further, during coal mining, when the mining working face advances forward, the effective support distance L ₃ of the advanced support is greater than or equal to the shortest safe support distance L ₁ .

Further, the roof support structure is a combined arch structure, and the combined arch structure includes steel mesh, steel strips, anchor rods and grouting anchor cables; the combined arch structure is divided into an anchor mesh combined arch area, an anchor rod compression area from the roof to the surrounding rock in turn. Combined arch area and slurry diffusion reinforcement arch area.

Further, the reinforced mesh is close to the roof of the roadway, and the steel strip is arranged on the outside of the reinforced mesh.

Further, the number of anchor rods is multiple, the grouting anchor cables and the anchor rods are alternately arranged, and at least one row of grouting anchor cables is arranged between two adjacent rows of anchor rods.

Further, the number of each row of grouting anchor cables is at least three.

Further, the anchor rod vertically passes through the steel belt and the steel mesh, and the anchoring end is connected to the roof of the roadway.

Further, the grouting anchor cable is inserted into the anchor cable hole, and the anchoring end is connected to the stable rock formation on the upper part of the roof of the roadway.

Further, the grouting anchor cable includes: a wire plug, an anchor, an external grouting stopper, a steel strand, a grouting pipe and a grouting outlet.

Compared with the prior art, the present invention has at least one of the following beneficial effects:

a) The grouting anchor cable advance support method provided by the present invention adopts the grouting anchor cable advance support, which significantly improves the support speed and overcomes the defect that the roof is broken due to repeated support and thus affects the strength of the roof. The advancement of the coal mining face 3 is carried out synchronously, and it is only necessary to supplement the support in front of the existing advanced support distance range. Reduce the labor intensity of workers.

b) The grouting anchor cable advanced support method provided by the present invention adopts the grouting anchor cable and the anchor net support to form a multi-layer effective composite arch structure with increased thickness, that is, the anchor net composite arch area, the anchor rod Combining the arch area in the compression area and the slurry diffusion reinforcement arch area avoids damage to the roadway roof and effectively maintains the overall stability of the roadway, thereby expanding the effective bearing range of the support structure, and improving the bearing capacity and support strength of the support structure. Improve the safety of the mining face.

In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Additional features and advantages of the invention will be set forth in the description which follows, and some of the advantages may become apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the things particularly pointed out in the description, claims and drawings.

Description of drawings

The drawings are for the purpose of illustrating specific embodiments only and are not to be considered limiting of the invention, and like reference numerals refer to like parts throughout the drawings.

Fig. 1 is the schematic diagram of the mining face in the implementation of the present invention;

Figure 2 is a schematic diagram of the grouting anchor cable structure;

Fig. 3 is the plan view of mining roadway support in the implementation of the present invention;

Figure 4 is a sectional view of the advance support of the grouting anchor cable in the mining roadway.

Reference number:

1- mining roadway; 2- coal and rock mass; 3- mining face; 4- goaf; 5- bolt; 6- grouting anchor cable; 7- steel belt; 8- pallet; 9- wire plug; 10 -Anchor; 11-External grouting stopper; 12-Steel strand; 13-Grouting pipe; 14-Grout outlet.

Detailed ways

The preferred embodiments of the present invention are specifically described below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present application, and together with the embodiments of the present invention, are used to explain the principles of the present invention, but are not used to limit the scope of the present invention.

A specific embodiment of the present invention discloses a grouting anchor cable advance support method, comprising the following steps:

Step 1: Determine the mining roadway 1 to be supported in the current mining face 3 . The determination of the mining roadway 1 is based on the geological conditions and engineering production conditions, and the mining roadway 1 that meets the above conditions is selected for advanced support.

Step 2, select a single or multiple mining roadways 1; determine the advance support distance L according to the advance support pressure distribution law of the mining roadway 1 and the engineering geological conditions.

Step 3: On the basis of the original permanent support, add grouting anchor cable advance support to the roof of the mining roadway 1 to form a roof support structure. During coal mining, while the working face 3 is pushed forward, the advance support of the grouting anchor cable 6 is continuously installed along the advancing direction, so that the advance support distance is maintained within a safe range.

In this embodiment, since the mining roadway has been dug in advance before coal mining, permanent support (anchor mesh support) is carried out during the excavation, and step 3 is carried out on the basis of the original permanent support. Specifically, while the coal mining face is being mined, along the advancing direction on the roof of the mining roadway 1, every other row of anchor rods 5 is constructed with anchor cable holes. While constructing the anchor cable hole, install the grouting anchor cable 6 and the tray 8 in the anchor cable hole; after the grouting anchor cable 6 is sealed, the high pressure pump is used to grouting the cracks of the roof to enrich the gaps and holes of the broken roof. The roof of the mining roadway is cemented into a whole, and the specific steps of adding grouting anchor cable for advance support are as follows:

S1. Drill anchor cable holes on the roof of mining tunnel 1;

S2. Send the grouting anchor cable 6 into the anchor cable hole. After the grouting anchor cable 6 is sent to the bottom of the anchor cable hole, install the external grouting stopper 11, the tray 8 and the anchor 10 in sequence;

S3. The grouting anchor cable 6 is grouted through the grouting pipe 13, the slurry is injected along the grouting pipe 13, and flows into the grouting anchor section from the grouting outlet 14; after the grouting is completed, the grouting pipe is blocked with a wire plug 9 13. Prevent the outflow of slurry.

S4. After the grouting of the grouting anchoring section is completed and completely solidified, the grouting anchor cable 6 is tensioned and pre-tightened by the anchor 10 .

Fig. 1 shows the positional relationship among the goaf 4, the mining face 3, the coal and rock mass 2 and the mining roadway 1. While the coal mining operation is carried out on the mining face 3, the coal and rock mass in front of the mining face 3 is monitored. 2. The roof of the mining roadway 1 within the range of the support distance that requires advanced support on both sides shall be supported by grouting anchor cables in advance. As the mining face 3 moves forward in the mining direction of the coal and rock mass 2, the advance support range of the mining roadway 1 is simultaneously moved forward along the mining direction, and the advance support distance in front of the mining face 3 is always maintained. remain within a safe range.

In this embodiment, the effective support distance L ₃ of the advance support refers to the support distance to ensure the safety of coal mining during the coal mining process; the shortest safe support distance L ₁ refers to the shortest effective support distance to ensure the safety of coal mining; The insurance support distance L ₂ refers to the artificially set distance L 3 to ensure that the effective support distance L ₃ of the advance support is always greater than or equal to the shortest safe support distance L ₁ in order to carry out advanced support while the mining face 3 is advancing forward. The support distance, the insurance support distance L ₂ is related to the advancing speed of the working face, the support speed and the grouting solidification time; the advanced support distance L is equal to the sum of the shortest safe support distance L ₁ and the insurance support distance L ₂ , That is, L=L ₁ +L ₂ , where L is the advance support distance, m; L ₁ is the shortest safe support distance, m; L ₂ is the insurance support distance, m.

In order to improve the support strength of the advance support and ensure the support effect, the roof support structure constructed by the grouting anchor cable advance support method of the present invention is a combined arch structure, and the combined arch structure includes a steel mesh, a steel strip 7, and an anchor rod 5. With the grouting anchor cable 6, the combined arch structure is divided into the anchor mesh combined arch area, the bolt compression area combined arch area and the grout diffusion reinforcement arch area in turn from the roof to the surrounding rock. The use of grouting anchor cable and anchor net support can form a multi-layer effective composite arch structure with increased thickness, that is, the anchor net composite arch area, the bolt compression area composite arch area and the grout diffusion reinforcement arch area, thereby expanding the The effective bearing range of the supporting structure improves the integrity and bearing capacity of the supporting structure. The reinforced mesh is close to the roof of the roadway, and the steel belt 7 is arranged on the outside of the reinforced mesh. The grouting anchor cable plays the multiple functions of the anchor cable in extrusion reinforcement, multi-layer composite arch structure and grouting, which improves the strength of the rock mass. The roof is reinforced twice, and the surrounding rock itself and as a part of the supporting structure form a whole with the original rock, so that the mining roadway is stable and not easy to be damaged.

In a preferred implementation of this embodiment, the number of anchor rods 5 is multiple, the grouting anchor cables 6 and the anchor rods 5 are alternately arranged, and at least one row of grouting anchor cables 6 is arranged between two adjacent rows of anchor rods 5, The number and spacing of each row of bolts 5 are determined according to the actual geological conditions, to ensure that the bolts 5 are evenly stressed, thereby ensuring the support strength of the roof, and improving the stability and safety of the support.

In order to further ensure the support strength, the grouting anchor cables 6 and the anchor rods 5 are arranged alternately, and one or more rows of grouting anchor cables 6 are arranged between two adjacent rows of anchor rods 5. The number of grouting anchor cables 6 in each row At least three, the number of grouting anchor cables 6 is determined according to the strength of the required advanced support and engineering geological conditions. As shown in Figure 4, the anchor rod 5 vertically passes through the steel strip 7 and the steel mesh, and the anchorage end of the anchor rod 5 Connected to the roadway roof. The grouting anchor cable 6 passes through the steel mesh and penetrates into the anchor cable hole; the anchoring end of the grouting anchor cable 6 is connected to the stable rock formation on the upper part of the roadway roof. Both the anchor rod 5 and the outer anchoring section of the grouting anchor cable 6 are provided with a tray 8 , as shown in FIGS. 3 and 4 . After the grouting anchor cable 6 is sealed, the high pressure pump is used to grouting the cracks of the roof. After the grouting is completed, the grouting pipe 13 is blocked with a wire plug 9 to prevent the outflow of the slurry, and the gaps and holes of the broken roof are filled and recovered. The roof of the roadway 1 is cemented into a whole. The use of grouting anchor cable and anchor net support can form a multi-layer effective composite arch structure with increased thickness, that is, the anchor net composite arch area, the bolt compression area composite arch area and the grout diffusion reinforcement arch area, thereby expanding the The effective bearing range of the supporting structure improves the integrity and bearing capacity of the supporting structure.

As shown in FIG. 2 , the structure of the grouting anchor cable 6 provided by the embodiment of the present invention includes a wire plug 9 , an anchor 10 , an external grouting stopper 11 , a steel strand 12 , a grouting pipe 13 , and a grouting outlet 14 . . The grouting anchor cable 6 can be sequentially divided into an outer anchoring section, a grouting anchoring section and a resin anchoring section. The outside of the grouting anchor cable 6 is a steel strand 12 , a grouting pipe 13 is arranged in the grouting anchor cable, and a grouting outlet 14 is arranged in the rear part of the grouting pipe. The surrounding rock is grouted through the grouting pipe 13, and the slurry flows out from the grouting outlet 14, filling the gaps and holes of the broken roof, and cementing the roof of the mining roadway into a whole. After grouting, the vertical load acting on the top plate can be effectively transmitted to the two sides, and the load can be transmitted to the bottom plate through the reinforcement of the opposite sides. The defect of degree, the bottom plate is more stable, and the occurrence of the bottom sagging phenomenon is reduced. In addition, the stability of the bottom plate contributes to the stability of the two gangs, and the stability of the bottom plate and the two gangs can also maintain the stability of the top plate. The advanced support method provided in this embodiment has obvious effects on the control, support and maintenance of the surrounding rock of the roadway disturbed by mining in the crack development zone and the roof broken zone.

In this embodiment, the grouting anchor cable 6 is sealed and fixed to the grouting port on the coal rock wall through an external grouting stopper 11, and the grouting anchor cable 6 is sequentially provided with an anchor 10, a tray 8, and the tray 8 is pressed The large end of the external grouting plug 11 is pre-tightened by the anchoring device 10 at the same time, which improves the bearing capacity and supporting effect of the anchor cable.

Compared with the prior art, the advanced support method of grouting anchor cable in this embodiment innovatively proposes a method of using grouting anchor cable for advanced support, and the advance support and the advancement of coal mining working face 3. Simultaneously, it is only necessary to supplement the support in front of the existing advanced support distance range, which is convenient to operate, improves the work efficiency of advanced support and reduces the labor intensity of workers while ensuring safe mining.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Substitutions should be covered within the protection scope of the present invention.

Claims (7)

1. A method for advanced support of a grouting anchor cable is characterized by comprising the following steps:

step one, determining a mining roadway (1) to be supported on a current mining working face (3);

determining a forepoling distance L according to a forepoling pressure distribution rule of the stoping roadway (1) and engineering geological conditions;

thirdly, a grouting anchor cable advance support is additionally arranged on a top plate of the stoping roadway (1) to form a top plate support structure;

during coal mining, the stope face (3) is propelled forwards, and meanwhile, a grouting anchor cable advance support is continuously additionally arranged along the propelling direction, so that the advance support distance L is maintained within a safety range;

in the third step, the step of additionally installing the grouting anchor cable advance support comprises the following steps:

s1, drilling an anchor cable hole on a top plate of the stoping roadway (1);

s2, feeding the grouting anchor cable (6) into the anchor cable hole, and sequentially installing a grout stop plug (11), a tray (8) and an anchorage device (10) after the grouting anchor cable (6) is fed to the bottom of the anchor cable hole;

s3, grouting the grouting anchor cable (6) through the grouting pipe (13), injecting slurry along the grouting pipe (13), and enabling the slurry to flow into a grouting anchoring section from a slurry outlet (14); after the grouting anchor cable (6) is used for sealing holes, a high-pressure pump is used for grouting cracks of the top plate, and the cracks and hole bodies of the broken top plate are filled;

s4, after grouting of the grouting anchoring section is completed and the grouting anchoring section is completely solidified, tensioning and pre-tightening the grouting anchor cable (6) through an anchorage device (10);

the roof supporting structure is a combined arch structure, and the combined arch structure comprises a steel bar mesh, a steel belt (7), an anchor rod (5) and a grouting anchor cable (6);

the combined arch structure is sequentially divided into an anchor net combined arch area, an anchor rod compression combined arch area and a slurry diffusion reinforcing arch area from a top plate to surrounding rocks;

the number of the anchor rods (5) is multiple, the grouting anchor cables (6) and the anchor rods (5) are alternately arranged, and at least one row of grouting anchor cables (6) is arranged between every two adjacent rows of anchor rods (5).

2. The method for the advance support of grouting anchor cables as claimed in claim 1, wherein the advance support distance L is,

L＝L₁+L₂，

in the formula, L is an advance support distance m; l is₁The shortest safe supporting distance, m; l is₂And m is the safety support distance.

3. The method for advance support of grouting anchor cables as claimed in claim 2, wherein the reinforcing mesh is tightly attached to the top plate of the roadway, and the steel band (7) is arranged on the outer side of the reinforcing mesh.

4. A method for the forepoling of grouting anchor cables according to claim 1, characterised in that the number of grouting anchor cables (6) per row is at least three.

5. The method for the advance support of grouting anchor cables as claimed in claim 4, wherein the anchor rods (5) vertically penetrate through the steel strips (7) and the reinforcing mesh, and the anchoring ends are connected into the top plate of the roadway.

6. The method for the advance support of grouting anchor cables as claimed in claim 5, characterized in that the grouting anchor cables (6) are passed into the anchor cable holes, and the anchoring ends are connected to the stable rock layer on the top of the roadway.

7. A method for pre-support of a grouted cable bolt according to any one of claims 1 to 6, characterised in that said grouted cable bolt (6) comprises: the device comprises a plug (9), an anchorage device (10), an external grout stop plug (11), a steel twisted wire (12), a grouting pipe (13) and a grout outlet (14).

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