Roadway protection coal pillar multi-time multi-stage reuse casing grouting device and roadway protection coal pillar multi-time multi-stage reuse casing grouting method

Abstract

The invention discloses a roadway protection coal pillar multi-time multi-stage reuse casing grouting device and method, and belongs to the field of coal mining, the roadway protection coal pillar multi-time multi-stage reuse casing grouting device comprises n grouting sections connected through flange plates, n grouting pipes, 2n-1 expansion capsules and a shell, the grouting pipes are arranged in the shell, the expansion capsules are arranged on the surface of the shell and connected with the grouting pipes through holes in the shell, and the expansion capsules are arranged in the shell. A one-way valve and an explosion valve which are connected with the grouting pipe are arranged on the inner wall surface of the shell; aiming at the circulating crack expansion characteristic of the roadway protection coal pillar and the problems of low efficiency and high cost of the current drilling and grouting technology, the device provided by the invention can be used for sequentially starting and starting the grouting pipe 1, the grouting pipe 2,..., and the grouting pipe n according to the coal wall reinforcing state after the coal wall is formed and mounted, so that the effects of single drilling and multiple grouting are realized. According to the method, expansion of multiple cracks of the coal pillar caused by mining-induced stress can be effectively coped, the hole forming utilization efficiency is improved, and the drilling construction cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a multiple-stage and multiple-reuse casing grouting device and method for protecting coal pillars in a tunnel. Background Art

[0002] The protective coal pillar in the process of coal mine mining is an important safety barrier located between the goaf and the roadway, playing a key role in supporting the roadway, isolating pressure transmission and alleviating the impact of mining stress. The stability of the protective coal pillar is directly related to the safe service life of the roadway. Therefore, maintaining its integrity is crucial to ensuring safe production in coal mines.

[0003] During the advancement of the working face, the mining disturbance suffered by the protective coal pillar is the main factor causing the coal pillar to rupture. With the continuous action of mining stress, cracks appear inside and on the surface of the coal pillar. The generation and expansion of these cracks are often accompanied by stress changes. Affected by the mining stress disturbance, these cracks will continue to cyclically expand, thereby weakening the supporting capacity of the coal pillar, causing roadway deformation, and even causing roadway collapse, equipment damage and casualties, seriously affecting the safe production of the mine.

[0004] In order to deal with the problem of crack expansion in coal pillars, traditional grouting reinforcement methods are widely used in crack repair. Common grouting techniques include one-time full-hole grouting and local grouting, both of which enhance the strength of coal pillar cracks by injecting slurry into them. However, these methods have obvious shortcomings: due to the long-term effect of mining stress, coal pillar cracks may expand multiple times, while traditional grouting methods usually only perform grouting once and cannot repair the cracks after expansion, resulting in limited effects; reducing drilling costs, improving grouting efficiency, and maintaining safe production in mines. Summary of the invention

[0005] In order to solve the problem that most of the existing coal mine underground grouting devices in the above-mentioned prior art can only achieve single grouting, and re-grouting requires re-drilling, and the utilization efficiency of single-hole single grouting is low, the present invention provides a tunnel protection coal pillar multiple and multi-stage reuse casing grouting device and method.

[0006] To realize the above technical scheme, the present invention provides a multiple and multi-stage reusable casing grouting device for protecting coal pillars in a tunnel, comprising n grouting sections connected by flanges, n grouting pipes, 2n-1 expansion capsules and an outer shell, wherein the grouting pipes are arranged inside the outer shell, the expansion capsules are arranged on the surface of the outer shell and connected to the grouting pipes through holes on the outer shell, and a one-way valve and a bursting valve connected to the grouting pipes are arranged on the inner wall surface of the outer shell; each grouting section comprises an outer shell, a grouting pipe, two expansion capsules, a plurality of eyelets arranged between the two expansion capsules, a bursting valve and two one-way valves matched with the expansion capsules; the nth grouting pipe can control the 2n-1th and 2n-2th expansion capsules; the nth grouting pipe is used for the grouting operation of the nth grouting section.

[0007] Furthermore, the grouting pipe is connected to the one-way valve and the expansion capsule through a three-way pipe, and the bursting valve arranged between each grouting section is connected to the extended grouting pipe.

[0008] Furthermore, the nth grouting pipe is connected to the 2n-1th and 2n-2th expansion capsules in a tree shape.

[0009] Furthermore, a circular hole matching the size of the grouting pipe is provided on the flange; the circular hole of the flange is connected to the grouting pipe by a connecting pipe and a quick connector; an annular groove is provided around the circular hole, and a rubber ring is provided inside the annular groove; the two flanges are connected by fixing screws.

[0010] Further, the expansion capsule is connected in series to a bursting valve matched therewith.

[0011] Furthermore, the outer shell is cylindrical.

[0012] Furthermore, a multiple-stage and multiple-reuse casing grouting method for protecting coal pillars in a tunnel is provided, which is used for a multiple-stage and multiple-reuse casing grouting device for protecting coal pillars in a tunnel, and comprises the following steps:

[0013] S1, use underground drilling equipment to drill the coal pillar to be grouted, and ensure that the diameter of the drill hole is >89mm;

[0014] S2, lowering n grouting sections, and ensuring that the end of the nth grouting section is at the bottom of the borehole, its end is closed to the circular steel pipe, and no flange is installed (13);

[0015] S3, connecting the grouting pipe to the connecting pipe (11) through the circular hole on the flange (13), placing the rubber ring (9) into the annular groove around the circular hole, and then connecting the two flanges (13) by fixing screws (8);

[0016] S4, after all the grouting sections are connected, the flange (13) on the first grouting section is tightly fitted to the housing, and the grouting drilling hole is sealed to prevent leakage of the grouting liquid;

[0017] S5, grouting. At the beginning of grouting, the expansion liquid is first injected through the first section of the grouting pipe. After the expansion capsule (4) expands, it isolates the first grouting section and the second grouting section. When the pressure reaches 1.5Mpa, the bursting valve (7) is opened and the grouting liquid is injected from the grouting pipe. The grouting liquid flowing out of the bursting hole penetrates into the fractured coal pillar along the annular eye (5). Since the expansion capsule (4) and the one-way valve (6) are connected in series, the one-way valve (6) only has one-way flow. When the grouting liquid is injected,

[0018] The expansion fluid will not flow back into the grouting pipe, and the pressure borne by the expansion capsule (4) is much greater than the grouting pressure;

[0019] S6, when the coal pillar fissure further develops into secondary fissure, tertiary fissure, ..., nth fissure, the first grouting pipe (2), the second grouting pipe (1), ..., the nth grouting pipe are activated in sequence, and grouting is continued in the corresponding grouting section according to the method of S6.

[0020] In summary, the present invention has the following beneficial effects compared with the prior art:

[0021] The present invention provides a multi-stage multiple-use casing grouting device. Through the multi-stage casing design, accurate grouting at different depths is achieved, and the grouting efficiency is improved. The three-stage multiple-use grouting strategy effectively blocks the internal cracks of the coal pillar and enhances the overall stability of the coal wall. Compared with the traditional grouting method, the present invention reduces the need for repeated drilling and reduces the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 This is a schematic diagram of the relative positions of grouting pipes at all levels on the sealing flange;

[0024] Figure 2 A schematic diagram of the internal flange connection of the multi-stage and multi-reuse casing grouting device provided by the present invention;

[0025] Figure 3 It is a schematic diagram of the grouting pipe connecting various components through a tee pipe;

[0026] Figure 4 This is a schematic structural diagram of the multi-stage and multi-reuse casing grouting device provided by the present invention.

[0027] The above drawings include the following reference numerals:

[0028] 1. Second grouting pipe; 2. First grouting pipe; 3. Third grouting pipe; 4. Expansion capsule; 401. First expansion capsule; 402. Second expansion capsule; 403. Third expansion capsule; 404. Fourth expansion capsule; 405. Fifth expansion capsule; 5. Eyelet; 6. One-way valve; 7. Burst valve; 8. Fixing screw; 9. Rubber ring; 10. Quick connector; 11. Connecting pipe; 12. Tee; 13. Flange; 131. First flange; 132. Second flange; 133. Third flange; 134. Fourth flange; 135. Fifth flange; 14. Outer shell; 15. Flange fixing one; 16. Flange fixing two. DETAILED DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] See also Figures 1 to 4 As shown, the present invention provides a multiple and multi-stage reused casing grouting device and method for tunnel protection coal pillars. Taking 2m as each grouting section as an example, it is divided into 3 sections with a total length of 6m, but it is not limited to this. As mentioned above, it can be expanded to n sections, then the total length is 2n (m), and the number of expansion capsules is 2n-1 (pieces).

[0032] The tunnel protection coal pillar multiple multi-stage reuse casing grouting device includes a circular cylinder shell 14, the outer diameter of the circular cylinder wall grouting section is designed to be 89mm, each grouting section is designed to be 2m, and the total length is 6m; an expansion capsule 4 with a length of 150mm is provided, and the expansion capsule 4 is tightly attached to the cylinder shell 14, the position of the first expansion capsule 401 is located 100mm inside the sealing flange 131, and the remaining expansion capsules 4 are 200mm away from the internal connection flange position; the grouting cylinder is divided into three sections (the first grouting section, the second grouting section, and the third grouting section), and each section is connected to the expansion capsule 4 through an opening on the cylinder to connect the internal components (the one-way valve 6, the bursting valve 7 and the internal grouting pipe 1 or 2);

[0033] The connection between the first grouting section and the second grouting section is fixed by flanges 132 and 133, and the connection between the second grouting section and the third grouting section is fixed by flanges (133 and 134). The cylindrical tail end of the third grouting section is directly closed. The grouting section in the area other than the position of the expansion capsule 4 is provided with a preset number of annular eyelets 5. The annular eyelets 5 are arranged at intervals of 200 mm, and the diameter of the eyelets 5 is 8 mm.

[0034] There are three grouting pipes 1, 2, and 3 with different lengths and independently built-in inside the cylinder. The length of the grouting pipe corresponds to the length of the corresponding grouting section. The first grouting pipe 2 of the first grouting section is used for the first grouting, the second grouting pipe 1 of the second grouting section is used for the second grouting, and the third grouting pipe 3 of the third grouting section is used for the third grouting; the first grouting pipe 2 and the second grouting pipe 1 respectively control the first expansion capsule 401, the second expansion capsule 402, the third expansion capsule 403 and the fourth expansion capsule 404, and the fifth expansion capsule 405 attached to the circular cylinder wall; the expansion capsule 4 controlled by the first grouting pipe 2 and the second grouting pipe 1 is connected in series with a bursting valve 7.

[0035] As a preferred embodiment, the grouting pipe is connected to the tee 12A side and then connected to the one-way valve 6 and the expansion capsule 4 of the cylindrical shell 14 through the tee 12B side. A bursting valve 7 is set in the middle part of each grouting section to connect with the extended grouting pipe; the first grouting section includes the first expansion capsule 401 and the second expansion capsule 402, the second grouting section includes the third expansion capsule 403 and the fourth expansion capsule 404, and the third grouting section includes the fifth expansion capsule 405; the grouting pipe 1 is connected in series with the two expansion capsules 401, 402 of the first grouting section and the third expansion capsule 403 of the second grouting section; the grouting pipe 2 is connected in series with the fourth expansion capsule of the second grouting section and the fifth expansion capsule 405 of the third grouting section; the grouting pipe 3 directly enters the grouting device of the third grouting section through the circular hole of the flange.

[0036] As a preferred embodiment, two flanges 132, 133 at the connection between the first grouting section and the second grouting section and two flanges 134, 135 at the connection between the second grouting section and the third grouting section are provided with spiral holes 8 on the outer circles of the four flanges so as to connect and fix them in pairs; a circular hole is provided in the middle of the flanges so that the grouting pipe can pass through, as shown in the schematic diagram. Figure 1 and hint Figure 2 As shown, in the middle of the two flanges where the circular hole is located, a connecting pipe 11 is used to connect the grouting pipe connected by the quick connector 10; in the middle of the two flanges where the circular hole is located, a connecting pipe 11 is used to connect the grouting pipe connected by the quick connector to ensure the airtightness and quick connection function of each section of the device during grouting.

[0037] As a preferred embodiment, the circular holes for grouting opened on each section of the connected and fixed flange 132, 133, 134, 135 are connected to the grouting pipes 1, 2, 3 using a quick connector 10, and all the circular holes opened have the same size and position; an annular groove is formed around the circular holes of the two flanges. Figure 2 As shown, a rubber ring 9 is used for sealing;

[0038] A grouting method for a multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillars, comprising the steps of:

[0039] S1, use the underground drilling equipment to drill the coal pillar to be grouting, the diameter of the drill hole should be larger than the outer diameter of the multi-stage multiple-use casing grouting device, after the drilling of the coal pillar wall is completed, put the multi-stage multiple-use casing grouting device into the coal pillar wall, and then put the multi-stage multiple-use casing grouting device into the coal pillar wall.

[0040] Pulp device;

[0041] S2, when the multi-stage multiple-use casing grouting device is lowered, the nth section is lowered first. The end of the nth section of the grouting section should be at the bottom of the borehole, and its end is closed to the circular steel pipe without installing a flange;

[0042] S3, before inserting the (n-1)th section of the grouting section, connect the connecting pipes of the (2n-1)th flange on the nth section and the (2n-2)th flange on the (n-1)th section, which have circular holes for the grouting pipe to pass through, and put the rubber ring into the annular groove around the circular hole, and connect the (2n-1)th flange on the nth section and the (2n-2)th flange on the (n-1)th section.

[0043] The flanges are fixed by tightening the screws on the two flanges. Similarly, when connecting the (n-1) grouting section and the (n-2) grouting section, first connect the connecting pipe and then put the rubber ring into the annular groove for sealing, and finally tighten it.

[0044] Screws on the flange plate; ...; complete the connection between all grouting sections;

[0045] S4, after all grouting sections are connected, the flange on the first grouting section is tightly fitted to the wall surface to seal the grouting drilling hole to prevent the grouting liquid from leaking out;

[0046] S5, when grouting is performed in the first grouting section, the first grouting pipe is connected to the first expansion capsule, the second expansion capsule, and the third expansion capsule in a tree shape, wherein each expansion capsule is connected in series with a one-way valve, and a bursting valve is connected between the first expansion capsule and the second expansion capsule; at the initial stage of grouting, the expansion liquid is first injected through the first grouting pipe, and after flowing into the expansion capsule and expanding, it plays an isolation role for the first grouting section and the second grouting section; when the pressure reaches 1.5Mpa, the bursting valve is opened, and the grouting liquid is injected from the grouting pipe, and the grouting liquid flowing out of the blasting port penetrates into the fractured coal pillar along the annular eye; since the expansion capsule and the one-way valve are connected in series, the one-way valve only has one-way inflow, and when the grouting liquid is injected, the expansion liquid will not flow back into the grouting pipe, and the pressure borne by the expansion capsule is much greater than the grouting pressure;

[0047] S6, when the coal pillar fissure further develops into secondary fissure, tertiary fissure, ..., nth fissure, the first grouting pipe, the second grouting pipe, ..., the nth grouting pipe are activated in sequence, and grouting is continued in the corresponding grouting section according to the method of S6.

[0048] During the implementation of the present invention, each grouting section is 2m long, and there are n sections in total; taking a total of 3 sections as an example, the diameter of the circular steel pipe is 89mm, and the diameters of the first, second, third, ..., and nth grouting pipes are the same. The difference is that the length of the grouting pipe corresponding to each grouting section is different, and the length increases with the increase in the number of grouting sections.

[0049] The length of the connecting pipe between the two grouting sections should be less than the gap distance after the flange screws are tightened, and the annular groove around the circular hole on the flange should be designed according to the annular diameter of the rubber ring to ensure that it can play the role of sealing the connecting pipe device.

[0050] The pressure bearing capacity of the expansion capsule should be much greater than the bursting pressure of the bursting valve 1.5Mpa, so that the expansion capsule will not burst after being filled with grouting liquid during grouting, preventing blockage of other grouting sections.

[0051] The present invention realizes precise grouting at different depths and improves grouting efficiency. The three-time multiplex grouting strategy effectively blocks the internal cracks of the coal pillar and enhances the overall stability of the coal wall. Compared with the traditional grouting method, the present invention reduces the need for repeated drilling and reduces construction costs.

[0052] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0053] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0054] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar, characterized in that: The invention comprises n grouting sections connected by flanges (13), n grouting pipes, 2n-1 expansion capsules (4) and a shell (14), wherein the grouting pipes are arranged inside the shell (14), the expansion capsules (4) are arranged on the surface of the shell (14) and connected to the grouting pipes through holes on the shell (14), and a one-way valve (6) and a bursting valve (7) connected to the grouting pipes are arranged on the inner wall surface of the shell (14); each grouting section comprises a shell (14), a grouting pipe, two expansion capsules (4), a plurality of eyelets (5) arranged between the two expansion capsules (4), a bursting valve (7) and two one-way valves (6) matched with the expansion capsules (4); the nth grouting pipe can control the 2n-1th and 2n-2th expansion capsules (4); the nth grouting pipe is used for the grouting operation of the nth grouting section.

2. The multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar according to claim 1 is characterized in that: The grouting pipe is connected to the one-way valve (6) and the expansion capsule (4) via a three-way pipe (12), and the bursting valve (7) provided between each grouting section is connected to the extended grouting pipe.

3. The multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar according to claim 1 is characterized in that: The nth grouting pipe is connected to the 2n-1th and 2n-2th expansion capsules (4) in a tree shape.

4. The multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar according to claim 1 is characterized in that: The flange (13) is provided with a circular hole matching the size of the grouting pipe; the circular hole of the flange (13) is connected to the grouting pipe via a connecting pipe (11) and a quick connector (10); an annular groove is provided around the circular hole, and a rubber ring (9) is provided inside the annular groove; the two flanges (13) are connected via fixing screws (8).

5. The multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar according to claim 1 is characterized in that: The expansion capsule (4) is connected in series to the bursting valve (7) matched therewith.

6. The multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar according to claim 1 is characterized in that: The housing (14) is cylindrical.

7. A method for multiple and multi-stage multiple-use casing grouting of a tunnel protection coal pillar, which is used for the multiple and multi-stage multiple-use casing grouting device for tunnel protection coal pillar as claimed in any one of claims 1 to 6, characterized in that: Includes steps: S1, use underground drilling equipment to drill the coal pillar to be grouted, and ensure that the diameter of the drill hole is >89mm; S2, lowering n grouting sections, and ensuring that the end of the nth grouting section is at the bottom of the borehole, its end is closed to the circular steel pipe, and no flange (13) is installed; S3, connecting the grouting pipe to the connecting pipe (11) through the circular hole on the flange (13), placing the rubber ring (9) into the annular groove around the circular hole, and then connecting the two flanges (13) by fixing screws (8); S4, after all the grouting sections are connected, the flange (13) on the first grouting section is tightly fitted to the housing (14), and the grouting drilling hole is sealed to prevent leakage of the grouting liquid; S5, grouting. At the beginning of grouting, the expansion liquid is first injected through the first section of the grouting pipe. After the expansion liquid flows into the expansion capsule (4) and expands, it isolates the first grouting section and the second grouting section. When the pressure reaches 1.5Mpa, the bursting valve (7) is opened and the grouting liquid starts to be injected from the grouting pipe. The grouting liquid flowing out of the bursting hole penetrates into the fractured coal pillar along the annular eye (5). Since the expansion capsule (4) and the one-way valve (6) are connected in series, the one-way valve (6) only has one-way flow. When the grouting liquid is injected, the expansion liquid will not flow back into the grouting pipe. The pressure on the expansion capsule (4) is much greater than the grouting pressure. S6, when the coal pillar fissure further develops into secondary fissure, tertiary fissure, ..., nth fissure, the first grouting pipe (2), the second grouting pipe (1), ..., the nth grouting pipe are activated in sequence, and grouting is continued in the corresponding grouting section according to the method of S6.

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