Sectional controllable level grouting device and method for surrounding rock of coal mine tunnel

Abstract

The application relates to the technical field of grouting equipment, in particular to a coal mine roadway surrounding rock segmented controllable hierarchical grouting device and a grouting method. The coal mine roadway surrounding rock segmented controllable hierarchical grouting device comprises a sleeve, a grouting assembly, a grouting pipe and a guide rail, the sleeve has an inner cavity, a plurality of grouting holes are arranged at intervals in the axial direction of the sleeve, the grouting holes are communicated with the inner cavity, a guide rail is arranged on the inner wall surface of the sleeve, the guide rail extends along the axial direction of the sleeve, the grouting pipe is arranged in the inner cavity of the sleeve and has a guide groove matched with the guide rail, so that the grouting pipe moves along the axial direction of the sleeve on the guide rail, the grouting assembly is arranged on the grouting pipe, the inlet of the grouting assembly is communicated with the grouting pipe, and the grouting pipe moves in the axial direction of the sleeve so that the outlet of the grouting assembly is communicated with the grouting holes at different axial positions of the sleeve. The coal mine roadway surrounding rock segmented controllable hierarchical grouting device is convenient for surrounding rock phased and layered grouting support, and the stability and convenience of the support are improved.

Description

Technical Field

[0001] This application relates to the field of grouting equipment technology, and more specifically, to a segmented and controllable layered grouting device and grouting method for coal mine roadway surrounding rock. Background Technology

[0002] During coal mining, the surrounding rock of roadways affected by mining activities undergoes a complex process of stress redistribution and fracture evolution. Traditional grouting reinforcement technology mainly adopts a one-time full-hole grouting method, which has many shortcomings and is difficult to adapt to the dynamic development of surrounding rock fractures during coal mining, resulting in unsatisfactory grouting effects and difficulties in controlling roadway deformation. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a segmented and controllable layered grouting device for coal mine roadways, which facilitates staged and layered grouting support of the surrounding rock, thereby improving the stability and convenience of the support.

[0005] An embodiment of the present invention provides a segmented and controllable layered grouting device for surrounding rock in coal mine roadways, comprising:

[0006] A casing having an inner cavity, and a plurality of grouting holes spaced apart in the axial direction of the casing, the grouting holes communicating with the inner cavity;

[0007] A grouting pipe and a guide rail are provided. The guide rail is provided on the inner wall of the casing and extends upward along the axial direction of the casing. The grouting pipe is disposed in the inner cavity of the casing and has a guide groove that cooperates with the guide rail, so that the grouting pipe can move along the axial direction of the casing on the guide rail.

[0008] A grouting assembly is provided on the grouting pipe. The inlet of the grouting assembly is connected to the grouting pipe. The grouting pipe moves axially in the casing so that the outlet of the grouting assembly is connected to grouting holes at different axial positions on the casing.

[0009] The coal mine roadway surrounding rock segmented controllable layered grouting device of the present invention facilitates the segmented and layered grouting support of the surrounding rock, thereby improving the stability and convenience of the support.

[0010] In some embodiments, the grouting assembly includes a convex nozzle, an elastic element, a connecting pipe, and a sliding sleeve. The inlet of the connecting pipe communicates with the grouting pipe, and the outlet of the connecting pipe communicates with the inlet of the sliding sleeve. The radial dimension of the sliding sleeve is smaller than that of the connecting pipe, and the sliding sleeve is at least partially disposed within the connecting pipe and movable relative to the connecting pipe. The convex nozzle is connected to one end of the connecting pipe away from the sliding sleeve. One end of the elastic element is connected to the connecting pipe and the convex nozzle. The convex nozzle contacts the inner wall surface of the sleeve or partially extends out of the grouting hole.

[0011] The grouting pipe moves axially upwards in the casing so that the convex nozzle contacts the inner wall of the casing or partially extends out of the grouting hole.

[0012] In some embodiments, the convex nozzle is at least a portion of a ball.

[0013] In some embodiments, the segmented controllable hierarchical grouting device for coal mine roadway surrounding rock further includes a separating component, which is disposed on the casing. There are multiple separating components, which are arranged at intervals on the casing, and two adjacent separating components have at least one grouting hole.

[0014] In some embodiments, the separation assembly includes an airbag, an inflation line, and an inflation member. The airbag is sleeved outside the sleeve, the output end of the inflation member is connected to one end of the inflation line, and the other end of the inflation line passes through the sleeve and is connected to the airbag.

[0015] In some embodiments, the number of grouting components is multiple, the multiple grouting components are arranged at intervals in the circumferential direction of the grouting pipe, and the multiple grouting holes are arranged at intervals in the circumferential direction of the sleeve.

[0016] The grouting method of this invention includes:

[0017] During tunneling, the drilling area is sealed with a spray coating, and then the drilling area is drilled.

[0018] Install the casing into the borehole, and install the grouting pipe and grouting assembly;

[0019] The borehole is divided into a first grouting section, a second grouting section, and a third grouting section that are connected in sequence, with the first grouting section adjacent to the borehole opening;

[0020] Grouting is carried out sequentially in the grouting holes corresponding to the first, second, and third grouting sections according to the tunneling progress, and the airbag components are inflated before grouting.

[0021] The grouting method described in the embodiments of the present invention improves the stability and convenience of the support by performing staged and layered grouting support on the surrounding rock.

[0022] In some embodiments, the method further includes: grouting through a first grouting section during tunneling;

[0023] After the tunneling has stabilized, grouting will be carried out in the second grouting section within a range of 200-300m behind the tunnel.

[0024] During the mining process, grouting is carried out on the third grouting section within a range of 50-150m in front of the mining section.

[0025] In some embodiments, the grouting pressure of the first grouting section is 20-10 kPa; the grouting pressure of the second grouting section is 35-15 kPa; and the grouting pressure of the third grouting section is 50-30 kPa.

[0026] In some embodiments, the grouting pressure of the first grouting section is less than or equal to the grouting pressure of the second grouting section, and the pressure of the second grouting section is less than the grouting pressure of the third grouting section.

[0027] In some embodiments, a roof separation meter is installed on the surrounding rock to detect data of the roof surrounding rock at different tunneling progresses, and the grouting timing is determined by the increase in the data of the roof separation meter within a preset time period at different times. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a segmented and controllable layered grouting device for coal mine roadway surrounding rock according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of a convex nozzle according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of the elastic element according to an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the first limiting part in an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the guide rail and arc-shaped protrusion in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of a segmented and controllable layered grouting device for coal mine roadway surrounding rock according to an embodiment of the present invention.

[0034] Figure label:

[0035] Sleeve 1, inner cavity 11, guide rail 12, arc-shaped protrusion 13, grouting hole 14

[0036] Grouting pipe 2, guide groove 21

[0037] Grouting assembly 3, convex nozzle 31, elastic element 32, connecting pipe 33.

[0038] Sliding sleeve 34, first limiting part 331,

[0039] Separator component 4,

[0040] Drill hole 5, surrounding rock 6. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0042] An embodiment of the present invention provides a segmented controllable layered grouting device for surrounding rock in coal mine roadways, comprising: a casing 1, a grouting assembly 3, a grouting pipe 2, and a guide rail 12. The casing 1 has an inner cavity 11, and a plurality of grouting holes 14 are spaced apart along the axial direction of the casing 1. The grouting holes 14 communicate with the inner cavity 11. The grouting pipe 2 and the guide rail 12 are provided on the inner wall surface of the casing 1 and extend along the axial direction of the casing 1. The grouting pipe 2 is located in the inner cavity 11 of the casing 1 and has a guide groove 21 that cooperates with the guide rail 12 so that the grouting pipe 2 can move along the axial direction of the casing 1 on the guide rail 12. The grouting assembly 3 is provided on the grouting pipe 2, and the inlet of the grouting assembly 3 communicates with the grouting pipe 2. The grouting pipe 2 moves along the axial direction of the casing 1 so that the outlet of the grouting assembly 3 communicates with the grouting holes 14 at different axial positions of the casing 1.

[0043] The coal mine roadway surrounding rock segmented controllable layered grouting device of the present invention facilitates the segmented and layered grouting support of the surrounding rock 6, thereby improving the stability and convenience of the support.

[0044] Specifically, such as Figures 1 to 6 As shown, the casing 1 is understood as a hollow pipe. Multiple grouting holes 14 are provided in the vertical direction of the casing 1. The multiple grouting holes 14 are arranged at intervals in the vertical direction so that the grouting assembly 3 can grout the surrounding rock 6 at different heights through the grouting holes 14 at different heights.

[0045] The casing 1 is equipped with a guide rail 12, or can be understood as an I-beam. The outer circumference of the grouting pipe 2 is provided with a guide groove 21 extending in the vertical direction, which cooperates with the guide rail 12 to allow the grouting pipe 2 to move in the vertical direction relative to the casing 1, so that the grouting assembly 3 can be connected to the grouting holes 14 at different heights, so as to grout the surrounding rock 6 at different heights or at different depths of the borehole 5. The inlet of the grouting pipe 2 is connected to the existing grouting system or grouting device and then enters the grouting pipe 2, and then the grouting pipe 2 enters the grouting assembly 3. When the grouting assembly 3 is connected to the grouting hole 14, grouting is started.

[0046] During the mining process, the surrounding rock 6 is affected by the mining progress. The shallow surrounding rock 6, the middle surrounding rock 6, and the deep surrounding rock 6 are disturbed in sequence. Before being disturbed, the surrounding rock 6 is difficult to support with grouting. The shallow surrounding rock 6 is closest to the roadway, the deep surrounding rock 6 is farthest from the roadway, and the distance of the middle surrounding rock 6 from the roadway is between that of the shallow surrounding rock 6 and the deep surrounding rock 6. The shallow surrounding rock 6 is disturbed first, followed by the middle surrounding rock 6, and the deep surrounding rock 6 is disturbed last. If a simple single borehole 5 is grouted multiple times, the grouting of the shallow surrounding rock 6 will completely seal the borehole 5. Therefore, it is necessary to perform multiple borehole 5 grouting support in the support area at different stages of mining.

[0047] The coal mine roadway surrounding rock segmented controllable layered grouting device of the present invention, by setting guide rail 12, facilitates the gradual up and down movement of grouting pipe 2 within casing 1, so as to connect grouting component 3 with grouting holes 14 at different positions, thereby performing layered and staged grouting on areas of different depths of borehole 5. For example, during tunneling, the grouting hole 14 closest to borehole 5 is connected to provide grouting support for shallow surrounding rock 6. Then, after tunneling and stabilization, the grouting holes 14 closer to borehole 5 are connected to provide grouting support for the middle surrounding rock 6. During mining, the grouting hole 14 farthest from borehole 5 is connected to provide grouting support for deep surrounding rock 6. This eliminates the need for grouting multiple boreholes 5, improving the convenience and stability of support.

[0048] In some embodiments, the grouting assembly 3 includes a convex nozzle 31, an elastic element 32, a connecting pipe 33, and a sliding sleeve 34. The inlet of the connecting pipe 33 is connected to the grouting pipe 2, and the outlet of the connecting pipe 33 is connected to the inlet of the sliding sleeve 34. The radial dimension of the sliding sleeve 34 is smaller than the radial dimension of the connecting pipe 33, and the sliding sleeve 34 is at least partially disposed within the connecting pipe 33 and movable relative to the connecting pipe 33. The convex nozzle 31 is connected to one end of the connecting pipe 33 away from the sliding sleeve 34. One end of the elastic element 32 is connected to the connecting pipe 33, and the elastic element 32 is connected to the convex nozzle 31. The convex nozzle 31 contacts the inner wall surface of the sleeve 1 or partially extends out of the grouting hole 14.

[0049] The grouting pipe 2 moves axially upward in the sleeve 1 so that the convex nozzle 31 contacts the inner wall surface of the sleeve 1 or partially extends out of the grouting hole 14.

[0050] Alternatively, the grouting pipe 2 can be moved axially upward in the casing 1 so that the convex nozzle 31 contacts the inner wall surface of the casing 1 or partially extends out of the grouting hole 14.

[0051] Specifically, such as Figures 1 to 6As shown, the grouting pipe 2 is connected to the inlet of the connecting pipe 33, and the outlet of the connecting pipe 33 is connected to the sliding sleeve 34. The outlet of the sliding sleeve 34 is connected to the convex nozzle 31, and the elastic element 32 is disposed on the connecting pipe 33 and connected to or abutting against the convex nozzle 31. When the convex nozzle 31 contacts the inner wall surface of the sleeve 1, the elastic element 32 is compressed. When the convex nozzle 31 moves to the position of the grouting hole 14, the elastic element 32 extends to cause the convex nozzle 31 to move radially in the sleeve 1 to extend into the grouting hole 14 for grouting, or the convex nozzle 31 partially but not entirely passes through the grouting hole 14 to extend out of the grouting hole 14 to grout the surrounding rock 6.

[0052] like Figure 1 As shown, simultaneously, after grouting is completed, the convex nozzle 31 is partially stuck inside the grouting hole 14. The operator needs significantly more force than when moving the grouting pipe 2 normally to retract the convex nozzle 31 back into the sleeve 1, and the elastic element 32 is compressed, so that the convex nozzle 31 contacts the inner wall surface of the sleeve 1 (e.g., Figure 6 (As shown).

[0053] The coal mine roadway surrounding rock segmented controllable layered grouting device of the present invention, by setting a convex nozzle 31, an elastic element 32, a connecting pipe 33 and a sliding sleeve 34, so that when the convex nozzle 31 moves to the position of the grouting hole 14, the elastic element 32 extends so that the convex nozzle 31 moves radially in the sleeve 1 to extend into or out of the grouting hole 14 for grouting, thereby improving the convenience and stability of layered grouting.

[0054] Furthermore, the casing 1 also has an arc-shaped protrusion 13, which extends along the axial direction of the casing 1. The arc-shaped protrusion 13 matches the outlet shape of the convex nozzle 31. When the convex nozzle 31 is not connected to the grouting hole 14, the outlet of the convex nozzle 31 fits against the arc-shaped protrusion 13 to prevent the residual grout in the grouting pipe 2 from overflowing into the inner cavity 11 of the casing 1, thereby reducing the amount of grout flowing into the inner cavity 11 and improving the grouting stability.

[0055] Furthermore, a first limiting part 331 is provided at one end of the sliding sleeve 34 that extends into the connecting pipe 33, and the radial dimension of the first limiting part 331 is greater than the radial dimension of the outlet of the connecting pipe 33, so as to limit the movement of the sliding sleeve 34 in the axial direction of the sleeve 1.

[0056] Furthermore, the grouting assembly 3 also includes a one-way valve, the inlet of which is connected to the grouting pipe 2, and the outlet of which is connected to the inlet of the connecting pipe 33, in order to prevent grout backflow during grouting and improve the stability of grouting.

[0057] In some embodiments, the convex nozzle 31 is at least part of a sphere. The spherical nozzle has a smoother surface, which reduces the adhesion and accumulation of slurry on the nozzle surface, thereby reducing the risk of nozzle clogging, and the spherical nozzle can enter or exit the grouting hole 14 more smoothly.

[0058] In some embodiments, the segmented controllable hierarchical grouting device for coal mine roadway surrounding rock further includes a partition component 4, which is disposed on the casing 1. There are multiple partition components 4, which are arranged at intervals on the casing 1, and two adjacent partition components 4 have at least one grouting hole 14.

[0059] The dividing component 4 divides the borehole 5 into multiple independent grouting sections, each corresponding to a specific depth range. By sealing the non-grouting areas of the borehole 5, it is ensured that the grout is injected only into the surrounding rock 6 within the preset depth range, improving the accuracy and efficiency of grouting. At least one grouting hole 14 is provided between adjacent dividing components 4 to ensure that each grouting section has an independent grouting channel, facilitating layered grouting support at different depths.

[0060] In some embodiments, the separator 4 includes an airbag, an inflation line, and an inflation member. The airbag is sleeved outside the sleeve 1, and the output end of the inflation member is connected to one end of the inflation line. The other end of the inflation line passes through the sleeve 1 and is connected to the airbag. After inflation, the outer peripheral surface of the airbag contacts the inner wall surface of the borehole 5 in the surrounding rock 6.

[0061] The segmented and controllable layered grouting device for coal mine roadways according to an embodiment of the present invention can divide the casing 1 into multiple independent grouting segments by expanding and contracting the airbag components. Each grouting segment corresponds to a preset depth range. This ensures that the grout is injected only into the surrounding rock 6 within the preset depth range, avoiding grout diffusion in non-target areas and improving the accuracy of grouting.

[0062] In some embodiments, there are multiple grouting components 3, which are arranged at intervals around the grouting pipe 2, and multiple grouting holes 14 are arranged at intervals around the casing 1. The circumferentially arranged grouting holes 14 correspond to the multiple grouting components 3, so that during grouting, the multiple grouting components 3 and the multiple grouting holes 14 operate simultaneously, thereby improving the efficiency of grouting.

[0063] The grouting method of this invention includes:

[0064] During the excavation, the area of ​​borehole 5 was sealed with a spray coating, and the area of ​​borehole 5 was drilled.

[0065] Install casing 1 into borehole 5, and install grouting pipe 2 and grouting assembly 3;

[0066] The borehole 5 is divided into a first grouting section, a second grouting section and a third grouting section that are connected in sequence, with the first grouting section adjacent to the opening of the borehole 5;

[0067] Grouting is carried out sequentially in the grouting holes 14 corresponding to the first grouting section, the second grouting section and the third grouting section according to the tunneling progress, and the airbag is inflated before grouting.

[0068] Specifically, such as Figures 1 to 6 As shown, during tunneling, grouting is performed on the pre-drilled borehole 5 in the tunnel, the area of ​​borehole 5 is sealed by spraying, borehole 5 is drilled in the area of ​​borehole 5, and the preset depth is reached in one go. The casing 1 is installed in the borehole 5, and the grouting pipe 2 and grouting assembly 3 are installed.

[0069] The borehole 5 is divided into a first grouting section, a second grouting section, and a third grouting section that are connected in sequence. The first grouting section is adjacent to the borehole 5 opening and is closest to the borehole 5. The third grouting section is farthest from the borehole 5. In the axial direction of the borehole 5, the second grouting section is located between the first grouting section and the third grouting section.

[0070] There can be multiple first grouting sections, second grouting sections, and third grouting sections, and any one of the first grouting section, second grouting section, and third grouting section can be grouted and supported individually.

[0071] The embodiments of the present invention provide a grouting method that improves the stability and convenience of support by performing staged and layered grouting support on the surrounding rock 6. The grouting pipe 2 moves up and down within the casing 1 to grout sections of different depths. For example, during tunneling, the first grouting section closest to the borehole 5 is connected to provide grouting support for the shallow surrounding rock 6. Then, after tunneling stabilizes, the second grouting section closer to the borehole 5 is connected to provide grouting support for the middle surrounding rock 6. During mining, the third grouting section furthest from the borehole 5 is connected to provide grouting support for the deep surrounding rock 6. This eliminates the need for grouting multiple boreholes 5, improving the convenience and stability of the support.

[0072] Furthermore, during tunneling, grouting is performed through the first grouting section. After the tunneling stabilizes, when the borehole 5 area is within 200-300m behind the tunnel, grouting is performed through the second grouting section. During mining, grouting is performed through the third grouting section within 50-150m in front of the mining area. The grouting pressure of the first grouting section is 20-10 kPa, the grouting pressure of the second grouting section is 35-15 kPa, and the grouting pressure of the third grouting section is 50-30 kPa. The grouting pressure of the first grouting section is less than or equal to the grouting pressure of the second grouting section, and the pressure of the second grouting section is less than the grouting pressure of the third grouting section.

[0073] The grouting method described in this invention improves the stability and convenience of the surrounding rock 6 by performing staged and layered grouting support. Furthermore, different grouting pressures are set to compensate for pressure loss at different grouting depths, thereby enhancing the grouting effect and stability.

[0074] In some embodiments, a roof separation meter is installed on the surrounding rock 6 to detect data of the roof surrounding rock 6 at different tunneling progresses, and the grouting timing is determined by the increase in the data of the roof separation meter within a preset time period at different times.

[0075] For example, during tunnel excavation, the shallow surrounding rock 6 is unloaded after excavation, forming a loosening zone. Surface fissures open first and evolve rapidly. At this time, the increase in the data detected by the roof separation instrument is not within the preset range. When the shallow fissures have basically opened and begun to stabilize, and the increase in the monitored data of the roof separation instrument over time falls within the first preset range, grouting support is applied to the shallow surrounding rock 6.

[0076] After the tunneling has stabilized and the borehole 5 area is within 200-300m behind the tunnel, if the increase in monitoring data is within the third preset range, it indicates that the central fracture has fully opened and the structure has not yet broken. At this point, grouting is performed on the second grouting section. During mining, if the increase in monitoring data is within the third preset range, grouting is performed on the third grouting section.

[0077] The grouting method described in this invention, by controlling the timing of grouting, ensures sufficient disturbance to the surrounding rock 6, thereby facilitating the stable injection of grout into the fissures of the surrounding rock 6 and improving the stability and convenience of grouting support. Furthermore, setting different grouting pressures compensates for pressure loss at different grouting depths, enhancing the grouting effect and stability.

[0078] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0081] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0082] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0083] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A segmented and controllable layered grouting device for surrounding rock in coal mine roadways, characterized in that, include: A casing having an inner cavity, and a plurality of grouting holes spaced apart in the axial direction of the casing, the grouting holes communicating with the inner cavity; A grouting pipe and a guide rail are provided. The guide rail is provided on the inner wall of the casing and extends upward along the axial direction of the casing. The grouting pipe is located inside the casing cavity and has a guide groove that cooperates with the guide rail, so that the grouting pipe can move along the axial direction of the casing on the guide rail. A grouting assembly is provided on the grouting pipe. The inlet of the grouting assembly is connected to the grouting pipe. The grouting pipe can move axially along the casing so that the outlet of the grouting assembly communicates with grouting holes at different axial positions on the casing. The grouting assembly includes a convex nozzle, an elastic element, a connecting pipe, and a sliding sleeve. The inlet of the connecting pipe is connected to the grouting pipe, and the outlet of the connecting pipe is connected to the inlet of the sliding sleeve. The radial dimension of the sliding sleeve is smaller than that of the connecting pipe, and the sliding sleeve is at least partially disposed within the connecting pipe and movable relative to the connecting pipe. The end of the connecting pipe away from the sliding sleeve is connected to the convex nozzle. One end of the elastic element is connected to the connecting pipe and the elastic element is connected to the convex nozzle. The convex nozzle contacts the inner wall surface of the casing or partially extends out of the grouting hole. The grouting pipe moves axially upwards along the casing so that the convex nozzle contacts the inner wall of the casing or partially extends out of the grouting hole; A separator assembly is disposed on the sleeve. There are multiple separator assemblies, which are arranged at intervals on the sleeve, and two adjacent separator assemblies have at least one grouting hole. The separation assembly includes an airbag component, an inflation line, and an inflation component. The airbag component is sleeved outside the sleeve. The output end of the inflation component is connected to one end of the inflation line, and the other end of the inflation line passes through the sleeve and is connected to the airbag component. The number of grouting components is multiple, and the multiple grouting components are arranged at intervals in the circumferential direction of the grouting pipe, and the multiple grouting holes are arranged at intervals in the circumferential direction of the sleeve.

2. The segmented and controllable layered grouting device for surrounding rock in coal mine roadways according to claim 1, characterized in that, The convex nozzle is at least a portion of a ball.

3. A grouting method, characterized in that, The coal mine roadway surrounding rock segmented controllable layered grouting device according to claim 1 or 2 includes: During tunneling, the drilling area is sealed with a spray coating, and then the drilling area is drilled. Install the casing into the borehole, and install the grouting pipe and grouting assembly; The borehole is divided into a first grouting section, a second grouting section, and a third grouting section that are connected in sequence, with the first grouting section adjacent to the borehole opening; Grouting is carried out sequentially in the grouting holes corresponding to the first, second, and third grouting sections according to the tunneling progress, and the airbag components are inflated before grouting.

4. The grouting method according to claim 3, characterized in that, Also includes: During tunneling, grouting is carried out through the first grouting section; After the tunneling has stabilized, grouting will be carried out in the second grouting section within a range of 200-300m behind the tunnel. During the mining process, grouting is carried out on the third grouting section within a range of 50-150m in front of the mining section.

5. The grouting method according to claim 4, characterized in that, Also includes: The grouting pressure of the first grouting section is 20-10 kPa; the grouting pressure of the second grouting section is 35-15 kPa; and the grouting pressure of the third grouting section is 50-30 kPa. The grouting pressure of the first grouting section is less than or equal to the grouting pressure of the second grouting section, and the pressure of the second grouting section is less than the grouting pressure of the third grouting section.

6. The grouting method according to claim 5, characterized in that, Also includes: A roof separation meter is installed in the surrounding rock to detect data on the roof and surrounding rock at different tunneling progresses. The timing of grouting is determined by the increase in the roof separation meter data within a preset time period at different times.

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