Hollow grouting anchor rod structure

Abstract

The utility model relates to the technical field of engineering supporting components, and particularly discloses a hollow grouting anchor rod structure which comprises a hollow rod body and a drill bit, a polished rod part is arranged on the hollow rod body, and a sliding plug is installed on the polished rod part; the sliding plug comprises a sliding sleeve and an elastic wall, and a filling cavity is formed between the elastic wall and the sliding sleeve; a liquid inlet hole is formed in the sliding sleeve, and a non-return component is arranged on the liquid inlet hole; a plug is arranged at the front end of the hollow rod body, and a push spring is arranged on the front side of the plug. In the grouting process, the sliding plug is matched with the anchor hole in a sealing mode, so that a space tending to be closed is formed in the front side of the sliding plug, grout in the closed space maintains high and tending to be constant pressure, the anchor hole and gaps around the anchor hole can be completely filled with the grout, then the grout drives the sliding plug to move backwards, and high-pressure grouting is completed. And the grouting balance and the overall plumpness can be obviously improved. Grouting is conducted in the mode, air in the anchor holes and gaps of the anchor holes can be fully exhausted, the grouting quality is further improved, and the anchoring effect is improved.

Description

Technical Field

[0001] This utility model relates to the field of engineering support components, and in particular to a hollow grouting anchor structure. Background Technology

[0002] Hollow grouting anchors are support components with a hollow design, consisting of a hollow rod body, pad, locking nut, and grout stopper. They combine drilling and grouting functions and are widely used in tunnels, slope reinforcement, mine roadways, water conservancy projects, fault fracture zones, and other surrounding rock support applications. Currently, while most hollow grouting anchor installations employ pressure grouting, it's difficult to establish effective hydrostatic pressure within the anchor hole before the grout flows back to the grout stopper. Even after the grout flows back to the stopper, while the pressure increases, the viscosity and surface tension of the grout prevent air from escaping smoothly, creating a "false fullness" cavity. This leads to insufficient grout fullness, resulting in reduced pull-out resistance and accelerated rod corrosion. This problem is particularly pronounced during elevation angle construction, especially in areas with large elevation angles at the arch crown, where gravity causes the grout to flow downwards, making it difficult to expel air and exacerbating the insufficient grout fullness issue. Utility Model Content

[0003] This utility model provides a hollow grouting anchor structure, which aims to solve the technical problems of insufficient fullness caused by the difficulty in maintaining pressure and expelling air during grouting of existing hollow grouting anchors.

[0004] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0005] A hollow grouting anchor structure includes a hollow rod body, a drill bit fixedly connected to the front end of the hollow rod body, and a grout outlet hole on the drill bit; a smooth rod section is provided on the hollow rod body, the smooth rod section is located behind the drill bit and has a side hole, and a sliding plug is installed on the smooth rod section; the sliding plug includes a sliding sleeve and an elastic wall wrapped around the outside of the sliding sleeve, and a filling cavity is formed between the elastic wall and the sliding sleeve; a liquid inlet hole is provided on the sliding sleeve, and a check valve is installed on the liquid inlet hole; the sliding sleeve is fitted onto the smooth rod section and the two are sealed together, and the liquid inlet hole on the sliding sleeve communicates with the inner cavity of the hollow rod body through the side hole of the smooth rod section; when the elastic wall is in a contracted state, the outer diameter of the sliding plug is smaller than the outer diameter of the drill bit; a plug that can move back and forth is provided at the front end of the hollow rod body, and a push spring is provided on the front side of the plug, and the plug seals the front end of the hollow rod body under the drive of the push spring.

[0006] In a preferred embodiment, the outer side of the elastic wall is provided with a plurality of annular elastic wings that are spaced apart front to back.

[0007] In a preferred embodiment, the outer wall of the hollow rod is provided with anchor bolt threads, which are located on the rear side of the smooth rod portion; the hollow rod is provided with a pad and a fastening nut.

[0008] In a preferred embodiment, side holes are provided on opposite sides of the optical rod, and liquid inlet holes are provided on opposite sides of the sliding sleeve.

[0009] In a preferred embodiment, the anti-reverse component is a rubber sleeve, which is fitted over the outside of the sliding sleeve and covers the liquid inlet hole.

[0010] In a preferred embodiment, a cylindrical recess is provided at the front end of the hollow rod body. The inner diameter of the recess is larger than the inner diameter of the hollow rod body, so that the rear end of the recess forms a step. The plug is located in the recess and abuts against the step. One end of the push spring contacts and engages with the plug, and the other end contacts and engages with the drill bit.

[0011] In a preferred embodiment, a positioning protrusion is provided at the front end of the optical rod, and the sliding sleeve is made of plastic or polymer material, with a positioning pit on the inner wall that cooperates with the positioning protrusion.

[0012] Compared with the prior art, the hollow grouting anchor structure of this utility model has the following beneficial technical effects:

[0013] During grouting, the sliding plug seals with the anchor hole, creating a nearly closed space in front of the plug. Within this closed space, the grout maintains a high and relatively constant pressure, completely filling the anchor hole and surrounding voids. The grout then drives the sliding plug backward, thus sequentially grouting each location of the anchor hole from front to back, significantly improving the uniformity and overall fullness of the grouting. This method of grouting allows air to be fully expelled from the anchor hole and its gaps, preventing air from accumulating inside the grout and further improving grouting quality and anchoring effect. Especially at elevation angles, particularly in the large elevation angle area of ​​the arch crown, the sliding plug provides excellent grout-stopping properties, making the above-mentioned technical advantages even more prominent. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only involve some embodiments of this utility model, and are not intended to limit this utility model.

[0015] Figure 1 This is a schematic diagram of the overall structure of the hollow grouting anchor bolt structure in the embodiment.

[0016] Figure 2 This is a schematic diagram of the front part of the hollow grouting anchor structure in the embodiment.

[0017] Figure 3 This is a schematic diagram of the structure of the sliding plug after it has been cut open in the embodiment.

[0018] Figure 4 This is a schematic diagram of the mating structure of the hollow rod, sliding plug, and drill bit in the embodiment.

[0019] Figure 5 This is a schematic diagram showing the state of the sliding plug being expanded by the grout during the grouting process in the embodiment.

[0020] Figure 6 This is a schematic diagram showing the state when the grout pushes the sliding plug backward during the grouting process in the embodiment.

[0021] Figure label:

[0022] 1-Fastening nut; 2-Washer plate; 3-Hollow rod body; 301-Smooth rod section; 302-Side hole; 303-Positioning protrusion; 304-Recessed seat; 4-Sliding plug; 401-Elastic wing; 402-Sliding sleeve; 403-Elastic wall; 404-Filling cavity; 405-Rubber sleeve; 406-Liquid inlet hole; 407-Positioning pit; 5-Drill bit; 501-Slurry outlet hole; 6-Plug; 7-Push spring; 8-Anchor hole. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0024] See Figures 1 to 4As shown, the hollow grouting anchor structure in this embodiment includes a hollow rod body 3. The hollow rod body 3 is hollow to facilitate grouting operations. A drill bit 5 is fixedly connected to the front end of the hollow rod body 3. The drill bit 5 has a grout outlet hole 501 that communicates with the inner cavity of the hollow rod body 3. The hollow rod body 3 has a smooth rod portion 301, which is located behind the drill bit 5. The outer contour of the smooth rod portion 301 is cylindrical. A side hole 302 is opened on the smooth rod portion 301 to penetrate the wall of the hollow rod body 3. A sliding plug 4 is installed on the smooth rod portion 301. The sliding plug 4 includes a sliding sleeve 402. The outer side of the sliding sleeve 402 is wrapped with an elastic wall 403 made of elastic material such as rubber. A sealed filling cavity 404 is formed between the elastic wall 403 and the sliding sleeve 402. A liquid inlet hole is opened on the sliding sleeve 402 to penetrate its wall. 406, a backflow preventer is installed on the inlet hole 406. The backflow preventer only allows the slurry to flow into the filling cavity 404 through the inlet hole 406, and does not allow the slurry that has entered the filling cavity 404 to be discharged outward through the inlet hole 406. When the sliding plug 4 is in the initial position, the sliding sleeve 402 is fitted on the polished rod 301 and the two are sealed together. The inlet hole 406 on the sliding sleeve 402 is directly opposite to the side hole 302 of the polished rod 301, so that the inlet hole 406 communicates with the inner cavity of the hollow rod 3 through the side hole 302. When the elastic wall 403 is in the contracted state, the outer diameter of the sliding plug 4 is smaller than the outer diameter of the drill bit 5. The front end of the hollow rod 3 is provided with a plug 6 that can move back and forth. The front side of the plug 6 is provided with a push spring 7 that applies a pushing force to it. The plug 6 seals the front end of the hollow rod 3 under the drive of the push spring 7.

[0025] The hollow rod 3 was installed in place using current construction techniques, followed by grouting. The specific process is as follows:

[0026] First, such as Figure 5 As shown, grout is slowly injected into the hollow rod body 3 using grouting equipment. Since the front end of the hollow rod body 3 is blocked by the plug 6, the grout will not be discharged directly into the anchor hole 8 through the grout outlet 501. Instead, it enters the filling cavity 404 between the elastic wall 403 and the sliding sleeve 402 through the side hole 302 and the inlet hole 406, causing the elastic wall 403 to expand and deform, so that the sliding plug 4 reaches the expanded state. When the elastic wall 403 contacts the side wall of the anchor hole 8, the sliding plug 4 and the anchor hole 8 achieve a sealing fit. When the sliding plug 4 is in the expanded state, the anti-reverse component can prevent the grout inside the filling cavity 404 from flowing out, so that the sliding plug 4 can stably maintain the expanded state.

[0027] After that, as Figure 6As shown, when the grout can no longer flow into the filling cavity 404, the grout pressure inside the hollow rod 3 will further increase. When the grout pressure overcomes the thrust of the push spring 7 and drives the plug 6 forward, the grout will enter the drill bit 5 through the front port of the hollow rod 3 and be discharged into the anchor hole 8 through the grout outlet 501. Under the obstruction of the sliding plug 4, the grout will not flow arbitrarily inside the anchor hole 8, but will be located in the space in front of the sliding plug 4. When the grout fills the space in front of the sliding plug 4, as the grout pressure increases, the grout will drive the sliding plug 4 to move backward, and high-pressure grouting will continue as the sliding plug 4 moves until the sliding plug 4 moves to the outer port of the anchor hole 8, completing the grouting operation. During the grouting process, when the sliding sleeve 402 moves backward and separates from the polished rod part 301, the grout can be output into the anchor hole 8 through the side hole 302, thereby ensuring the grouting pressure and grouting efficiency.

[0028] During grouting, the sliding plug 4 seals against the anchor hole 8, creating a nearly enclosed space in front of the sliding plug 4. Within this enclosed space, the grout maintains a high and relatively constant pressure, completely filling the anchor hole 8 and the surrounding voids. The grout then drives the sliding plug 4 to move backward, thus sequentially performing high-pressure grouting at each location of the anchor hole 8 from front to back. This significantly improves the uniformity and overall fullness of the grouting. Furthermore, this grouting method allows for the full expulsion of air from the anchor hole 8 and surrounding gaps, preventing air from accumulating within the grout and further improving grouting quality and anchoring effect. Based on these characteristics, the sliding plug 4 provides excellent grout-stopping properties, especially in the high-angle areas of the arch crown, where these technical advantages are even more pronounced.

[0029] See Figures 2 to 4 As shown, in a further technical solution, the outer side of the elastic wall 403 is provided with a plurality of annular elastic wings 401 distributed at intervals. Since the elastic wings 401 have good deformation ability, they can better adapt to the inner wall of the anchor hole 8. On the one hand, this can improve the sealing effect between the sliding plug 4 and the inner wall of the anchor hole 8. On the other hand, it can prevent the sliding plug 4 from getting stuck in the anchor hole 8 and being unable to move, thereby improving the stability of this hollow grouting anchor structure during use.

[0030] See Figure 1 , Figure 2As shown, in a further technical solution, the outer wall of the hollow rod 3 is provided with anchor threads, which are located on the rear side of the smooth rod portion 301; the hollow rod 3 is provided with a pad 2 and a fastening nut 1; when the outer wall of the hollow rod 3 is provided with anchor threads, the sliding sleeve 402 can be made of elastic material, or an elastic liner can be provided inside the sliding sleeve 402 to ensure that the fit between the sliding sleeve 402 and the anchor threads can achieve the necessary sealing requirements. During the grouting process, a small amount of grout seeps out between the sliding sleeve 402 and the hollow rod 3, which will not have a substantial impact on the grouting process.

[0031] See Figure 3 , Figure 4 As shown, in a further technical solution, the smooth rod portion 301 has side holes 302 on both sides to ensure the grouting efficiency during grouting and to help improve the uniformity of grout pressure distribution in the anchor hole; correspondingly, the sliding sleeve 402 has inlet holes 406 on both sides.

[0032] In this hollow grouting anchor structure, because the outer diameter of the sliding plug 4 is smaller than the outer diameter of the drill bit 5 in the initial state, and the sliding plug 4 is located behind the drill bit 5, the relative position of the sliding plug 4 and the polished rod portion 301 is less likely to change during the drilling process of the hollow rod body 3. Simultaneously, during manufacturing, the tightness of the fit between the sliding sleeve 402 and the polished rod portion 301 can be reasonably set to prevent the sliding plug 4 from shifting during the drilling process of the hollow rod body 3. Furthermore, as... Figure 4 As shown, as a preferred technical feature, a positioning mechanism is provided between the sliding sleeve 402 and the polished rod portion 301. Specifically, a positioning protrusion 303 is provided at the front end of the polished rod portion 301. The sliding sleeve 402 is made of plastic or polymer material, and its inner wall has a positioning pit 407 that mates with the positioning protrusion 303. Thus, the engagement of the positioning protrusion 303 and the positioning pit 407 ensures that the sliding sleeve 402 and the polished rod portion 301 maintain a stable engagement, preventing displacement of the sliding plug 4 during drilling of the hollow rod body 3. During grouting, the grout pressure on the front side of the sliding plug 4 is relatively high, sufficient to disengage the positioning protrusion 303 from the positioning pit 407, allowing the sliding plug 4 to move backward as expected. Furthermore, the engagement of the positioning protrusion 303 and the positioning pit 407 helps improve the assembly accuracy of the sliding sleeve 402 and the polished rod portion 301.

[0033] In this hollow grouting anchor structure, the check valve is installed at the inlet hole 406. Together, they function as a one-way valve, allowing high-pressure grout to enter the filling cavity 404 through the inlet hole 406 while preventing grout from flowing out of the filling cavity 404. Based on this design, the check valve can be implemented with reference to the check valve structure in commonly used one-way valves, such as ball valves, diaphragm valves, and duckbill valves. In this hollow grouting anchor structure, when multiple inlet holes 406 are provided, the preferred embodiment of the check valve is as follows:

[0034] See Figure 3 , Figure 4 As shown, the anti-reverse component is a rubber sleeve 405 made of elastic material. The rubber sleeve 405 is fitted over the outside of the sliding sleeve 402 and covers the liquid inlet 406. Thus, the rubber sleeve 405 can provide anti-reverse function for multiple liquid inlets 406 at the same time. When the pressure of the slurry inside the hollow rod 3 is high enough, the slurry can drive the rubber sleeve 405 to undergo local deformation, forming a temporary flow channel between the rubber sleeve 405 and the sliding sleeve 402, so that the slurry can flow into the filling cavity 404 from the liquid inlet 406. When the sliding plug 4 is in an expanded state, the rubber sleeve 405, under the action of the pressure inside the filling cavity 404, abuts against the outside of the sliding sleeve 402 and blocks the liquid inlet 406, thereby preventing the slurry inside the filling cavity 404 from flowing out.

[0035] See Figure 4 As shown, in a further technical solution, a cylindrical recess 304 is provided at the front end of the hollow rod 3. The inner diameter of the recess 304 is larger than the inner diameter of the hollow rod 3, thereby forming a step at the rear end of the recess 304. The plug 6 is located inside the recess 304 and abuts against the step. One end of the push spring 7 contacts and engages with the plug 6, and the other end contacts and engages with the drill bit 5. Thus, during the assembly of the hollow rod 3 and the drill bit 5, the assembly of the plug 6 and the push spring 7 can be easily completed, improving the ease of implementation of this hollow grouting anchor structure.

Claims

1. A hollow grouting anchor structure, comprising a hollow rod body, a drill bit fixedly connected to the front end of the hollow rod body, and a grout outlet hole provided on the drill bit; characterized in that: The hollow rod body has a polished rod section located behind the drill bit and has a side hole. A sliding plug is installed on the polished rod section. The sliding plug includes a sliding sleeve and an elastic wall wrapped around the outside of the sliding sleeve, forming a filling cavity between the elastic wall and the sliding sleeve. A liquid inlet hole is provided on the sliding sleeve, and a check valve is installed on the liquid inlet hole. The sliding sleeve is fitted onto the polished rod section and the two are sealed together. The liquid inlet hole on the sliding sleeve communicates with the inner cavity of the hollow rod body through the side hole of the polished rod section. When the elastic wall is in a contracted state, the outer diameter of the sliding plug is smaller than the outer diameter of the drill bit. The front end of the hollow rod body has a plug that can move back and forth. A push spring is provided on the front side of the plug. The plug seals the front end of the hollow rod body under the drive of the push spring.

2. The hollow grouting anchor structure according to claim 1, characterized in that: The outer side of the elastic wall is provided with several annular elastic wings that are spaced apart front and back.

3. The hollow grouting anchor structure according to claim 1, characterized in that: The hollow rod body has an anchor thread on its outer wall, and the anchor thread is located on the rear side of the smooth rod part; the hollow rod body is provided with a pad and a fastening nut.

4. The hollow grouting anchor structure according to claim 1, characterized in that: Side holes are provided on opposite sides of the optical rod, and liquid inlet holes are provided on opposite sides of the sliding sleeve.

5. The hollow grouting anchor structure according to claim 1, characterized in that: The anti-reverse component is a rubber sleeve, which is fitted over the outside of the sliding sleeve and covers the liquid inlet hole.

6. The hollow grouting anchor structure according to claim 1, characterized in that: A cylindrical recess is provided at the front end of the hollow rod. The inner diameter of the recess is larger than the inner diameter of the hollow rod, so that the rear end of the recess forms a step. The plug is located in the recess and abuts against the step. One end of the push spring contacts the plug and the other end contacts the drill bit.

7. The hollow grouting anchor structure according to claim 1, characterized in that: The front end of the optical rod is provided with a positioning protrusion, and the sliding sleeve is made of plastic or polymer material, with a positioning pit on the inner wall that cooperates with the positioning protrusion.

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