In-situ grouting anchor cable structure for open mining broken surrounding rock

Abstract

This utility model discloses an in-situ grouting anchor cable structure for hollow mining of fractured surrounding rock, comprising: an anchor cable assembly including an anchor cable rod, an anchor, and a tray; one end of the anchor cable rod extends into the borehole in the surrounding rock, the anchor is installed at the other end of the anchor cable rod, and the tray is fitted onto the anchor cable rod, with the tray located between the anchor and the borehole; and a grouting component fitted onto the outside of the anchor cable rod, with its inner wall forming an annular grouting channel extending into the surrounding rock between the component and the surface of the anchor cable rod. The grouting component includes a grouting part and a channel part arranged coaxially, the grouting part being located between the anchor and the tray, one end of the channel part being connected to the grouting part, and the other end passing through the center of the tray and extending along the surface of the anchor cable rod. A grouting pipe is connected to the bottom of the grouting component. This utility model allows for external in-situ grouting without altering the original anchor cable structure and support performance, achieving the purpose of reinforcing the rock mass and improving the integrity and stability of the surrounding rock.

Description

Technical Field

[0001] This utility model relates to an in-situ grouting anchor cable structure for mining fractured surrounding rock in open-pit mining, belonging to the field of coal mining technology. Background Technology

[0002] With the gradual depletion of shallow coal resources, deep residual coal goaf mining has become an important direction for the continued development of coal resources in my country. However, goaf mining faces extremely complex geological conditions: First, the overlying strata of the goaf have been affected by multiple mining operations, resulting in a significant increase in the degree of rock fragmentation; second, the stress environment of the surrounding rock in the roadway is complex, exhibiting obvious asymmetric characteristics; and third, the surrounding rock has poor self-stabilizing ability and long deformation duration. Under these conditions, conventional support systems are insufficient to meet engineering requirements, and grouting reinforcement technology must be adopted to improve the overall strength and stability of the surrounding rock.

[0003] The hollow grouting anchor cables commonly used in current engineering projects have significant technical defects: due to their unique hollow structure design, while ensuring the function of the grouting channel, the tensile strength of the rod is severely weakened. In actual engineering, this structural defect leads to frequent anchor cable breakage accidents. The failure of the anchoring system not only causes the failure of surrounding rock control but also increases the harmful deformation of the surrounding rock in the roadway, seriously affecting the safe and efficient production of the mine. Summary of the Invention

[0004] To address the problems existing in the prior art, this utility model provides an in-situ grouting anchor cable structure for mining fractured surrounding rock in open-pit mines, which reinforces the fractured surrounding rock through grouting to ensure safe and efficient mine production.

[0005] To achieve the above objectives, this utility model employs an in-situ grouting anchor cable structure for excavating fractured surrounding rock, comprising:

[0006] An anchor cable assembly includes an anchor cable body, an anchor, and a tray. One end of the anchor cable body extends into a borehole in the surrounding rock, the anchor is installed at the other end of the anchor cable body, and the tray is fitted onto the anchor cable body and is located between the anchor and the borehole in the surrounding rock.

[0007] The grouting component is fitted onto the outside of the anchor rod body, and its inner wall forms an annular grouting channel extending into the surrounding rock between the surface of the anchor rod body and the inner wall of the grouting component. The grouting component includes a grouting part and a channel part arranged coaxially. The grouting part is located between the anchor and the tray. One end of the channel part is connected to the grouting part, and the other end passes through the center of the tray and extends along the surface of the anchor rod body. A grouting pipe is connected to the bottom of the grouting component.

[0008] As an improvement, the channel portion is annular and has an internal mounting cavity for installing the anchor rod, the diameter of which is larger than the outer diameter of the anchor rod.

[0009] As an improvement, the grouting part is cylindrical with a circular inner cavity inside. The bottom has a grouting interface that communicates with the inner cavity. One end of the grouting part has a fastening hole that communicates with the inner cavity and is arranged coaxially. The other end communicates with the mounting cavity of the channel part. The diameter of the fastening hole is smaller than the diameter of the inner cavity. Both the diameter of the inner cavity and the diameter of the fastening hole are larger than the outer diameter of the anchor rod.

[0010] As an improvement, a leak-proof gasket is installed between the grouting section and the anchor, and a leak-proof plug is installed between the tray and the surrounding rock.

[0011] As an improvement, the leak-proof gasket is made of rubber, and the leak-proof plug is conical and made of plastic or rubber.

[0012] As an improvement, the grouting interface is threadedly connected to the grouting pipe.

[0013] As an improvement, the grouting component is made of stainless steel.

[0014] As an improvement, the diameter of the surrounding rock borehole is 30 mm, the anchor cable rod is 1×19 strands with a diameter of 21.8 mm, and the outer diameter of the channel section is 27-28 mm.

[0015] Compared with existing technologies, the in-situ grouting anchor cable structure of this invention for hollow mining of fractured surrounding rock allows for external in-situ grouting without altering the original anchor cable's structure and support performance. This achieves the goal of reinforcing the rock mass and improving its integrity and stability. This invention avoids the easy breakage of hollow grouting anchor cable rods, effectively controls grouting in hollow mining tunnels, reduces rock fragmentation and deformation, has a reasonable structural design, is easy to use, and has a low cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a partially enlarged structural schematic diagram of the present invention;

[0018] Figure 3 This is the left view of the present invention;

[0019] Figure 4 This is a schematic diagram of the grouting component of this utility model;

[0020] In the diagram: 1. Anchor rod body, 2. Anchor, 3. Leak-proof gasket, 4. Grouting component, 41. Grouting part, 411. Fastening hole, 412. Inner cavity, 413. Grouting interface, 42. Channel part, 421. Installation cavity, 5. Grouting pipe, 6. Tray, 7. Leak-proof plug, 8. Grouting channel. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this application will be described in detail below through specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0022] like Figures 1-4 As shown, an in-situ grouting anchor cable structure for drilling broken surrounding rock includes an anchor cable assembly and a grouting component 4; the anchor cable assembly includes an anchor cable body 1, an anchor 2 and a tray 6, one end of the anchor cable body 1 extends into the surrounding rock borehole, the anchor 2 is installed at the other end of the anchor cable body 1, and the tray 6 is fitted onto the anchor cable body 1, with the tray 6 located between the anchor 2 and the surrounding rock borehole;

[0023] The grouting component 4 is fitted onto the outside of the anchor rod 1. Its inner wall forms an annular grouting channel 8 extending into the surrounding rock between itself and the surface of the anchor rod 1. The grouting channel 8 wraps around the rod 360°, and the grout, under pressure, permeates evenly into the surrounding rock fissures along the annular grouting channel 8. The grouting component 4 includes a coaxially arranged grouting part 41 and a channel part 42. The grouting part 41 is located between the anchor 2 and the tray 6. One end of the channel part 42 is connected to the grouting part 41, and the other end passes through the center of the tray 6 and extends along the surface of the anchor rod 1. A grouting pipe 5 is connected to the bottom of the grouting component 4. This invention employs external in-situ grouting. The grouting part 41 serves as a grout storage and pressure buffer cavity, stabilizing the grouting pressure. The channel part 42 extends along the anchor rod into the deep part of the surrounding rock, forming a grouting path of "storage near the borehole opening - permeation far from the borehole opening," effectively covering the fractured area of ​​the surrounding rock caused by open-hole mining. The anchor cable assembly (anchor cable rod, anchor, and tray) bears the tensile stress, while the grouting component serves as an auxiliary reinforcement component, avoiding the weakening of the rod strength caused by the grouting channel in traditional hollow anchor cables.

[0024] In some embodiments, such as Figure 4 As shown, the channel portion 42 is annular, with an internal mounting cavity 421 for installing the anchor rod 1. The diameter of the mounting cavity 421 is larger than the outer diameter of the anchor rod 1. The annular gap (i.e., the grouting channel 8) between the mounting cavity 421 and the anchor rod 1 forms a continuous grout delivery path, allowing the grout to penetrate evenly into the surrounding rock along the surface of the anchor rod. Compared to non-annular structures, this design avoids clogging of the grouting channel, ensuring a wider grout coverage area, and is particularly suitable for all-round reinforcement of fractured surrounding rock.

[0025] In some embodiments, such as Figure 4As shown, the grouting part 41 is cylindrical, conforming to the principle of uniform force distribution in mechanics, and can withstand lateral pressure during the grouting process, avoiding deformation. The grouting part 41 has a circular inner cavity 412, providing ample space to store grouting material. The bottom of the grouting part 41 has a grouting interface 413 communicating with the inner cavity 412. The grouting interface 413 directly connects to the inner cavity 412, allowing for rapid introduction of the grout transported by the grouting pipe 5 into the inner cavity 412, reducing energy loss during transmission and improving grouting efficiency. One end of the grouting part 41 has a fastening device that communicates with and is coaxially arranged with the inner cavity 412. The other end of the hole 411 is connected to the mounting cavity 421 of the channel 42. The diameter of the fastening hole 411 is smaller than the diameter of the inner cavity 412, forming a stepped structure, which restricts the grouting component 4 from moving axially along the anchor rod 1, ensuring the stability of the grouting channel 8 and avoiding grouting failure due to component displacement during grouting. The diameter of the inner cavity 412 and the diameter of the fastening hole 411 are both larger than the outer diameter of the anchor rod 1, ensuring that the anchor rod can pass smoothly through the grouting part 41. At the same time, an annular grouting channel 8 is formed between the inner wall of the grouting component 4 and the surface of the anchor rod, providing a path for the grout to penetrate into the surrounding rock.

[0026] In some embodiments, such as Figure 1 , Figure 2 As shown, a leak-proof gasket 3 is installed between the grouting section 41 and the anchor 2. The leak-proof gasket 3 can tightly fill the connection gap between the grouting section 41 and the anchor 2, preventing high-pressure grout from overflowing from the interface during grouting. This ensures that the grout penetrates deep into the surrounding rock along the preset annular grouting channel 8, improving the uniformity and effectiveness of grouting. A leak-proof plug 7 is installed between the tray 6 and the surrounding rock. The tray 6 is in close contact with the surface of the surrounding rock, and the leak-proof plug 7 is installed between the tray 6 and the surrounding rock. This forms a sealed boundary during grouting. When the grout is injected into the surrounding rock borehole through the channel section 42, the leak-proof plug 7 can prevent the grout from flowing back or overflowing from the gap between the borehole and the tray, allowing the grout to concentrate and diffuse in the fractured area of ​​the surrounding rock, thereby effectively filling the cracks and improving the integrity of the surrounding rock. Without the leak-proof plug 7, the grout may accumulate or leak from the borehole, resulting in insufficient grouting of the deep surrounding rock.

[0027] In some embodiments, the leak-proof gasket 3 is made of rubber; the leak-proof plug 7 is conical. The grouting pressure or anchor cable tension will cause the cone to be squeezed towards the orifice, resulting in increased contact pressure between the cone surface and the tray hole wall and the surrounding rock surface, forming a self-sealing effect of "the more it is pressed, the tighter it becomes". The leak-proof plug 7 is made of plastic or rubber. The rubber leak-proof gasket 3 and leak-proof plug 7 have high elasticity and flexibility, and can form a tight fit at the connection interface between the grouting part 41 and the anchor 2, and between the tray 6 and the surrounding rock. Even if there are small tolerances or stress deformations at the interface, they can fill the gaps through elastic deformation, effectively preventing grout leakage.

[0028] In some embodiments, the grouting interface 413 and the grouting pipe 5 are connected by threads. For example, the grouting interface 413 is provided with internal threads, and the end of the grouting pipe 5 is provided with external threads. The engagement of the internal and external threads forms a rigid connection, which can withstand the high pressure during the grouting process, avoid the interface from falling off or loosening due to pressure fluctuations, and ensure the continuity of the grouting operation.

[0029] In some embodiments, the grouting component 4 is made of stainless steel, which has good high tensile strength and compressive strength.

[0030] In some embodiments, the diameter of the surrounding rock borehole can be 30 mm, the anchor cable rod 1 is 1×19 strands (1 central steel wire + 19 outer steel wires; suitable for medium and high stress surrounding rock support) with a diameter of 21.8 mm, the outer diameter of the channel part 42 is 27-28 mm, the diameter of the mounting cavity 421 is 24-25 mm, the diameter of the inner cavity 412 is 30-34 mm, and the outer diameter of the grouting part 41 is 38-44 mm.

[0031] The specific steps for installation and use are as follows:

[0032] 1) Place the anchor 2 on the exposed end (non-drilled insertion end) of the anchor rod 1, and then install a leak-proof gasket 3 between the contact surface of the anchor 2 and the grouting component 4 to ensure that the gasket completely covers the connection gap; the installation position of the anchor 2 should reserve enough space (e.g., 30-50mm from the hole) to facilitate the subsequent installation and fastening of the grouting anchor structure 4.

[0033] 2) Pass the fastening hole 411 of the grouting part 4 through the anchor rod body 1, so that the grouting part 41 is located at the preset position of the anchor 2 and the tray 6. Tighten the grouting part 41 with a wrench or special tool to ensure that the fastening hole 411 is tightly fitted with the anchor rod body 1. At the same time, check whether the direction of the grouting interface 413 is convenient for connecting the grouting pipe 5.

[0034] 3) Pass the tray 6 through the anchor rod 1 and fit it on the outside of the channel 42 so that it is tightly attached to the surface of the surrounding rock; then install the conical anti-leakage plug 7 between the tray 6 and the surrounding rock, and use the tensioning equipment to apply a pre-tightening force (usually 80% of the design anchoring force) to the anchor rod 1 so that the tray 6 compacts the surface of the surrounding rock through the anti-leakage plug 7.

[0035] 4) Tighten the external thread end of the grouting pipe 5 to the internal thread of the grouting interface 413 (use PTFE tape or sealant to enhance the sealing), connect the grouting pump pipeline, start the grouting pump for no-load test run, and check whether the grouting pressure and flow rate are stable.

[0036] 5) Inject the prepared grout into the hopper of the grouting pump, slowly increase the pressure to the initial pressure of 2MPa, and continue grouting until the grout seeps out evenly from the cracks in the surrounding rock; then gradually increase the pressure to 8MPa, maintain the pressure for 5-10 minutes, and stop grouting when the grout volume is significantly reduced. Disassemble the grouting pipe 5 and clean the grouting system.

[0037] This invention relates to an in-situ grouting anchor cable structure for hollow mining of fractured surrounding rock. Without altering the original anchor cable's structure and support performance, it allows for external in-situ grouting, thereby reinforcing the rock mass and improving its integrity and stability. This invention avoids the easy breakage of hollow grouting anchor cable rods, effectively controls grouting in hollow mining tunnels, reduces rock fragmentation and deformation, features a reasonable structural design, is easy to use, and has a low cost.

[0038] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this utility model and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

Claims

1. A structure of in-situ grouting anchor cable for open mining broken surrounding rock, characterized in that, include: An anchor cable assembly includes an anchor cable body (1), an anchor (2) and a tray (6). One end of the anchor cable body (1) extends into the surrounding rock borehole, the anchor (2) is installed at the other end of the anchor cable body (1), and the tray (6) is fitted onto the anchor cable body (1) and is located between the anchor (2) and the surrounding rock borehole. Grouting component (4) is fitted onto the outside of the anchor rod body (1). Its inner wall forms an annular grouting channel (8) extending into the surrounding rock between the surface of the anchor rod body (1) and the inner wall of the grouting component (4). The grouting component (4) includes a grouting part (41) and a channel part (42) arranged coaxially. The grouting part (41) is located between the anchor (2) and the tray (6). One end of the channel part (42) is connected to the grouting part (41), and the other end passes through the center of the tray (6) and extends along the surface of the anchor rod body (1). A grouting pipe (5) is connected to the bottom of the grouting component (4). The channel part (42) is annular and has a hole inside for installing the anchor rod. The installation cavity (421) of the body (1) has a diameter greater than the outer diameter of the anchor rod body (1); the grouting part (41) is cylindrical and has a circular inner cavity (412) inside. The bottom is provided with a grouting interface (413) communicating with the inner cavity (412). One end of the grouting part (41) is provided with a fastening hole (411) communicating with the inner cavity (412) and arranged coaxially. The other end is connected to the installation cavity (421) of the channel part (42). The diameter of the fastening hole (411) is smaller than the diameter of the inner cavity (412). The diameter of the inner cavity (412) and the diameter of the fastening hole (411) are both greater than the outer diameter of the anchor rod body (1).

2. The in-situ grouting anchor cable structure for mining broken surrounding rock by kicking off according to claim 1, characterized in that, A leak-proof gasket (3) is installed between the grouting part (41) and the anchor (2), and a leak-proof plug (7) is installed between the tray (6) and the surrounding rock.

3. The in-situ grouting anchor cable structure for mining broken surrounding rock by kicking off according to claim 2, characterized in that, The leak-proof gasket (3) is made of rubber, and the leak-proof plug (7) is conical and made of plastic or rubber.

4. The in-situ grouting anchor cable structure for mining broken surrounding rock by kicking off according to claim 1, characterized in that, The grouting interface (413) and the grouting pipe (5) are connected by threads.

5. The in-situ grouting anchor cable structure for mining broken surrounding rock by kicking off according to claim 1, characterized in that, The grouting component (4) is made of stainless steel.

6. The in-situ grouting cable structure for mining broken surrounding rock by kicking off according to claim 1, characterized in that, The diameter of the surrounding rock borehole is 30mm, the anchor rod (1) is 1×19 strands with a diameter of 21.8mm, and the outer diameter of the channel (42) is 27-28mm.

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