Single-hole pressure concentration type anchor cable cluster for mine and construction method
Patent Information
- Application Number
- CN202610998811.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-06
- Publication Date
- 2026-08-11
AI Technical Summary
从受力分析上该技术仍存在以下问题：1）锚索孔密集布置，顶板岩体受到一定程度损伤；2）锚索锚固机制仍属拉力集中型锚索，锚索载荷分布集中；3）单根锚索难以承受顶板不均匀变形或水平错动带来的软剪切破坏
[0022]随着开采深度的加大、工程地质条件恶化等影响，矿用单体锚索以显现出力所不及的现象，支护失效问题日趋频繁。目前，出现的部分矿用锚索为基础研发的线性锚索束、盘式锚索束、笼式锚索等等，但从力学机制上看，仍属拉力集中型锚索，受力机制没有改变，对围岩大变形控制仍然较为困难。本发明针对单孔多根锚索束式结构特点，开展锚索选型、单孔多根锚索束式尾部锚定结构设计改进及配套垫板形式研究。针对单孔锚索束注浆锚固形式，提出合适的施工安装工艺，明确顶板单孔锚索束钻孔封孔及注浆工艺，实现单孔锚索束强力有效锚固，提高支护结构体整体承载性能。与拉力集中型锚索相比，压力集中型锚索具有承载能力大、受力更合理等显著优势。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of underground roadway support technology in coal mines, and in particular to a single-hole pressure-concentrated anchor cable cluster for mining and its construction method. Background Technology
[0002] With the increasing mining depth in coal mines in central and eastern my country, after entering the deep layers, the practice of roadway support engineering has encountered problems such as continuous and uncontrollable large deformation of the surrounding rock, severe cross-sectional convergence, and roadways with anchor bolts and cables as the main support technology experiencing breakage and ejection leading to disasters. The frequency of these problems has increased significantly and is becoming the norm. The mileage of roadways in disrepair is showing a continuous upward trend, exacerbating the tight situation of mine succession and seriously restricting the safe and efficient production of coal mines.
[0003] Extensive engineering practice has demonstrated that anchor cables play a crucial role in the support of complex roadways (such as high-stress roadways, soft rock roadways, roadways affected by dynamic pressure, and roadways with goaf retention), and to some extent, have become an indispensable support method. However, in the engineering field, once anchor cables fail, the only recourse is to passively adjust support parameters and install additional anchor cables to control further damage to the surrounding rock. In this situation, the mechanical coupling between the old and new support structures inevitably encounters problems, resulting in a less than expected effect in controlling the surrounding rock.
[0004] To improve the safety level of roadway roof, research teams have proposed roof anchor cable bundle safety assurance technology in recent years. The main mechanism involves arranging 3-5 anchor cables on the same high-strength external anchor member, using anchor cables of different lengths to achieve tiered anchoring with other anchor cables, avoiding stress concentration in the same rock stratum within the inner anchor section. Simultaneously, a single hollow grouting anchor cable is used to achieve full-length anchoring of all anchor cables in the bundle, thus preventing individual cable breakage. However, this technology still has the following problems from a stress analysis perspective: 1) The dense arrangement of anchor cable holes causes some damage to the roof rock mass; 2) The anchoring mechanism is still a tension-concentrated type, resulting in concentrated anchor cable load distribution; 3) A single anchor cable is difficult to withstand soft shear failure caused by uneven roof deformation or horizontal displacement.
[0005] Therefore, it is necessary to provide a single-hole pressure-concentrated anchor cable cluster for mining and a construction method to solve the above-mentioned technical problems. Summary of the Invention
[0006] To address the challenge of controlling the surrounding rock of the roadway roof after entering deep mining and to prevent large-scale roof collapse accidents caused by the systematic failure of the anchor mesh support system, this paper proposes a single-hole pressure-concentrated anchor cluster support structure based on the analysis of the anchoring stress and failure modes of conventional single anchor cables. The research focuses on the support mechanism of pressure-concentrated anchor clusters, and the development of steel strand selection, in-hole and tail anchoring structure design, high-strength pad design, and sealing structure. This clarifies the construction process, including the installation and grouting parameters of the single-hole anchor clusters, achieving strong and effective anchoring of the single-hole anchor clusters, significantly improving the overall bearing capacity of the roadway roof, and ensuring roadway support safety.
[0007] To solve the above-mentioned technical problems, the present invention provides a single-hole pressure-concentrated anchor cable cluster for mining, comprising:
[0008] A single-hole pressure-concentrated anchor cable cluster for mining is installed in a hole body, which is pre-drilled at the top of the roadway. The single-hole pressure-concentrated anchor cable cluster for mining includes: a support plate, a grouting pipe, an unbonded prestressed anchor cable, an inner anchor plate, an outer anchor plate, an outer anchor wedge, a through hole, an inner anchor wedge, and a pad plate.
[0009] Preferably, there are multiple sets of support plates arranged in parallel to each other; the support plates are in the shape of circular plates, with through holes in the middle and outer sides for grouting pipes and unbonded prestressed anchor cables to pass through; multiple sets of elastic fixing clips are provided on the edge of the support plate at the top.
[0010] Preferably, the unbonded prestressed anchor cable is configured as three cables, which are integrated with the grouting pipe by multiple sets of support plates and placed in the borehole.
[0011] Preferably, an inner anchor plate is provided on the upper side of the support plate at the top position. The middle of the inner anchor plate is also provided with a through hole for the grouting pipe to pass through. The end of the unbonded prestressed anchor cable is assembled and locked together with the inner anchor plate by the inner anchor clamp.
[0012] Preferably, the bottom end of the unbonded prestressed anchor cable is assembled with the outer anchoring plate by means of the outer anchoring clip.
[0013] Preferably, the opening of the hole is sealed by the pad outside the hole, and the pad is also provided with through holes for the grouting pipe and the unbonded prestressed anchor cable to pass through.
[0014] Preferably, a section of the body placed inside the hole on one side of the hole opening is designated as a sealing section, which is pre-filled with a foaming agent.
[0015] This invention also proposes a construction method for the single-hole pressure-concentrated anchor cable cluster used in mining, the main steps of which are:
[0016] S1. Drill holes in the tunnel to obtain anchor cable installation holes, forming a hole body;
[0017] S2. The unbonded prestressed anchor cable and grouting pipe are installed using multiple sets of support plates. The top and bottom of the unbonded prestressed anchor cable are assembled and locked together with the inner anchor plate and the outer anchor plate respectively through the inner anchor clip and the outer anchor clip. Then, the entire anchor cable cluster is placed into the hole and rotated at a certain angle. Under the action of the fixing clip, the entire anchor cable cluster is prevented from falling.
[0018] S3. Foaming agent is pre-injected into the sealing section to form a sealing structure after molding, which facilitates subsequent grouting.
[0019] S4. Inject the prepared grout into the hole through the grouting pipe. During the grouting process, the grouting pipe also serves as an air vent. After the grouting is completed, wait for it to set.
[0020] S5. Under the operation of the tensioning machine, the prestressed tension is completed at the preset pressure.
[0021] Compared with related technologies, the present invention has the following beneficial effects:
[0022] With increasing mining depth and deteriorating engineering geological conditions, single anchor cables used in mining are showing signs of inadequacy, leading to increasingly frequent support failures. Currently, some linear anchor bundles, disc anchor bundles, and cage anchor cables have been developed based on existing mining anchor cables. However, from a mechanical perspective, they are still tension-concentrated anchor cables, and the stress mechanism remains unchanged, making it difficult to control large deformations of the surrounding rock. This invention addresses the characteristics of single-hole multi-anchor cable bundle structures, focusing on anchor cable selection, design improvements to the tail anchoring structure, and the form of matching pads. For grouting anchoring of single-hole anchor bundles, a suitable construction and installation process is proposed, clarifying the drilling, sealing, and grouting processes for single-hole anchor bundles in the roof, achieving strong and effective anchoring of single-hole anchor bundles and improving the overall load-bearing capacity of the support structure. Compared with tension-concentrated anchor cables, pressure-concentrated anchor cables have significant advantages such as greater load-bearing capacity and more rational stress distribution. Attached Figure Description
[0023] Figure 1 A schematic diagram of the structure of the first embodiment of the single-hole pressure-concentrated anchor cable cluster for mining provided by the present invention;
[0024] Figure 2 for Figure 1 View from AA direction;
[0025] Figure 3 for Figure 1 BB-direction view;
[0026] Figure 4A schematic diagram of the structure of a second embodiment of the single-hole pressure-concentrated anchor cable cluster for mining provided by the present invention;
[0027] Figure 5 for Figure 4 CC view.
[0028] The following are the labels in the diagram: 1. Hole body, 2. Support plate, 3. Grouting pipe, 4. Unbonded prestressed anchor cable, 5. Inner anchor plate, 6. Outer anchor plate, 7. Outer anchor clamp, 8. Sealing section, 9. Through hole, 10. Inner anchor clamp, 11. Positioning clamp, 12. Pad, 13. Fixing clip. Detailed Implementation
[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0030] First Embodiment
[0031] Please refer to the following: Figure 1 , Figure 2 , Figure 3 ,in, Figure 1 A schematic diagram of the structure of the first embodiment of the single-hole pressure-concentrated anchor cable cluster for mining provided by the present invention; Figure 2 for Figure 1 View from AA direction; Figure 3 for Figure 1 BB view.
[0032] A single-hole pressure-concentrated anchor cable cluster for mining is installed in a hole body 1, including: a support plate 2, a grouting pipe 3, an unbonded prestressed anchor cable 4, an inner anchor plate 5, an outer anchor plate 6, an outer anchor wedge 7, a through hole 9, an inner anchor wedge 10, and a pad plate 12.
[0033] The hole is formed by pre-drilling holes in the top of the tunnel. The hole has a diameter of about 63 mm and a depth of about 8-10 m.
[0034] There are multiple sets of support plates 2, arranged in parallel to each other. The support plates are circular in shape with a diameter of about 50 mm. Through holes 9 are opened in the middle and on the outer side for the grouting pipe 3 and the unbonded prestressed anchor cable 4 to pass through. The diameter of the through holes 9 is slightly larger than the outer diameter of the grouting pipe 3 and the unbonded prestressed anchor cable 4.
[0035] The outer diameter of the unbonded prestressed anchor cable 4 is approximately 17.8 mm. In this embodiment, three unbonded prestressed anchor cables 4 are used, and three through holes are opened at corresponding positions on the support plate. The three unbonded prestressed anchor cables 4 and the grouting pipe 3 are integrated by multiple sets of support plates 2 and placed in the hole body 1. Multiple sets of elastic fixing clips 13 are provided on the edge of the top support plate, which play a role in fixing and limiting the anchor cable cluster after it is placed into the hole body.
[0036] In addition, an inner anchor plate 5 is provided on the upper side of the support plate 2 at the top position. The middle of the inner anchor plate 5 also has a through hole for the grouting pipe 3 to pass through. The end of the unbonded prestressed anchor cable 4 is assembled and locked together with the inner anchor plate 5 through the inner anchor clamp 10. The outer anchor plate 6 is tightly attached to the pad plate 12.
[0037] On the outside of the opening of the borehole 1, the opening of the borehole is sealed by a pad plate 12. The pad plate 12 is also provided with a through hole for the grouting pipe and the unbonded prestressed anchor cable to pass through. In addition, the bottom end of the unbonded prestressed anchor cable 4 is assembled with the outer anchor plate 6 by the outer anchor clamp 7.
[0038] It should be noted that for the unbonded prestressed anchor cable, the sheath on its surface needs to be removed before assembly with the inner and outer anchor plates, while the sheath needs to be retained for the section placed between the inner and outer anchor plates.
[0039] In this embodiment, a section of the body placed inside the hole on one side of the hole opening is designated as the sealing section 8. The sealing section 8 is pre-filled with a foaming agent, and the depth of the sealing section is approximately 300-400 mm.
[0040] The construction process of this invention, a single-hole pressure-concentrated anchor cable cluster for mining, mainly includes the following steps:
[0041] S1. Drill holes in the tunnel to obtain anchor cable installation holes, forming hole body 1.
[0042] S2. The unbonded prestressed anchor cable 4 and the grouting pipe 3 are installed using multiple sets of support plates 2. The spacing between adjacent anchor cables is slightly greater than or slightly less than the spacing between the two corresponding through holes in the support plate. The top and bottom of the unbonded prestressed anchor cable 4 are assembled and locked together with the inner anchor plate 5 and the outer anchor plate 6 respectively through the inner anchor clamp 10 and the outer anchor clamp 7. Then, the entire anchor cable cluster is placed into the hole 1 and rotated at a certain angle. Under the action of the fixing clip, the entire anchor cable cluster is prevented from falling down.
[0043] S3. Foaming agent is pre-injected at position 8 of the sealing section to form a sealing structure after molding, which facilitates subsequent grouting.
[0044] S4. Inject the prepared grout (usually cement mortar) into the hole through grouting pipe 3. During the grouting process, the grouting pipe also serves as an air vent. After grouting is completed, wait for it to set.
[0045] S5. Under the operation of the tensioning machine, the prestressed tension is completed at the preset pressure.
[0046] Compared with related technologies, the single-hole pressure-concentrated anchor cable cluster for mining provided by this invention has the following beneficial effects:
[0047] This invention enables strong and effective anchoring of a single-hole anchor cable bundle, improving the overall load-bearing capacity of the support structure. Compared with tension-concentrated anchor cables, pressure-concentrated anchor cables have significant advantages such as greater load-bearing capacity and more rational stress distribution.
[0048] Second Embodiment
[0049] Please refer to the following: Figure 4 , Figure 5 Based on the first embodiment of this application which provides a single-hole pressure-concentrated anchor cable cluster for mining, the second embodiment of this application proposes another single-hole pressure-concentrated anchor cable cluster for mining. The second embodiment is merely a preferred embodiment of the first embodiment, and the implementation of the second embodiment will not affect the separate implementation of the first embodiment.
[0050] Specifically, the second embodiment of this application provides a mining single-hole pressure-concentrated anchor cable cluster that differs in that multiple sets of positioning clamps 11 are used to limit and support the unbonded prestressed anchor cables 4 and the grouting pipe 3, which can replace the support plate in the first embodiment. The positioning clamps 11, relying on moderate compression between themselves and the three unbonded prestressed anchor cables 4, prevent them from falling off. Simultaneously, during the grouting process and subsequent support processes, uniform stress distribution can be achieved, improving the overall load-bearing capacity of the support structure.
Claims
1. A single-hole pressure-concentrating anchor cable cluster for mining, installed in a borehole body, the borehole body being pre-drilled in the top of the roadway, characterized in that, The single-hole pressure-concentrated anchor cable cluster for mining includes: a support plate, a grouting pipe, an unbonded prestressed anchor cable, an inner anchor plate, an outer anchor plate, an outer anchor wedge, a through hole, an inner anchor wedge, and a pad.
2. The single-hole pressure-concentrated anchor cable cluster for a mine according to claim 1, characterized by, The support plates are arranged in multiple sets, parallel to each other; the support plates are circular, with through holes in the middle and outer sides for grouting pipes and unbonded prestressed anchor cables to pass through; multiple sets of elastic fixing clips are provided on the edge of the top support plate.
3. The single-hole, pressure-concentrated, anchor-cable cluster for mining use according to claim 2, characterized in that, The unbonded prestressed anchor cable is set to 3 cables, which are integrated with the grouting pipe by multiple sets of support plates and placed in the borehole.
4. The single-hole, pressure-concentrated, anchor-cable cluster for mining use according to claim 3, characterized in that, An inner anchor plate is provided on the upper side of the support plate at the top position. The middle of the inner anchor plate is also provided with a through hole for the grouting pipe to pass through. The end of the unbonded prestressed anchor cable is assembled and locked together with the inner anchor plate by the inner anchor clamp.
5. The single-hole, pressure-concentrated, anchor-cable cluster for mining use according to claim 4, characterized in that, The bottom end of the unbonded prestressed anchor cable is assembled with the outer anchor plate by means of the outer anchor clamp.
6. The single-hole, pressure-concentrated, anchor-cable cluster for mining use according to claim 5, characterized in that, The opening of the hole is sealed off by the pad plate on the outside of the hole body. The pad plate is also provided with through holes for grouting pipes and unbonded prestressed anchor cables to pass through.
7. The single-hole, pressure-concentrated, anchor-cable cluster for mining use according to claim 6, characterized in that, The section of the body placed inside the hole on one side of the hole opening is designated as the sealing section, which is pre-filled with a foaming agent.
8. The method of constructing a single-hole pressure-concentrated anchor cable cluster for mining according to claim 7, characterized by, The main steps are as follows: S1. Drill holes in the tunnel to obtain anchor cable installation holes, forming a hole body; S2. The unbonded prestressed anchor cable and grouting pipe are installed using multiple sets of support plates. The top and bottom of the unbonded prestressed anchor cable are assembled and locked together with the inner anchor plate and the outer anchor plate respectively through the inner anchor clip and the outer anchor clip. Then, the entire anchor cable cluster is placed into the hole and rotated at a certain angle. Under the action of the fixing clip, the entire anchor cable cluster is prevented from falling. S3. Foaming agent is pre-injected into the sealing section to form a sealing structure after molding, which facilitates subsequent grouting. S4. Inject the prepared grout into the hole through the grouting pipe. During the grouting process, the grouting pipe also serves as an air vent. After the grouting is completed, wait for it to set. S5. Under the operation of the tensioning machine, the prestressed tension is completed at the preset pressure.