A vertical claw type prestressed anchor rod pad device

Abstract

The utility model relates to a kind of vertical claw type prestressed anchor rod backing plate device, including steel backing plate and vertical claw subassembly, the steel backing plate has the central aperture for the anchor rod to pass and set, the vertical claw subassembly includes three vertical claws, each the vertical claw is bent into the supporting member with elastic deformability by round steel, it is welded in the bottom surface of the steel backing plate in the way of triangular type uniform distribution, as the reverse support of steel backing plate and realize leveling by elastic deformation when rock surface uneven;The tail of the anchor rod is fixed on the steel backing plate by nut, when nut is tightened, the distance of steel backing plate and rock surface is compressed, ensure that the steel backing plate is always parallel to rock surface, the anchor rod, steel backing plate and nut are installed and fixed vertically with rock surface in a straight line.The utility model realizes the supporting effect that anchor rod force transmission is stable, and sticking performance is reliable.

Description

Technical Field

[0001] This utility model relates to the field of tunnel construction, and in particular to a claw-type prestressed anchor plate device. Background Technology

[0002] After excavation, the surrounding rock of a tunnel will loosen and deform to varying degrees, requiring timely reinforcement by the support system to maintain structural stability. As a key component of the initial tunnel support system, rock bolts improve the overall stability of weak and loose surrounding rock by providing prestress to the rock mass, limiting rock deformation, and forming a load-bearing framework. Traditional construction methods typically involve directly attaching steel plates to the rock surface, combined with shotcrete and steel arches to form a combined support structure, providing timely and effective stabilization and restraint of the surrounding rock, which is crucial for ensuring the safety of tunnel construction and operation.

[0003] However, traditional anchor bolt installation techniques are often hampered by factors such as uneven rock surfaces and difficulty in controlling drilling inclination, making it difficult to ensure a tight fit between the anchor bolt, bearing plate, and rock surface, leading to unstable force transmission. Firstly, poor rock surface flatness makes it difficult for the steel bearing plate to achieve a reliable fit, thus affecting the effective transmission of axial force and reducing the anchor bolt's reinforcement effect. Secondly, when the steel bearing plate is in direct contact with irregular rock surfaces, problems such as bearing plate tilting and localized suspension are common, resulting in a decrease in the overall stability of the support structure. Thirdly, the large fluctuations in the stress state of a single anchor bolt can affect the collaborative load-bearing capacity of the support system formed by the anchor bolt, shotcrete, and steel arch, making it difficult for the support system to achieve the expected overall stiffness and safety reserve. Therefore, how to improve the quality of anchor bolt installation, enhance the stability of the bearing plate, and strengthen the collaborative load-bearing capacity of the support system has become an urgent technical problem to be solved. Utility Model Content

[0004] In view of the above-mentioned defects of the existing technical solutions, the main purpose of this utility model is to develop a claw-type prestressed anchor plate device to achieve a stable force transmission and reliable fit performance of the anchor.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A prestressed anchor plate device with vertical claws includes a steel plate and a claw assembly. The steel plate has a central opening for the anchor to pass through. The claw assembly includes three claws, each of which is a round steel bent into an elastic and deformable support member, and is welded to the bottom surface of the steel plate in a triangular and evenly distributed manner. These claws serve as a reverse support for the steel plate and achieve leveling through elastic deformation when the rock surface is uneven. The tail of the anchor is fixed to the steel plate by a nut. When the nut is tightened, the distance between the steel plate and the rock surface is compressed, ensuring that the steel plate is always parallel to the rock surface. The anchor, steel plate, and nut are installed and fixed in a straight line perpendicular to the rock surface.

[0006] Preferably, the anchor bolt is an expansion-shell type anchor bolt, with an expansion shell at the bottom of the anchor bolt to form radial expansion support within the anchoring hole.

[0007] Preferably, the diameter of the central opening is 25-30 mm.

[0008] Preferably, the steel pad has a size of 20cm × 20cm.

[0009] Preferably, an initial gap of 2 to 5 cm is formed between the steel pad and the rock surface.

[0010] Preferably, when encountering a large, uneven rock surface, the vertical claw can adjust the height of the three-point support by auxiliary drilling to further improve the flatness of the steel pad installation.

[0011] Preferably, the diameter of the round steel bar is 6 mm.

[0012] Preferably, the bending angle at the contact point between the vertical claw and the rock surface is 120°.

[0013] Preferably, after the steel pad is installed, a layer of sprayed concrete is applied, and the concrete layer and the steel pad form an integral and solidified structure.

[0014] Preferably, a compression spring is fitted on the outer side of the anchor bolt. The compression spring is located between the steel pad and the rock surface and can generate elastic compression when the nut is tightened or the surrounding rock undergoes convergent deformation, so as to provide continuous elastic support for the steel pad.

[0015] The beneficial effects of this utility model are as follows: By adopting a vertical claw structure with elastic leveling capability, this utility model enables the steel pad to reliably fit under uneven rock surface conditions, thereby significantly improving the overall installation quality and stability of the anchor rod, pad, and bolts; each anchor rod works under a more ideal stress state, giving the support system formed by the anchor rod, shotcrete, and steel arch a stronger synergistic bearing capacity, constructing a stable and continuous reinforcement ring, and improving the overall safety reserve of the surrounding rock; at the same time, good installation quality can effectively avoid rework caused by problems such as the shell not opening, rod breakage, and hole misalignment, reducing material waste and equipment occupation, and lowering the overall construction cost; in addition, a more stable surrounding rock environment also provides a safer, flatter, and more controllable working surface for subsequent secondary lining and other processes, helping to reduce the risks of deformation encroachment and local collapse, and improving the safety and quality level of the entire construction process. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the vertical claw type prestressed anchor plate device of this utility model; Figure 2 yes Figure 1 Cross-sectional view at point AA; Figure 3 This is a schematic diagram of the vertical claw assembly structure of this utility model; Figure 4 This is a schematic diagram of the overall structure of the vertical claw type prestressed anchor plate device according to another embodiment of this utility model; Explanation of reference numerals in the attached drawings: 1-Steel pad; 11-Center opening; 2-Claw assembly; 21-Claw; 3-Anchor bolt; 4-Nut; 5-Rock surface; 6-Expansion shell; 7-Concrete layer; 8-Compression spring. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model belong to the present utility model.

[0019] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0020] Please see Figure 1-3This embodiment discloses a claw-type prestressed anchor plate device, including a steel plate 1 and a claw assembly 2. The steel plate 1 has a central opening 11 for the anchor 3 to pass through. The steel plate 1 serves as a force transmission and support component for the outer end of the anchor 3. Its central opening 11 is used to ensure that the anchor 3 can accurately pass through the plate and form a stable connection with the fastener, so that the prestress can be transmitted more evenly to the steel plate 1 and the surrounding rock behind it. The support claw assembly 2 includes three support claws 21. Each support claw 21 is made of round steel bent into a support member with elastic deformation capability. They are welded to the bottom surface of the steel pad 1 in a triangular and evenly distributed manner. The triangular arrangement of the support claws 21 can naturally form a support geometry in which three points determine a plane. This allows the steel pad 1 to rotate and adjust the fulcrum appropriately even when the rock surface 5 is uneven. Automatic leveling is achieved through the elastic deformation of the support claws 21, which improves the problem of unstable rock adhesion of traditional pads. At the same time, the elastic characteristics of the round steel structure enable it to buffer and adjust local protrusions or depressions, maintaining the stable stress state of the steel pad 1. The tail of the anchor bolt 3 is fixed to the steel pad 1 by the nut 4. When the nut 4 is tightened, it compresses the distance between the steel pad 1 and the rock surface 5, causing the vertical claw 21 to deform further during the compression process to compensate for the undulation of the rock surface 5. This ensures that the steel pad 1 is always parallel to the rock surface 5 and maintains a reliable fit. The anchor bolt 3, the steel pad 1, and the nut 4 are installed and fixed in a straight line perpendicular to the rock surface 5. This vertical arrangement can ensure that the force axis of the anchor bolt 3 is accurate, the pre-tightening force is fully transmitted, and improve the stress stability and collaborative bearing capacity of the overall support system.

[0021] Furthermore, the anchor bolt 3 is an expansion shell type anchor bolt, with an expansion shell 6 at the bottom of the anchor bolt 3 to form radial expansion support in the anchor hole. After being stretched, the expansion shell 6 can open radially and press tightly against the hole wall, so that the anchor bolt 3 forms a reliable anchor point in the surrounding rock, thereby ensuring that the prestress can be stably transmitted to the rock mass and improving the overall support effect.

[0022] In this embodiment, the diameter of the central opening 11 is 25-30mm. The size of the central opening 11 is matched with the outer diameter of the anchor rod 3, so that the anchor rod 3 can smoothly pass through the steel pad 1 and reliably cooperate with the fastener, i.e., the nut 4. This avoids shaking or eccentric force caused by an excessively large opening diameter, and also avoids the insertion efficiency of the anchor rod 3 being affected by an excessively small opening diameter. The size of the steel pad 1 is 20cm×20cm, but it can be adjusted according to the design drawings and the surrounding rock conditions on site to meet different anchor rod specifications and support requirements. An initial distance of 2-5cm is formed between the steel pad 1 and the rock surface 5, preferably 5cm. This initial distance provides the necessary elastic deformation space for the upright claw 21, so that the upright claw 21 can automatically level itself according to the unevenness of the rock surface 5 during installation, and maintain the flatness of the steel pad 1 through compression deformation after the nut 4 is tightened, thereby adapting to different geological conditions.

[0023] In addition, when encountering a large uneven rock surface 5, the vertical claw 21 can adjust the height position of the three-point support by auxiliary drilling to further improve the installation flatness of the steel pad 1. By setting small holes in the local concave area as support points for the vertical claw 21, the triangular support structure of the vertical claw 21 can obtain better geometric stability, ensuring that the steel pad 1 can achieve reliable fit even when facing a complex rock surface 5.

[0024] Specifically, the diameter of the round steel is 6mm, and the vertical claw 21 is machined from 6mm round steel to give it sufficient strength and elasticity. This allows it to maintain structural stability under prestress and provide necessary elastic adjustment under compression. The bending angle at the contact point between the vertical claw 21 and the rock surface 5 is 120°. This 120° angle gives the vertical claw 21 good stability and mechanical distribution characteristics, enabling it to achieve a larger contact range and reduce eccentric load when in contact with the uneven rock surface 5, thereby improving the reliability of the support.

[0025] After the steel pad 1 is installed, a layer of concrete 7 is sprayed. The concrete layer 7 and the steel pad 1 form an integral and solidified structure. The concrete layer 7 covers the steel pad 1, which can connect the anchor 3, the steel pad 1 and the surrounding rock 5 into a whole, so that the support system has a stronger synergistic bearing capacity and improves the overall stability of the tunnel surrounding rock, forming a continuous and effective reinforcement ring.

[0026] Please see Figure 4 In another embodiment, a compression spring 8 is sleeved on the outer side of the anchor rod 3. As a component capable of elastic deformation in the axial direction, the compression spring 8, by being sleeved on the outer side of the anchor rod 3, can participate in force adjustment when the steel pad 1 is tightened by the nut 4 or when the surrounding rock 5 deforms, thereby improving the traditional rigid contact force mode of the pad. The compression spring 8 is located between the steel pad 1 and the rock surface 5. At this position, the compression spring 8 can directly participate in the contact adjustment between the steel pad 1 and the rock surface 5, allowing the steel pad 1 to automatically find a more stable force plane through the elastic displacement of the spring when there are undulations in the rock surface 5, thus enhancing the overall contact capability. The compression spring 8 can generate elastic compression when the nut 4 is tightened or the surrounding rock 5 undergoes convergent deformation. The compression spring 8 provides flexible support to the steel pad 1 through continuous elastic compression, so that the steel pad 1 can maintain a stable stress state in the early stage of construction and the later stage of deformation of the surrounding rock 5. This makes the prestress transfer of the anchor bolt 3 more sufficient and lasting, so as to provide continuous elastic support to the steel pad 1 and further improve the synergistic bearing capacity and long-term stability of the entire anchor bolt support system.

[0027] The working mechanism of this utility model is as follows: the upright claw 21 is formed by bending round steel and has elasticity. As a three-point support between the steel pad 1 and the rock surface 5, it can automatically rotate and generate elastic deformation according to the concavity and convexity of the rock surface 5, thereby compensating for the surface height difference and making the steel pad 1 achieve a near-planar fit. After the nut 4 is tightened, the upright claw 21 continues to deform under the action of axial compression force, compressing the distance between the steel pad 1 and the rock surface 5 to a stable position, ensuring that the steel pad 1 maintains a parallel state for a long time, and improving the installation accuracy and force uniformity of the anchor bolt 3. For surrounding rock with greater topographic relief, the three-point support position of the upright claw 21 can be fixed by auxiliary drilling to enhance its geometric stability. In the embodiment with compression spring 8, the compression spring 8 continuously provides additional elastic support during pre-tightening and the convergence of the surrounding rock 5, enabling the steel pad 1 to adapt to the micro-deformation of the surrounding rock 5, realizing the synergistic effect of the elastic leveling of the upright claw 21 and the subsequent compensation of the compression spring 8, thereby making the entire anchor bolt support system more stable and reliable in terms of force, and significantly improving its long-term performance.

[0028] In summary, this utility model discloses a claw-type prestressed anchor plate device. By configuring a claw assembly 2 formed by bending round steel bars below the steel plate 1, and optionally equipping it with a compression spring 8, the steel plate 1 can automatically level itself on uneven rock surfaces 5 using the elastic adjustment capability of the claw 21. Simultaneously, the tightening action of the nut 4 ensures the steel plate 1 reliably adheres to the surrounding rock surface, thereby ensuring accurate vertical installation of the anchor 3 and the formation of a stable load-bearing system. The structure of this utility model can compensate for the unevenness of the surrounding rock surface during installation, maintain axial stability of the anchor 3 during the load-bearing stage, and form an effective reinforcement ring with the concrete layer 7 during the support system coordination stage. Therefore, this utility model not only significantly improves the installation quality of the anchor and the stress stability of the plate, but also improves the overall coordinated load-bearing effect between the anchor 3, shotcrete, and surrounding rock, reduces rework rates due to installation deviations, and enhances the overall reliability and long-term safety of tunnel and underground engineering support structures. This invention has broad application value in geotechnical engineering, tunnel engineering, and underground space support construction. It can effectively improve the problem of insufficient adaptability of traditional anchor bolt devices under complex geological conditions, and provide the industry with a higher quality, higher stability, and more economical anchor bolt support solution.

[0029] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Under the concept of this utility model, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this utility model as described above. For the sake of brevity, they are not provided in detail. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A claw-type prestressed anchor plate device, characterized in that, The system includes a steel pad (1) and a claw assembly (2). The steel pad (1) has a central opening (11) for the anchor rod (3) to pass through. The claw assembly (2) includes three claws (21). Each claw (21) is made of round steel bent into a support member with elastic deformation capability. They are welded to the bottom surface of the steel pad (1) in a triangular and evenly distributed manner, serving as a reverse support for the steel pad (1) and achieving leveling through elastic deformation when the rock surface is uneven. The tail of the anchor rod (3) is fixed to the steel pad (1) by a nut (4). When the nut (4) is tightened, the distance between the steel pad (1) and the rock surface is compressed, ensuring that the steel pad (1) is always parallel to the rock surface (5). The anchor rod (3), the steel pad (1), and the nut (4) are installed and fixed in a straight line perpendicular to the rock surface.

2. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, The anchor rod (3) is an expansion shell type anchor rod, and an expansion shell (6) is provided at the bottom of the anchor rod to form radial expansion support in the anchor hole.

3. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, The diameter of the central opening (11) is 25-30 mm.

4. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, The steel pad (1) has a size of 20cm × 20cm.

5. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, An initial distance of 2 to 5 cm is formed between the steel pad (1) and the rock surface (5).

6. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, When encountering a large, uneven rock surface, the vertical claw (21) can adjust the height position of the three-point support by auxiliary drilling to further improve the installation flatness of the steel pad (1).

7. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, The diameter of the round steel bar is 6mm.

8. The vertical claw type prestressed anchor plate device according to claim 1, characterized in that, The bending angle at the point where the vertical claw (21) contacts the rock surface (5) is 120°.

9. The vertical claw type prestressed anchor plate device according to any one of claims 1-8, characterized in that, After the steel pad (1) is installed, a concrete layer (7) is sprayed on it, and the concrete layer (7) and the steel pad (1) form an integral solidified structure.

10. The vertical claw type prestressed anchor plate device according to claim 9, characterized in that, A compression spring (8) is fitted on the outside of the anchor rod. The compression spring (8) is located between the steel pad (1) and the rock surface (5). It can generate elastic compression when the nut (4) is tightened or the surrounding rock undergoes convergent deformation, so as to provide continuous elastic support for the steel pad (1).

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