A non-rotating steel strand rod body anchor rod

Abstract

The application belongs to the technical field of anchor rod support, and particularly discloses a non-rotation steel strand rod body anchor rod, which comprises a steel strand, a polygonal connecting sleeve, a rotation-stopping plate and a steel strand tray, one end of the steel strand is inserted into a drill hole to serve as an anchoring anchor rod; the polygonal connecting sleeve comprises a head connecting section for connecting the steel strand and a tail threaded section for fastening; the rotation-stopping plate is provided with a polygonal hole in the middle portion, is sleeved outside the head connecting section and forms radial limiting for the polygonal connecting sleeve; the steel strand tray comprises a supporting surface for abutting against a surrounding rock of a roadway, the middle portion of the supporting surface is sunken to form a plurality of rotation-stopping grooves, the rotation-stopping grooves can accommodate the rotation-stopping plate to be put in and form limiting; the center of the steel strand tray is located at the connecting position of the plurality of rotation-stopping grooves, is upwardly protruded with a spherical protruding end face, the center of the end face is provided with a spherical taper hole, and the tail threaded section is connected with a fastening nut through the spherical taper hole. The device utilizes the cooperation of the rotation-stopping plate and the steel strand tray to limit the rebound of the steel strand, so that the fastening purpose is achieved.

Description

Technical Field

[0001] This invention belongs to the field of anchor bolt support technology, and particularly relates to a non-rotating steel strand anchor bolt. Background Technology

[0002] During the excavation of underground roadways in coal mines, roadway support is necessary to prevent deformation or collapse of the surrounding rock due to ground stress. The most common support method is combined anchor cable and anchor bolt support. By applying preload, the surrounding rock and bedrock are integrated, forming a unified and stable rock zone around the roadway. The anchor bolts and cables work together with the surrounding rock to maintain roadway stability.

[0003] Anchor bolts (rigid anchor bolts) are made of threaded steel or round steel and fixed with nuts. The advantages are that they are easy and quick to install and can help control the surrounding rock in a timely manner to prevent rock delamination. The disadvantages are that they are limited by the underground space, the length cannot fully meet the requirements, and the strength is insufficient.

[0004] Anchor cables (flexible anchor bolts) are made by tensioning and installing steel strands with anchors using special hydraulic tools. Their advantages are high strength, no space limitations, and freely selectable length. Their disadvantages are complex installation, slow speed, inability to provide timely support, difficulty in timely control of the surrounding rock, long exposed length exceeding safety regulations, resulting in a small effective cross-section of the roadway, and the exposed steel strands posing a safety hazard of injury.

[0005] In view of this, the present invention proposes a non-rotating steel strand rod anchor rod to overcome the disadvantages of the above-mentioned anchor rods and anchor cables, while possessing the advantages of both. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a non-rotating steel strand anchor rod, aiming to solve or improve at least one of the aforementioned technical problems.

[0007] To achieve the above objectives, the present invention provides a non-rotating steel strand anchor rod, comprising:

[0008] A steel strand, one end of which can be inserted into a drill hole to be used as an anchor rod;

[0009] A polygonal connecting sleeve, the polygonal connecting sleeve including a head connecting section for supporting and connecting the steel strand and a tail threaded section for fastening;

[0010] An anti-rotation plate has a polygonal hole in the middle and is fitted around the head connecting section to form a radial limit on the polygonal connecting sleeve; the anti-rotation plate is connected to the surrounding rock of the roadway for limiting.

[0011] A steel strand tray includes a support surface for abutting against the surrounding rock of the roadway. The support surface is recessed in the middle to form multiple anti-rotation grooves, which can accommodate an anti-rotation plate to form a radial limit. At the center of the steel strand tray, located at the connection of the multiple anti-rotation grooves, a spherical protrusion end face is raised upward. A spherical conical hole is opened in the center of the spherical protrusion end face, and the tail threaded section passes through the spherical conical hole and is connected to a fastening nut for fastening.

[0012] The non-rotating steel strand anchor rod of the present invention is used to reinforce the roadway during the excavation of underground roadways in coal mines. It can achieve the anchor cable support effect that anchor rods cannot achieve in a limited space, while also achieving the purpose of immediate excavation and support, improving efficiency, increasing safety, and saving working space. The present invention utilizes the cooperation of anti-rotation plate and steel strand tray to achieve non-rotation of steel strand, thereby achieving the purpose of fastening.

[0013] Preferably, the fastening nut is a ball-head nut with a hemispherical top, supported below the spherical protrusion end face.

[0014] Preferably, the aforementioned anti-rotation groove is formed by multiple arched connecting end faces folded outwards from the spherical conical hole, and reinforcing ribs are provided between adjacent arched connecting end faces.

[0015] Preferably, the aforementioned plurality of arched connecting end faces are arranged in an eight-petaled lotus flower shape.

[0016] Preferably, the lower end of the fastening nut has a recessed groove, and a nut damping plate is installed in the groove. The nut damping plate is interference-fitted with the inner hole of the fastening nut.

[0017] Preferably, a centering locator is provided at one end of the steel strand that penetrates the drilled hole, and the centering locator is sleeved on the end of the steel strand.

[0018] Preferably, the upper end of the aforementioned centering locator is provided with a plurality of axially extending anchoring agent brackets along its periphery, and a receiving cavity is formed between the plurality of anchoring agent brackets, wherein the receiving cavity is encapsulated with anchoring agent.

[0019] Preferably, the aforementioned receiving cavity has a guide hole that passes through the upper and lower ends of the centering positioner.

[0020] Preferably, the anchoring agent holder is fixed with a side blade facing the receiving cavity, and a bottom blade is provided at the bottom of the receiving cavity. The side blade and the bottom blade are used to cut through the packaging of the anchoring agent.

[0021] Preferably, the outer cross-section of the head connecting section is a regular hexagon, and correspondingly, the polygonal hole of the anti-rotation plate is a regular hexagonal hole.

[0022] Compared with the prior art, the present invention has the following advantages and technical effects:

[0023] This invention addresses the design of flexible anchor rods such as steel strands by incorporating a polygonal connecting sleeve, an anti-rotation plate, and a steel strand tray. This overcomes the limitations of existing technologies where, without an anti-rotation plate, the steel strands, being rigid structures composed of several round steel bars twisted together, experience internal stress and rebound when the drilling rig stops. This causes the fastening nuts to unravel, failing to meet protective requirements. In this invention, the anti-rotation plate and its matching steel strand tray are integrated. The anti-rotation plate sinks into the anti-rotation groove of the steel strand tray, and the hexagonal hole in the center of the anti-rotation plate secures the polygonal connecting sleeve. Since the steel strand tray remains stationary, the rebound of the steel strands after the drilling rig stops achieves a secure hold. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 A schematic diagram of the structure of the non-rotating steel strand rod anchor provided by the present invention;

[0026] Figure 2 This is a schematic diagram showing the connection relationship between the steel strand and the polygonal connecting sleeve in this invention;

[0027] Figure 3 This is a process state diagram of pushing the steel strand into the borehole in this invention;

[0028] Figure 4 This is a schematic diagram of the centering positioner in this invention;

[0029] Figure 5 This is a process diagram showing the state of the non-rotating steel strand anchor rod of the present invention being fixed below the surrounding rock using a quick installation device.

[0030] In the diagram: 1. Steel strand; 2. Polygonal connecting sleeve; 3. Tubular filling steel strand sleeve; 4. Anti-rotation plate; 5. Steel strand tray; 6. Fastening nut; 7. Anchoring agent; 9. Centering positioner; 10. Drilling rig; 11. Quick installation device; 201. Head connecting section; 202. Tail threaded section; 401. Positioning pin; 901. Anchoring agent bracket; 902. Guide hole; 903. Side cutting edge; 904. Bottom cutting edge. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The following is combined Figures 1-5 The present invention describes a non-rotating steel strand rod anchor.

[0034] refer to Figure 1 , Figure 1 This diagram illustrates a structural schematic of a non-rotating steel strand anchor rod provided by the present invention. The non-rotating steel strand anchor rod of this embodiment is used for reinforcing roadways during underground coal mine tunnel excavation. The non-rotating steel strand anchor rod may include a steel strand 1, a polygonal connecting sleeve 2 for connecting the steel strand 1, an anti-rotation plate 4 detachably fitted outside the polygonal connecting sleeve 2, a steel strand tray 5 supporting and limiting the bottom of the anti-rotation plate 4, and a fastening nut 6 supported at the bottom of the steel strand tray 5 and threadedly connected to the rod body below the polygonal connecting sleeve 2.

[0035] Specifically, such as Figure 2 As shown, the steel strand 1 is cut to the required length. The polygonal connecting sleeve 2 is an alloy sleeve structure, including a head connecting section 201 at the upper end and a tail threaded section 202 at the lower end. The head connecting section 201 is a polygonal right prism with a connecting sleeve hole drilled in the center. This connecting sleeve hole accommodates one end of the steel strand 1 for insertion and fixation. The tail threaded section 202 is a cylinder with external threads for threaded engagement with the fastening nut 6.

[0036] When the steel strand 1 is inserted into the connecting sleeve hole of the head connecting section 201, a tubular filling steel strand sleeve 3 is placed between them. The tubular filling steel strand sleeve 3 is made of fine steel wire evenly wound into a cylindrical shape. Its diameter is determined by the diameter of the steel strand 1, and its length is determined by the depth of the connecting sleeve hole. During fixing, one end of the steel strand 1 with the tubular filling steel strand sleeve 3 is inserted into the connecting sleeve hole. A diameter reduction machine is used to reduce the diameter of the polygonal connecting sleeve 2, so that the steel strand 1 is firmly installed in the polygonal connecting sleeve 2. One end of the steel strand 1 is fixed in the polygonal connecting sleeve 2, and the other end extends into the drilled hole as a free end.

[0037] The anti-rotation plate 4 has a polygonal hole in the middle, which mates with the polygonal connecting sleeve 2. It can accommodate the head connecting section 201 of the polygonal connecting sleeve 2 to be freely inserted axially, while restricting its rotation in the circumferential direction. The anti-rotation plate 4 is an elliptical steel plate with upward positioning pins 401 at both ends. The positioning pins 401 are used to insert into the surrounding rock of the tunnel. The anti-rotation plate 4 can be placed into the steel strand tray 5, forming a concave-convex fit with the steel strand tray 5, so that when the two are in contact, they are mutually engaged and cannot rotate.

[0038] The steel strand tray 5 is made of steel plate by stamping or hot forging. The steel strand tray 5 includes a quadrilateral planar support surface. The center of the support surface is recessed to form multiple anti-rotation grooves that cooperate with the anti-rotation plate 4. The multiple anti-rotation grooves are arranged around the center and form an upwardly convex spherical end face at the central connection. A spherical conical hole is opened in the center of the spherical convex end face to accommodate the threaded section 202 of the tail of the polygonal connecting sleeve 2. The threaded section 202 passes through the spherical conical hole and has a certain gap, allowing it to rotate freely. The anti-rotation groove is formed by multiple arched connecting end faces formed by folding outward from the spherical conical hole. A reinforcing rib is provided between two adjacent arched connecting end faces. The arched connecting end faces are uneven and sunken in the shape of an eight-petaled lotus flower, including eight petal end faces. The supporting surface of the steel strand tray 5 is the working surface. During operation, only the supporting surface is in contact with the rock mass. An anti-rotation plate 4 is placed in the eight-petal lotus-shaped anti-rotation groove on the arched connecting end face. The anti-rotation plate 4 is preferably elliptical in shape and can sink into the anti-rotation groove to form a positioning connection with the anti-rotation groove. Positioning pins 401 are respectively provided on both sides of the polygonal connecting sleeve 2 on its upper end face. The positioning pins 401 are inserted into the surrounding rock of the tunnel to form a positioning.

[0039] The fastening nut 6 is connected to the threaded section 202 at the tail of the polygonal connecting sleeve 2. Its upper end is spherical, its inner hole is an internal thread structure, and its outer circumference is hexagonal.

[0040] The steel strand 1 is inserted into the connecting sleeve hole of the polygonal connecting sleeve 2. The polygonal prism of the polygonal connecting sleeve 2 is installed in the middle opening of the anti-rotation plate 4. The anti-rotation plate 4 is installed on the upper end of the steel strand tray 5. The two end faces are in concave-convex fit, so they cannot rotate. The tail threaded section 202 of the polygonal connecting sleeve 2 passes through the steel strand tray 5 and through the spherical conical hole. The fastening nut 6 is installed on the tail threaded section 202.

[0041] Furthermore, the polygonal prism of the polygonal connecting sleeve 2 is a regular hexagonal prism, and correspondingly, the central opening of the anti-rotation plate 4 is a regular hexagonal hole.

[0042] Furthermore, a centering positioner 9 is provided at the free end of the steel strand 1, such as... Figure 4As shown, the centering positioner 9 has multiple axially extending anchoring agent brackets 901 on its upper end along its periphery. The multiple anchoring agent brackets 901 form a receiving cavity, which is filled with anchoring agent 7. The receiving cavity has a guide hole 902 that passes through the upper and lower ends of the centering positioner 9. The anchoring agent bracket 901 is fixed with a side blade 903 facing the receiving cavity, and a bottom blade 904 is provided at the bottom of the receiving cavity. The side blade 903 and the bottom blade 904 are used to cut through the packaging of the anchoring agent 7, so that the outer packaging of the anchoring agent 7 is peeled off, the two colloidal materials are fully mixed, and are squeezed and diffused into the borehole wall along the outer periphery of the steel strand 1 through the guide hole 902 on the centering positioner 9.

[0043] The function of centering positioner 9:

[0044] 1. Ensure that steel strand 1 is always in the center of the borehole;

[0045] 2. Ensure that anchoring agent 7 is not lost during the process;

[0046] 3. Ensure that the anchoring agent 7 is mixed evenly, firmly wraps the steel strand, and completely fills the borehole wall;

[0047] 4. Support the outer packaging containing anchoring agent 7;

[0048] 5. Use the blades set inside the anchoring agent bracket 901 and at the bottom of the receiving cavity to cut the outer packaging of the anchoring agent 7.

[0049] Multiple tests have shown that adding the centering locator 9 significantly improves the anchoring strength of the steel strand 1 by 15%-20%.

[0050] The specific installation of the non-rotating steel strand anchor rod according to this embodiment of the invention includes the following steps:

[0051] 1. Use a drilling rig to drill holes for steel strands in the surrounding rock.

[0052] 2. Place the anchoring agent 7 into the borehole, press one end of the steel strand 1 against the anchoring agent 7 and push it into the borehole. In a further preferred embodiment, the free end of the steel strand 1 is provided with a centering locator 9, which can fix the anchoring agent 7 in the centering locator 9 and then push it into the borehole.

[0053] 3. Using a drilling rig and a dedicated mixer, the steel strand 1 is rotated and pushed into the borehole, causing the steel strand 1 to pierce the anchoring agent 7 in a spiral upward manner and reach the bottom of the borehole.

[0054] 4. Insert the anti-rotation plate 4, the steel strand tray 5, and the fastening nut 6 sequentially from one end of the threaded section 202 at the tail of the polygonal connecting sleeve 2.

[0055] 5. Use the dedicated quick-installation device 11 for installation and tightening, specifically, as follows: Figure 5As shown, the drilling rig 10 pushes the quick installation device 11 upward with its propulsion cylinder. Under the action of the spring, the guide rod of the quick installation device 11 smoothly and firmly presses the steel strand tray 5 and the anti-rotation plate 4 against the surrounding rock, keeping them stationary. At this time, the head connecting section 201 of the upper half of the polygonal connecting sleeve 2 is in the polygonal inner hole of the anti-rotation plate 4 and cannot make radial rotation. Therefore, the steel strand 1 fixed on the polygonal connecting sleeve 2 cannot make rotation. Since the center hole of the anti-rotation plate 4 and the head connecting section 201 are axially slidingly fitted, the polygonal connecting sleeve 2 can move freely relative to the anti-rotation plate 4 in the axial direction.

[0056] 6. Start the drilling rig 10, the drilling rig connector in the quick installation device 11 rotates, the fastening nut 6 rotates and moves quickly upward along the axis of the polygonal connecting sleeve 2, and fits against the spherical protruding end face of the steel strand tray 5 to reach the design torque and complete the quick installation, while keeping the steel strand rod anchor rod perpendicular to the surrounding rock.

[0057] During the above installation process, since the non-rotating steel strand anchor rod of the present invention does not rotate, no stress is generated in the steel strand 1, and the anchoring performance at the junction of the free section and the anchoring section of the steel strand 1 will not be damaged. The test shows that its anchoring strength is 2% to 3% higher than that of the traditional rigid rod (hard rod) anchor rod.

[0058] Application effects of the embodiments of the present invention:

[0059] A mine roadway is 6m wide and 4m high, with a rectangular cross-section of 24m. 2 The normal design uses a combination of 2.4m diameter 22mm left-handed unreinforced anchor bolts and 6.8m diameter 21.8mm 1860MPa anchor cables for support. Two rows of anchor bolts plus one row of anchor cables reinforce the support. There are three anchor cables on each side and five anchor cables on the roof, with 240mm of exposed steel strand and a 60mm high anchorage. The total effective net area of ​​the roadway is only 300mm, which is (4-0.3)*(6-0.6)=19m². 2 5m 2 The area is unusable. Now, 3.5m and 6.8m diameter, 21.8mm, 1860MPa non-rotating steel strand anchor rods are used, with 35-45mm of exposed thread and a 40mm nut height. The effective net area of ​​the tunnel is (4-0.085)*(6-0.170)=22.8m². 2 This can greatly reduce the amount of tunneling work.

[0060] From the perspective of support effectiveness: Non-rotating steel strand anchor bolt support, due to its longer rods and deeper anchorage, thickens the surrounding rock stratum, significantly reducing roadway deformation. The rapid construction speed also prevents roof delamination, contributing to the minimal roadway deformation. In contrast, combined anchor bolt and cable support, due to the delayed tensioning of the cables, experiences some roof delamination. Insufficient tension could pose a threat to surrounding rock control.

[0061] From the perspective of anchoring effect: Under high torque, the anchor rod body experiences slight loosening of the lower end of the anchoring agent and the rod body due to the twisting of the rod body, resulting in a loss of 0.5-0.8 kN in anchoring force. The steel strand rod anchor and the polygonal anti-rotation plate restrict the rotational movement of the polygonal connecting sleeve. Even without rotation, the steel strand rod anchor cannot rotate significantly. Small-amplitude vibrations are absorbed by the steel strand itself, so the anchoring end of the anchoring agent is very stable.

[0062] From a construction speed perspective: Combined anchor bolt and anchor cable support requires initial anchor bolt support followed by additional anchor cable support from workers, necessitating the use of hydraulic tension jacks. This installation is time-consuming and labor-intensive, and can lead to hidden engineering quality issues. In contrast, non-rotating steel strand anchor bolts, like traditional anchor bolts, can quickly achieve the high strength requirements for anchor cable installation.

[0063] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, 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, and therefore should not be construed as a limitation of this invention.

[0064] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A non-rotating steel strand anchor rod, characterized in that, include: Steel strand (1), one end of which can be inserted into a borehole to be used as an anchor rod; Polygonal connecting sleeve (2), the polygonal connecting sleeve (2) includes a head connecting section (201) for supporting and connecting the steel strand (1) and a tail threaded section (202) for fastening. An anti-rotation plate (4) has a polygonal hole in the middle and is fitted around the head connecting section (201) to form a radial limit on the polygonal connecting sleeve (2); the anti-rotation plate is connected to the surrounding rock of the roadway and the two ends of the anti-rotation plate (4) are provided with upwardly extending positioning pins (401). The steel strand tray (5) includes a support surface for abutting against the surrounding rock of the roadway. The support surface is recessed in the middle to form multiple anti-rotation grooves. The anti-rotation grooves can accommodate the anti-rotation plate (4) to form a radial limit. The center of the steel strand tray (5) is located at the connection of the multiple anti-rotation grooves and has a spherical protruding end face protruding upward. A spherical conical hole is opened in the center of the spherical protruding end face. The tail thread section (202) passes through the spherical conical hole and is connected to a fastening nut (6) for fastening. The anti-rotation groove is formed by multiple arched connecting end faces that are folded outwards from the spherical conical hole, and a reinforcing rib is provided between two adjacent arched connecting end faces; the multiple arched connecting end faces are arranged in an eight-petal lotus shape.

2. The non-rotating steel strand anchor bolt according to claim 1, characterized in that, The fastening nut (6) is a ball-head nut with a hemispherical top, which is supported under the steel strand tray (5).

3. The non-rotating steel strand anchor bolt according to claim 1, characterized in that, The steel strand (1) is provided with a centering locator (9) at one end of the drilled hole, and the centering locator (9) is sleeved on the end of the steel strand (1).

4. The non-rotating steel strand anchor bolt according to claim 3, characterized in that, The centering locator (9) has multiple axially extending anchoring agent brackets (901) on its upper end along its periphery, and a receiving cavity is formed between the multiple anchoring agent brackets (901), and the receiving cavity is encapsulated with anchoring agent (7).

5. The non-rotating steel strand anchor bolt according to claim 4, characterized in that, The receiving cavity has a guide hole (902) that passes through the upper and lower ends of the centering positioner (9).

6. The non-rotating steel strand anchor bolt according to claim 5, characterized in that, The anchoring agent holder (901) is fixed with a side blade (903) facing the receiving cavity, and a bottom blade (904) is provided at the bottom of the receiving cavity. The side blade (903) and the bottom blade (904) are used to cut through the packaging of the anchoring agent (7).

7. The non-rotating steel strand anchor bolt according to claim 1, characterized in that, The outer cross section of the head connecting section (201) is a regular hexagon, and correspondingly, the polygonal hole of the anti-rotation plate (4) is a regular hexagonal hole.

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