Anti-rock-burst full-thread degumming anchor rod

Abstract

The present application relates to underground engineering supporting equipment field, especially to a kind of anti-rock burst full thread degumming anchor rod, including rod body, rod body outside reserved connecting portion;With the end of rod body when using located in anchor hole as rod body rear end, it further includes spring, fixedly sleeved in the front part outside of rod body;Sleeve, it is sleeved in the outside of rod body, and sleeve is located between spring rear end and rod body rear end;Connecting piece, with sleeve fixed connection, sleeve is fixedly connected with the connecting portion of rod body by connecting piece;Tray, it is sleeved in the rear part of rod body, tray rear side is sequentially provided with pad body assembly and nut, and nut is threadedly connected with the tail end of rod body.The beneficial effects of the present application are that: the anchor rod aims to solve the problem that the existing anchor rod does not have centering structure, which leads to uneven distribution of anchoring agent and how to make both ends of anchor rod and rock fixed firmly when rock burst occurs, and the middle section is separated from rock.It is reasonable in structure, easy to install, suitable for earthquake-prone areas, rock burst or extrusion rock area.

Description

Technical Field

[0001] This invention relates to the field of underground engineering support equipment, specifically a rockburst-resistant, fully threaded debonded anchor bolt. Background Technology

[0002] Rockburst is a dynamic phenomenon in which the elastic deformation potential energy accumulated in the rock mass of underground engineering projects is suddenly released under excavation or other external disturbances, leading to the bursting and ejection of the surrounding rock. Rockbursts are characterized by their suddenness, randomness, and hazard. With the rapid development of the national economy, the development of underground resources and the construction of underground infrastructure are progressing at an unprecedented pace into deeper areas. As the burial depth increases and the level of in-situ stress rises, the geological environment of the rock mass becomes more complex, and the rockburst disasters induced by excavation (mining) become more prominent and severe, bringing unprecedented challenges to the design, construction, and production of deep underground engineering projects.

[0003] Rockbursts often cause severe damage to excavation faces, equipment damage, and casualties, becoming a global challenge in the fields of underground rock engineering and rock mechanics. Minor rockbursts only involve the detachment of rock fragments without ejection. Severe rockbursts can reach magnitude 4.6 and typically last for days or months. Rockbursts occur when high in-situ stress within the rock mass exceeds the rock's inherent strength, while the rock also exhibits high brittleness and elasticity. If underground engineering work disrupts the rock mass's equilibrium, the powerful energy breaks the rock and ejects fragments.

[0004] Currently, rock bolt support has become the main support method for underground engineering rock mass support. For example, Chinese utility model patent application number 201521082078.9 discloses a sleeve-type rock bolt, in which a sleeve is fitted onto the rod body, and the rod body slides freely along the inner wall of the sleeve. One end of the rod body and the bottom of the sleeve form a gap, which stores hydraulic fluid. The huge vacuum generated when the rod body and the sleeve are stretched and separated causes the hydraulic fluid to vaporize, thereby generating a huge tensile force to resist the delamination of the surrounding rock. Another example is Chinese utility model patent application number 202121014458.4, which discloses a self-drilling prestressed spring rock bolt. The diameter of part of the main rod is larger than the diameter of the sleeve. During the movement out of the hole, the larger diameter part of the main rod expands and stretches the sleeve, making it better locked in the hole and preventing loosening.

[0005] During anchor bolt installation, anchor holes are typically drilled at designated locations, and the bolt is then directly inserted into the borehole. Because anchoring agent is injected, the diameter of the anchor hole must be larger than the outer diameter of the bolt. This results in uneven gaps between the bolt and the surrounding area of ​​the anchor hole, leading to uneven distribution of the anchoring agent and weakened anchoring strength in areas with less agent. Furthermore, in the event of a rockburst, the impact force is transmitted to the bolt through the anchoring agent, making the middle section of the bolt prone to breakage, which is also a problem that urgently needs to be addressed. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a rockburst-resistant fully threaded debonded anchor bolt. This anchor bolt aims to solve the problems of uneven distribution of anchoring agent caused by the lack of a centering structure in existing anchor bolts, and how to ensure that both ends of the anchor bolt are firmly fixed to the rock when a rockburst occurs, while the middle section detaches from the rock.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a rockburst-resistant, fully threaded, debonded anchor bolt, comprising,

[0008] The rod body includes a pre-reserved connecting portion on its outer side; with the end of the rod body located outside the anchor hole during use as the rear end of the rod body, it also includes...

[0009] The spring is fixedly sleeved on the outer front part of the rod.

[0010] A sleeve is fitted onto the outside of the rod, and the sleeve is located between the rear end of the spring and the rear end of the rod.

[0011] A connector is fixedly connected to the sleeve, and the sleeve is fixedly connected to the connecting part of the rod body through the connector.

[0012] The tray is fitted onto the rear of the rod. A pad assembly and a nut are sequentially arranged on the rear side of the tray, and the nut is threaded to the tail end of the rod.

[0013] Preferably, the spring material is high carbon steel wire, the outer diameter of the spring is 2-3 mm smaller than the diameter of the drill hole, and the spring length is 40 mm-60 mm.

[0014] Preferably, the spring is fixedly connected to the rod body through at least three connection points, which are distributed at the front end, middle end and end of the spring.

[0015] Preferably, the rod body is a fully threaded, high-strength threaded steel anchor rod body, specifically a hot-rolled steel bar with discontinuous external threaded transverse ribs.

[0016] Preferably, the rod material is hot-rolled steel bar with a tensile strength ≥630MPa, a yield strength 500MPa, and an elongation after fracture ≥16%;

[0017] The connecting part is a discontinuous external thread provided on the outside of the rod.

[0018] Preferably, the sleeve is made of an antistatic and flame-retardant material.

[0019] Preferably, the inner diameter of the connector is 2-3 mm larger than the outer diameter of the sleeve, and the connector is deformed by extrusion at multiple angles using special tooling to fix the sleeve on the rod.

[0020] Preferably, the pad assembly includes a spherical washer and a pad, the spherical washer being in contact with the tray, and the pad being disposed between the spherical washer and the nut; one side of the tray is concave and the other side is convex, the concave surface of the tray facing the front of the rod, the spherical washer having a hemispherical structure, and the outer spherical surface of the spherical washer being in contact with the outer convex surface of the tray.

[0021] Preferably, auxiliary rods are provided on both sides of the rod body, the auxiliary rods are parallel to the rod body and have the same structure, a first collar is fixedly provided at the rear end of the auxiliary rod body, a second collar is fixedly provided on both sides of the nut of the rod body, and a steel wire rope is fixedly connected between the first collar and the second collar.

[0022] Preferably, the rod body and the auxiliary rod body are provided with a number of short rods, the axial direction of the short rods is perpendicular to the axial direction of the rod body, and a number of through holes are opened on the short rods, the axis of the through holes is perpendicular to the axis of the rod body, and the axes of the through holes, the short rods and the rod body are distributed in the xyz three-axis three-dimensional rectangular coordinate system direction.

[0023] Preferably, the height of the short rod is less than the distance from the outer surface of the spring to the rod body.

[0024] Compared with the prior art, the present invention provides a rockburst-resistant fully threaded debonded anchor bolt, which has the following beneficial effects:

[0025] 1. The present invention utilizes a structure of discontinuous external thread transverse ribs on the rod body. The discontinuous external thread helps to increase the connection strength with the anchoring agent, and the transverse ribs can increase the axial tensile strength of the rod body.

[0026] 2. The present invention uses a spring sleeved and welded to the front end of the rod body, with the spring serving as the centering structure of the anchor rod body. This centering function ensures that the distance between the rod body periphery and the inner wall of the anchor hole is not too different, which helps to distribute the anchoring agent evenly and thus increases the anchoring force of the rod body.

[0027] 3. This invention features a sleeve fitted around the middle section of the rod, with a connector fitted near the spring end of the sleeve. The connector secures the sleeve and the rod together. A tray is fitted at the rear end of the rod, and a spherical washer and a pad are fitted sequentially on the outside of the tray. A nut is screwed onto the rod outside the pad. In use, the drilled portion of the rod is fixed with an anchoring agent, while the outside of the drilled portion is fixed with the tray and nut. The sleeve isolates the outer anchoring agent from the inner rod. Thus, during a rockburst, the rod inside the sleeve is not bound by the anchoring agent and can fully utilize its plasticity under the impact of ground pressure. This allows the two ends of the anchor rod to be firmly fixed to the rock, while the middle section is separated from the rock and the anchoring agent. This allows the plasticity of this section of the anchor rod to be fully utilized, reducing the possibility of direct breakage and providing a certain degree of rockburst resistance.

[0028] 4. This invention features auxiliary rods on both sides of the main rod, with a first collar fixed to the outer end of each auxiliary rod. Second collars are fixed to the upper and lower sides of the rod nut, respectively. A steel wire rope is fixedly connected between the first and second collars. In use, holes can be drilled on both sides of the main rod to fix the auxiliary rods, and the outer ends of the main rod and auxiliary rods can be fixedly connected by the steel wire rope, thereby increasing the fixing area of ​​the rock and enhancing the fixing effect on the rock.

[0029] 5. In this invention, several short rods are provided on the vertical rods of the front and rear sides of the sleeve and the auxiliary rods. Several transverse through holes are embedded in the short rods. In use, the short rods and through holes can increase the contact area between the rods and the anchoring agent, thereby enhancing the fixing effect. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the main structure of the first embodiment of the present invention;

[0031] Figure 2 for Figure 1 Enlarged structural diagram at point A;

[0032] Figure 3 for Figure 1 Enlarged structural diagram at point B;

[0033] Figure 4 for Figure 3 Left view of the connecting component;

[0034] Figure 5 for Figure 1 Enlarged structural diagram at point C;

[0035] Figure 6 This is a schematic diagram of the main structure of the second embodiment of the present invention;

[0036] Figure 7 for Figure 6 Right view of the structure of the middle nut;

[0037] Figure 8 This is a schematic diagram of the main structure of the third embodiment of the present invention;

[0038] Figure 9 for Figure 8 Enlarged structural diagram at point D;

[0039] Figure 10 for Figure 9 Enlarged structural diagram of the short and medium-length rod.

[0040] The diagram shows: 1. Rod body; 2. Nut; 21. Second collar; 3. Washer plate; 4. Spherical washer; 5. Spring; 6. Connector; 7. Sleeve; 8. Tray; 81. Boss; 811. Shear pin mounting hole; 9. Weld point; 10. Auxiliary rod body; 101. First collar; 11. Wire rope; 12. Short rod; 121. Through hole. Implementation

[0041] 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.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not 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 on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. Example 1

[0045] like Figures 1 to 5As shown, an anti-rockburst fully threaded debonded anchor rod includes a rod body 1, which is a fully threaded, high-strength steel anchor rod body, specifically a hot-rolled steel bar with discontinuous external thread transverse ribs. Any cross section of the rod body 1 can be connected with a nut 2. A spring 5 is sleeved and welded to the front end of the rod body 1. The spring 5 has a centering function, ensuring that the anchor rod is basically centered in the anchor hole, increasing the contact area with cement or resin anchoring agent, thereby increasing the anchoring strength. The spring 5 is made of high-carbon steel wire with a diameter of 4.5 mm and a thread pitch of 38 mm. The outer diameter of the spring 5 is 2.5 mm smaller than the drill hole diameter, and the spring length is 50 mm. The spring 5 is connected to the rod body 1 by three welding points 9 at the front end, middle end, and end end. A sleeve 7 is sleeved in the middle part of the rod body 1, and a connector 6 is sleeved on the end of the sleeve 7 near the spring 5, which fixes the sleeve 7 and the rod body 1 together.

[0046] A tray 8 is fitted onto the rear end of the rod 1. A spherical washer 4 and a pad 3 are sequentially fitted onto the outside of the tray 8. The pad 3 can be made of plastic. A nut 2 is screwed onto the rod 1 outside the pad 3. The tray 8 has a dome-shaped convex structure, providing high load-bearing capacity, light weight, and easy installation. The spherical washer 4 has a hemispherical structure with its spherical surface facing the outer convex surface of the tray 8. A through hole is provided in the center of the tray 8. When this device is in use, the spherical surface of the spherical washer 4 rests against the through hole of the tray 8 at the point where the concave surface of the tray 8 contacts the outer side of the anchor hole. With the position of the tray 8 unchanged, the rod 1 can perform a small-amplitude ball-joint rotation with the cooperation of the spherical washer 4 and the through hole of the tray 8. The pad 3 reduces the friction between the spherical washer 4 and the nut 2 when the nut 2 rotates. The pad 3 is made of antistatic, flame-retardant high-density polyethylene (HDPE).

[0047] The material of rod 1 is hot-rolled steel bar with a tensile strength of 700MPa, a yield strength of 500MPa, and an elongation after fracture of 18%.

[0048] The sleeve 7 is made of antistatic and flame-retardant material, and high-density polyethylene can also be used. The inner diameter of the sleeve 7 is 2.5 mm larger than the outer diameter of the discontinuous external thread transverse rib of the rod. The length of the sleeve 7 has been verified by field simulation and experiments. While ensuring the anchoring strength of the rod 1, the length of the sleeve 7 can be increased to the maximum extent.

[0049] The inner diameter of connector 6 is 2.5mm larger than the outer diameter of the sleeve. Connector 6 is deformed by extrusion at multiple angles using a special tooling, which fixes the sleeve 7 onto the rod body 1. Connector 6 is a circular ring made of brass. Pressure is applied simultaneously to various positions evenly distributed on the circumference of connector 6 by the tooling, with the pressure direction towards the central axis of connector 6. In this way, several concave structures are evenly distributed on the circumference of connector 6, which clamp the rod body 1.

[0050] The outer spherical surface of the spherical washer 4 engages with the inner conical hole of the tray 8, ensuring that the borehole axis is less than 18° from the vertical plane of the rock wall, and that the spherical washer 4 does not disengage from the hole in the tray 8. A boss 81 is also fixedly provided on the outer edge of the tray 8 (see reference). Figure 5 The vertical rod 1 on the boss 81 is provided with a shear pin mounting hole 811. The shear pin mounting hole 811 is used to install the anchor bolt shear pin. The anchor bolt shear pin restricts the rotation between the anchor bolt and the nut. The breaking force value of the shear pin is fixed, therefore the breaking torque of the shear pin is fixed. The anchor bolt installation torque can be controlled through the shear pin, thereby controlling the initial anchoring force of the anchor bolt. The shear pin mounting hole 811 can be machined as needed; not all pallets have it.

[0051] In use, the drilled part of the rod body 1 is fixed with anchoring agent, and the outside of the drilled hole is fixed with tray 8 and nut 2; in the event of rock burst, the sleeve 7 can effectively isolate the anchor rod body 1 from the anchoring agent, and can give full play to the plasticity (elongation of the anchor rod) when the anchor rod is subjected to ground pressure impact. Example 2

[0052] like Figures 6-7 As shown, auxiliary rods 10 are provided on both sides of the rod 1. The auxiliary rods 10 are parallel to the rod 1 and have the same structure. A first collar 101 is fixedly provided at the outer end of the auxiliary rod 10. A second collar 21 is fixedly provided on the upper and lower sides of the nut 2 of the rod 1. A steel wire rope 11 is fixedly connected between the first collar 101 and the second collar 21.

[0053] In use, holes are drilled on both sides of the rod 1 and auxiliary rod 10 is fixed thereon. The outer ends of the rod 1 and auxiliary rod 10 are then fixedly connected by steel wire rope 11, which increases the fixing area of ​​the rock and thus enhances the fixing effect on the rock. Example 3

[0054] like Figures 8-10 As shown, the rod body 1 and the auxiliary rod body 10 are provided with a number of short rods 12 on the vertical rod body 1, and a number of transverse through holes 121 are embedded in the short rods 12.

[0055] The height of the short rod 12 is less than the distance from the outer surface of the spring 9 wire to the rod body 1, ensuring that the rod body can be smoothly inserted into the drill hole.

[0056] In use, the short rod 12 and the through hole 121 can increase the contact area between the rod body 1 and the anchoring agent, thereby enhancing the fixing effect.

[0057] This invention is particularly suitable for areas with large deformations, such as earthquake-prone areas, rockburst zones, and areas of compressed rock. When used in the field, this invention can significantly improve the safety performance of underground rock mass construction, substantially reduce production costs for users, and increase production efficiency.

[0058] All components used in this invention are general standard parts or parts known to those skilled in the art, and their structures and principles are well known to those skilled in the art.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A rockburst-resistant, fully threaded, debonded anchor bolt, characterized in that: include, The rod body includes a pre-reserved connecting portion on its outer side; with the end of the rod body located outside the anchor hole during use as the rear end of the rod body, it also includes... The spring is fixedly sleeved on the outer front part of the rod. A sleeve is fitted onto the outside of the rod, and the sleeve is located between the rear end of the spring and the rear end of the rod. A connector is fixedly connected to the sleeve, and the sleeve is fixedly connected to the connecting part of the rod body through the connector. The tray is fitted onto the rear of the rod. A pad assembly and a nut are sequentially arranged on the rear side of the tray, and the nut is threaded to the tail end of the rod. Auxiliary rods are provided on both sides of the main rod. The auxiliary rods are parallel to the main rod and have the same structure. A first collar is fixed at the rear end of the auxiliary rod. A second collar is fixed on both sides of the nut of the main rod. A steel wire rope is fixedly connected between the first collar and the second collar. The rod body and auxiliary rod body are provided with a number of short rods. The axial direction of the short rods is perpendicular to the axial direction of the rod body. A number of through holes are opened on the short rods. The axis of the through holes is perpendicular to the axis of the rod body. The axes of the through holes, short rods and rod body are distributed in the xyz three-axis three-dimensional rectangular coordinate system. The spring is made of high carbon steel wire, the outer diameter of the spring is 2-3 mm smaller than the diameter of the drill hole, and the length of the spring is 40 mm-60 mm. The spring is fixedly connected to the rod through at least three connection points, which are located at the front end, middle end and end of the spring.

2. The rockburst-resistant fully threaded debonded anchor bolt according to claim 1, characterized in that: The rod is made of hot-rolled steel bar with a tensile strength ≥630MPa, a yield strength 500MPa, and an elongation after fracture ≥16%. The connecting part is a discontinuous external thread provided on the outside of the rod.

3. The rockburst-resistant, fully threaded, debonded anchor bolt according to claim 1, characterized in that: The sleeve is made of antistatic and flame-retardant material.

4. The rockburst-resistant fully threaded debonded anchor bolt according to claim 1, characterized in that: The inner diameter of the connector is 2-3mm larger than the outer diameter of the sleeve. The connector is deformed by extrusion at multiple angles using special tooling, so that the sleeve is fixed on the rod.

5. The rockburst-resistant, fully threaded, debonded anchor bolt according to claim 1, characterized in that: The pad assembly includes a spherical washer and a pad. The spherical washer is attached to the tray, and the pad is disposed between the spherical washer and the nut. One side of the tray is concave, and the other side is convex. The concave surface of the tray faces the front of the rod. The spherical washer has a hemispherical structure, and the outer spherical surface of the spherical washer is attached to the outer convex surface of the tray.

6. The rockburst-resistant fully threaded debonded anchor bolt according to claim 1, characterized in that: The height of the short rod is less than the distance from the outer surface of the spring to the rod body.

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