Double-anchor-head anchor rod device suitable for lamellar rock mass anchor-shotcrete net support

Abstract

The utility model relates to a double-anchor-head anchor rod device suitable for lamellar rock mass anchor shotcrete net support, which comprises a rod body, a first anchor head assembly and a second anchor head assembly, the first anchor head assembly and the second anchor head assembly are arranged on the rod body, and the first anchor head assembly comprises a first base plate and a limiting nut used for limiting the first base plate to move outwards. The second anchor head assembly comprises a second base plate and a double-nut locking structure used for pressing the second base plate, a plurality of spring base plates are arranged on the side, away from the double-nut locking structure, of the second base plate, and each spring base plate is connected with the second base plate through a spring. The anchor-shotcreting net support is convenient to use, active pre-tightening force is applied to a rock wall by arranging a double-nut locking structure, so that the anchor-shotcreting net support for the thin-layer rock mass is enabled to be safe and stable in a short term by applying the pre-tightening force through the second anchor head assembly after a double-anchor-head anchor rod support is constructed and before re-shotcreting concrete construction, and the anchor-shotcreting net support for the thin-layer rock mass is safe and stable. After a reinforcing mesh is hung at the first anchor head assembly and concrete is sprayed again, long-term safety and stability of the lamellar rock mass can be ensured.

Description

Technical Field

[0001] This utility model relates to a double-headed anchor bolt device suitable for anchor spraying mesh support in thin-layered rock masses. Background Technology

[0002] Underground engineering projects such as mine roadways, working areas, traffic tunnels, and oil and gas storage caverns often encounter thin-layered rock masses. These rock masses, due to the cutting action of dense structural planes and the unloading effect of excavation, are prone to damage such as bending, sliding, or falling of the surrounding rock walls, severely impacting the safe and efficient construction of underground projects. To avoid disasters during excavation of thin-layered surrounding rock, anchor-sprayed mesh support is typically used for stability control. The on-site construction sequence for this type of support is as follows: after excavation, initial shotcrete is applied to the tunnel walls, followed by drilling and installation of anchor bolts, then installation of steel mesh, and finally, final shotcrete application. However, there is generally a gap of several hours to several days between the installation of anchor bolts and the completion of final shotcrete application. During this time, the anchor bolts cannot effectively provide support, and the risk of surrounding rock instability is high. Improving the stability of the surrounding rock during this stage is a challenging problem that researchers and engineers highly value.

[0003] Currently, significant progress has been made in the in-depth research of anchor bolts both domestically and internationally. Regarding anchor bolt materials, new materials such as titanium alloys, aluminum alloys, fiberglass, and carbon fiber have been proposed, along with fiber-reinforced and micro-expansion early-strength cement grouting materials. In terms of anchor bolt structures, pressure-absorbing anchor bolts, detachable anchor bolts, and expanded-body anchor bolts have been developed. Regarding anchor bolt construction technology, precision drilling control technology, segmented pressure grouting technology, and integrated anchoring and grouting technology have seen good development. In terms of anchor bolt monitoring technology, fiber optic grating anchor bolts and intelligent monitoring and early warning technology are current development trends. Importantly, new anchor bolts or construction techniques such as short-anchorage anchor bolts and prestressed adjustable anchor bolts have been proposed for thin-layered rock masses. However, these anchor bolts are either too costly, inconvenient to construct, or cannot guarantee the stability of the rock mass after anchor bolt support and before shotcrete application. Therefore, it is necessary and urgent to develop a new type of anchor bolt device suitable for shotcrete mesh support in thin-layered rock masses. Utility Model Content

[0004] This utility model improves upon the aforementioned problems. Specifically, the technical problem it aims to solve is a double-headed anchor bolt device suitable for anchor-sprayed mesh support in thin-layered rock masses. It addresses the issue that in underground engineering projects, after anchor bolt support is implemented but before re-spraying concrete, the pull-out force generated by the solidification of grout around the anchor bolts in the thin-layered rock mass is insufficient to support the weight of the thin-layered rock mass. In this situation, the anchor bolts cannot effectively perform their support function, leading to a high risk of surrounding rock instability. Furthermore, it addresses the problem that in underground engineering projects, ordinary mortar anchor bolt support cannot apply active pre-tightening force, constituting a passive support measure that cannot effectively control the stability of the surrounding rock.

[0005] This utility model is constructed as follows: it includes a rod body and a first anchor head assembly and a second anchor head assembly disposed on the rod body. The first anchor head assembly includes a first pad and a limiting nut for restricting the outward movement of the first pad. The second anchor head assembly includes a second pad and a double nut locking structure for pressing the second pad. A plurality of spring pads are disposed on the side of the second pad away from the double nut locking structure, and each spring pad is connected to the second pad by a spring.

[0006] Furthermore, the double-nut locking structure includes a main nut and a secondary nut, with the secondary nut screwed onto the main nut to form a mutual pre-tightening.

[0007] Furthermore, a first through hole is provided in the middle of the first pad for the rod to pass through.

[0008] Furthermore, the second pad has a groove in the middle, and a second through hole in the middle of the groove for the rod to pass through.

[0009] Furthermore, a locking washer is provided inside the settling tank.

[0010] Furthermore, the thickness of the first pad and the second pad is not less than 10mm.

[0011] Furthermore, the adjacent spring pads are spaced 5mm apart.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) This device inserts the rod of the anchor into the anchor hole that has been filled with cement grout, installs the second pad and the spring and spring pad welded on it, then installs the locking washer and locking nut, and then tightens the locking nut. The pre-tightening force is evenly transmitted to the second pad through the locking washer, so that the spring is compressed and deformed, and finally the spring pad automatically adjusts to fit tightly against the rock wall, so that it applies a uniform active pre-tightening force to the rock wall. Then the first pad and the limiting nut are installed on the rod in sequence, and the limiting nut is rotated to fit tightly against the first pad. Then the steel mesh is mounted on the inside of the first pad, and finally the shotcrete is applied to complete the entire process of anchor shotcrete mesh support. (2) For anchor shotcrete mesh support of thin-layered rock mass, after the double anchor head anchor rod support is constructed and before the shotcrete is applied, the pre-tightening force applied by the second anchor head assembly can ensure the short-term safety and stability of the thin-layered rock mass. (3) For the uneven rock surface of the tunnel wall, the spring pad can apply a uniform pre-tightening force to the rock wall to ensure that the rock wall is subjected to uniform force. (4) The locking nut of this utility model can better resist the loosening effect caused by explosive vibration. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the device structure according to an embodiment of the present utility model;

[0015] Figure 2 This is a schematic diagram of the connection structure between the rod body, the locking nut, and the locking washer in an embodiment of this utility model.

[0016] Figure 3 This is a schematic diagram of the second pad structure according to an embodiment of the present utility model;

[0017] Figure 4 This is a schematic diagram of the connection structure between the second pad and the spring, and the spring pad, in an embodiment of this utility model.

[0018] Figure 5 This is a schematic diagram of the spring pad splicing structure of an embodiment of this utility model;

[0019] In the diagram: 1-Limit nut; 2-First washer; 3-Locking nut; 4-Locking washer; 5-Second washer; 6-Through hole; 7-Spring; 8-Rod; 9-Sink; 10-Spring washer. Detailed Implementation

[0020] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0021] Example: Refer to Appendix Figure 1-5 As shown, a double-anchor head anchor bolt device suitable for anchor-sprayed mesh support in thin-layered rock masses is provided. It includes a rod body with an external thread and a first anchor head assembly and a second anchor head assembly disposed on the rod body. The first anchor head assembly includes a first pad and a limiting nut for restricting the outward movement of the first pad. The limiting nut is threadedly engaged with the rod body. The second anchor head assembly includes a second pad and a double-nut locking structure for pressing the second pad. The double-nut locking structure is threadedly engaged with the rod body. Multiple spring pads are disposed on the side of the second pad away from the double-nut locking structure, and each spring pad is connected to the second pad via a spring.

[0022] The aforementioned double-nut locking structure includes a main nut and a secondary nut. The secondary nut is screwed onto the main nut to form a mutual preload. The two nuts are preloaded together, forming a threaded pair subjected to opposite forces. The spring washers are separated to transmit a uniform active preload force to the rock wall. The active preload force is applied to the rock wall through the locking nuts and locking washers. Because multiple spring washers are staggered and separated, the preload force can be uniformly transmitted to the uneven rock wall.

[0023] In this embodiment of the utility model, a first through hole is provided in the middle of the first pad for the rod to pass through.

[0024] The first pad is used to hang the reinforcing mesh on the inner side, and to transfer the pressure on the reinforcing mesh to the anchorage section.

[0025] In this embodiment of the utility model, a groove is provided in the middle of the second pad, and a second through hole is provided in the middle of the groove for the rod to pass through.

[0026] In this embodiment of the utility model, a locking washer is provided in the sink.

[0027] In this embodiment of the utility model, the thickness of the first pad and the second pad is not less than 10mm, and the first pad and the second pad can be made of steel pad material.

[0028] In this embodiment of the invention, eight springs are welded to the side of the second pad closest to the rock wall, and a spring pad is welded to the other side of each spring, for a total of eight spring pads. The spring pads are spaced 5mm apart, and the flat plate composed of the eight spring pads is considered as a whole, with a hole in the middle for the rod to pass through.

[0029] In this embodiment of the utility model, the usage steps are as follows:

[0030] Step 1: Apply initial shotcrete to the thin-layered rock wall that requires anchor-sprayed mesh support, drill anchor bolt holes, and inject an appropriate amount of cement grout into the anchor bolt holes.

[0031] Step 2: Insert the rod of this utility model into the anchor hole that has been filled with cement grout, install the second pad and the spring and spring pad welded on it, then install the locking washer and locking nut, and then tighten the locking nut. The preload is evenly transmitted to the second pad through the locking washer, thereby compressing and deforming the spring, and finally causing the spring pad to automatically adjust to fit tightly against the rock wall, so that it applies a uniform active preload to the rock wall.

[0032] Step 3: Install the first pad and the limiting nut onto the rod body in sequence, rotate the limiting nut to make it fit tightly against the first pad, then place the steel mesh on the inside of the first pad, and finally spray concrete to complete all the procedures of the anchor spray mesh support.

[0033] Unless otherwise stated, if any of the technical solutions disclosed in this utility model discloses a numerical range, then the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is merely one among many feasible numerical values ​​that has a more obvious or representative technical effect. Because there are many numerical values, it is impossible to list them all. Therefore, this utility model discloses only some numerical values ​​to illustrate the technical solutions of this utility model. Furthermore, the numerical values ​​listed above should not constitute a limitation on the scope of protection of this utility model.

[0034] If the terms "first" or "second" are used in this document to specify the components, those skilled in the art should know that the use of "first" or "second" is merely for the purpose of distinguishing the components in the description, and unless otherwise stated, the above terms have no special meaning.

[0035] Meanwhile, if the present invention discloses or relates to mutually fixedly connected parts or structural components, then unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, the mutually fixed connection can also be replaced by an integral structure (e.g., manufactured by casting process) (except where it is obviously impossible to use an integral forming process).

[0036] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this utility model above include states or shapes that are similar to, close to, or approximate with them.

[0037] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A double-headed anchor bolt device suitable for shotcrete mesh support in thin-layered rock masses, characterized in that, The device includes a rod body and a first anchor head assembly and a second anchor head assembly disposed on the rod body. The first anchor head assembly includes a first pad and a limiting nut for restricting the outward movement of the first pad. The second anchor head assembly includes a second pad and a double nut locking structure for pressing the second pad. A plurality of spring pads are disposed on the side of the second pad away from the double nut locking structure, and each spring pad is connected to the second pad by a spring.

2. The double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 1, characterized in that, The double-nut locking structure includes a main nut and a secondary nut, with the secondary nut screwed onto the main nut to form a mutual pre-tightening.

3. A double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 1, characterized in that, The first pad has a first through hole in the middle for the rod to pass through.

4. A double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 1, characterized in that, The second pad has a groove in the middle, and a second through hole in the middle of the groove for the rod to pass through.

5. A double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 4, characterized in that, The settling tank is equipped with a locking washer.

6. A double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 1, characterized in that, The thickness of the first pad and the second pad is not less than 10mm.

7. A double-headed anchor bolt device for shotcrete mesh support in thin-layered rock masses according to claim 1, characterized in that, The adjacent spring pads are spaced 5mm apart.

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