Reinforcing and supporting device and method for underground tunneling roadway

Abstract

The invention relates to the technical field of roadway supporting, and discloses a reinforcing and supporting device and method for underground tunneling roads.The reinforcing and supporting device and method for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device for underground tunneling roads.The reinforcing and supporting device comprises a roadway inner wall and a protective fence, the mounting assembly comprises a threaded anchor rod. According to the reinforcing and supporting device and method for the underground tunneling roadway, in order to enable the device to be suitable for the tunneling roadway with high surrounding rock stress, a mounting assembly is arranged and matched with a threaded anchor rod to be fixed to the inner wall of the roadway through an anchor rod tray, a nut and a locking screw, and a hook is clamped to the threaded anchor rod; the two sets of metal nets are connected with the hooks through the metal frames to form a double-layer protection structure, the supporting ring is arranged between the two layers of metal nets, the installation precision of the second layer of metal net is ensured, compared with a traditional single-layer net, the supporting strength is obviously improved, and the device is suitable for tunneling roadways with high surrounding rock stress.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel support, and in particular to a reinforced support device and method for an underground tunnel. Background Art

[0002] During the tunnel excavation process in underground mines such as coal mines and metal mines, due to factors such as complex geological structure, changes in ground stress, and rock fragmentation, the tunnel surrounding rock is prone to deformation, spalling, and even collapse, which not only leads to interruption of excavation work, but also seriously threatens the lives of underground workers.

[0003] Reinforced support systems for underground tunneling typically consist of high-strength anchors, retractable supports, a grouting reinforcement system, and an intelligent monitoring module. High-strength anchors are made from high-toughness steel and prestressed to penetrate deep into the rock formation, enhancing the integrity of the surrounding rock. Retractable supports are made from U-shaped steel or steel pipes and have a certain degree of deformation capacity to adapt to dynamic pressure changes in the surrounding rock. The grouting reinforcement system uses a high-pressure grouting pump to inject cement slurry or chemical slurry into the fractured rock formation, filling cracks and increasing its strength. The intelligent monitoring module uses pressure sensors and displacement monitors to monitor the stress on the support structure and deformation of the surrounding rock in real time.

[0004] However, the above-mentioned equipment has obvious shortcomings when used. Traditional support devices mostly use a single-layer metal mesh simply connected with anchor rods. When facing high-stress surrounding rock, the metal mesh is easily torn and cannot effectively prevent the collapse of broken surrounding rock, resulting in an increased risk of tunnel collapse. In view of this, we proposed a reinforced support device and method for underground excavation tunnels. Summary of the Invention

[0005] The object of the present invention is to provide a reinforced support device and method for underground tunneling to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A reinforced support device for an underground tunnel includes a tunnel inner wall and a guardrail. An anchor hole is opened on the tunnel inner wall. An installation component is provided on the tunnel inner wall. The installation component includes:

[0008] A threaded anchor rod is fixedly mounted on the inner wall of the tunnel, an anchor rod tray and a nut are threadedly mounted on the threaded anchor rod, and a locking screw is threadedly mounted on the anchor rod tray and the nut;

[0009] A hook is mounted on the threaded anchor rod, a metal frame is fixedly mounted on the hook, and a metal mesh is fixedly mounted on the metal frame;

[0010] A positioning handle is fixedly mounted on the metal frame, and a support ring is clamped and mounted on the threaded anchor rod.

[0011] In a further solution, the threaded anchor rods, anchor rod trays, nuts, locking screws, metal meshes, metal frames, hooks, positioning handles, support rings and threaded protective sleeves are provided in multiple groups.

[0012] In a further solution, two sets of metal meshes, metal frames and hooks are clamped and installed on each set of threaded anchor rods, and the locking screw threads pass through the anchor rod tray, nuts and hooks.

[0013] In a further solution, the support ring is arranged between two groups of metal meshes, metal frames and hooks, and a threaded protective sleeve is provided on the threaded anchor rod before installing the second group of metal meshes, metal frames and hooks, and the guardrail is arranged below the two groups of metal meshes, metal frames and hooks.

[0014] In a further solution, a locking assembly is provided on the threaded anchor rod, and the locking assembly includes an expansion plate, an expansion plate is fixedly installed on the threaded anchor rod, a limiting slide groove is provided on the threaded anchor rod, a sliding rod is slidably installed inside the threaded anchor rod, a limiting slider is fixedly installed on one end of the sliding rod, a raindrop block is fixedly installed on the other end of the sliding rod, a gasket is adhered to the inner wall of the tunnel, a spike is fixedly installed on the gasket, and a rubber pad is fixedly installed on the end of the anchor rod tray away from the nut.

[0015] In a further solution, the expansion pieces, limiting slide grooves, slide rods, limiting sliders, raindrop blocks, gaskets, spikes and rubber pads are provided in multiple groups, the limiting sliders slide inside the limiting slide grooves, and the raindrop blocks are provided between the multiple groups of expansion pieces.

[0016] In a further solution, a positioning assembly is provided on the inner wall of the lane, and the positioning assembly includes a positioning plate, and the positioning plate is fixedly mounted on the inner wall of the lane, and the positioning plate is provided with a mounting groove and a sliding groove, and one end of a spring is fixedly mounted inside the positioning plate, and one end of a round rod is fixedly mounted on the other end of the spring, and one end of a sliding block is fixedly mounted on the other end of the round rod, and a positioning block is fixedly mounted on the other end of the sliding block.

[0017] In a further solution, the positioning plates, mounting slots, sliding slots, springs, round rods, sliding blocks and positioning blocks are provided in multiple groups.

[0018] In a further solution, the round rod slides inside the installation groove, the sliding block slides inside the sliding groove, and the gaps left between the multiple groups of positioning blocks are consistent with the cross-sectional size of the positioning handle.

[0019] A method for reinforcing support of an underground tunnel using a reinforcing support device for an underground tunnel comprises the following steps:

[0020] S1. After the tunnel excavation is completed, anchor holes are immediately drilled on the inner wall of the tunnel. Threaded anchor rods are inserted into the holes so that the expansion piece is embedded in the surrounding rock cracks to achieve initial anchoring. At this time, the sliding rod, raindrop block and other components remain in their initial positions to ensure that the expansion piece does not expand. Subsequently, a rubber hammer is used to hammer the threaded anchor rod to push the sliding rod and raindrop block so that the expansion piece expands evenly and embeds deeper into the cracks to enhance the anchoring force.

[0021] S2. Attach the metal mesh to the threaded anchor rod through the metal frame and hook. Adjust the positioning handle to align with the gap between the positioning blocks. Use the spring to push the positioning blocks to clamp the handle. Quickly determine the horizontal position of the metal mesh. The sliding block adapts to the ups and downs of the roadway. Then install the anchor rod tray and secure the components with nuts and locking screws. At the same time, attach the support ring to the anchor rod. Finally, put on the thread protection sleeve to prevent the spraying from contaminating the threads.

[0022] S3. Start the shotcrete equipment and spray 100mm thick concrete onto the inner wall of the tunnel to cover the first layer of metal mesh. Install guardrails to prevent debris from falling. Fill rubber pads between the anchor tray and the surrounding rock to reduce stress concentration. Use the spikes on the pads to increase friction between the tray and the surrounding rock to stabilize the first layer of support structure.

[0023] S4. After the first layer of concrete has completely solidified, remove the thread protection sleeve to expose the exposed threads of the anchor rod. At this time, the first layer of metal mesh has formed a preliminary support with the inner wall of the tunnel. The support ring maintains the distance between the two layers of mesh, creating conditions for subsequent construction.

[0024] S5. Refer to the installation steps for the first layer and attach the second layer of metal mesh to the exposed part of the threaded anchor rod. Position it by using the positioning handle and positioning block. Then, use locking screws to fix the second layer of hooks, trays, and nuts to form a double-layer metal mesh structure to improve support strength.

[0025] S6. Spray 100mm thick concrete onto the inner wall of the tunnel again to cover the second layer of metal mesh, forming a double-layer reinforced concrete structure with a total thickness of 200mm. The support ring isolates the double-layer metal mesh, and concrete fills the gap to form a "sandwich" composite support system.

[0026] Compared with the prior art, the present invention provides a reinforced support device and method for underground tunneling, which has the following beneficial effects:

[0027] 1. The reinforced support device and method for underground tunneling is provided. In order to make the device suitable for tunneling tunnels with high surrounding rock stress, an installation component is provided. The component is fixed to the inner wall of the tunnel through an anchor tray, a nut and a locking screw in conjunction with a threaded anchor rod. The hook is clamped on the threaded anchor rod. Two sets of metal meshes are connected to the hook through a metal frame to form a double-layer protection structure. The support ring is arranged between the two layers of metal mesh, which not only provides spacing support but also isolates the anchor rod threads through a threaded protective sleeve to avoid contamination of the threaded interface during concrete spraying, thereby ensuring the installation accuracy of the second layer of metal mesh. The locking screw passes through the anchor tray, the nut and the hook to form a rigid connection. Compared with the traditional single-layer mesh support, the strength is significantly improved. At the same time, the positioning handle facilitates construction personnel to quickly align the metal frame position, thereby effectively preventing the collapse of broken surrounding rock. It is suitable for tunneling tunnels with high surrounding rock stress.

[0028] 2. The reinforced support device and method for underground tunnel excavation is provided with a locking component. The component is fixed to the front end of the threaded anchor rod in conjunction with the expansion plate. When the sliding rod is pushed by the surrounding rock pressure to squeeze the raindrop block to squeeze the expansion plate, the expansion plate expands outward and embeds into the surrounding rock cracks, thereby increasing the anchoring force of the anchor rod. At the same time, the cooperation between the limiting slider and the limiting slide groove limits the displacement direction of the sliding rod, ensuring that the expansion plate is evenly stressed, avoiding local stress concentration that causes anchor rod breakage, the spikes on the gasket are embedded in the surrounding rock surface, and the rubber pad fills the gap between the anchor rod tray and the surrounding rock, reducing stress concentration points, and improving the uniformity of force on the anchor rod, making the device more suitable for rapid tunneling support needs.

[0029] 3. The reinforced support device and method for underground excavation tunnels provide a reliable reference point for the installation of subsequent tunnel monitoring equipment by providing a positioning assembly. The assembly is fixed to the inner wall of the tunnel in conjunction with a positioning plate. The spring pushes the round rod to extend the positioning block. The gaps between multiple groups of positioning blocks match the cross-section of the positioning handle. During construction, the horizontal position of the metal frame can be determined by simply inserting the positioning handle into the gap. The sliding design of the sliding block in the sliding groove can adapt to the undulations of the tunnel surface. The elastic compensation of the spring ensures that the positioning block always fits the metal frame. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram showing the completion of the installation of the present invention;

[0031] Figure 2 This is a schematic diagram showing the completion of the installation of the second metal mesh of the present invention;

[0032] Figure 3 For the present invention Figure 2 Schematic diagram of the enlarged structure of area A in the middle;

[0033] Figure 4 This is a cross-sectional diagram of the first metal mesh of the present invention after installation;

[0034] Figure 5 For the present invention Figure 4 Schematic diagram of the enlarged structure of the middle B area;

[0035] Figure 6 Schematic diagram of the metal mesh structure of the present invention;

[0036] Figure 7 This is a schematic cross-sectional view of the positioning assembly structure of the present invention;

[0037] Figure 8 Schematic cross-sectional view of the threaded anchor structure of the present invention;

[0038] Figure 9 This is a partial structural explosion diagram of the present invention;

[0039] Figure 10 Flow chart of the method of the present invention.

[0040] Description of Figure Numbers:

[0041] 1. Guardrail;

[0042] 2. Mounting assembly; 21. Threaded anchor rod; 22. Anchor rod tray; 23. Nut; 24. Locking screw; 25. Metal mesh; 26. Metal frame; 27. Hook; 28. Positioning handle; 29. ​​Support ring; 210. Threaded protective sleeve;

[0043] 3. Locking assembly; 31. Expansion piece; 32. Limiting slide; 33. Slide rod; 34. Limiting slider; 35. Raindrop block; 36. Gasket; 37. Spike; 38. Rubber pad;

[0044] 4. Positioning assembly; 41. Positioning plate; 42. Mounting slot; 43. Sliding slot; 44. Spring; 45. Round rod; 46. Sliding block; 47. Positioning block. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] In this application, the term "upper" indicates an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. This is primarily for the purpose of better describing this application and its embodiments, and is not intended to limit the indicated devices, elements, or components to a specific orientation, or to be constructed and operated in a specific orientation. Furthermore, the term "upper" may also be used in certain circumstances to indicate a dependency or connection relationship. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0047] See also Figures 1-10 , the present invention provides a technical solution:

[0048] A reinforced support device for an underground tunnel comprises a tunnel inner wall and a guardrail 1. Anchor holes are provided on the tunnel inner wall.

[0049] In one embodiment of the present invention, a mounting assembly 2 is provided on the inner wall of the tunnel, and the mounting assembly 2 includes a threaded anchor rod 21, a threaded anchor rod 21 is fixedly installed on the inner wall of the tunnel, an anchor rod tray 22 and a nut 23 are threadedly installed on the threaded anchor rod 21, a locking screw 24 is threadedly installed on the anchor rod tray 22 and the nut 23, a hook 27 is clamped and installed on the threaded anchor rod 21, a metal frame 26 is fixedly installed on the hook 27, a metal mesh 25 is fixedly installed on the metal frame 26, a positioning handle 28 is fixedly installed on the metal frame 26, a support ring 29 is clamped and installed on the threaded anchor rod 21, the threaded anchor rod 21, the anchor rod tray 22, the nut 23, the lock screw 24, the hook 27 is clamped and installed on the hook 27, a metal frame 26 is fixedly installed on the metal frame 26, a metal mesh 25 is fixedly installed on the metal frame 26, a positioning handle 28 is fixedly installed on the metal frame 26, a support ring 29 is clamped and installed on the threaded anchor rod 21, the threaded anchor rod 21, the anchor rod tray 22, the nut 23, the lock screw There are multiple groups of fixed screws 24, metal mesh 25, metal frame 26, hook 27, positioning handle 28, support ring 29 and threaded protective sleeve 210. Two groups of metal mesh 25, metal frame 26 and hook 27 are clamped and installed on each group of threaded anchor rods 21. The locking screw 24 thread passes through the anchor rod tray 22, nut 23 and hook 27. The support ring 29 is arranged between the two groups of metal mesh 25, metal frame 26 and hook 27. A threaded protective sleeve 210 is provided on the threaded anchor rod 21 before the second group of metal mesh 25, metal frame 26 and hook 27 is installed. The guardrail 1 is arranged below the two groups of metal mesh 25, metal frame 26 and hook 27.

[0050] In one embodiment of the present invention, a locking assembly 3 is provided on the threaded anchor rod 21, and the locking assembly 3 includes an expansion piece 31, an expansion piece 31 is fixedly installed on the threaded anchor rod 21, a limiting slide groove 32 is provided on the threaded anchor rod 21, a sliding rod 33 is slidably installed inside the threaded anchor rod 21, a limiting slider 34 is fixedly installed on one end of the sliding rod 33, and a raindrop block 35 is fixedly installed on the other end of the sliding rod 33, a gasket 36 is affixed to the inner wall of the tunnel, a spike 37 is fixedly installed on the gasket 36, and a rubber pad 38 is fixedly installed on the end of the anchor rod tray 22 away from the nut 23, and multiple groups of expansion pieces 31, limiting slide groove 32, sliding rod 33, limiting slider 34, raindrop block 35, gasket 36, spike 37 and rubber pad 38 are provided, and the limiting slider 34 slides inside the limiting slide groove 32, and the raindrop block 35 is arranged between multiple groups of expansion pieces 31.

[0051] In one embodiment of the present invention, a positioning assembly 4 is provided on the inner wall of the lane, and the positioning assembly 4 includes a positioning plate 41, and the positioning plate 41 is fixedly installed on the inner wall of the lane, and a mounting groove 42 and a sliding groove 43 are provided on the positioning plate 41. One end of a spring 44 is fixedly installed inside the positioning plate 41, and one end of a round rod 45 is fixedly installed on the other end of the spring 44, and one end of a sliding block 46 is fixedly installed on the other end of the round rod 45, and a positioning block 47 is fixedly installed on the other end of the sliding block 46. There are multiple groups of positioning plates 41, mounting grooves 42, sliding grooves 43, springs 44, round rods 45, sliding blocks 46 and positioning blocks 47, and the round rods 45 slide inside the mounting grooves 42, and the sliding blocks 46 slide inside the sliding grooves 43. The gaps left between the multiple groups of positioning blocks 47 are consistent with the cross-sectional size of the positioning handle 28.

[0052] A method for reinforcing support of an underground tunnel using a reinforcing support device for an underground tunnel comprises the following steps:

[0053] After the tunnel excavation work is completed, the anchor hole is drilled on the inner wall of the tunnel. After the drilling is completed, the threaded anchor rod 21 is accurately inserted into the hole, so that the expansion piece 31 fixed at the front end of the anchor rod is smoothly embedded in the surrounding rock crack, achieving initial anchoring. At this time, the slide rod 33 is received in the threaded anchor rod 21, the raindrop block 35 is tightly fitted with the expansion piece 31, and the limiting slider 34 remains stationary in the limiting slide groove 32, structurally ensuring that the expansion piece 31 will not expand in the initial stage, laying a stable foundation for subsequent construction. Subsequently, the threaded anchor rod 21 is hammered with a rubber hammer, so that the slide rod 33 is subjected to pressure to push the raindrop block 35 towards the expansion piece 31. During this process, the limiting slider 34 strictly limits the displacement direction of the slide rod 33 in the limiting slide groove 32, ensuring that the expansion piece 31 can expand evenly outward and embed into the deeper cracks in the surrounding rock, greatly improving the anchoring force of the anchor rod;

[0054] S2. Then, the metal mesh 25 is clamped on the threaded anchor rod 21 with the help of the metal frame 26 and the hook 27. Then, the positioning handle 28 is carefully adjusted to align it with the gap between the positioning block 47 of the positioning assembly 4. The positioning plate 41 pushes the round rod 45 through the elastic force of the spring 44, causing the positioning block 47 to extend and firmly clamp the positioning handle 28, thereby quickly and accurately determining the horizontal position of the metal mesh 25. During this process, the sliding block 46 moves flexibly in the sliding groove 43, adapting to the undulating conditions of the roadway surface, further ensuring the positioning accuracy. Then, the anchor rod tray 22 is installed. Make it fit tightly against the inner wall of the tunnel, and then firmly fix the hook 27, the anchor tray 22 and the threaded anchor 21 through the nut 23 and the locking screw 24, wherein the locking screw 24 passes through the anchor tray 22, the nut 23 and the hook 27 to form a stable rigid connection. At the same time, the support ring 29 is clamped on the threaded anchor 21 so that it is located above the first layer of metal mesh 25, and a suitable spacing is reserved for the subsequent installation of the second layer of metal mesh 25. Finally, the thread protection sleeve 210 is put on to cover the exposed part of the threaded anchor 21, effectively preventing the subsequent spraying operation from contaminating the threaded interface;

[0055] S3. Start the spraying equipment and evenly spray 100 mm thick concrete onto the inner wall of the roadway, completely covering the first layer of metal mesh 25. To ensure construction safety, a guardrail 1 is installed below the metal mesh 25 to prevent debris from falling and injuring people during the spraying process. At the same time, a rubber pad 38 is filled between the anchor tray 22 and the surrounding rock to reduce stress concentration. The spikes 37 on the pad 36 are embedded in the surrounding rock surface, further enhancing the friction between the anchor tray 22 and the surrounding rock, ensuring the stability of the first layer of support structure.

[0056] S4. After the first layer of sprayed concrete has completely solidified, remove the thread protection sleeve 210 to expose the exposed threads of the anchor rod. At this point, the first layer of metal mesh 25 has formed a preliminary support system with the inner wall of the roadway through the concrete. The previously installed support ring 29 continues to function, maintaining a fixed distance between the two layers of metal mesh 25, creating good conditions for the installation of the second layer of metal mesh 25.

[0057] S5. Referring to the installation steps of the first layer of metal mesh 25, the second layer of metal mesh 25 is clamped to the exposed part of the threaded anchor 21 through the metal frame 26 and hook 27. The positioning handle 28 and the positioning block 47 are used again to accurately determine the position of the second layer of metal mesh 25. Then, the second layer of hook 27 is fixed together with the anchor tray 22 and nut 23 using the locking screw 24. The double-layer metal mesh 25 structure is successfully constructed, which significantly improves the strength of the support system.

[0058] S6. Then, 100 mm thick concrete is sprayed onto the inner wall of the tunnel again to cover the second layer of metal mesh 25, thereby forming a double-layer reinforced concrete structure with a total thickness of 200 mm. At this time, the double-layer metal mesh 25 is separated from each other by the support ring 29, and the concrete fully fills the gap between the two layers of mesh, ultimately forming a high-efficiency composite support structure similar to a "sandwich".

[0059] Among them, the standard parts used in this application document can all be purchased from the market, and the specific connection methods of each part are connected by conventional means such as rivets and welding that are mature in the existing technology, and the machinery, parts and equipment all adopt conventional models in the existing technology. The supporting structures of the hydraulic drive structure that appear in this application document, such as the hydraulic box and hydraulic pump, are existing equipment, and the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.

[0060] While the present invention has been generally described above, modifications and improvements are readily apparent to those skilled in the art. Therefore, modifications and improvements that do not depart from the spirit of the present invention are intended to be within the scope of the present invention.

Claims

1. A reinforced support device for an underground tunnel, comprising a tunnel inner wall and a guardrail (1), wherein the tunnel inner wall is provided with an anchor hole, and is characterized in that: A mounting assembly (2) is provided on the inner wall of the lane, and the mounting assembly (2) comprises: A threaded anchor rod (21), wherein the threaded anchor rod (21) is fixedly mounted on the inner wall of the tunnel, an anchor rod tray (22) and a nut (23) are threadedly mounted on the threaded anchor rod (21), and a locking screw (24) is threadedly mounted on the anchor rod tray (22) and the nut (23); A hook (27), the threaded anchor rod (21) is clamped with the hook (27), the hook (27) is fixedly mounted with a metal frame (26), and the metal frame (26) is fixedly mounted with a metal mesh (25); A positioning handle (28) is fixedly mounted on the metal frame (26), and a support ring (29) is clamped and mounted on the threaded anchor rod (21).

2. The reinforced support device for underground tunneling according to claim 1, characterized in that: The threaded anchor rod (21), anchor rod tray (22), nut (23), locking screw (24), metal mesh (25), metal frame (26), hook (27), positioning handle (28), support ring (29) and threaded protective sleeve (210) are provided in multiple groups.

3. The reinforced support device for underground tunneling according to claim 1, characterized in that: Two sets of metal meshes (25), metal frames (26) and hooks (27) are clamped and installed on each set of threaded anchor rods (21); the locking screws (24) are threadedly passed through the anchor rod tray (22), the nuts (23) and the hooks (27).

4. The reinforced support device for underground tunneling according to claim 1, characterized in that: The support ring (29) is arranged between two groups of metal meshes (25), metal frames (26) and hooks (27); a threaded protective sleeve (210) is provided on the threaded anchor rod (21) before the second group of metal meshes (25), metal frames (26) and hooks (27) are installed; and the guardrail (1) is arranged below the two groups of metal meshes (25), metal frames (26) and hooks (27).

5. The reinforced support device for underground tunneling according to claim 1, characterized in that: The threaded anchor rod (21) is provided with a locking assembly (3), and the locking assembly (3) includes an expansion piece (31), the threaded anchor rod (21) is fixedly mounted with the expansion piece (31), the threaded anchor rod (21) is provided with a limiting sliding groove (32), the threaded anchor rod (21) is slidably mounted with a sliding rod (33) inside the threaded anchor rod (21), one end of the sliding rod (33) is fixedly mounted with a limiting sliding block (34), the other end of the sliding rod (33) is fixedly mounted with a raindrop block (35), a gasket (36) is attached to the inner wall of the tunnel, a spike (37) is fixedly mounted on the gasket (36), and a rubber pad (38) is fixedly mounted on the end of the anchor rod tray (22) away from the nut (23).

6. The reinforced support device for underground tunneling according to claim 5, characterized in that: The expansion piece (31), the limiting chute (32), the slide rod (33), the limiting slider (34), the raindrop block (35), the gasket (36), the spike (37) and the rubber pad (38) are provided in multiple groups, the limiting slider (34) slides inside the limiting chute (32), and the raindrop block (35) is provided between the multiple groups of expansion pieces (31).

7. The reinforced support device for underground tunneling according to claim 1, characterized in that: A positioning assembly (4) is provided on the inner wall of the lane, and the positioning assembly (4) includes a positioning plate (41). The positioning plate (41) is fixedly installed on the inner wall of the lane, and the positioning plate (41) is provided with a mounting groove (42) and a sliding groove (43). One end of a spring (44) is fixedly installed inside the positioning plate (41), and one end of a round rod (45) is fixedly installed on the other end of the spring (44). One end of a sliding block (46) is fixedly installed on the other end of the round rod (45), and a positioning block (47) is fixedly installed on the other end of the sliding block (46).

8. The reinforced support device for underground tunneling according to claim 7, characterized in that: The positioning plate (41), the mounting groove (42), the sliding groove (43), the spring (44), the round rod (45), the sliding block (46) and the positioning block (47) are provided in multiple groups.

9. The reinforced support device for underground tunneling according to claim 7, characterized in that: The round rod (45) slides inside the installation groove (42), and the sliding block (46) slides inside the sliding groove (43). The gaps between the multiple groups of positioning blocks (47) are consistent with the cross-sectional size of the positioning handle (28).

10. A method for reinforcing support of an underground tunnel according to claim 9, characterized in that: The following steps are involved: S1. After the tunnel is excavated, a hole is drilled on the wall and a threaded anchor rod (21) is inserted to embed the expansion piece (31) into the crack to complete the initial anchoring. The anchor rod is hammered with a rubber hammer to push the sliding rod (33) and the raindrop block (35). Under the action of the limiting structure, the expansion piece (31) is evenly expanded to enhance the anchoring force between the anchor rod and the surrounding rock; S2, clamp the metal mesh (25) to the anchor rod through the metal frame (26) and the hook (27), quickly position it using the positioning assembly (4), install the anchor rod tray (22), fix each component with nuts (23) and locking screws (24), clamp the support ring (29), and then put on the thread protection sleeve (210) to prevent the spraying from contaminating the threaded interface; S3, start the spraying equipment, spray 100mm thick concrete to the tunnel wall to cover the metal mesh (25), set up a guardrail (1) to prevent falling, fill the rubber pad (38) between the tray and the surrounding rock to reduce stress, use the gasket (36) to enhance friction, and stabilize the first layer support; S4. After the first layer of concrete solidifies, remove the thread protection sleeve (210) to expose the threads on the threaded anchor rod (21). At this time, the first layer of support has been formed, and the support ring (29) maintains the distance between the two layers of mesh, creating conditions for installing the second layer of metal mesh (25); S5. Repeat the steps of the first layer, clamp the second layer of metal mesh (25) to the exposed part of the anchor rod, position it with the positioning assembly (4), and fix it with locking screws (24) to form a double-layer mesh structure to improve the support strength; S6. Spray 100mm thick concrete to cover the second layer of metal mesh (25) to form a 200mm double-layer concrete structure. The support ring (29) isolates the double-layer mesh and the concrete fills the gap to form a "sandwich" composite support to achieve long-term and stable support.

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