Strong impact load chamber support anchor rod and its supporting process

Abstract

This invention discloses a high-impact load chamber support anchor and its support process, relating to the field of chamber support technology. It is safe, reliable, easy to operate, and can reduce the impact of high-impact loads on the chamber. The technical solution of this invention is as follows: the high-impact load chamber support anchor includes an integrated hollow anchor and a detachably connected grouting connection device; the integrated hollow anchor includes a hollow anchor body, with an anchoring end fixedly connected to one end, and a grout outlet in the middle of the hollow anchor body; threads are formed on the outer wall of the other end of the hollow anchor body, and a grout stop plug, a tray, and a fastening nut are sequentially fitted at this end; an internal thread adapted to the thread on the hollow anchor body is formed at the front of the grouting connection device, and an external thread for connecting grouting equipment is formed at the rear of the grouting connection device. The entire anchor support process has multiple functions, including far-end wave damping and buffering, overall combined support, and effective anchoring.

Description

Technical Field

[0001] This invention relates to the field of tunnel support technology, and in particular to a strong impact load tunnel support anchor bolt and its support process applicable to the support and reinforcement of mine roadways, tunnels and other engineering fields affected by strong impact loads. Background Technology

[0002] When shallow underground chambers, air-raid shelters, oil depots, etc. are subjected to strong impact loads such as bunker buster bombs, and especially when roadways in deep mines are subjected to strong rockbursts, traditional support methods can no longer meet the current needs under the stress wave action of strong impact loads. In particular, in deep coal mining, the roadway is subjected to variable stress and rockbursts occur frequently. If only simple anchor bolts, anchor cables, anchor nets, and brackets are used for support, it is difficult to provide effective anchoring and support after strong impact loads.

[0003] Currently, mainstream improvements to rock bolt support involve either enhancing its anchoring force through the use of high-strength rock bolts, high-quality grouting materials, and reinforced anchoring agents, or by grouting and bonding rock bolts to fractured surrounding rock, or by adding pressure-relief devices to the rock bolts. However, these methods often suffer from high material costs and insufficient penetration of the grouting material into the surrounding rock, resulting in inadequate support capacity. Furthermore, rigid supports in chambers and tunnels subjected to strong impact loads can be severely damaged by stress waves caused by these loads, leading to support failure or even personnel casualties within the chamber. This is particularly problematic in areas with frequent rockbursts and underground refuges threatened by bunker buster bombs, where a combination of flexible support with wave-damping buffers at the far end of the chamber and rock bolt support is lacking. Summary of the Invention

[0004] To address the above problems, this invention proposes a support anchor for chambers subjected to strong impact loads and its support process, which is safe, reliable, easy to operate, and can reduce the impact of strong impact loads on the chamber.

[0005] The technical solution of the present invention is as follows: the high impact load chamber support anchor rod includes an integrated hollow anchor rod 16 and a grouting connection device 7 that is detachably connected to it;

[0006] The integrated hollow anchor rod 16 includes a hollow anchor rod body 1, an anchor end 2 is fixedly connected to one end of the hollow anchor rod body 1, and a grout outlet 3 is opened in the middle of the hollow anchor rod body 1.

[0007] A thread is provided on the outer wall of the other end of the hollow anchor rod body 1, and a grout stop plug 4, a tray 5 and a fastening nut 6 are sequentially installed at this end. The fastening nut 6 is threadedly connected to the hollow anchor rod body 1. The grouting connection device 7 can also be detachably installed at this end of the hollow anchor rod body 1.

[0008] An internal thread 11 adapted to the thread on the hollow anchor rod body 1 is provided at the front of the grouting connection device 7, and an external thread 12 for connecting grouting equipment is provided at the rear of the grouting connection device 7. A one-way grouting device 13 is provided in the grouting connection device 7, which is unidirectionally connected from the side where the external thread 12 is located to the side where the internal thread 11 is located.

[0009] The one-way grouting device 13 is arranged in the channel between the external thread 12 and the internal thread 11. The one-way grouting device 13 includes six one-way grouting plates 15 evenly distributed in the circumferential direction, and there is an angle between the one-way grouting plates 15 and the channel axis. A spring 14 is fixedly installed between the one-way grouting plates 15 and the inner wall of the channel.

[0010] When there is no external force, one end of the one-way grouting piece 15 is attached to the inner wall of the channel, while the other end is attached to another one-way grouting piece 15 under the action of the restoring force of the spring 14.

[0011] Establish the support structure according to the following steps:

[0012] Step 1: Use a drilling rig to drill anchor cable holes 10 in the surrounding rock 9 around the chamber, with the diameter matching that of the integrated hollow anchor rod 16;

[0013] Step 2: Install the hollow anchor rod body 1 of the multiple integrated hollow anchor rods 16 into the anchor cable hole 10, use resin anchoring for the anchor end 2, and install the grout stop plug 4 and tray 5 at the tail end, and then apply pre-tightening force using the fastening nut 6.

[0014] Step 3: Connect the grouting equipment, grouting connection device 7, and hollow anchor rod body 1 sequentially using threads;

[0015] Step 4: Use grouting equipment to press water into the grouting connection device 7, and then eject it from the grout outlet 3 through the inside of the hollow anchor rod body 1 to increase the grouting pressure and generate a fracture network 17 in the surrounding rock around the grout outlet.

[0016] Step 5: Replace the grouting material with foamed cement grout, and use the grouting equipment to press the foamed cement grout into the grouting connection device 7, and inject it into the fracture network 17 through the grout outlet 3.

[0017] Step 6: After the grout has solidified, use a torque wrench to tighten the fastening nut 6 to the specified preload, and remove the grouting connection device 7 and the grouting equipment to form an effective anchoring structure.

[0018] After grouting is completed, the grouting connection device 7 is not removed temporarily. It is removed after the cement grout has dried slightly (becomes non-flowing) for recycling, flushing, and reuse. The internal thread 11 of the grouting connection device 7 is screwed onto the end of the anchor rod, and the cement grout mainly remains inside the anchor rod.

[0019] The beneficial effects of this invention are:

[0020] 1. By first hydraulically fracturing the surrounding rock at the far end of the chamber, a fracture network is formed in the surrounding rock. Then, foamed cement grout is injected into the fracture network, which is safe, reliable, and easy to operate. When the stress wave of a strong impact load is transmitted from the far end, the wave-damping buffer ring made of foamed cement can effectively weaken the transmission of the stress wave to the chamber and absorb the energy of the strong impact load. At the same time, it can form a joint support network inside the surrounding rock, which can enhance the anchoring capacity of the anchor bolts to a certain extent.

[0021] Second, the combined support of multiple strong impact load chamber anchor bolts achieves effective anchoring at the anchoring end, while forming a wave-absorbing buffer ring in the surrounding rock at a certain distance from the chamber, weakening the impact of strong impact loads on the chamber and strengthening the anchoring effect.

[0022] Third, the injection molding device at the tail end of the anchor bolt can be quickly and easily disassembled and matched with various types of grouting equipment connectors. At the same time, the internal one-way grouting device allows the grouting material to be injected into the anchor bolt through hole from the outside, preventing the grouting material from overflowing from the inside.

[0023] Fourth, this invention can form an effective wave-damping buffer ring between the anchoring end and the chamber. During the transmission of stress waves from strong impact loads to the chamber, this support technology can weaken the stress waves, absorb the stress wave energy, reduce the impact of strong impact loads on the chamber, and enhance the anchoring capacity of the anchor bolts.

[0024] V. The special structural design of the grouting connection device in this invention has a series of advantages such as simple construction, convenient assembly, and convenient use.

[0025] Overall, this invention is applicable to the reinforcement of underground air-raid shelters, the support and reinforcement of mine roadways affected by strong rock bursts, and deep underground engineering projects. The entire anchor bolt support process has multiple functions, including remote wave damping and buffering, overall combined support, and effective anchoring. It also features simple structure, stable performance, low cost, compatibility with various grouting equipment joints, and ease of promotion. Attached Figure Description

[0026] Figure 1 This is a detailed drawing of the anchor bolt structure of the present invention;

[0027] Figure 2 This is a detailed structural diagram of the grouting connection device of the present invention;

[0028] Figure 3 This is a detailed structural diagram of the unidirectional grouting device of the present invention, wherein... Figure 3 a is a side view of a unidirectional grouting device. Figure 3 b is a schematic diagram of a single unidirectional grouting device component;

[0029] Figure 4 This is a schematic diagram of the overall installation of the anchor bolts according to the present invention;

[0030] Figure 5 This is a schematic diagram of the hydraulically fracturing surrounding rock of the anchor bolt device of the present invention;

[0031] Figure 6 This is a schematic diagram of the foam cement filling crack network of the anchor bolt device of the present invention.

[0032] In the diagram: 1 - Hollow anchor rod body, 2 - Anchoring end, 3 - Grout outlet, 4 - Grout stop plug, 5 - Tray, 6 - Fastening nut, 7 - Grouting connection device, 8 - Anchor rod through hole, 9 - Surrounding rock, 10 - Anchor cable hole, 11 - Internal thread, 12 - External thread, 13 - One-way grouting device, 14 - Spring, 15 - One-way grouting plate, 16 - Integrated hollow anchor rod, 17 - Fracturing network, 18 - Wave damping buffer ring. Detailed Implementation

[0033] To clearly illustrate the technical features of this patent, the following detailed description is provided through specific embodiments and in conjunction with the accompanying drawings.

[0034] As attached Figure 1 As shown, the high impact load chamber support anchor bolt includes an integrated hollow anchor bolt 16 and a grouting connection device 7 that is detachably connected to it;

[0035] The integrated hollow anchor rod 16 includes a hollow anchor rod body 1, an anchor end 2 is fixedly connected to one end of the hollow anchor rod body 1, and a grout outlet 3 is opened in the middle of the hollow anchor rod body 1.

[0036] A thread is provided on the outer wall of the other end of the hollow anchor rod body 1, and a grout stop plug 4, a tray 5 and a fastening nut 6 are sequentially installed at this end. The fastening nut 6 is threadedly connected to the hollow anchor rod body 1. The grouting connection device 7 can also be detachably installed at this end of the hollow anchor rod body 1.

[0037] An internal thread 11 adapted to the thread on the hollow anchor rod body 1 is provided at the front of the grouting connection device 7, and an external thread 12 for connecting grouting equipment is provided at the rear of the grouting connection device 7. A one-way grouting device 13 is provided in the grouting connection device 7, which is unidirectionally connected from the side where the external thread 12 is located to the side where the internal thread 11 is located.

[0038] The one-way grouting device 13 is arranged in the channel between the external thread 12 and the internal thread 11. The one-way grouting device 13 includes six one-way grouting plates 15 evenly distributed in the circumferential direction, and there is an angle between the one-way grouting plates 15 and the channel axis. A spring 14 is fixedly installed between the one-way grouting plates 15 and the inner wall of the channel.

[0039] When there is no external force, one end of the one-way grouting piece 15 is attached to the inner wall of the channel, while the other end is attached to another one-way grouting piece 15 under the action of the restoring force of the spring 14.

[0040] Specifically, such as Figure 3 As shown in a and 3b, there is a cavity in the channel ( Figure 3 (circular dashed line in a) When there is no external force, the end of the one-way grouting plate 15 facing the external thread 12 presses against the inner wall of the cavity (allowing to retain gaps). When material is injected, the spring 14 is compressed, and the ends of the six one-way grouting plates 15 away from the external thread 12 separate from each other, exposing space to achieve one-way conduction. After the material is injected, the spring returns to its original position to achieve one-way backflow prevention.

[0041] A high-impact load chamber support process according to the present invention:

[0042] As attached Figure 4 As shown, a drilling rig is used to drill anchor cable holes 10 in the surrounding rock 9 around the chamber, with the diameter matching that of the integrated hollow anchor rod 16. The hollow anchor rod bodies 1 of multiple integrated hollow anchor rods 16 are installed in the anchor cable holes 10, and the anchoring ends 2 are anchored with resin. A grout stop plug 4 and a tray 5 are installed at the tail end, and a pre-tightening force is applied using a fastening nut 6.

[0043] As attached Figure 5 As shown, the joint of the grouting equipment is connected to the hollow anchor rod body 1 with a grouting connection device 7 of the corresponding size and model. Water is injected into the grouting connection device 7 by the grouting equipment and ejected from the grout outlet 3 through the anchor rod through hole 8 inside the hollow anchor rod body 1. The grouting pressure is increased to generate a fracture network 17 in the surrounding rock around the grout outlet.

[0044] As attached Figure 6 As shown, the grouting material is replaced with foamed cement grout. The foamed cement grout is pumped into the grouting connection device 7 using grouting equipment, and then injected into the fracture network 17 through the anchor bolt through hole 8 and the grout outlet 3. After the grout solidifies, the fastening nut 6 is tightened to the specified preload using a torque wrench to form an effective anchoring structure.

[0045] The anchoring end 2 of the hollow anchor rod body 1 is anchored in the anchor cable hole in the surrounding rock 9 under the action of resin. The grout stop plug 4 and the tray 5 are installed in sequence at the tail end of the hollow anchor rod body 1, and the pre-tightening force is applied to the fastening nut 6 so that the anchor rod has a certain anchoring capacity.

[0046] In the above:

[0047] The hollow anchor rod body 1 is connected to the grouting equipment through the grouting connection device 7. The different types of external threads 12 at the end of the grouting connection device 7 can be compatible with various types of grouting equipment joints.

[0048] The unidirectional grouting device 13 in the grouting connection device 7 enables unidirectional flow of grouting material, and works in conjunction with the grout stop plug 4 to prevent grout overflow. Specifically, the grout stop plug 4 prevents the grout injected into the rock mass from overflowing along the gap between the anchor rod and the rock mass, while the unidirectional grouting device 13 prevents the grout from overflowing from the end along the hollow anchor rod (inside the rod). Together, they achieve the purpose of preventing grout overflow.

[0049] When the grouting equipment injects water from the grouting connection device 7 through the anchor bolt through hole 8 and out of the grout outlet 3, the large water pressure causes a network of fractures 17 to appear in the surrounding rock around the grout outlet 3. The water pressure and hydraulic fracturing time are controlled to prevent the fracture network from affecting the anchoring end. Then the grouting material is replaced, and foamed cement grout is injected into the fracture network 17. Multiple anchor bolts are constructed in sections to finally form a combined support, forming a wave-damping buffer ring 18 between the chamber and the anchor bolt anchoring end 2.

[0050] When a strong impact load stress wave is transmitted from a distance to the chamber, the anchoring force at the two anchoring ends that are impacted is weakened. The stress wave passes through the porous wave-absorbing buffer ring 18 made of foamed cement. Part of the energy of the stress wave is absorbed by the wave-absorbing buffer ring 18. Cracks are formed in the wave-absorbing buffer ring 18. The stress wave transmitted to the chamber is continuously weakened by the wave-absorbing buffer ring 18 until the stress wave after wave absorption can still completely cause the anchor rod to lose its anchoring ability.

[0051] In summary, by utilizing the anchoring capacity of the integrated hollow anchor bolt end and the combined support of multiple anchor bolts to form a wave-damping buffer ring 18 at the far end of the chamber to absorb and weaken the stress waves of strong impact loads, this invention provides a certain anchoring force when the chamber is subjected to strong impact loads. In projects such as the reinforcement of air-raid shelters, mine roadways affected by strong impact loads, and deep underground engineering projects using this invention as the support material and support technology, the stress waves transmitted from the strong impact load to the chamber will first crack the wave-damping buffer ring 18. The wave-damping buffer ring 18, composed of porous foamed cement, absorbs and weakens the stress wave energy, thus protecting the chamber. At the same time, the anchor bolt itself has a certain anchoring force, maintaining the stability and safety of the chamber. The combined support of multiple anchor bolts constitutes a stable support system for chambers subjected to strong impact loads, further enhancing the safety of chambers affected by strong impact loads.

[0052] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A support technology based on anchor bolts for chamber support under high impact load, characterized in that, The high impact load chamber support anchor includes an integrated hollow anchor (16) and a grouting connection device (7) that is detachably connected to it. The integrated hollow anchor rod (16) includes a hollow anchor rod body (1), an anchor end (2) is fixedly connected to one end of the hollow anchor rod body (1), and a grout outlet (3) is opened in the middle of the hollow anchor rod body (1). A thread is provided on the outer wall of the other end of the hollow anchor rod (1), and a grout stop plug (4), a tray (5) and a fastening nut (6) are sequentially installed at this end. The fastening nut (6) is threadedly connected to the hollow anchor rod (1), and the grouting connection device (7) is also detachably installed at this end of the hollow anchor rod (1). An internal thread (11) adapted to the thread on the hollow anchor rod body (1) is provided at the front of the grouting connection device (7), and an external thread (12) for connecting grouting equipment is provided at the rear of the grouting connection device (7). A one-way grouting device (13) is provided inside the grouting connection device (7) that conducts unidirectionally from the side where the external thread (12) is located to the side where the internal thread (11) is located. Establish the support structure according to the following steps: Step 1: Use a drilling rig to drill anchor holes (10) in the surrounding rock (9) around the chamber, with the diameter matching that of the integrated hollow anchor rod (16). Step 2: Install the hollow anchor rod body (1) of the multiple integrated hollow anchor rods (16) into the anchor cable hole (10), use resin anchoring for the anchor end (2), and install the grout stop plug (4) and tray (5) at the tail end, and then apply pre-tightening force using fastening nut (6); Step 3: Connect the grouting equipment, grouting connection device (7), and hollow anchor rod body (1) in sequence by thread; Step 4: Use grouting equipment to press water into the grouting connection device (7), and then eject it from the grout outlet (3) through the hollow anchor rod body (1), increasing the grouting pressure to generate a fracture network (17) in the surrounding rock around the grout outlet. Step 5: Replace water with foamed cement grout, and use grouting equipment to press the foamed cement grout into the grouting connection device (7), and inject it into the fracture network (17) through the grout outlet (3). Step 6: After the grout has solidified, use a torque wrench to tighten the fastening nut (6) to the specified preload, and remove the grouting connection device (7) and the grouting equipment to form an effective anchoring structure.

2. The support process based on high-impact load chamber support anchor bolts according to claim 1, characterized in that, The one-way grouting device (13) is arranged in the channel between the external thread (12) and the internal thread (11). The one-way grouting device (13) includes six one-way grouting plates (15) evenly distributed in the circumferential direction, and has an angle between the one-way grouting plates (15) and the axial direction of the channel. A spring (14) is fixedly installed between the one-way grouting plates (15) and the inner wall of the channel. When there is no external force, one end of the one-way grouting piece (15) is attached to the inner wall of the channel, while the other end is attached to another one-way grouting piece (15) under the action of the restoring force of the spring (14).

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