A kind of underground tunnel support device and support method

Abstract

The present invention discloses an underground tunnel support device, comprising: an anchor hole, which is arc-shaped and embedded in the surrounding rock, with two openings of the anchor hole being opened on the surface of a layer prone to collapse; an anchor cable running through the anchor hole; and an anchoring agent filled in the anchor hole, the anchoring agent filling the anchor hole. The present invention adopts an anchor cable for anchor support, and the anchor cable not only has tensile resistance, but also has excellent shear resistance. When an oblique dislocation occurs at the junction of the layer prone to collapse and the solid layer and shear force is generated, the anchor cable can resist the shear force, thereby ensuring the integrity and effectiveness of the support device. In addition, the anchor hole in the present invention is arc-shaped, and the arc-shaped anchor support can effectively resist shear forces in different directions, that is, the arc-shaped anchor support in the present invention can adapt to the complex shear force distribution at the junction, and form effective support for the layer prone to collapse. The present invention also discloses an underground tunnel support method.

Description

Technical Field

[0001] The present invention relates to the field of underground tunnel support, and more specifically, to an underground tunnel support device and a support method. Background Art

[0002] The roof of the underground tunnel consists of a prone-to-collapse layer and a solid layer. The boundary between the prone-to-collapse layer and the solid layer is prone to dislocation and separation, which causes the prone-to-collapse layer to sink. Therefore, a support device is needed to support the prone-to-collapse layer to prevent it from sinking. The conventional support method is to use anchor rods. The specific operation of anchor rod support is to drill a hole perpendicular to the prone-to-collapse layer at the top of the tunnel, then insert the anchor rod into the anchor hole, inject the anchoring agent, and fix the exposed end of the anchor rod on the surface of the prone-to-collapse layer through a lock, and use the tensile force of the anchor rod to resist the sinking of the prone-to-collapse layer.

[0003] However, during the support process, the anchor rods often break. Therefore, technicians in this field will select anchor rods with better tensile strength. However, no matter how high the tensile strength of the anchor rods is, it still cannot improve the problem that the anchor rods are prone to breakage. Summary of the invention

[0004] The purpose of the present invention is to improve the problem of fracture of anchor support, thereby ensuring the integrity and effectiveness of the anchor support.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] An underground tunnel support device, comprising:

[0007] An anchor hole, the anchor hole is arc-shaped, the anchor hole is embedded in the surrounding rock, and two openings of the anchor hole are opened on the surface of the easy-to-collapse layer;

[0008] An anchor cable running through the anchor hole;

[0009] The anchoring agent is filled in the anchoring hole, and the anchoring agent fills the anchoring hole.

[0010] Preferably, the anchor hole is semicircular.

[0011] Preferably, the highest point of the anchor hole passes over the boundary between the collapse-prone layer and the solid layer.

[0012] Preferably, the end of the anchor cable is locked on the surface of the collapse-prone layer by a lock.

[0013] Preferably, the anchor holes are arranged in rows along the tunnel.

[0014] Preferably, in two adjacent rows of the anchor holes, one row includes two anchor holes arranged side by side, and the other row includes one anchor hole, and the one anchor hole is staggered with the two anchor holes.

[0015] The present invention also discloses an underground tunnel support method, comprising the following steps:

[0016] S1: Use a drilling rig to drill arc-shaped anchor holes in the prone-to-collapse layer;

[0017] S2: inserting the anchor cable into the anchor hole;

[0018] S3: Fill the anchor hole with anchoring agent, and fasten the first end and the second end of the anchor cable to the surface of the collapse-prone layer by means of a lock.

[0019] Preferably, the step S3 specifically includes:

[0020] S31: fixing the first end of the anchor cable in the anchor hole by using an anchoring agent, and fastening the first end of the anchor cable to the surface of the collapse-prone layer by using a lock;

[0021] S32: inserting a grouting pipe of a grouting machine into the anchor hole from the hole where the second end of the anchor cable is located, and the pipe opening of the grouting pipe passes over the highest point of the anchor hole;

[0022] S33: injecting a liquid anchoring agent into the anchor hole through the grouting pipe;

[0023] S34: Determine whether there is anchoring agent overflowing from the hole where the second end of the anchor cable is located, if so, proceed to step S35;

[0024] S35: Stop injecting the anchoring agent into the anchor hole;

[0025] S36: Fasten the second end of the anchor cable to the surface of the collapse-prone layer by means of a lock.

[0026] Preferably, before injecting the anchor into the anchor hole, a preset amount of the anchor to be injected is calculated in advance based on the volume of the anchor hole and the volume of the anchor cable. If the anchor overflows when the injected amount is less than the preset amount, the grouting pressure of the injected anchor is adjusted.

[0027] Preferably, before step S1, the method further includes fastening one end of the traction rope to the rear of the drill rod of the drilling rig;

[0028] The step S2 specifically includes: after the drill rod is pulled out from the drill-out side, the traction rope is removed from the drill rod, and then the anchor rope is fastened to the other end of the traction rope, and the anchor rope is inserted into the anchor hole by the traction effect of the traction rope.

[0029] It can be seen from the above technical scheme that the present invention adopts anchor cables for anchor support, and the anchor cables not only have tensile resistance, but also have excellent shear resistance. When the collapse-prone layer and the solid layer are misaligned and shear force is generated, the anchor cables can resist the shear force, thereby ensuring the integrity and effectiveness of the support device. In addition, the anchor hole in the present invention is arc-shaped, that is, the anchor cables are arranged in an arc shape, thereby forming an arc-shaped anchor support. It can be understood by those skilled in the art that wrinkles are likely to appear at the junction of the collapse-prone layer and the solid layer during the operation of the earth's crust, and oblique dislocation is prone to occur at the wrinkles, and oblique dislocation will generate shear force. The wrinkles are usually irregularly distributed, that is, the direction of the shear force is not fixed. The anchor support arranged in an arc in the present invention can effectively resist shear forces in different directions, that is, the arc-shaped anchor support in the present invention can adapt to the complex shear force distribution at the junction of the collapse-prone layer and the solid layer, thereby forming effective support for the collapse-prone layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the scheme in the embodiment of the present invention, the following is a brief introduction to the drawings required for describing the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 A cross-sectional view of an arc-shaped anchor support provided in a specific embodiment of the present invention;

[0032] Figure 2 A schematic diagram of an anchor cable subjected to different shear forces provided by a specific embodiment of the present invention;

[0033] Figure 3 A front view of an underground tunnel support device provided by a specific embodiment of the present invention;

[0034] Figure 4 A top view of an underground tunnel support device provided in a specific embodiment of the present invention.

[0035] Among them, 1 is the anchor hole, 2 is the anchor cable, 3 is the prone to collapse layer, 4 is the lock, 5 is the hole mouth, and 6 is the solid layer. DETAILED DESCRIPTION

[0036] The invention discloses an underground tunnel support device, which can resist the shear force and tension force at the interface between the easy-to-collapse layer and the solid layer, thereby ensuring the integrity and effectiveness of the support device. The invention also discloses an underground tunnel support method.

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0038] When using anchor rods to support underground tunnels, the applicant found that no matter how strong the tensile strength of the anchor rods is, the anchor rods will still break during the support operation, and the broken part is a neat cross-section. After in-depth research, the applicant found that the force that causes the anchor rod to break is not the tensile force, but the shear force formed after the oblique dislocation of the junction of the easy-to-collapse layer 3 and the solid layer 6. Although the anchor rod has a strong tensile strength, it does not have a strong shear strength. When the junction is dislocated to form a shear force, the anchor rod will break. For some support devices that are supported by anchor rods and anchor cables, although the anchor cable has shear resistance, the anchor rod will resist the shear force before the anchor cable, so the anchor rod will still break. Based on this discovery, the applicant creatively designed the underground tunnel support device in the present invention.

[0039] Please refer to the attached Figure 1 and attached Figure 2 , the underground tunnel support device in the present invention includes: an anchor hole 1, an anchor cable 2 and an anchoring agent. The shape of the anchor hole 1 in the present invention is special, which is an arc shape. The anchor hole 1 is embedded in the surrounding rock. The two openings 5 ​​of the anchor hole 1 are opened on the surface of the prone to collapse layer 3. The anchor cable 2 is arranged through the anchor hole 1. The anchor hole 1 is filled with an anchoring agent, and the anchoring agent bonds the anchor cable 2 to the inner wall of the anchor hole 1. Moreover, the anchoring agent fills the entire anchor hole 1, that is, the support in the present invention is a full-section anchoring support. The function of the full-section anchoring support is that after one section is destroyed, the other parts can still maintain the tensile and shear resistance.

[0040] The present invention adopts anchor cable 2 for anchor support, and anchor cable 2 not only has tensile resistance, but also has excellent shear resistance. When oblique dislocation occurs at the junction and shear force is generated, anchor cable 2 can resist the shear force, thereby ensuring the integrity and effectiveness of the support device. In addition, the anchor hole 1 in the present invention is arc-shaped, that is, the anchor cable 2 is arranged in an arc shape, thereby forming an arc-shaped anchor support. It can be understood by those skilled in the art that in the operation of the earth's crust, wrinkles are likely to appear at the junction of the prone to collapse layer and the solid layer 6, and oblique dislocation is prone to occur at the wrinkles, thereby generating shear force. The wrinkles are usually irregularly distributed, that is, the direction of the shear force is not fixed. The anchor support arranged in an arc shape in the present invention can effectively resist shear forces in different directions, that is, the arc-shaped anchor support in the present invention can adapt to the complex shear force distribution at the junction and form effective support for the prone to collapse layer. Please refer to the attached Figure 3 , in the attached Figure 3 The schematic diagram of the anchor cable 2 bearing the shear force of F1-F7 is shown in FIG.

[0041] The present invention further optimizes the shape of the anchor hole 1 into a semicircular shape. The semicircular anchor support can resist shear forces in more directions.

[0042] In order to enable the support device of the present invention to have a better tensile resistance effect, thereby preventing the collapse-prone layer from falling off, the present invention limits the highest point of the arc-shaped anchor hole 1 to pass over the junction of the collapse-prone layer 3 and the solid layer 6, or the highest point of the anchor cable 2 is located above the junction. The anchor cable 2 located above the collapse-prone layer 3 is glued to the solid layer 6. When the collapse-prone layer has a tendency to sink, the anchor cable 2 will exert an upward pulling force on the collapse-prone layer 3, thereby preventing the collapse-prone layer 3 from falling off.

[0043] It should be noted that the anchor cables 2 in the present invention are arranged in a semicircle. Compared with the anchor cables 2 arranged in a straight line, the anchor cables 2 in the present invention have a smaller pressure-releasing capacity, so the prone-to-collapse layer 3 will not be allowed to sink to a large extent, thereby ensuring that the tunnel has sufficient space.

[0044] In order to improve the firmness of the anchor cable 2 , the present invention fastens the two ends of the anchor cable 2 to the surface of the prone-to-collapse layer 3 through locks 4 .

[0045] Please refer to the attached Figure 3 and attached Figure 4 The distribution structure of the arc-shaped anchor support in the present invention is as follows: along the tunnel, the anchor holes 1 are arranged in rows, or the arc-shaped anchor supports are arranged in rows. Each row is provided with one, two, or more anchor holes 1. In a preferred specific embodiment, the arc-shaped anchor supports are arranged in a 2-1-2 manner, that is, two arc-shaped anchor supports are arranged in the first row, one arc-shaped anchor support is arranged in the second row, two arc-shaped anchor supports are arranged in the third row, and so on. Moreover, when one arc-shaped anchor support is arranged, the arc-shaped anchor support is located in the middle position of the two arc-shaped anchor supports in the front row or the rear row, or is staggered with the two arc-shaped anchor supports in the front row or the rear row. In this way, not only is full coverage support ensured along the width direction of the tunnel, but the number of supports is also greatly reduced, thereby improving work efficiency.

[0046] It should be noted that in the prior art solution using anchor rod support, the anchor rods in each row are densely arranged and multiple holes need to be drilled in each row. However, in the present invention, at most two arc-shaped anchor holes 1 are drilled in each row, thereby greatly reducing the number of holes drilled.

[0047] The present invention also discloses an underground tunnel support method, comprising the following steps:

[0048] S1: Use a drilling rig to drill an arc-shaped anchor hole 1 in the prone-to-collapse layer 3. The present invention uses a directional arc drilling rig to drill holes.

[0049] S2: insert the anchor cable 2 into the anchor hole 1.

[0050] Regarding the method of threading the anchor cable 2, the present invention specifically adopts the following scheme:

[0051] Before drilling, one end of the traction rope is fastened to the rear of the drill rod of the drilling rig, and then drilling is started. After the drilling is completed and the drill rod is pulled out from the drilled side, the traction rope is removed from the drill rod, and then the anchor cable 2 is fastened to the other end of the traction rope. The anchor cable 2 is inserted into the anchor hole 1 through the traction effect of the traction rope.

[0052] Next, step S3 is entered: fill the anchor hole 1 with anchoring agent, and fasten the first end and the second end of the anchor cable 2 to the top plate through the lock 4. The specific injection steps are as follows:

[0053] S31: fix the first end of the anchor cable 2 in the anchor hole 1 by using an anchoring agent, and fasten the first end of the anchor cable 2 to the surface of the prone-to-collapse layer 3 by using a lock 4.

[0054] S32: inserting the grouting pipe of the grouting machine into the anchor hole 1 from the hole 5 where the second end of the anchor cable 2 is located, and ensuring that the pipe opening of the grouting pipe passes over the highest point of the anchor hole 1.

[0055] S33: injecting liquid anchoring agent into the anchor hole 1 through the grouting pipe.

[0056] The injection method in the present invention is a countercurrent injection method. If the side where the first end of the anchor cable 2 is located is defined as the first side of the anchor hole 1, and the side where the second end of the anchor cable 2 is located is defined as the second side of the anchor hole 1, then the grouting pipe enters from the second side, and then the anchoring agent is injected into the first side of the anchor hole 1. The anchoring agent gradually rises in the first side, and then overflows into the second side of the anchor hole 1. Next, step S34 is entered.

[0057] S34: Determine whether there is anchoring agent overflowing from the hole 5 where the second end of the anchor cable 2 is located. If so, proceed to step S35.

[0058] S35: Stop injecting anchoring agent into the anchor hole 1. If anchoring agent overflows from the hole 5 where the second end of the anchor cable 2 is located, it means that the anchor hole 1 is already full of anchoring agent.

[0059] S36: Fasten the second end of the anchor cable 2 to the surface of the collapse-prone layer by means of the lock 4.

[0060] It should be noted that when injecting anchoring agent into the anchor hole 1, anchoring agent overflow may occur due to excessive grouting pressure. So how to judge whether the overflow of anchoring agent is due to fullness or excessive grouting pressure. To this end, the present invention adopts the following method to solve the problem: before injecting anchoring agent into the anchor hole 1, a preset amount of anchoring agent to be injected is calculated in advance according to the volume of the anchor hole 1 and the volume of the anchor cable 2. If anchoring agent overflows when the injected amount is less than the preset amount, it means that the grouting pressure is too high, and then the grouting pressure of the anchoring agent should be adjusted.

[0061] Finally, it should be noted that the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0062] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0063] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An underground tunnel support device, characterized in that: include: An anchor hole, wherein the anchor hole is embedded in the surrounding rock, and two openings of the anchor hole are opened on the surface of the prone-to-collapse layer; An anchor cable running through the anchor hole; An anchoring agent filled in the anchor hole, wherein the anchoring agent fills the anchor hole; The anchor hole is semicircular; The highest point of the anchor hole passes over the boundary between the collapse-prone layer and the solid layer.

2. The underground tunnel support device according to claim 1, characterized in that: The end of the anchor cable is locked on the surface of the prone-to-collapse layer by a lock.

3. The underground tunnel support device according to claim 1, characterized in that: Along the roadway, the anchor holes are arranged in rows.

4. The underground tunnel support device according to claim 3, characterized in that: In two adjacent rows of anchor holes, one row includes two anchor holes arranged side by side, and the other row includes one anchor hole, which is staggered with the two anchor holes.

5. An underground tunnel support method, characterized in that: The steps include: S1: using a drilling machine to drill an arc-shaped anchor hole in the prone-to-collapse layer; the highest point of the anchor hole passes over the junction of the prone-to-collapse layer and the solid layer; the anchor hole is semicircular; S2: inserting the anchor cable into the anchor hole; S3: Fill the anchor hole with anchoring agent, and fasten the first end and the second end of the anchor cable to the surface of the collapse-prone layer by means of a lock.

6. The underground tunnel support method according to claim 5, characterized in that: The step S3 specifically includes: S31: fixing the first end of the anchor cable in the anchor hole by using an anchoring agent, and fastening the first end of the anchor cable to the surface of the collapse-prone layer by using a lock; S32: inserting a grouting pipe of a grouting machine into the anchor hole from the hole where the second end of the anchor cable is located, and the pipe opening of the grouting pipe passes over the highest point of the anchor hole; S33: injecting a liquid anchoring agent into the anchor hole through the grouting pipe; S34: Determine whether there is anchoring agent overflowing from the hole where the second end of the anchor cable is located, if so, proceed to step S35; S35: Stop injecting the anchoring agent into the anchor hole; S36: Fasten the second end of the anchor cable to the surface of the collapse-prone layer by means of a lock.

7. The underground tunnel support method according to claim 6, characterized in that: Before injecting the anchoring agent into the anchor hole, a preset amount of the anchoring agent to be injected is calculated in advance based on the volume of the anchor hole and the volume of the anchor cable. If the anchoring agent overflows when the injected amount is less than the preset amount, the grouting pressure of the injected anchoring agent is adjusted.

8. The underground tunnel support method according to claim 5, characterized in that: Before the step S1, the method further includes fastening one end of the traction rope to the rear of the drill rod of the drilling rig; The step S2 specifically includes: after the drill rod is pulled out from the drill-out side, the traction rope is removed from the drill rod, and then the anchor rope is fastened to the other end of the traction rope, and the anchor rope is inserted into the anchor hole by the traction effect of the traction rope.

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