A self-propelled graded pressure-yielding anchor device and its use method

Abstract

The present invention discloses a self-advancing graded pressure-yielding anchor device and a method of using the same, which belong to the field of underground engineering support such as lanes, tunnels and boreholes. The device includes a sleeve, an anchor body and a drill bit. The anchor includes an anchor threaded section and an anchor smooth section. A high-strength nut and an enlarged end are provided at the end of the anchor smooth section for squeezing the arc-shaped protrusion on the inner wall of the sleeve. A drill bit is provided at the end of the sleeve for self-advancing drilling of the anchor body. The high-strength nut squeezes the arc-shaped protrusion on the inner wall of the sleeve and the enlarged end expands the inner wall of the sleeve to achieve relative movement with the sleeve, thereby achieving constant resistance pressure-yielding; the self-advancing drilling of the drill bit solves the hole collapse phenomenon in the project. The structure of the invention can achieve the pressure-yielding effect and solve the hole collapse problem. It has the advantages of diverse functions, reasonable structure, cost saving and good economy.

Description

Technical Field

[0001] The invention relates to the field of underground engineering support such as lanes, tunnels and tunnels, and is a self-propelled graded yielding anchor rod device suitable for supporting soft and broken surrounding rocks and a method for using the same. Background Art

[0002] As mining depths increase for solid minerals like coal, iron ore, and nonferrous metals, the engineering geology and geostress conditions faced become increasingly complex. Due to the significant contradiction between the high geostresses within deep confining pressure and the low strength of the surrounding rock mass, the impact of engineering actions and environmental conditions during excavation, and the mining-induced stresses generated during solid mineral resource extraction, the surrounding rock in deep tunnels is highly fragmented, weak in strength, and prone to large deformation failure. This poses a significant challenge to safe and efficient mine production and represents a critical issue that urgently needs to be addressed in deep solid mineral resource mining.

[0003] Anchor bolts are a widely and effectively used primary support method for stability control in underground projects such as roadways, tunnels, and tunnels. The traditional construction method involves drilling anchor holes at pre-set locations, injecting a resin anchoring agent into the holes along with the anchor rods, and then mixing the anchor rods to anchor them into the surrounding rock, forming an anchor body. However, in actual projects, problems such as hole collapse and hole blockage in soft or broken rock are common. This occurs when the rock mass surrounding the anchor hole collapses after the pre-set hole is drilled, blocking the hole. To address anchor drilling construction issues such as hole collapse and hole blockage, pipe-slot anchors can be used in underground engineering support. These anchors are driven into broken or soft rock using external forces such as hammers and jackhammers. The anchors are anchored by friction (frictional resistance) between the anchor and the hole wall, thereby providing support for the surrounding rock. However, pipe-slot anchors, currently suitable for supporting deep broken or weak surrounding rock, also have some problems. First, they cannot generate sufficient elongation to meet the large deformation requirements of deep broken or weak surrounding rock. In other words, pipe-slot anchors themselves are unable to support large deformations under compression. Second, they cannot apply preload, and can only passively support the surrounding rock rather than actively control deformation of the roadway surrounding rock. Furthermore, they cannot provide constant resistance, resulting in poor support effectiveness. Third, due to their hollow, flat structure, the rod body itself is relatively weak and can easily break and fail in actual engineering, thus losing its support function for the surrounding rock. This poses a significant threat to the safety of workers and related equipment working in the roadway. Based on the above problems, there is an urgent need to develop an anchor device that can not only provide a constant support force to effectively control the deformation of the surrounding rock, but also produce a large elongation deformation to meet the requirements of large deformation of broken or weak surrounding rock, and can also be driven into the broken or weak surrounding rock in a self-propelled manner to solve drilling construction problems such as anchor hole collapse and hole blockage. That is, an anchor device that integrates self-propelled driving, constant resistance, deformation pressure relief and active support functions to solve the existing technical problems in the construction and installation of broken or weak anchors. Summary of the Invention

[0004] Technical problem: The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a self-propelled graded pressure-yielding anchor device and its use method, which can not only self-propelled into deep broken or weak surrounding rocks to solve drilling construction problems such as anchor hole collapse and hole blockage, but also provide a constant support force to effectively control the deformation of the surrounding rock, and can also produce a large elongation deformation to meet the requirements of large deformation of deep broken or weak surrounding rocks.

[0005] Technical solution: To achieve the above technical objectives, the present invention provides a self-propelled graded pressure anchor device, comprising an anchor body, an anti-slip nut and a tray for anchoring the anchor body. The tail end of the anchor body is a threaded anchor section, and the rest is a smooth anchor section. The end of the anchor body is provided with a head, and a sleeve is provided on the outside of the anchor body and the head. A drill bit is provided at the front end of the sleeve.

[0006] The anchor rod body and the outer side of the end are covered with a sleeve, which includes a sleeve II stage segment that wraps the smooth section and the end of the anchor rod. The sleeve II stage segment is a tubular structure, and a gap is left between the sleeve II stage segment and the smooth section of the anchor rod. The sleeve II stage segment is provided with annular arc-shaped protrusions at equal intervals along the inner wall. Each arc-shaped protrusion corresponds to a square groove on the outer wall of the sleeve II stage segment. The bottom of the square groove is connected to a resistance-increasing steel tooth through a threaded protrusion.

[0007] The end head includes a high-strength nut connected to the end of the anchor rod body through an end thread and an enlarged end head. A steel strand bundle with a margin is provided between the enlarged end head and the high-strength nut. The through hole in the second stage section of the sleeve at the enlarged end head is made larger than the rest of the diameter by an excessive diameter change, thereby forming a shoulder structure. The side of the enlarged end head pointing to the high-strength nut is a conical structure, and the circumferential edge of the conical structure is just stuck at the diameter change. When the anchor rod body deforms with the surrounding rock and undergoes relative displacement with the sleeve, the first level of pressure relief begins and the high-strength nut moves. By sliding the arc-shaped protrusion with constant resistance, when the steel strand bundle is straightened, the enlarged end head is pulled to perform the second level of pressure relief, and the capacity of the second stage section of the sleeve is expanded, thereby achieving constant resistance.

[0008] Furthermore, the tail end of the sleeve II stage segment is also connected to the sleeve I stage segment through a thread, which is used to screw the sleeve II stage segment into the anchor hole during installation. The diameter of the sleeve I stage segment is smaller than that of the sleeve II stage segment and wraps around the threaded section of the anchor rod. During engineering construction, the sleeve I stage segment should be connected by rotating clockwise first, and after the anchor rod device is driven into the surrounding rock, the sleeve I stage segment should be removed by rotating counterclockwise.

[0009] Furthermore, the drill bit and the end of the sleeve are fixedly connected by bolts, a conical drill bit is provided at the center of the front end of the drill bit, and a cylindrical pointed tooth is provided around the conical drill bit, and a self-feeding thread is provided around the conical drill bit.

[0010] Furthermore, the material of the sleeve II stage has plasticity, and when the second stage of the end is expanded and the pressure is released, the capacity is expanded.

[0011] Furthermore, the steel strand bundle is twisted into ~ steel wires and has thermal softness. The two ends of the steel strand bundle are welded steel balls. A funnel hole is provided at the center of the high-strength nut, and a reserved wiring hole is provided at the center of the enlarged end. The steel strand bundle passes through the funnel hole and the reserved wiring hole and is limited by the steel ball at the end, thereby connecting the high-strength nut and the enlarged end; the remaining part of the steel strand bundle is coiled at the end of the sleeve.

[0012] Furthermore, the outer diameter of the sleeve II stage section where the enlarged end is located increases along with the variable diameter section. When the surrounding rock undergoes large deformation, the enlarged end will expand the sleeve II stage section under the pull of the steel strand bundle. When selecting the material for the enlarged end, its strength and rigidity should also be ensured to be greater than the sleeve II stage section material. When the surrounding rock undergoes large deformation, the high-strength nut squeezes and deforms the arc-shaped protrusion to provide a constant resistance first-level yield pressure. The expansion of the sleeve II stage section by the enlarged end provides a constant resistance second-level yield pressure.

[0013] A method for using a self-propelled graded yielding anchor device, comprising the following steps:

[0014] First, slide the anchor body into the sleeve, then connect the high-strength nut, enlarged end, and strand bundle and lock them in place. Then, bolt the drill bit to the end of the sleeve. Finally, rotate the sleeve, stage I, clockwise along the threads on stage II to connect.

[0015] Then, use a general drilling machine such as a handheld pneumatic drill to drive the sleeve clockwise to further drive the drill bit forward in the surrounding rock; when drilling to the preset depth, drive the sleeve counterclockwise to remove the sleeve I section; then, install the tray and anti-slip nut on the anchor bolt thread section exposed in the surrounding rock in sequence, and pre-tighten the anti-slip nut to provide pre-tightening force along the thread rise angle;

[0016] When the surrounding rock undergoes a large deformation, the anchor bolt body and the sleeve will shift relative to each other. At this time, the high-strength nut squeezes the arc-shaped protrusion on the inner wall of the sleeve II stage, causing it to deform in the opposite direction. This causes the square groove to bulge upwards, squeezing the resistance-enhancing steel teeth into the surrounding rock, thereby providing a constant resistance and first-level yield pressure.

[0017] When the surrounding rock continues to deform, the anchor rod body will pull the expanded end through the steel strand bundle. Since the sleeve II stage segment is plastic under the pressure of the expanded end, and the outer diameter of the expanded end is larger than the outer diameter of the sleeve II stage segment, the expanded end will expand the sleeve II stage segment, thereby providing a constant resistance secondary pressure relief.

[0018] Beneficial effects: Due to the adoption of the above technical solution, the present invention has the functions of providing a constant support force, generating a large elongation deformation to meet the requirements of large deformation of the surrounding rock, and self-propelled driving into the surrounding rock to solve the collapse phenomenon. The beneficial effects produced are undoubted: (1) prestress (pretightening force) can be applied to actively support the tunnel surrounding rock, and constant resistance can be provided to ensure the support effect of the tunnel; (2) large expansion and contraction deformation can be generated to meet the requirements of large deformation of deep broken or weak surrounding rock; (3) broken or weak surrounding rock can be self-propelled to solve drilling construction problems such as anchor hole collapse and hole blocking, which greatly simplifies the process flow and saves a lot of manpower and material resources. At the same time, the reasonable support structure ensures the stability of deep broken or weak surrounding rock tunnels. It utilizes the high-strength nut to squeeze the arc-shaped protrusion on the inner wall of the sleeve and the enlarged end to expand the inner wall of the sleeve to achieve relative movement with the sleeve, thereby achieving constant resistance pressure relief; the self-propelled drilling of the drill bit is used to solve the problems of hole collapse and hole blockage in anchor drilling construction. The anchor device integrates multiple functions in one, solving the problems of hole collapse and hole blockage in anchor hole construction with ordinary anchors, as well as the problems of low strength of existing pipe seam anchors that are easy to be broken and the inability of existing self-propelled anchors to release pressure to meet the needs of deep crushing or large deformation of weak surrounding rocks. The present invention has a simple structure, low cost, stable function, and can greatly improve the support efficiency. The deformation pressure relief function of the anchor can effectively reduce the occurrence of accidents and ensure the life safety of workers.

[0019] This method solves the problem of soft rock collapse, directly drives the anchor rod into the hole, realizes the integrated operation of drilling and anchoring, and saves time and effort; 2. The pressure-relieving function realizes the two-level pressure-relieving through the combination of rigid (anchor rod) and flexible (steel strand bundle), the first section is constant resistance pressure-relieving, and the second section is constant resistance pressure-relieving (greater than the first section resistance). BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a self-advancing graded pressure-yielding anchor device before driving into the surrounding rock according to an embodiment of the present invention;

[0021] Figure 2 Schematic diagram of the structure of a self-advancing graded pressure-yielding anchor device after driving into the surrounding rock according to an embodiment of the present invention;

[0022] Figure 3 Schematic diagram of a self-propelled graded pressure-yielding anchor device during construction in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the installation of the self-propelled graded pressure-yielding anchor device in an embodiment of the present invention;

[0024] FIG5( a ) is a schematic diagram of a constant resistance first-level pressure relief according to an embodiment of the present invention;

[0025] FIG5( b ) is a schematic diagram of a constant resistance two-stage pressure relief according to an embodiment of the present invention;

[0026] Figure 6 Schematic diagram of the cross section of the arc-shaped protrusion in an embodiment of the present invention;

[0027] Figure 7 This is a front view of a drill bit in an embodiment of the present invention;

[0028] In the figure: 1-surrounding rock, 2-anchor body, 3-anti-slip wire nut, 4-tray, 5-funnel channel, 6-anchor threaded section, 7-anchor smooth section, 8-thread, 9-sleeve, 10-arc-shaped protrusion, 11-resistance-increasing steel teeth, 12-square groove, 13-high-strength nut, 14-end thread, 15-steel strand bundle, 16-enlarged end, 17-reserved wiring hole, 18-steel ball, 19-cylindrical pointed teeth, 20-conical drill bit, 21-bolt, 22-threaded protrusion, 23-drill bit, 24-sleeve II stage section, 25-sleeve I stage section. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the embodiments in the accompanying drawings:

[0030] like Figure 1 and Figure 2 As shown, it includes an anchor rod body 2, a sleeve 9 and a drill bit 23. The anchor rod body 2 includes an anchor rod threaded section 6 and an anchor rod smooth section 7 arranged left and right along the axis. The anchor rod threaded section 6 is provided with threads all over its body, and a tray 4 and an anti-slip nut 3 are sequentially arranged on the threads; the anchor rod smooth section 7 is inserted into the sleeve 9, and a high-strength nut 13 is provided at its end, which is connected to the enlarged end 16 through a steel strand bundle 15. When the anchor rod body 2 deforms with the surrounding rock 1 and undergoes relative displacement with the sleeve 9, the high-strength nut 13 will move synchronously with the anchor rod body 2, further pulling the enlarged end 16 to move in the sleeve 9.

[0031] The anchor rod threaded section 6 and the anchor rod smooth section 7 are an integrated structure and have the same outer diameter. The sleeve 9 is divided into a sleeve II stage section 24 and a sleeve I stage section 25. The sleeve I stage section 25 is connected by rotating the thread 8 on the sleeve II stage section 24 in a clockwise direction, and the outer diameter of the sleeve I stage section 25 is smaller than that of the sleeve II stage section 24. During engineering construction, the sleeve I stage section 25 should be connected by rotating it clockwise first, and after the anchor rod device is driven into the surrounding rock 1, the sleeve I stage section 25 should be disassembled by rotating it counterclockwise. A drill bit 23 is provided at the end of the sleeve II stage section 24 that penetrates into the surrounding rock 1, and the two are fixedly connected by bolts 21. When selecting the material of the sleeve II stage section 24, it should be ensured that it has a certain plasticity, and when selecting the material of the resistance-increasing steel teeth 11 and the drill bit 23, it should be ensured that their strength and rigidity are large enough.

[0032] like Figure 3 and Figure 4As shown, the anchor rod body 2 is slid into the sleeve II stage 24, and the high-strength nut 13, the enlarged end 16 and the steel strand bundle 15 are connected and clamped in the corresponding position, and then the drill bit 23 is fixed to the end of the sleeve 9 with a bolt 21. Finally, the sleeve I stage 25 is rotated clockwise along the thread 8 on the sleeve II stage 24. Then, a general drilling machine such as a handheld pneumatic drill is used to drive the sleeve 9 clockwise to further drive the drill bit 23 forward in the surrounding rock 1. After drilling to the required depth, the sleeve 9 is driven counterclockwise to remove the sleeve I stage 25. After the above work is completed, the tray 4 and the anti-slip nut 3 are sequentially installed on the anchor rod threaded section 6 exposed on the surrounding rock 1, and the pre-tightening force is provided along the thread rise angle by pre-tightening the anti-slip nut 3.

[0033] As shown in Figures 5(a) and 5(b), when the surrounding rock 1 undergoes significant deformation, the anchor bolt body 2 and sleeve 9 experience relative displacement. At this point, the high-strength nut 13 squeezes the arc-shaped protrusion 10 on the inner wall of the sleeve's second-stage segment 24. Because the corresponding position of the arc-shaped protrusion 10 contains a square groove 12, the wall at that location is relatively weak. Therefore, the upward bulge of the square groove 12 squeezes the resistance-enhancing steel teeth 11 into the surrounding rock 1, thereby providing a constant resistance and first-stage yield pressure. As the surrounding rock 1 continues to deform, the anchor bolt body 2 pulls the enlarged end 16 through the steel strand 15. Because the sleeve's second-stage segment 24 has a certain degree of plasticity and its outer diameter is larger than that of the sleeve's second-stage segment 24, the enlarged end 16 will expand the sleeve's second-stage segment 24, thereby providing a constant resistance and second-stage yield pressure.

[0034] like Figure 6 As shown, the sleeve II stage section 24 is a hollow rod body, which is provided with 4 to 6 arc-shaped protrusions 10 along the inner wall. A square groove 12 is provided along the outer wall of the sleeve II stage section 24 at the corresponding position of the arc-shaped protrusion 10, and a threaded protrusion 22 is provided at the bottom of the square groove 12. The threaded protrusion 22 is connected to the resistance-increasing steel tooth 11.

[0035] like Figure 7 As shown, the drill bit 23 is fixed to the sleeve 9 by bolts 21, and 4 to 6 cylindrical pointed teeth 19 are provided along the circumference thereof, and a conical drill bit 20 is provided in the center, and the conical drill bit 20 is provided with a self-feeding thread around the circumference thereof.

Claims

1. A self-propelled graded pressure-yielding anchor device, characterized by: The invention comprises an anchor rod body (2), an anti-slip nut (3) and a tray (4) for anchoring the anchor rod body (2); the tail end of the anchor rod body (2) is an anchor rod threaded section (6), and the rest is an anchor rod smooth section (7); the end of the anchor rod body (2) is provided with a terminal head; the anchor rod body (2) and the terminal head are covered with a sleeve (9); the front end of the sleeve (9) is provided with a drill bit (23); The anchor rod body (2) and the outer side of the end portion are sleeved with a sleeve (9), the sleeve (9) includes a sleeve II stage (24) that wraps the anchor rod smooth section (7) and the end head, the sleeve II stage (24) is a tubular structure, a gap is left between the sleeve II stage (24) and the anchor rod smooth section (7), the sleeve II stage (24) is provided with annular arc-shaped protrusions (10) at equal intervals along the inner wall, each arc-shaped protrusion (10) corresponds to a square groove (12) on the outer wall of the sleeve II stage (24), and the bottom of the square groove (12) is connected to a resistance-increasing steel tooth (11) through a threaded protrusion (22); The end head includes a high-strength nut (13) connected to the end of the anchor rod body (2) through an end thread (14) and an enlarged end head (16). A steel strand bundle (15) with a margin is provided between the enlarged end head (16) and the high-strength nut (13). The inner through hole of the sleeve II stage (24) at the enlarged end head (16) is made larger than the inner diameter of the other part by an excessively large diameter change, thereby forming a shoulder structure. The side of the enlarged end head (16) pointing to the high-strength nut (13) is a conical structure, and the circumferential edge of the conical structure is just stuck at the diameter change. The tail end of the sleeve II stage (24) is also connected to the sleeve I stage (25) through a thread (8) for screwing the sleeve II stage (24) into the anchor hole during installation. The diameter of the sleeve I stage (25) is smaller than that of the sleeve II stage (24) and wraps around the anchor threaded section (6). During construction, the sleeve I stage (25) should first be connected by rotating it clockwise, and after the anchor device is driven into the surrounding rock (1), the sleeve I stage (25) should be disassembled by rotating it counterclockwise. When the surrounding rock (1) undergoes a large deformation, the anchor rod body (2) and the sleeve (9) undergo relative displacement. At this time, the high-strength nut (13) squeezes the arc-shaped protrusion (10) on the inner wall of the sleeve II stage (24) to cause it to deform in the opposite direction, so that the square groove (12) bulges upward to squeeze the resistance-increasing steel teeth (11) into the surrounding rock (1), thereby providing a constant resistance first-level pressure relief. When the surrounding rock (1) continues to deform, the anchor rod body (2) will pull the enlarged end (16) through the steel strand bundle (15). Since the sleeve II stage (24) is plastic under the pressure of the enlarged end (16), and the outer diameter of the enlarged end (16) is larger than the outer diameter of the sleeve II stage (24), the enlarged end (16) will expand the sleeve II stage (24), thereby providing a constant resistance second-level pressure relief.

2. The self-advancing graded pressure-yielding anchor device according to claim 1, characterized in that: The drill bit (23) is fixedly connected to the end of the sleeve (9) by a bolt (21). A conical drill bit (20) is provided at the center of the front end of the drill bit (23). Four to six cylindrical pointed teeth (19) are provided around the conical drill bit (20). The conical drill bit (20) is provided with a self-feeding thread around its periphery.

3. The self-advancing graded pressure-yielding anchor device according to claim 1, characterized in that: The material of the sleeve II stage section (24) is plastic, and expansion is achieved when the expanded end head (16) is released at the second stage.

4. The self-advancing graded pressure-yielding anchor bolt device according to claim 1, characterized in that: The steel strand bundle (15) is formed by twisting 3 to 4 steel wires and is heat-soft. The two ends of the steel strand bundle (15) are welded steel balls (18). A funnel hole (5) is provided at the center of the high-strength nut (13). A reserved wiring hole (17) is provided at the center of the enlarged end (16). The steel strand bundle (15) passes through the funnel hole (5) and the reserved wiring hole (17) and is limited by the steel ball (18) at the end, thereby connecting the high-strength nut (13) and the enlarged end (16); the remaining part of the steel strand bundle (15) is coiled on the end of the sleeve (9).

5. A method for using the self-advancing graded pressure-yielding anchor device according to any one of claims 1 to 4, characterized in that Here are the steps: First, slide the anchor rod body (2) into the sleeve II stage (24), and connect the high-strength nut (13), the enlarged end (16) and the steel strand bundle (15) and clamp them in the corresponding position, and then use the bolt (21) to fix the drill bit (23) to the end of the sleeve (9); finally, rotate the sleeve I stage (25) clockwise along the thread (8) on the sleeve II stage (24) to connect; Then, the sleeve (9) is driven clockwise by a handheld pneumatic drill to further drive the drill bit (23) forward in the surrounding rock (1); after drilling to a preset depth, the sleeve (9) is driven counterclockwise to remove the sleeve I section (25); the tray (4) and the anti-slip nut (3) are sequentially mounted on the anchor rod thread section (6) exposed in the surrounding rock (1), and a pre-tightening force is provided along the thread rise angle by pre-tightening the anti-slip nut (3); When the surrounding rock (1) undergoes a large deformation, the anchor rod body (2) and the sleeve (9) undergo relative displacement. At this time, the high-strength nut (13) squeezes the arc-shaped protrusion (10) on the inner wall of the sleeve II stage (24) to cause it to deform in the opposite direction, so that the square groove (12) bulges upward and squeezes the resistance-enhancing steel teeth (11) into the surrounding rock (1), thereby providing a constant resistance and a first-level pressure relief. When the surrounding rock (1) continues to deform, the anchor rod body (2) will pull the enlarged end (16) through the steel strand bundle (15). Since the sleeve II stage (24) is plastic under the pressure of the enlarged end (16), and the outer diameter of the enlarged end (16) is larger than the outer diameter of the sleeve II stage (24), the enlarged end (16) will expand the sleeve II stage (24), thereby providing a constant resistance secondary pressure relief.

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