A segmental grouting porous yielding anchor rod device and a method of using the same

Abstract

The application discloses a segmented grouting porous yielding anchor rod device and a use method thereof, and belongs to the field of underground engineering support such as a roadway, a tunnel, a tunnel and the like. The device comprises an anchor rod and a sleeve, the inside of the sleeve is provided with plastic teeth, the high-strength nut at the end of the anchor rod is used to extrude the plastic teeth on the inner wall of the sleeve, plastic damage is caused to realize the yielding property of the anchor rod device; when the surrounding rock is deformed greatly, the device can realize constant resistance large deformation synchronously, and the anchor rod device is guaranteed not to be damaged; the device can also be grouted in segments, and the inherent circular isolation disc outside the anchor rod and the steel wire are used to pull the segmented grouting stopper inside the anchor rod to realize local segmented grouting reinforcement. The application has the advantages of multiple functions, constant resistance, reasonable structure and economical applicability.

Description

Technical Field

[0001] This invention relates to the field of underground engineering support for roadways, tunnels, and culverts, and is a multi-hole pressure-yielding anchor bolt device capable of segmented grouting and its application method. Background Technology

[0002] With the rapid development of underground engineering construction in my country, including railway and highway tunnels, mine roadways, water conservancy and hydropower projects, and water conveyance tunnels, and with the continuous increase in the depth of solid mineral mining and the burial depth of tunnels, the mining environment and engineering geological conditions are becoming increasingly complex. Deep surrounding rock roadways are prone to deformation and damage due to the influence of "three highs and one disturbance," making their support a crucial task in deep mining and tunnel construction.

[0003] Anchor bolts are a widely and efficiently used support method in underground engineering. To solve the problem of large deformation in fractured surrounding rock, anchor bolts must not only provide constant support force but also generate large elongation deformation to meet the requirements of large deformation in fractured surrounding rock. In addition, to address the low strength of fractured surrounding rock, existing methods use grouting to reinforce it and increase its strength. However, during on-site construction, after grouting in many projects, it is often unclear where the grout flows, making it impossible to precisely reinforce localized fractured surrounding rock. This results in poor efficiency of grouting repair and reinforcement. Furthermore, the commonly used end-grouting reinforcement method on construction sites is limited by the grouting location and equipment. After grouting, pre-drilling is required, and after the grout cures, sometimes secondary drilling is necessary before anchor bolts can be used for reinforcement to ensure the anchor bolt's support effect on the surrounding rock. This process is time-consuming, complex, and inefficient, affecting the anchoring effect and having extremely low on-site feasibility. In contrast, resin anchoring agents have a shorter curing time and superior anchoring effect, overcoming the above shortcomings. Based on the above problems, there is an urgent need to develop an anchor bolt device that can provide constant support force to effectively control the deformation of the surrounding rock, can perform segmented grouting to accurately repair the cracks in the surrounding rock and reinforce the fractured surrounding rock, and can combine anchoring agent anchoring and grouting reinforcement to carry out the operation simultaneously. That is, an anchor bolt device that integrates multiple functions, constant resistance, reasonable structure, economic applicability and deformation pressure relief function to solve the existing engineering and technical problems and realize the integrated operation of "anchoring-grouting" of fractured surrounding rock. Summary of the Invention

[0004] Technical problem: The purpose of this invention is to overcome the shortcomings of the prior art and provide a multi-hole pressure relief anchor bolt device and its usage method that can be grouted in sections. It can not only provide constant support force to effectively control the deformation of the surrounding rock, but also grout in sections to accurately repair the cracks in the surrounding rock and reinforce the broken surrounding rock. Furthermore, it can combine anchoring agent anchoring and grouting reinforcement to carry out the operation simultaneously.

[0005] Technical Solution: This invention provides a multi-hole pressure-yielding anchor bolt device capable of segmented grouting and its usage method, comprising an anchor bolt with a sleeve on it; the anchor bolt includes an integrally structured threaded section, a hollow section, and a solid section of the anchor bolt with the same outer diameter, wherein the solid section is located at the end of the hollow section, the threaded section is located at the tail of the hollow section, the threaded section has threads for installing a tray and an anti-slip nut, the hollow section has an axially extending through-hole through the threaded section, the through-hole contains a segmented grout-stopping plug, a limiter, and a grouting steel pipe that can move within and seal the through-hole, wherein the segmented grout-stopping plug and the grouting steel pipe are respectively located at both ends of the limiter, the segmented grout-stopping plug has a steel wire extending to the outside of the through-hole, and the hollow section of the anchor bolt has... Multiple grouting holes communicating with the through hole are spaced apart. Three circular isolation discs are spaced apart on the outer side of the hollow section of the anchor rod. The size of the circular isolation discs matches the anchor hole, thereby dividing the space inside the anchor hole into region I, region II, region III and region IV. Region I is the space where the threaded section of the anchor rod is located, regions II and III are the spaces where the hollow section of the anchor rod is located, and region IV is the space where the solid section of the anchor rod is located. Grouting can be performed in sections of region II or region III as needed. The end of the solid section of the anchor rod is provided with a high-strength nut through the thread. A sleeve is fitted over the entire solid section of the anchor rod. The front end of the sleeve is provided with a sealing disc to prevent the entry of rock debris and dust. The inner side of the sleeve is provided with multiple plastic teeth at intervals to achieve pressure relief with the high-strength nut.

[0006] Furthermore, there are a total of 8 to 12 grouting holes on the hollow section of the anchor bolt, which are evenly spaced on the side wall of the hollow section of the anchor bolt between the three circular isolation discs.

[0007] Furthermore, an expanding agent or annular plug is provided at the outer edge of the circular barrier to improve the sealing effect. The expanding agent is wrapped with a highly elastic film and is equipped with a delayed expansion start device.

[0008] Furthermore, 4 to 6 plastic teeth are evenly arranged on each cross section of the inner wall of the sleeve. The plastic tooth material has a certain degree of plasticity and deforms under the compression of the high-strength nut.

[0009] Furthermore, the circular isolation disc closest to the solid section of the anchor rod among the three circular isolation discs is located at the connection between the solid section and the hollow section of the anchor rod. The end face of this circular isolation disc has a cylindrical protrusion for connecting and moving with the sleeve. The cylindrical protrusion is locked in the reserved hole of the circular isolation disc, which can ensure that the sleeve rotates together with the anchor rod.

[0010] Furthermore, the limiter is a bolt installed on the hollow section of the anchor rod at the junction of Zone II and Zone III. The bolt is inserted radially into the hollow section of the anchor rod and tightened with a nut, which can limit the movement range of the segmented grout stop plug and the grouting steel pipe.

[0011] Furthermore, an annular grout stopper is installed at the grouting pipe opening to prevent grout backflow during grouting.

[0012] A method for using a multi-hole pressure-yielding anchor bolt device capable of segmented grouting includes the following steps:

[0013] Drill anchor holes at the pre-marked location in the surrounding rock, slide the solid section of the anchor rod into the sleeve, open the sealing disc at the end of the sleeve, and add a high-strength nut to the solid section of the anchor rod by thread on that side;

[0014] A highly elastic film containing an expanding agent is wrapped around the groove on the outer periphery of the circular insulating disk;

[0015] Use the grouting steel pipe to push the segmented grout-stopping plug connected with the steel wire to the bottom of the hollow section of the anchor rod, and then install the bolts and nuts;

[0016] The anchoring agent, curing agent, and anchor rod are inserted into the anchor hole.

[0017] The mixer is started to rotate the anchor rod and mix the anchoring agent and curing agent rolls thoroughly to form an anchoring agent binder. The sleeve is linked to the circular isolation disc through the cylindrical protrusion. After the anchoring agent has cured, the tray and anti-slip nut are sequentially installed on the exposed thread section of the anchor rod outside the anchor hole. The pre-tightening force is provided along the thread helix angle by pre-tightening the anti-slip nut.

[0018] When it is detected that area III, which is divided by the circular isolation plate, has too many fissures or is located in a rock strata cross zone, it is determined that area III needs to be reinforced by grouting. The grouting steel pipe is pushed into the bolted section of the anchor bolt. Due to the obstruction of the bolt, the further pushing of the grouting steel pipe is limited. The exposed end of the grouting steel pipe is connected to the high-pressure grouting pump through a rubber conduit. The high-pressure grouting pump is started, and the grout is injected into area III of the anchor hole through the grouting hole to repair and reinforce the fissures in the surrounding rock of area III.

[0019] Similarly, when grouting reinforcement is required for part II of the area, the steel wire is pulled to move the segmented grout stop plug (26). Since there is a bolt blocking the hollow section of the anchor rod, the segmented grout stop plug (26) will stop at the bolt. At this time, the grouting steel pipe is pushed into the threaded section of the anchor rod for grouting to ensure that only the surrounding rock fissures in part II of the reinforcement area are repaired.

[0020] When the surrounding rock undergoes large deformation, the high-strength nut at the end of the solid section of the anchor rod squeezes the plastic teeth on the inner wall of the sleeve, causing the plastic teeth to undergo plastic deformation. At this time, the high-strength nut slides and contacts the plastic teeth of the next section, thereby achieving constant resistance large deformation of the device.

[0021] Beneficial Effects: Due to the adoption of the above technical solution, this invention combines the functions of providing constant support force, generating large elongation deformation to meet the requirements of large deformation of the surrounding rock, and segmented grouting for precise repair of surrounding rock fissures and reinforcement of fractured surrounding rock. It overcomes the shortcomings of existing traditional anchor bolts that cannot deform with the surrounding rock, and the inability to precisely reinforce the surrounding rock due to grout loss after large-scale grouting. Constant resistance is provided by the compression deformation of the plastic teeth by the high-strength nut, allowing it to deform with the surrounding rock within the allowable range to meet the requirements of large deformation. The circular isolation disc isolates the grout during injection into the anchor hole and pulls the segmented grout stop plug to achieve selective segmented grouting. The anchor bolt device integrates multiple functions, solving the problem that ordinary anchor bolts cannot meet the requirements of large deformation of the surrounding rock, the problem of excessively high cost of existing pressure-relief anchor bolts, and the problem that existing grouting methods are difficult to accurately reinforce the surrounding rock and repair fissures, resulting in poor reinforcement effects. It realizes integrated "anchoring-grouting" operation for fractured surrounding rock. This invention has a simple structure, low cost, stable function, and simple process, which can greatly improve work efficiency. Moreover, the deformation and pressure relief function of the anchor bolt can effectively reduce the occurrence of accidents and ensure the safety of workers. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the anchor hole in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the anchoring device in an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the installation of the anchoring device in an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the pressure relief of the sleeve device in an embodiment of the present invention;

[0026] Figure 5(a) is a schematic diagram of grouting reinforcement in the surrounding rock area III in an embodiment of the present invention;

[0027] Figure 5(b) is a schematic diagram of grouting reinforcement in the surrounding rock area II in an embodiment of the present invention;

[0028] Figure 6 This is an enlarged schematic diagram of the grouting steel pipe and rubber conduit in an embodiment of the present invention;

[0029] Figure 7(a) is a schematic diagram of the cross-section where the bolt is located in an embodiment of the present invention;

[0030] Figure 7(b) is a schematic diagram of the cross-section of the grouting hole in an embodiment of the present invention;

[0031] Figure 7(c) is a schematic cross-sectional view of the plastic teeth inside the sleeve in an embodiment of the present invention;

[0032] Figure 8(a) is a front view of the circular isolation disk in an embodiment of the present invention;

[0033] Figure 8(b) is a perspective view of the circular isolation disk in an embodiment of the present invention.

[0034] In the diagram: 1-surrounding rock, 2-anchor bolt, 3-anti-slip threaded nut, 4-pallet, 5-crack, 6-threaded section of anchor bolt, 7-hollow section of anchor bolt, 8-solid section of anchor bolt, 9-high-strength nut, 10-circular isolation disc, 11-expansion agent, 12-sleeve, 13-cylindrical protrusion, 14-plastic tooth, 15-anchoring agent binder, 16-sealing disc, 17-grouting hole, 18-steel wire, 19-bolt, 20-nut, 21-grouting steel pipe, 22-rubber conduit, 23-anchor hole, 24-high-elasticity film, 25-ring grout stopper, 26-segmented grout stopper. Detailed Implementation

[0035] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings:

[0036] like Figure 1 and Figure 2As shown, a multi-hole pressure-relief anchor bolt device capable of segmented grouting includes an anchor bolt 2 and a sleeve 12. The anchor bolt 2 is divided into a threaded section 6, a hollow section 7, and a solid section 8. The threaded section 6 is threaded, with a tray 4 and an anti-slip nut 3 sequentially arranged on the thread. The hollow section 7 has a circular isolation disc 10, through which the surrounding rock 1 can be divided into region I, region II, region III, and region IV. The solid section 8 extends into the sleeve 12. The threaded section 6, hollow section 7, and solid section 8 of the anchor rod are an integral structure with the same outer diameter. Each section of the hollow section 7 is provided with four grouting holes 17 at intervals along the circumference, as shown in Figure 7(b). The spacing between the sections is reasonable. During grouting, the grout can be injected into the anchor hole 23 from the grouting holes 17, thereby repairing the crack 5 and reinforcing the surrounding rock 1. A segmented grout stop plug 26 is provided at the junction of the hollow section 7 and the solid section 8 of the anchor rod to block the grout. A steel wire 18 is connected to the segmented grout stop plug 26. Pulling the steel wire 18 outside the anchor hole 23 can move the segmented grout stop plug 26. The hollow section 7 of the anchor bolt is equipped with a bolt 19 and a nut 20 near the junction of region II and region III. When the segmented grout stop plug 26 is pulled by the steel wire 18, the segmented grout stop plug 26 will slide to the bolt 19 and be stuck. The hollow section 7 of the anchor bolt is also equipped with a circular isolation disc 10, which is surrounded by an expanding agent 11, which is wrapped with a high-elasticity film 24. The circular isolation disc 10 can isolate the grout when it is injected into the anchor hole 23, so as to achieve the effect of selective segmented grouting. The solid section 8 of the anchor bolt is inserted into the sleeve 12, and its end is provided with a high-strength nut 9 by threads. The selected high-strength nut 9 should have sufficient strength and rigidity. The pressure relief function is achieved by the high-strength nut 9 compressing and breaking the plastic teeth 14 provided on the inner wall of the sleeve 12.

[0037] like Figure 3 As shown, the anchoring agent mortar roll, curing agent roll, and anchor rod 2 are fed into the anchor hole 23. The agitator is started to rotate the anchor rod 2 and stir the anchoring agent mortar roll and curing agent roll to fully stir and form the anchoring agent colloid. The sleeve 12 is linked to the circular isolation plate 10 through the cylindrical protrusion 13. After the anchoring agent has cured, the tray 4 and anti-slip nut 3 are sequentially installed on the exposed threaded section 6 of the anchor rod outside the anchor hole 23. The pre-tightening force is provided by pre-tightening the anti-slip nut 3 along the thread helix angle.

[0038] like Figure 4As shown, each cross section of the inner wall of the sleeve 12 is evenly arranged with 4 to 6 plastic teeth 14. The selected plastic teeth 14 material should have a certain plasticity and be able to deform under the compression of the high-strength nut 9, as shown in Figure 7(c). The sleeve 12 is provided with a sealing plate 16 on the side near the bottom of the anchor hole 23 to prevent the entry of rock debris and dust; on the other side, there is a cylindrical protrusion 13, which is stuck in the reserved hole of the circular isolation plate 10 to ensure that the sleeve 12 rotates together with the anchor rod 2. When the surrounding rock 1 deforms, the high-strength nut 9 at the end of the solid section 8 of the anchor rod compresses the plastic teeth 14 on the inner wall of the sleeve 12, and the plastic teeth 14 undergo plastic deformation. At this time, the high-strength nut 9 slides to contact the plastic teeth 14 of the next cross section, thereby achieving constant resistance large deformation of the device.

[0039] As shown in Figures 5(a) and 5(b), the surrounding rock 1 and anchor hole 23 can be divided into region I, region II, region III, and region IV according to the location of the circular isolation plate 10. When more fissures are detected in region III or when this part is located in the rock strata cross zone, i.e., when grouting reinforcement of region III is required, the grouting steel pipe 21 can be pushed into the position of the bolt 19 in the hollow section 7 of the anchor rod. Due to the obstruction of the bolt 19, the further pushing of the grouting steel pipe 21 will be restricted, as shown in Figure 7(a). When grouting reinforcement of region II is required, the steel wire 18 can be pulled to pull the segmented grout stop plug 26. Due to the obstruction of the bolt 19 in the hollow section 7 of the anchor rod, the segmented grout stop plug 26 will stop at the bolt 19. At this time, the grouting steel pipe 21 can be pushed into the threaded section 6 of the anchor rod for grouting to reinforce the surrounding rock fissures 5 in region II. The grouting steel pipe 21 is composed of spliced ​​sections of steel pipe and can also be connected to the rubber conduit 22. Figure 6 As shown, an annular grout stopper 25 is provided at the inlet of the grouting steel pipe 21. The annular grout stopper 25 can prevent the grout from flowing back during grouting.

[0040] As shown in Figures 8(a) and 8(b), a circular isolation disc 10 is also provided on the hollow section 7 of the anchor bolt, which is surrounded by an expanding agent 11. The expanding agent 11 is wrapped with a highly elastic film 24. The outer diameter of the circular isolation disc 10 is slightly smaller than the diameter of the anchor hole 23. When the surrounding expanding agent 11 expands, it can isolate the grout when it is injected into the anchor hole 23, so as to achieve the effect of selective segmented grouting.

Claims

1. A multi-hole pressure-relief anchor bolt device capable of segmented grouting, characterized in that: Includes an anchor rod (2), on which a sleeve (12) is provided; the anchor rod (2) includes an anchor rod threaded section (6) of integral structure with the same outer diameter, an anchor rod hollow section (7) and an anchor rod solid section (8), wherein the anchor rod solid section (8) is located at the end of the anchor rod hollow section (7), the anchor rod threaded section (6) is located at the tail of the anchor rod hollow section (7), and the anchor rod threaded section (6) is provided with threads for installing a tray (4) and an anti-slip nut (3). The hollow section (7) of the anchor rod is provided with an axial through hole that passes through the threaded section (6) of the anchor rod. The through hole is provided with a segmented grout stop plug (26), a limiter, and a grouting steel pipe (21) that can move in the through hole and seal the through hole. The segmented grout stop plug (26) and the grouting steel pipe (21) are respectively set at both ends of the limiter. The segmented grout stop plug (26) is provided with a steel wire (18) extending to the outside of the through hole. The hollow section (7) of the anchor rod is provided with a spacer that communicates with the through hole. Multiple grouting holes (17) are provided. Three circular isolation discs (10) are provided at intervals on the outer side of the hollow section (7) of the anchor rod. The size of the circular isolation discs (10) matches the anchor hole (23), thereby dividing the space inside the anchor hole (23) into region I, region II, region III and region IV. Region I is the space where the threaded section (6) of the anchor rod is located. Regions II and III are the spaces where the hollow section (7) of the anchor rod is located. Region IV is the space where the solid section (8) of the anchor rod is located. Grouting is performed in sections of region II or region III as needed. A high-strength nut (9) is provided at the end of the solid section (8) of the anchor rod through the thread. A sleeve (12) is fitted over the entire solid section (8) of the anchor rod. A sealing disc (16) is provided at the front end of the sleeve (12) to prevent rock and soil debris and dust from entering. A plastic tooth (14) with multiple turns and matching the high-strength nut (9) is provided at intervals on the inner side of the sleeve (12) to achieve pressure relief. The limiter is a bolt (19) located on the hollow section (7) of the anchor rod at the junction of region II and region III. The bolt (19) is inserted radially into the hollow section (7) of the anchor rod and tightened by a nut (20).

2. The multi-hole pressure-relief anchor bolt device capable of segmented grouting according to claim 1, characterized in that: There are a total of 8 grouting holes (17) on the hollow section (7) of the anchor rod, which are arranged at equal intervals on the side wall of the hollow section (7) of the anchor rod between the three circular isolation plates (10).

3. The multi-hole pressure-relief anchor bolt device capable of segmented grouting according to claim 2, characterized in that: The outer edge of the circular insulating disc (10) is provided with an expanding agent (11) or an annular plug to improve the sealing effect. The expanding agent (11) is wrapped with a highly elastic film (24) and is provided with a delayed expansion start device.

4. The multi-hole pressure-relief anchor bolt device capable of segmented grouting according to claim 3, characterized in that: Four to six plastic teeth (14) are evenly arranged on each cross section of the inner wall of the sleeve (12). The material of the plastic teeth (14) has a certain plasticity and deforms under the extrusion of the high-strength nut (9).

5. The multi-hole pressure-relief anchor bolt device capable of segmented grouting according to claim 4, characterized in that: The circular isolation disc (10) closest to the solid section (8) of the anchor rod among the three circular isolation discs (10) is set at the connection between the solid section (8) and the hollow section (7) of the anchor rod. The end face of the circular isolation disc (10) has a cylindrical protrusion (13) for connecting and moving with the sleeve (12). The cylindrical protrusion (13) is stuck in the reserved hole of the circular isolation disc (10), which can ensure that the sleeve (12) rotates together with the anchor rod (2).

6. The multi-hole pressure-relief anchor bolt device capable of segmented grouting according to claim 5, characterized in that: An annular grout stopper (25) is provided at the opening of the grouting steel pipe (21). The annular grout stopper (25) can prevent the grout from flowing back during grouting.

7. A method of using the multi-hole pressure-yielding anchor bolt device with segmented grouting capability as described in claim 6, characterized in that... The steps are as follows: Drill anchor holes (23) at the pre-marked position in the surrounding rock (1), slide the solid section (8) of the anchor rod (2) into the sleeve (12), open the sealing plate (16) at the end of the sleeve (12), and add a high-strength nut (9) to the solid section (8) of the anchor rod on this side by thread; A highly elastic film (24) containing an expanding agent (11) is wrapped around the outer periphery groove of the circular insulating disk (10). Use the grouting steel pipe (21) to push the segmented grout stop plug (26) connected with the steel wire (18) to the bottom of the hollow section (7) of the anchor rod, and then install the bolt (19) and nut (20). Insert the anchoring agent mortar cartridge, the curing agent cartridge, and the anchor rod (2) into the anchor hole (23); Start the mixer to drive the anchor rod (2) to rotate and stir the anchoring agent and curing agent to fully stir and form the anchoring agent cement body (15). The sleeve (12) is linked with the circular isolation plate (10) through the cylindrical protrusion (13). After the anchoring agent has cured, the tray (4) and anti-slip nut (3) are sequentially installed on the exposed anchor rod thread section (6) of the anchor hole (23). The pre-tightening force is provided along the thread helix angle by pre-tightening the anti-slip nut (3). When it is detected that the area III, which is divided by the circular isolation plate (10), has too many cracks (5) or is located in the rock strata cross zone, it is determined that the area III needs to be reinforced by grouting. The grouting steel pipe (21) is pushed into the anchor rod hollow section (7) where the bolt (19) is located. Due to the obstruction of the bolt (19), the further pushing of the grouting steel pipe (21) will be restricted. The exposed tail end of the grouting steel pipe (21) is connected to the high-pressure grouting pump through the rubber conduit (22). The high-pressure grouting pump is started, and the grout is injected into the anchor hole (23) area III through the grouting hole (17) to repair and reinforce the surrounding rock cracks (5) in area III. Similarly, when grouting reinforcement is required for part II of the area, the steel wire (18) is pulled to move the segmented grout stop plug (26). Since there is a bolt (19) blocking the hollow section (7) of the anchor rod, the segmented grout stop plug (26) will stop at the bolt (19). At this time, the grouting steel pipe (21) is pushed into the threaded section (6) of the anchor rod for grouting to ensure that only the surrounding rock fissures (5) of part II of the area are repaired and reinforced.

8. The method of use according to claim 7, characterized in that: When the surrounding rock (1) undergoes large deformation, the high-strength nut (9) at the end of the solid section (8) of the anchor rod squeezes the plastic teeth (14) on the inner wall of the sleeve (12), and the plastic teeth (14) undergo plastic deformation. At this time, the high-strength nut (9) slides to contact the plastic teeth (14) of the next section, thereby achieving constant resistance large deformation of the device.

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