A sectional grouting anchor rod for surrounding rock of a roadway and a grouting method

Abstract

The application discloses a kind of roadway surrounding rock sectional grouting anchor rod and grouting method, it is related to roadway reinforcement technical field, including: anchor rod body and plugging mechanism, the top of anchor rod body is provided with self-feeding drill bit, self-feeding drill bit is communicated with anchor rod body, grouting hole is arranged on self-feeding drill bit, the surface of anchor rod body is arranged with elastic clamping mechanism, plugging mechanism is slidably arranged in the periphery of anchor rod body, plugging mechanism includes first annular air bag, second annular air bag and sliding support and sleeve pipe, sliding support is slidably arranged in the top of sleeve pipe, first annular air bag is arranged in the top of sliding support, first annular air bag is communicated with sliding support, second annular air bag is arranged in the top of sleeve pipe side wall, second annular air bag is communicated with sleeve pipe.The application avoids the situation that grouting hole is grouted before and after grouting pressure is different by sectional grouting mode, and guarantees the complete filling of surrounding rock fissure.

Description

Technical Field

[0001] This invention belongs to the field of tunnel reinforcement technology, specifically relating to a segmented grouting anchor bolt and grouting method for tunnel surrounding rock. Background Technology

[0002] With the continuous development of my country's coal industry, unsafe conditions naturally exist during mine construction, primarily due to roof falls and collapses. Extensive engineering practice has shown that anchoring and grouting support technology is an effective measure to maintain the stability of the surrounding rock in roadways and reduce such accidents.

[0003] Due to the development of fissures in the surrounding rock, the rock loosens after tunnel excavation, leading to a decrease in strength. After reinforcement with anchor bolt grouting, the mechanical properties of the surrounding rock, such as strength, can be improved and enhanced.

[0004] The conventional method for anchor bolt support construction involves first drilling holes in the surrounding rock mass, then inserting the support anchor bolts, installing grout stoppers and pads, and injecting grout into the anchor bolts until the grout overflows from the grout stoppers. Chinese patent CN 210829326U discloses a grout stopper device for high-pressure grouting of grouting anchor cables. This device uses sealing rubber to seal any gaps that may exist at the borehole opening of the grouting anchor cable, ensuring the required grouting pressure. However, due to the uncertainty of surrounding rock fissures (some fissures may be narrow at first and then widen, causing the grout flow rate to slow down rapidly at this point), the grout cannot quickly penetrate when it flows back into the surrounding rock fissures from the inside out. During the grouting process, the grouting pressure often reaches the set requirement initially, but after stabilization, the grout continues to penetrate, resulting in pressure differences before and after the grouting hole. This continuous penetration leads to insufficient grout, failing to effectively repair the surrounding rock fissures.

[0005] Therefore, how to provide a segmented grouting anchor bolt and grouting method for roadway surrounding rock has become a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the present invention provides a segmented grouting anchor bolt and grouting method for roadway surrounding rock. The present invention ensures complete filling of surrounding rock fissures through segmented grouting and avoids situations where the grouting pressure does not reach the set value.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a segmented grouting anchor bolt for roadway surrounding rock, comprising an anchor bolt body and a sealing mechanism. A self-drilling bit is provided at the top of the anchor bolt body, and the self-drilling bit is connected to the anchor bolt body. A grouting hole is provided on the self-drilling bit. An elastic locking mechanism is arranged on the surface of the anchor bolt body. The sealing mechanism is slidably disposed around the periphery of the anchor bolt body. The sealing mechanism includes a first annular airbag, a second annular airbag, a sliding support, and a casing. The sliding support is slidably disposed at the top of the casing. The first annular airbag is disposed at the top of the sliding support and is connected to the sliding support. The second annular airbag is disposed at the top of the side wall of the casing and is connected to the casing.

[0008] Furthermore, it also includes a third annular airbag, which is housed at the tail end of the anchor bolt body and is used to assist in the removal of the sealing mechanism. The anchor bolt body is provided with a vent hole, and the third annular airbag is connected to the vent hole.

[0009] Furthermore, it also includes a one-way exhaust pipe, which is equipped with an automatic exhaust valve, and the one-way exhaust pipe is respectively installed on the sliding bracket and the sleeve.

[0010] Furthermore, it also includes a pressure sensor, which is installed at the grout inlet of the anchor bolt body.

[0011] Furthermore, the surface of the anchor body is provided with a limit guide rail, and the sliding bracket and the sleeve are both provided with corresponding limit grooves.

[0012] Furthermore, the elastic locking mechanism includes a compression spring, a sliding rod, a sliding block, a connecting rod, and a limiting baffle. The limiting guide rail is provided with a stepped groove, the limiting baffle is hinged in the stepped groove, the stepped groove is provided with an installation groove, the sliding rod is disposed in the installation groove, the compression spring is slidably disposed on the surface of the sliding rod, the sliding block is slidably inserted on the sliding rod and slidably connected to the compression spring, one end of the connecting rod is hinged to the sliding block, and the other end of the connecting rod is hinged to the limiting baffle.

[0013] Furthermore, the limiting baffle is arc-shaped at one end near the anchor rod body, and knife-shaped at the other end, with the tip deviating outward.

[0014] Furthermore, it also includes a grout stopper, a gasket, and a locking nut. The grout stopper is located at the tail end of the anchor bolt body to prevent grout leakage. The gasket passes through the anchor bolt body and is fixed to the surrounding rock surface. The gasket is fixed by the locking nut.

[0015] A grouting method for segmented grouting anchor bolts in roadway surrounding rock includes the following steps:

[0016] S01. The sealing mechanism is slidably inserted into the anchor bolt body through the cooperation of the limiting guide rail and the limiting slide groove. The anchor bolt body is driven by the drilling rig to drill into the surrounding rock.

[0017] S02. The sliding support extends and air is injected into the first annular airbag by the air pump, causing the first annular airbag to expand and seal the front of the surrounding rock hole. Grouting is then injected into the surrounding rock through the grouting anchor until the grouting pressure reaches the set requirements.

[0018] S03. Inject air into the second annular airbag to expand and seal the surrounding rock. After sealing is completed, extract the air from the first annular airbag and retract the sliding support. Continue grouting until the grouting pressure reaches the set requirements.

[0019] S04. Inject air into the first annular airbag again. After the first annular airbag seals the surrounding rock, extract the air from the second annular airbag. At this time, pull the sleeve back to the set position, inject air into the second annular airbag to seal the surrounding rock. After sealing, extract the air from the first annular airbag and retract the sliding support. Continue grouting until the grouting pressure reaches the set requirements.

[0020] S05. During the grouting process, the first annular airbag on the sliding support and the second annular airbag on the casing alternately seal the surrounding rock hole. As the sliding support and casing move backward, the limiting baffle set in the limiting groove extends and provides support.

[0021] S06. When grouting reaches the tail end of the anchor bolt body, and when the sliding bracket moves behind the third annular airbag, air is injected into the vent hole of the anchor bolt body. The third annular airbag expands and seals. At this time, the air in the sealing mechanism is discharged, removed from the anchor bolt body, and the grout stop plug, gasket and locking nut are installed.

[0022] S07. Extract the air from the third annular airbag and continue grouting until the grouting pressure at the tail end of the anchor bolt body reaches the set requirement, and the grouting is completed.

[0023] The beneficial effects of this invention are as follows:

[0024] (1) This invention avoids the problem that when the grout of the traditional hollow grouting anchor rod flows back from the front end of the grouting core tube to the surrounding rock fissures, due to the long distance, there is less grout flowing back in the shallow and medium-deep parts, resulting in uneven grout diffusion and penetration, weak surfaces, which may lead to problems such as water seepage, water leakage, water inrush, rockfall, and landslides. In the process of grout backflow, this invention can continuously adjust and increase the grouting pressure to ensure the balance of grouting pressure before and after, that is, to ensure that the grouting pressure of the deep rock fissures reaches the set requirements before the next segment of grouting is carried out. The grout will fully diffuse into the surrounding rock fissures. Through the uniform diffusion and penetration of the grout, the grouting and anchoring effect of the surrounding rock mass of the roadway is guaranteed.

[0025] (2) The elastic locking mechanism of the present invention is inverted wedge type. When the grouting anchor rod is injected, the frictional resistance of the anchor rod body is increased by the limiting baffle, the impact force borne by the anchor rod body is evenly distributed, the stress concentration at the anchor head is reduced, and the anchoring is achieved quickly to form anchoring force. It has a good stable anchoring effect on fractured surrounding rock under complex geological conditions.

[0026] (3) The sealing mechanism in this invention can be reused. Drilling, anchoring and pre-tightening can be completed continuously in one construction. The loose surrounding rock is reinforced by grouting through the anchor body, which improves the construction speed and efficiency of tunneling support for broken surrounding rock. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the main structure of the present invention;

[0028] Figure 2 This is a schematic diagram of the inflation of the first annular airbag of the present invention;

[0029] Figure 3 This is a schematic diagram of the expansion of the second annular airbag of the present invention;

[0030] Figure 4 for Figure 3 A magnified view of part A;

[0031] Figure 5 This is a schematic diagram of the storage of the third annular airbag of the present invention.

[0032] In the diagram: 1. Anchor bolt body; 2. Sealing mechanism; 3. Self-propelled drill bit; 4. Vent hole; 5. First annular airbag; 6. Second annular airbag; 7. Third annular airbag; 8. Sliding bracket; 9. Sleeve; 10. Limiting guide rail; 11. Limiting slide groove; 12. Compression spring; 13. Sliding rod; 14. Sliding block; 15. Connecting rod; 16. Limiting baffle. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0034] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "horizontal," "inner," "outer," and "one side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] Example 1

[0036] like Figure 1-5 As shown, the present invention proposes a segmented grouting anchor bolt for roadway surrounding rock, comprising: an anchor bolt body 1 and a sealing mechanism 2. The top end of the anchor bolt body 1 is provided with a self-drilling bit 3, which is connected to the anchor bolt body 1. The self-drilling bit 3 is provided with a grouting hole. An elastic locking mechanism is arranged on the surface of the anchor bolt body 1. The tail end of the anchor bolt body 1 houses a third annular airbag 7 for assisting in the removal of the sealing mechanism 2. The anchor bolt body 1 is provided with a vent hole 4, which is connected to the third annular airbag 7. A pressure sensor is provided at the grout inlet of the anchor bolt body 1 for detecting the grouting pressure.

[0037] The sealing mechanism 2 is slidably disposed on the periphery of the anchor body 1. The sealing mechanism 2 includes a first annular airbag 5, a second annular airbag 6, a sliding support 8, and a sleeve 9. The sliding support 8 is slidably disposed on the top of the sleeve 9 and can be driven by a waterproof cylinder. The first annular airbag 5 is disposed inside the steel ring at the top of the sliding support 8 and is connected to the sliding support 8. The second annular airbag 6 is disposed on the top of the side wall of the sleeve 9 and is connected to the sleeve 9. The sliding support 8 and the sleeve 9 are connected to the air pump through a three-way valve. In this embodiment, the annular airbag is made of uniform polyurethane rubber material, and the surface of the sealing airbag is provided with a wear-resistant coating. The sliding support 8 and the sleeve 9 are also provided with a one-way exhaust pipe, which is equipped with an automatic exhaust valve. It can only discharge gas and not liquid during pressurized grouting, promote the discharge of air from the crack gaps during grouting, ensure the pressure balance inside and outside the hole, and further make the grouting effect in the surrounding rock more uniform.

[0038] In a preferred embodiment of the present invention, the surface of the anchor body 1 is provided with a limiting guide rail 10, and the sliding bracket 8 and the sleeve 9 are both provided with limiting grooves 11.

[0039] The elastic locking mechanism includes a compression spring 12, a sliding rod 13, a sliding block 14, a connecting rod 15, and a limiting baffle 16. A stepped groove is provided in the limiting guide rail 10, and the limiting baffle 16 is hinged in the stepped groove. One end of the limiting baffle 16 near the anchor rod body 1 is arc-shaped, and the other end is knife-shaped with the tip deviating outward. An installation groove is provided in the stepped groove, and the sliding rod 13 is set in the installation groove. The compression spring 12 is slidably set on the surface of the sliding rod 13. The sliding block 14 is slidably inserted on the sliding rod 13 and slidably connected to the compression spring 12. One end of the connecting rod 15 is hinged to the sliding block 14, and the other end of the connecting rod 15 is hinged to the limiting baffle 16.

[0040] As a preferred embodiment of the present invention, it also includes a grout stopper, a gasket, and a locking nut. After the sealing mechanism 2 is removed, the grout stopper is placed at the tail end of the anchor body 1 to prevent grout leakage. The gasket passes through the anchor body 1 and is fixed to the surrounding rock surface. The gasket is fixed by the locking nut.

[0041] Example 2

[0042] This embodiment discloses a grouting method for segmented grouting anchor bolts in roadway surrounding rock, including the following steps:

[0043] S01. The sealing mechanism 2 is slidably inserted into the anchor body 1 through the cooperation of the limiting guide rail 10 and the limiting slide groove 11. The anchor body 1 is driven by the drilling machine to drill into the surrounding rock.

[0044] S02. The sliding support 8 extends and air is injected into the first annular airbag 5 through the air pump, causing the first annular airbag 5 to expand and seal the front of the surrounding rock hole. Grouting is then injected into the surrounding rock through the grouting anchor until the grouting pressure reaches the set requirements.

[0045] S03. Inject air into the second annular airbag 6 to expand and seal the surrounding rock. After sealing is completed, extract the air from the first annular airbag 5 and retract the sliding support 8. Continue grouting until the grouting pressure reaches the set requirements.

[0046] S04. Inject air into the first annular airbag 5 again. After the first annular airbag 5 seals the surrounding rock, extract the air from the second annular airbag 8. At this time, pull the sleeve 9 back to the set position and inject air into the second annular airbag 6 to seal the surrounding rock. After sealing, extract the air from the first annular airbag 5 and retract the sliding support 8. Continue grouting until the grouting pressure reaches the set requirements.

[0047] S05. During the grouting process, the first annular airbag 5 on the sliding support 8 and the second annular airbag 6 on the casing 9 alternately seal the surrounding rock hole. During the backward movement of the sliding support 8 and the casing 9, the limiting baffle 16 set in the limiting groove 11 extends out and provides support.

[0048] S06. When grouting reaches the tail end of the anchor body 1, and the sliding bracket 8 moves behind the third annular airbag 7, air is injected into the vent hole 4 of the anchor body 1. The third annular airbag 7 expands and seals, at which point the air in the sealing mechanism 2 can be discharged, removed from the anchor body 1, and the grout stop plug, gasket and locking nut are installed.

[0049] S07. Extract the air from the third annular airbag 7 and continue grouting until the grouting pressure at the tail end of the anchor bolt body 1 reaches the set requirement, and the grouting is completed.

[0050] It is worth noting that as the segmented grouting proceeds, the grouting pressure of subsequent grouting can be appropriately increased to ensure that the grout fully penetrates the surrounding rock fissures.

[0051] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A segmented grouting anchor bolt for roadway surrounding rock, characterized in that, include: The anchor bolt body comprises an anchor bolt body and a sealing mechanism. The anchor bolt body has a self-drilling bit at its top, which is connected to the anchor bolt body and has grouting holes. An elastic locking mechanism is arranged on the surface of the anchor bolt body. The sealing mechanism is slidably disposed around the anchor bolt body and includes a first annular airbag, a second annular airbag, a sliding support, and a casing. The sliding support is slidably disposed at the top of the casing. The first annular airbag is disposed at the top of the sliding support and is connected to the sliding support. The second annular airbag is disposed at the top of the side wall of the casing and is connected to the casing. The first annular airbag on the sliding support and the second annular airbag on the casing alternately seal the surrounding rock holes. It also includes a third annular airbag, which is housed at the tail end of the anchor bolt body and is used to assist in the removal of the sealing mechanism. The anchor bolt body is provided with a vent hole, and the third annular airbag is connected to the vent hole. It also includes a pressure sensor, which is installed at the grout inlet of the anchor bolt body.

2. The segmented grouting anchor bolt for roadway surrounding rock according to claim 1, characterized in that, It also includes a one-way exhaust pipe, which is equipped with an automatic exhaust valve. The one-way exhaust pipe is respectively installed on the sliding bracket and the sleeve.

3. The segmented grouting anchor bolt for roadway surrounding rock according to claim 1, characterized in that, The surface of the anchor bolt body is provided with a limit guide rail, and the sliding bracket and the sleeve are both provided with corresponding limit grooves.

4. The segmented grouting anchor bolt for roadway surrounding rock according to claim 3, characterized in that, The elastic locking mechanism includes a compression spring, a sliding rod, a sliding block, a connecting rod, and a limiting baffle. The limiting guide rail is provided with a stepped groove, the limiting baffle is hinged in the stepped groove, the stepped groove is provided with an installation groove, the sliding rod is disposed in the installation groove, the compression spring is slidably disposed on the surface of the sliding rod, the sliding block is slidably inserted on the sliding rod and slidably connected to the compression spring, one end of the connecting rod is hinged to the sliding block, and the other end of the connecting rod is hinged to the limiting baffle.

5. A segmented grouting anchor bolt for roadway surrounding rock according to claim 4, characterized in that, The limiting baffle is arc-shaped at one end near the anchor rod body and knife-shaped at the other end, with the tip deviating outward.

6. The segmented grouting anchor bolt for roadway surrounding rock according to claim 1, characterized in that, It also includes a grout stopper, a gasket, and a locking nut. The grout stopper is located at the tail end of the anchor bolt body to prevent grout leakage. The gasket passes through the anchor bolt body and is fixed to the surrounding rock surface. The gasket is fixed by the locking nut.

7. A grouting method for segmented grouting anchor bolts in roadway surrounding rock, characterized in that, The test includes the following steps: S01. The sealing mechanism is slidably inserted into the anchor bolt body through the cooperation of the limiting guide rail and the limiting slide groove. The anchor bolt body is driven by the drilling rig to drill into the surrounding rock. S02. The sliding support extends and air is injected into the first annular airbag by the air pump, causing the first annular airbag to expand and seal the front of the surrounding rock hole. Grouting is then injected into the surrounding rock through the grouting anchor until the grouting pressure reaches the set requirements. S03. Inject air into the second annular airbag to expand and seal the surrounding rock. After sealing is completed, extract the air from the first annular airbag and retract the sliding support. Continue grouting until the grouting pressure reaches the set requirements. S04. Inject air into the first annular airbag again. After the first annular airbag seals the surrounding rock, extract the air from the second annular airbag. At this time, pull the sleeve back to the set position, inject air into the second annular airbag to seal the surrounding rock. After sealing, extract the air from the first annular airbag and retract the sliding support. Continue grouting until the grouting pressure reaches the set requirements. S05. During the grouting process, the first annular airbag on the sliding support and the second annular airbag on the casing alternately seal the surrounding rock hole. As the sliding support and casing move backward, the limiting baffle set in the limiting groove extends and provides support. S06. When grouting reaches the tail end of the anchor bolt body, and when the sliding bracket moves behind the third annular airbag, air is injected into the vent hole of the anchor bolt body. The third annular airbag expands and seals. At this time, the air in the sealing mechanism is discharged, removed from the anchor bolt body, and the grout stop plug, gasket and locking nut are installed. S07. Extract the air from the third annular airbag and continue grouting until the grouting pressure at the tail end of the anchor bolt body reaches the set requirement, and the grouting is completed.

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