Grouting anchor rod capable of conducting segmented grouting and segmented grouting method

Abstract

The grouting anchor rod comprises an anchor rod body, a self-drilling bit communicated with the anchor rod body is arranged at the front end of the anchor rod body, a plurality of grouting holes I are formed in the anchor rod body and the self-drilling bit, the grouting piece is provided with a hollow inner cavity, a plurality of grouting holes II are evenly distributed in the outer wall of the grouting piece, and internal threads are arranged on the inner wall of the hollow inner cavity; external threads are arranged on the outer wall of the anchor rod body, and the anchor rod body is in threaded connection with the hollow inner cavity of the grouting piece so as to adjust the axial length, and then segmented grouting is completed; the grouting channel is communicated with the hollow inner cavity; the two blocking air bags are annular and are arranged on the outer sides of the two ends of the grouting piece in a sleeving mode correspondingly; the grout stopping assembly is detachably connected to the rear end of the anchor rod body. Thus, the grouting piece is rotated to freely move in the drill hole in the axial direction of the anchor rod body, corresponding grouting pressure is set for the selected grouting position, the structure is simple, construction is easy and convenient, and the grouting operation efficiency can be greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel reinforcement, and in particular to a grouting anchor capable of segmented grouting and a segmented grouting method. Background Art

[0002] In recent years, the demand for coal in my country has continued to increase, resulting in many domestic coal mines entering deep mining. The deep burial depth, high ground stress and complex support conditions are major challenges faced by coal mine roadway support. For roadways with broken roofs or top coal, the weak and broken surrounding rock will cause poor integrity of the roadway surrounding rock, uneven distribution of surrounding rock stress, severe deformation of the roadway surrounding rock, and difficulty in effective support of the roadway. In order to solve this engineering problem, grouting is usually used to reinforce the broken surrounding rock to restrain surrounding rock deformation and improve the integrity of the surrounding rock.

[0003] A large number of engineering practices have shown that anchor-grouting support technology is an effective measure to maintain the stability of tunnel surrounding rock and reduce such accidents. In the weak surrounding rock tunnels in the fault fracture zone, local grouting is often required at one or more locations. The existing conventional grouting method usually performs overall grouting from the hole mouth. The grouting range is uncontrollable, resulting in a great waste of slurry. At the same time, due to the uncertainty of geological conditions, pressure runaway, pressure leakage, and insufficient grouting pressure are prone to occur during the grouting process, making it difficult to ensure the grouting effect. The use of segmented grouting to seal the borehole and surrounding cracks can effectively prevent tunnel deformation and improve mining safety.

[0004] For example, the patent document with patent application number CN202322095598.4 provides a deep and shallow segmented grouting device, which separates the shallow grouting part from the outside of the borehole through a first plugging component, and separates the deep grouting part from the shallow grouting part through a second plugging component, and then grouting and sealing the shallow grouting part through the grouting port of the short grouting pipe, and grouting and sealing the deep grouting part through the grouting port of the long grouting pipe, thereby realizing deep and shallow segmented grouting and sealing of the borehole and surrounding cracks. However, the device can only make a simple deep and shallow division of the grouting area, and cannot adjust the length of the deep and shallow areas, and change the grouting pressure according to the conditions of different areas. At the same time, grouting and leakage are still prone to occur.

[0005] In order to solve the above problems, the technical solution in patent application No. 202310651606.0 discloses a segmented grouting anchor rod and grouting method for tunnel surrounding rock. The device consists of: an anchor rod body and a sealing mechanism. Through this device, the pressure before and after the grouting hole can be kept consistent, thereby ensuring the complete filling of the surrounding rock cracks. However, the segmented grouting device is complex in design and cumbersome in use, resulting in a decrease in the efficiency of the grouting operation and is prone to failure during use. Summary of the invention

[0006] In order to solve the technical problems existing in the background technology, the present invention provides a grouting anchor rod capable of segmented grouting and a segmented grouting method.

[0007] The present invention provides a grouting anchor capable of segmented grouting, comprising an anchor body, a self-drilling head provided at the front end of the anchor body, the self-drilling head being connected to the anchor body, a plurality of grouting holes I being provided on the anchor body and the self-drilling head, and further comprising:

[0008] The grouting piece has a hollow inner cavity, and its outer wall is uniformly provided with a plurality of grouting holes II. The self-drilling bit can pass through the hollow inner cavity and is located outside the hollow inner cavity. The inner wall of the hollow inner cavity is provided with an internal thread, and the outer wall of the anchor body is provided with an external thread. The anchor body is threadedly connected with the hollow inner cavity of the grouting piece to adjust the axial length, thereby completing segmented grouting;

[0009] A grouting channel communicated with the hollow inner cavity;

[0010] Two sealing air bags are provided in annular shape and are respectively sleeved on the outer sides of the two ends of the grouting piece;

[0011] The grout stopping assembly is detachably connected to the rear end of the anchor rod body.

[0012] Preferably, the grout-stopping assembly comprises a fastening nut, a tray and a grout-stopping plug which are sequentially sleeved on the outer periphery of the anchor body from outside to inside.

[0013] Preferably, it also includes an inflation channel, which is connected to the two blocking airbags, and a valve I is provided at the air inlet end of the inflation channel.

[0014] Preferably, a valve II is provided at the grouting end of the grouting channel.

[0015] Preferably, the grouting member is configured as a hollow sleeve, and the rear end of the hollow sleeve is connected to a screw member via a connecting rod.

[0016] Preferably, the anchor rod body is configured as a hollow cylindrical steel tube.

[0017] This embodiment also provides a segmented grouting method, using any of the above-mentioned segmented grouting anchor rods, comprising the following steps:

[0018] S1: Drill anchor holes at pre-marked locations in the tunnel;

[0019] S2: Detect the crack development and strength in the borehole, and obtain the grouting opening pressure of the coal rock mass at different depths from the borehole mouth to the bottom of the borehole through a grouting simulation experiment, and divide the grouting area into zones;

[0020] S3: Drill the anchor body into the borehole and fix it;

[0021] S4: Connect the hollow inner cavity of the grouting piece with the outer thread of the anchor body through the inner thread, rotate the grouting piece, and move it along the axial direction of the anchor body to the grouting position specified at the deepest part of the borehole;

[0022] S5: opening the inflation channel and injecting air into the two blocking air bags. The blocking air bags at both ends expand to seal the front and rear areas of the grouting part respectively, and closing the inflation channel.

[0023] S6: Open the grouting channel and perform grouting until the grouting pressure reaches the set requirement, completing the grouting of the area, and then open the inflation channel to extract the air in the plugging airbag;

[0024] S7: rotating the grouting piece to move outward to the next grouting position, and repeating the above steps S5 and S6;

[0025] S8: After all grouting work is completed, the grouting piece is rotated to separate it from the anchor body, and a grout stop assembly is installed at the rear end of the anchor body;

[0026] S9: Continue grouting through the grouting port at the rear end of the anchor body until the grouting pressure at the rear end of the anchor body reaches the set requirement, install the grouting stop assembly to close the tail of the anchor body, and complete the segmented grouting.

[0027] In summary, the present invention has the following beneficial effects: by rotating the grouting piece to freely move along the axial direction of the anchor body in the borehole, the corresponding grouting pressure is set for the selected grouting position, the structure is simple, the construction is simple, and the grouting efficiency can be greatly improved; and the grouting piece of the present invention is reusable, and after a borehole is constructed, the grouting can be recovered and used in combination with the next anchor body. The problem of less slurry in the shallow part caused by the distance when the slurry of the traditional hollow grouting anchor slurry flows back from the front end of the grouting pipe and is injected into the surrounding rock fissure is avoided. The present invention ensures the balance of grouting pressure in each area, and the slurry will be fully diffused into the surrounding rock fissure, ensuring the grouting and anchoring effect of the tunnel surrounding rock body.

[0028] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a grouting anchor capable of segmented grouting according to an embodiment of the present invention;

[0030] Figure 2 It is an axial end view of a grouting anchor capable of segmented grouting according to an embodiment of the present invention;

[0031] Figure 3 It is a schematic structural diagram of the anchor rod body according to an embodiment of the present invention.

[0032] In the figure:

[0033] 1. Anchor body; 2. Self-drilling bit; 3. Grouting hole I; 4. Grouting parts; 5. Grouting hole II; 6. Grouting channel; 61. Valve II; 7. Sealing airbag; 8. Grouting stop assembly; 81. Fastening nut; 82. Tray; 83. Grouting stop plug; 9. Inflation channel; 91. Valve I; 10. Screw-on parts. DETAILED DESCRIPTION

[0034] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0035] like Figure 1-3 As shown, the present embodiment provides a grouting anchor capable of segmented grouting, comprising an anchor body 1, a self-drilling bit 2 is provided at the front end of the anchor body 1, the self-drilling bit 2 is connected to the anchor body 1, a plurality of grouting holes Ⅰ3 are provided on the anchor body 1 and the self-drilling bit 2, and further comprising:

[0036] The grouting member 4 has a hollow inner cavity, and a plurality of grouting holes II5 are evenly distributed on its outer wall. The drill bit 2 can pass through the hollow inner cavity and is located outside the hollow inner cavity. The inner wall of the hollow inner cavity is provided with an internal thread, and the outer wall of the anchor body 1 is provided with an external thread. The anchor body 1 is threadedly connected with the hollow inner cavity of the grouting member 4 to adjust the axial length, thereby completing segmented grouting from the inside to the outside.

[0037] Specifically, the grouting member 4 is configured as a hollow sleeve, and the rear end of the hollow sleeve is connected to a screw member 10 via a connecting rod.

[0038] Meanwhile, the anchor body 1 is configured as a hollow cylindrical steel pipe.

[0039] A grouting channel 6, communicating with the hollow inner cavity;

[0040] Furthermore, a valve II 61 is provided at the grout delivery end of the grouting channel 6 to facilitate the control of the start and stop of the grouting. Specifically, the grouting channel 6 is connected to a grouting pump.

[0041] Two plugging air bags 7 are provided in annular shape and are respectively sleeved on the outer sides of the two ends of the grouting member 4;

[0042] Furthermore, it also includes an inflation channel 9, which is connected to both blocking airbags 7, and a valve I 91 is provided at the air inlet end of the inflation channel 9 to facilitate the control of the start and stop of the inflation or exhaust action. Specifically, the inflation channel 9 is connected to an air pump.

[0043] The grout-stopping assembly 8 is detachably connected to the rear end of the anchor body 1. Specifically, the detachable connection may be a threaded connection, etc. When grouting, the grout-stopping assembly 8 is removed from the rear end of the anchor body 1; after the grouting is completed, the grout-stopping assembly 8 is installed at the rear end of the anchor body 1.

[0044] Furthermore, the grout-stopping assembly 8 comprises a fastening nut 81 , a tray 82 and a grout-stopping plug 83 which are sequentially sleeved on the outer circumference of the anchor body 1 from the outside to the inside.

[0045] In this way, by rotating the grouting piece 4 to freely move along the axial direction of the anchor body 1 in the borehole, the corresponding grouting pressure is set for the selected grouting position. The structure is simple and the construction is simple, which can greatly improve the efficiency of the grouting operation; and the grouting piece 4 of the present invention can be reused. After a borehole is constructed, the grouting can be recovered and used in combination with the next anchor body 1. The problem of less grout in the shallow part caused by the influence of distance when the grout of the traditional hollow grouting anchor slurry from the front end of the grouting pipe is injected into the surrounding rock fissure is avoided. The present invention ensures the balance of grouting pressure in each area, and the slurry will be fully diffused into the surrounding rock fissure, ensuring the grouting and anchoring effect of the tunnel surrounding rock body.

[0046] In summary, the above-mentioned grouting anchor includes a hollow casing and an anchor body 1 with a hollow structure; the anchor body 1 is drilled into the surrounding rock and fixed by the self-drilling bit 2 at the front end of the anchor body 1, and a guiding effect is provided for the hollow casing; the inner thread of the hollow casing is connected to the outer thread of the anchor body 1, and the hollow casing is driven to move axially along the anchor body 1 by rotating the screw 10, and the two blocking air bags 7 are cooperated to perform grouting on the designated area, and the designated grouting pressure is realized by segmented grouting, which solves the problem of large strength difference before and after grouting drilling, and ensures the grouting and anchoring effect of the tunnel surrounding rock body; at the same time, the corresponding grouting pressure can be set for the selected grouting position, the structure is simple, the construction is simple, the grouting operation efficiency is greatly improved, and it can be reused. After a drilling hole is constructed, the hollow casing is recovered and combined with the next anchor body for use.

[0047] This embodiment also provides a grouting method, using the grouting anchor rod capable of segmented grouting according to any one of the above embodiments, comprising the following steps:

[0048] S1: Drill anchor holes at pre-marked locations in the tunnel;

[0049] S2: Detect the development and strength of cracks in the borehole, obtain the grouting opening pressure of coal and rock mass at different depths from the borehole mouth to the bottom of the borehole through grouting simulation experiments, and divide the grouting area into different zones;

[0050] S3: Drilling the anchor body 1 into the borehole and fixing it;

[0051] S4: Connect the hollow inner cavity of the grouting member 4 to the outer thread of the anchor body 1 through the inner thread, rotate the grouting member 4, and move it along the axial direction of the anchor body 1 to the grouting position specified at the deepest part of the borehole;

[0052] The hollow sleeve is driven to rotate by the screwing member 10, which saves time and effort and facilitates rotation.

[0053] S5: opening the inflation channel 9 and injecting air into the two blocking airbags 7. The blocking airbags 7 at both ends expand to seal the front and rear areas of the grouting member 4 respectively, and closing the inflation channel;

[0054] S6: Open the grouting channel 6 and perform grouting until the grouting pressure reaches the set requirement, completing the grouting of the area, and then open the inflation channel 9 to extract the air in the blocking airbag 7;

[0055] The opening or closing of the inflation channel 9 is controlled by opening or closing the valve Ⅰ91. When the valve Ⅰ91 is opened, air is injected into the blocking airbag 7 through the air pump; when the valve Ⅰ91 is closed, the air in the blocking airbag 7 is extracted through the air pump.

[0056] S7: rotating the grouting member 4 to move outward to the next grouting position, and repeating the above steps S5 and S6;

[0057] S8: After all grouting work is completed, the grouting member 4 is rotated to separate it from the anchor body 1, and the grouting stop assembly 8 is installed at the rear end of the anchor body 1;

[0058] S9: Continue grouting through the grouting port at the rear end of the anchor body 1 until the grouting pressure at the rear end of the anchor body 1 reaches the set requirement, install the grouting stop assembly 8 to close the tail of the anchor body 1, and complete the segmented grouting.

[0059] Among them, the grouting port is connected with the grouting pump.

[0060] It should be noted that the derivation process of the beneficial effects of the grouting method in the above embodiment is generally similar to the derivation process of the beneficial effects brought about by the above-mentioned grouting anchor rod that can be grouted in sections, so it will not be repeated in this article.

[0061] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0062] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0063] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0064] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A grouting anchor capable of segmented grouting, comprising an anchor body, a self-drilling head provided at the front end of the anchor body, the self-drilling head being connected to the anchor body, a plurality of grouting holes I being provided on the anchor body and the self-drilling head, characterized in that: Also includes: The grouting piece has a hollow inner cavity, and its outer wall is uniformly provided with a plurality of grouting holes II. The self-drilling bit can pass through the hollow inner cavity and is located outside the hollow inner cavity. The inner wall of the hollow inner cavity is provided with an internal thread, and the outer wall of the anchor body is provided with an external thread. The anchor body is threadedly connected with the hollow inner cavity of the grouting piece to adjust the axial length, thereby completing segmented grouting; A grouting channel communicated with the hollow inner cavity; Two sealing air bags are provided in annular shape and are respectively sleeved on the outer sides of the two ends of the grouting piece; The grout stopping assembly is detachably connected to the rear end of the anchor rod body.

2. The grouting anchor capable of segmented grouting according to claim 1, characterized in that: The grout-stopping assembly comprises a fastening nut, a tray and a grout-stopping plug which are sequentially sleeved on the outer periphery of the anchor rod body from outside to inside.

3. The grouting anchor capable of segmented grouting according to claim 1, characterized in that: It also includes an inflation channel, which is connected to the two blocking airbags, and a valve I is provided at the air inlet end of the inflation channel.

4. The grouting anchor capable of segmented grouting according to claim 1, characterized in that: A valve II is provided at the grout delivery end of the grouting channel.

5. The grouting anchor capable of segmented grouting according to claim 1, characterized in that: The grouting part is configured as a hollow sleeve, and the rear end of the hollow sleeve is connected to a screwing part via a connecting rod.

6. The grouting anchor capable of segmented grouting according to claim 4, characterized in that: The anchor rod body is configured as a hollow cylindrical steel pipe.

7. A segmented grouting method, using the segmented grouting anchor rod according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1: Drill anchor holes at pre-marked locations in the tunnel; S2: Detect the crack development and strength in the borehole, and obtain the grouting opening pressure of the coal rock mass at different depths from the borehole mouth to the bottom of the borehole through a grouting simulation experiment, and divide the grouting area into zones; S3: Drill the anchor body into the borehole and fix it; S4: Connect the hollow inner cavity of the grouting piece with the outer thread of the anchor body through the inner thread, rotate the grouting piece, and move it along the axial direction of the anchor body to the grouting position specified at the deepest part of the borehole; S5: opening the inflation channel and injecting air into the two blocking air bags. The blocking air bags at both ends expand to seal the front and rear areas of the grouting part respectively, and closing the inflation channel. S6: Open the grouting channel and perform grouting until the grouting pressure reaches the set requirement, completing the grouting of the area, and then open the inflation channel to extract the air in the plugging airbag; S7: rotating the grouting piece to move outward to the next grouting position, and repeating the above steps S5 and S6; S8: After all grouting work is completed, the grouting piece is rotated to separate it from the anchor body, and a grout stop assembly is installed at the rear end of the anchor body; S9: Continue grouting through the grouting port at the rear end of the anchor body until the grouting pressure at the rear end of the anchor body reaches the set requirement, install the grouting stop assembly to close the tail of the anchor body, and complete the segmented grouting.

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