Hollow grouting combined anchor rod and construction method

Abstract

The invention discloses a hollow grouting combined anchor rod and a construction method, and belongs to the field of roadway surrounding rock shoring, the hollow grouting combined anchor rod comprises an umbrella framework center rod, a nut cover, a rubber sealing washer, an anti-skid gasket, a nut, a tray, a stop-grouting plug and a hollow anchor rod, the umbrella framework center rod is placed in the hollow anchor rod, then the combined anchor rod is placed in a drill hole, and then the hollow anchor rod is placed in the drill hole like umbrella opening. The center rod of the umbrella framework is pulled, the umbrella framework extends out of the hole of the hollow anchor rod and is inserted into the hole wall of a drill hole, the prestress of the anchor rod is increased, the friction force between the rod body and mortar is increased, and then grouting is conducted from the hollow rod body of the center rod of the umbrella framework. According to the method, no complex accessory is arranged, the construction steps are simple, the construction time is greatly shortened, the economic burden is reduced, the pressure of constructors is relieved, and the expected supporting effect can be achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mine tunnel support, and in particular to a hollow grouting combined anchor rod suitable for supporting underground structures such as tunnels and a construction method. Background Art

[0002] The emergence of anchor rods has creatively changed the support methods of underground structures such as tunnels. By giving full play to the self-bearing capacity of the surrounding rock and adopting a reasonable excavation method, the disturbance to the surrounding rock can be reduced. According to the deformation of the surrounding rock, the surrounding rock is subjected to a constraint force, which makes the surrounding rock in a three-dimensional compression state, improves the strength of the surrounding rock, reduces the thickness of the rigid structure of the support, and significantly improves the economic efficiency. In engineering, broken and weak surrounding rocks are often encountered, and ordinary mortar anchor rods have significant problems, such as frequent hole collapse, weak anchor rod foundation, poor support effect, and frequent extension of construction progress. A series of technical difficulties. In terms of support effect, hollow grouting anchor rods are significantly higher than ordinary mortar anchor rods. Ordinary mortar anchor rods can be replaced in engineering to achieve better support effects.

[0003] However, currently simple hollow anchor rods often fail to achieve the desired support effect, while complex hollow anchor rods have complex accessories and numerous construction steps, which prolongs the construction schedule and increases the economic burden. Summary of the invention

[0004] Technical problem: The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a hollow grouting combined anchor rod and construction method which has a simple structure, fast construction progress, low cost and good support effect.

[0005] Technical solution: A hollow grouting combined anchor rod of the present invention comprises a hollow anchor rod entering a borehole, wherein an "umbrella frame" central rod is arranged inside the hollow anchor rod, a plurality of strip-shaped square holes are arranged at intervals on the hollow anchor rod entering the borehole, a grouting stopper is arranged on the hollow anchor rod at the entrance of the borehole, and a tray, a nut, an anti-slip gasket, a rubber sealing gasket and a nut cover passing through the "umbrella frame" central rod are arranged in sequence on the hollow anchor rod exposed outside the borehole; the "umbrella frame" central rod comprises a hollow rod body, a plurality of grouting holes arranged at intervals on the hollow rod body and multiple groups of "umbrella frames" corresponding to the positions of the multiple groups of strip square holes. The "umbrella frames" include multiple arc-shaped triangular support bodies that can swing through the strip square holes, small pins that fix the arc-shaped triangular support bodies back to the center rod of the "umbrella frame", corresponding slots are welded on the hollow rod body, and the arc-shaped triangular support bodies are inserted into the corresponding slots on the hollow rod body through the small pins and fixed to the hollow rod body; a small handle is welded on the arc-shaped triangular support body, which is convenient for construction workers to pull out the "umbrella frame" and stabilize it on the side of the square opening close to the drill hole.

[0006] The plurality of groups of strip-shaped square holes arranged at intervals on the hollow anchor rod are distributed at 90 degrees up and down and front and back.

[0007] There are at least two groups of multiple groups of strip-shaped square holes arranged at intervals on the hollow anchor rod.

[0008] The plurality of pulp holes arranged at intervals on the hollow rod body are arranged up and down or left and right, with 3 to 10 holes in each row.

[0009] There are at least two groups of "umbrella frames" corresponding to the positions of the multiple groups of strip-shaped square holes, and each group of "umbrella frames" is distributed at 90 degrees up and down and front and back.

[0010] A construction method using the above hollow grouting combined anchor rod comprises the following steps:

[0011] a. According to the actual situation on site, multiple slurry outlet holes are drilled on the hollow rod body, symmetrically distributed front and back, and multiple sets of "umbrella frames" are installed on the hollow rod body;

[0012] b. Insert the multiple arc-shaped triangular supports of the "umbrella frame" into the corresponding slots on the hollow rod body through small pins and fix them on the hollow rod body; and weld a small handle on the arc-shaped triangular supports to facilitate the construction workers to pull out the arc-shaped triangular supports and stabilize them on the side of the square opening close to the drill hole; after the parts on the hollow rod body are installed, put the hollow rod body into the hollow anchor rod, and pull out the arc-shaped triangular supports and stabilize them on the side of the square opening close to the drill hole to prepare for the hollow anchor rod to be put into the drill hole;

[0013] c. After the hollow anchor is placed in the borehole, a stop plug, which is a hydraulic expansion stop plug, is inserted into the borehole, a tray is installed behind the stop plug, an anti-skid pad is installed behind the tray, and a nut is screwed behind the anti-skid pad;

[0014] d. Install an anti-skid gasket behind the nut, screw on a nut cover behind the anti-skid gasket, and add a rubber sealing gasket inside the nut cover;

[0015] e. By pulling the center rod of the "umbrella frame", the "umbrella frame" extends out of the square hole of the hollow anchor rod and is inserted into the wall of the drilled hole;

[0016] f. Inject grout into the hollow rod body through the opening of the hollow rod body. The slurry flows out from the circular hole on the center rod of the "umbrella frame" and enters the interior of the hollow anchor rod. Then, it flows into the drilled hole from the square hole of the hollow anchor rod. Stop grouting when slurry flows out from the opening of the hollow rod body.

[0017] Beneficial effect: Due to the adoption of the above technical solution, the present invention extends the "umbrella frame" from the hole of the hollow anchor rod by pulling the center rod of the "umbrella frame", inserts it into the wall of the drilled hole, and then injects slurry into the center rod of the "umbrella frame", so that the slurry flows out from the circular hole on the center rod of the "umbrella frame", enters the inside of the hollow anchor rod, and then flows into the drilled hole from the square hole of the hollow anchor rod. Grouting is performed into the hollow rod body through the opening of the hollow rod body, and grouting is stopped when slurry flows out of the opening of the hollow rod body. It has a simple structure, greatly shortens the construction time, reduces the economic burden, relieves the pressure of construction personnel, and has a good support effect. The advantages compared with the prior art are as follows:

[0018] 1) The rod body of the center rod of the "umbrella frame" is a hollow rod body that can serve as a grouting pipe, eliminating the need for an additional grouting port.

[0019] 2) Two rows of slurry holes are drilled on the hollow rod body, which increases the efficiency of mortar outflow in the drilled hole and saves time.

[0020] 3) The hollow anchor has a 90° square opening up and down and front and back, which allows the "umbrella frame" to extend and also serves as a slurry outlet.

[0021] 4) The “umbrella frame” extends from the square hole of the hollow anchor and is inserted into the wall of the drilled hole, which increases the prestress compared to a simple straight anchor.

[0022] 5) The “umbrella frame” is covered with threads, which increases the contact area and thus increases the friction between the mortar. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the hollow grouting combined anchor rod and the construction method of the present invention.

[0024] Figure 2 It is a schematic diagram of the extended structure of the "umbrella frame" of the present invention.

[0025] Figure 3 It is a schematic diagram of the central rod structure of the "umbrella frame" of the present invention.

[0026] Figure 4 It is a schematic diagram of the hollow anchor structure of the present invention.

[0027] Figure 5 It is a schematic diagram of the structure of the "umbrella frame" of the present invention.

[0028] In the figure: 1. Center rod of "umbrella frame"; 101. Hollow rod body; 102. Slurry outlet hole; 103. "umbrella frame"; 104. Small latch; 105. Small handle; 2. Nut cover; 3. Rubber sealing gasket; 4. Anti-slip gasket; 5. Nut; 6. Tray; 7. Slurry stop plug; 8. Hollow anchor rod; 801. Square opening; 9. Drilling hole. DETAILED DESCRIPTION

[0029] The following is a further description of the embodiments in conjunction with the accompanying drawings:

[0030] The hollow grouting composite anchor rod of the present invention comprises a hollow anchor rod (8) entering a drill hole (9), wherein an "umbrella frame" central rod (1) is arranged in the hollow anchor rod (8), and a plurality of groups of strip-shaped square holes (801) are arranged at intervals on the hollow anchor rod (8) entering the drill hole (9), wherein the plurality of groups of strip-shaped square holes (801) arranged at intervals on the hollow anchor rod (8) are distributed at 90 degrees up and down and front and back, and there are at least two groups of the plurality of groups of strip-shaped square holes (801) arranged at intervals on the hollow anchor rod (8). A slurry stopper (7) is provided on the hollow anchor rod (8) at the entrance of the borehole (9), and a tray (6), a nut (5), an anti-slip gasket (4), a rubber sealing gasket (3) and a nut cover (2) passing through the "umbrella frame" center rod (1) are provided in sequence on the hollow anchor rod (8) exposed outside the borehole (9); the "umbrella frame" center rod (1) comprises a hollow rod body (101), a plurality of slurry holes (102) arranged at intervals on the hollow rod body (101) and a plurality of groups of "umbrella frames" corresponding to the positions of the plurality of groups of strip-shaped square holes (801), and the plurality of groups of "umbrella frames" corresponding to the positions of the plurality of groups of strip-shaped square holes (801) are at least two groups, and each group of "umbrella frames" is distributed at 90 degrees up and down and front and back. The "umbrella frame" comprises a plurality of arc-shaped triangular support bodies (103) that can swing through the strip-shaped square hole (801), a small pin (104) that fixes the arc-shaped triangular support body (103) back to the center rod (1) of the "umbrella frame", a corresponding slot is welded on the hollow rod body (101), and the arc-shaped triangular support body (103) is inserted into the corresponding slot on the hollow rod body (101) through the small pin (104) and fixed on the hollow rod body (101); the plurality of slurry holes (102) arranged at intervals on the hollow rod body (101) are arranged up and down or left and right, with 3 to 10 holes in each row. A small handle (105) is welded on the arc-shaped triangular support body (103), so that construction workers can pull out the "umbrella frame" and stabilize it on the side of the square opening (801) close to the drill hole.

[0031] The construction method of the hollow grouting combined anchor rod of the present invention comprises the following specific steps:

[0032] a. According to the actual situation on site, a plurality of slurry outlet holes (102) are drilled on the hollow rod body (101), which are symmetrically distributed front and back, and a plurality of sets of "umbrella frames" are installed on the hollow rod body (101);

[0033] b. Insert the multiple arc-shaped triangular support bodies (103) of the "umbrella frame" into the corresponding slots on the hollow rod body (101) through the small pins (104) and fix them on the hollow rod body (101); and weld a small handle (105) on the arc-shaped triangular support body (103) to facilitate the construction personnel to pull out the arc-shaped triangular support body (103) and stabilize it on the side of the square opening (801) close to the drill hole; after the parts on the hollow rod body (101) are installed, put the hollow rod body (101) into the hollow anchor rod (8), and pull out the arc-shaped triangular support body (103) and stabilize it on the side of the square opening (801) close to the drill hole to prepare for the hollow anchor rod (8) to be put into the drill hole;

[0034] c. After the hollow anchor rod (8) is placed in the borehole, a stop plug (7), which is a hydraulic expansion stop plug, is inserted into the borehole, a tray (6) is installed behind the stop plug (7), an anti-skid pad (4) is installed behind the tray (6), and a nut (5) is screwed behind the anti-skid pad (4);

[0035] d. Install an anti-skid gasket (4) behind the nut (5), screw the nut cover (2) behind the anti-skid gasket (4), and add a rubber sealing gasket (3) inside the nut cover (2);

[0036] e. By pulling the center rod (1) of the "umbrella frame", the "umbrella frame" extends from the square hole of the hollow anchor rod (8) and is inserted into the borehole wall;

[0037] f. Grouting is injected into the hollow rod body (101) through the opening of the hollow rod body (101). The slurry flows out from the circular hole on the center rod (1) of the "umbrella frame", enters the interior of the hollow anchor rod (8), and then flows into the drilled hole (9) from the square hole of the hollow anchor rod (8). When slurry flows out from the opening of the hollow rod body (101), the grouting is stopped.

Claims

1. A hollow grouting combined anchor bolt, characterized in that: The invention comprises a hollow anchor rod (8) entering a borehole (9), wherein an "umbrella frame" central rod (1) is arranged in the hollow anchor rod (8), a plurality of groups of strip-shaped square holes (801) are arranged at intervals on the hollow anchor rod (8) entering the borehole (9), a slurry stopper (7) is arranged on the hollow anchor rod (8) at the entrance of the borehole (9), and a tray (6), a nut (5), an anti-slip gasket (4), a rubber sealing gasket (3) and a nut cover (2) passing through the "umbrella frame" central rod (1) are arranged in sequence on the hollow anchor rod (8) exposed outside the borehole (9); the "umbrella frame" central rod (1) comprises a hollow rod body (101), a plurality of slurry holes (102) arranged at intervals on the hollow rod body (101) and a plurality of strip-shaped square holes (801) arranged at intervals on the hollow anchor rod (8). A plurality of groups of "umbrella frames" corresponding to the positions of the square holes (801), the "umbrella frames" comprising a plurality of arc-shaped triangular support bodies (103) capable of swinging through the strip-shaped square holes (801), a small latch (104) for fixing the arc-shaped triangular support bodies (103) on the center rod (1) of the "umbrella frame", a corresponding slot welded on the hollow rod body (101), the arc-shaped triangular support bodies (103) are inserted into the corresponding slot on the hollow rod body (101) through the small latch (104), and are fixed on the hollow rod body (101); a small handle (105) is welded on the arc-shaped triangular support body (103), so that construction workers can pull out the "umbrella frame" and stabilize it on the side of the square opening (801) close to the drill hole.

2. A hollow grouting combined anchor rod according to claim 1, characterized in that: The plurality of groups of strip-shaped square holes (801) arranged at intervals on the hollow anchor rod (8) are distributed at 90° up and down and front and back.

3. A hollow grouting combined anchor rod according to claim 1 or 2, characterized in that: There are at least two groups of multiple groups of strip-shaped square holes (801) arranged at intervals on the hollow anchor rod (8).

4. The hollow grouting combined anchor rod according to claim 1, characterized in that: The plurality of pulp holes (102) arranged at intervals on the hollow rod body (101) are arranged up and down or left and right, with 3 to 10 holes in each row.

5. The hollow grouting combined anchor rod according to claim 1, characterized in that: There are at least two groups of "umbrella frames" corresponding to the positions of the multiple groups of strip-shaped square holes (801), and each group of "umbrella frames" is distributed at 90 degrees up and down and front and back.

6. A construction method using the hollow grouting composite anchor rod according to claim 1, 2, 4 or 5, characterized in that The steps include: a. According to the actual situation on site, a plurality of slurry holes (102) are drilled on the hollow rod body (101), which are symmetrically distributed front and back, and multiple groups of "umbrella skeletons" are installed on the hollow rod body (101); b. Insert the multiple arc-shaped triangular support bodies (103) of the "umbrella frame" into the corresponding slots on the hollow rod body (101) through the small pins (104) and fix them on the hollow rod body (101); and weld a small handle (105) on the arc-shaped triangular support body (103) to facilitate the construction personnel to pull out the arc-shaped triangular support body (103) and stabilize it on the side of the square opening (801) close to the drill hole; after the parts on the hollow rod body (101) are installed, put the hollow rod body (101) into the hollow anchor rod (8), and pull out the arc-shaped triangular support body (103) and stabilize it on the side of the square opening (801) close to the drill hole to prepare for the hollow anchor rod (8) to be placed in the drill hole; c. After the hollow anchor rod (8) is placed in the borehole, a stop plug (7), which is a hydraulic expansion stop plug, is inserted into the borehole, a tray (6) is installed behind the stop plug (7), an anti-skid pad (4) is installed behind the tray (6), and a nut (5) is screwed behind the anti-skid pad (4); d. Install an anti-skid gasket (4) behind the nut (5), screw the nut cover (2) behind the anti-skid gasket (4), and add a rubber sealing gasket (3) inside the nut cover (2); e. By pulling the "umbrella frame" center rod (1), the "umbrella frame" extends from the square hole of the hollow anchor rod (8) and is inserted into the drilled hole wall; f. Grouting is injected into the hollow rod body (101) through the opening of the hollow rod body (101). The grout flows out from the circular hole on the center rod (1) of the "umbrella frame", enters the interior of the hollow anchor rod (8), and then flows into the drill hole (9) from the square hole of the hollow anchor rod (8). When grouting begins to flow out of the opening of the hollow rod body (101), grouting is stopped.

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