A locking anchor support system and support method

Abstract

The present invention discloses a locking foot anchor support system and a support method, wherein the support system comprises a hollow rod body, a grouting plug, a connecting steel plate, a steel arch frame, a connecting angle steel, a spherical nut and a pad, wherein: a rectangular hole is opened at the web of the steel arch frame close to the surrounding rock side, and the connecting steel plate is welded to the steel arch frame after passing through the rectangular hole. Compared with the prior art, the present invention has the following positive effects: (i) the use of prestressed anchor rods in combination with connecting steel plates as locking foot anchor rods can provide radial restraint for the steel arch frame and reduce the amount of clearance convergence; (ii) the use of a new type of grouting plug and grouting interface device improves the grouting efficiency; (iii) the use of a new type of grouting plug and grouting interface device can maintain the grouting pressure during grouting, making the grouting fuller, and the mortar infiltrates and fills more surrounding rock cracks, making the surrounding rock more stable and having a stronger ability to bear the locking foot anchor rod, and can reduce the amount of steel arch frame sinking.

Description

Technical Field

[0001] The invention relates to a locking foot anchor rod supporting system and a supporting method. Background Art

[0002] The existing locking foot anchor support method has been used for many years, but its effect is always lacking. In particular, the connection between the locking foot anchor pipe and the steel arch frame is not strong enough, resulting in the locking foot anchor pipe not playing its due role; and the existing grouting method is simple and cannot achieve high-pressure splitting grouting, resulting in a poor support effect after grouting. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings of the prior art, the present invention proposes a locking foot anchor support system and a support method.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a locking foot anchor support system, including a hollow rod body, a slurry stopper, a connecting steel plate, a steel arch frame, a connecting angle steel, a spherical nut and a pad, wherein: a rectangular hole is opened on the web of the steel arch frame close to the surrounding rock side, and the connecting steel plate is welded to the steel arch frame after passing through the rectangular hole.

[0005] The present invention also provides a method for supporting a locking foot anchor rod, comprising the following steps:

[0006] Step 1: Place sleepers on the horizontal plane of tunnel excavation and then install the steel arch frame, and then weld the connecting steel plate to the steel arch frame;

[0007] Step 2: Drill holes and ensure that the anchor hole angle is tilted downward by 15° to 20°;

[0008] Step 3: After the hole is formed, the resin anchoring agent is introduced, and then the hollow rod body is introduced into the top of the anchor hole, and the hollow rod body is rotated to break the resin anchoring agent;

[0009] Step 4: After the resin anchoring agent solidifies, install the grout stopper and its exhaust pipe, backing plate, and ball nut in sequence, and apply prestress;

[0010] Step 5: Install the grouting interface device at the end of the hollow rod body for grouting. After the grouting is completed, install reinforcing steel bars into the hollow rod body, and then use connecting angle steel to weld the hollow rod body and the steel arch frame into a whole.

[0011] Compared with the prior art, the present invention has the following positive effects:

[0012] (i) Using prestressed anchor rods and connecting steel plates as locking anchor rods can provide radial restraint for the steel arch frame and reduce the amount of clearance convergence;

[0013] (ii) The use of new grouting plugs and grouting interface devices has improved grouting efficiency;

[0014] (III) The use of new grouting plugs and grouting interface devices can maintain the grouting pressure during grouting, making the grouting fuller and filling more surrounding rock cracks with mortar, making the surrounding rock more stable and capable of bearing the locking anchor rods, thereby reducing the amount of steel arch frame sinking. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0016] Figure 1 This is the overall diagram of the locking foot anchor support system structure;

[0017] Figure 2 It is a top view of the locking foot anchor support system structure;

[0018] Figure 3 The diagram of using the stopper plug;

[0019] Figure 4 It is a structural schematic diagram of the grouting interface device;

[0020] The accompanying drawings in the figure are marked as follows:

[0021] Hollow rod body 1, exhaust pipe 2, slurry stopper 3, connecting steel plate 4, steel arch frame 5, sleeper 6, reinforcing steel bar 7, connecting angle steel 8, ball nut 9, pad 10, surrounding rock 11, connecting sleeve 12, three-way valve 13, hydraulic gauge 14, quick connector 15, two-way valve 16, grouting pipe 17, exhaust hose 21, exhaust hard pipe 22. DETAILED DESCRIPTION

[0022] A locking foot anchor support system, such as Figure 1 and Figure 2 As shown, it includes: a hollow rod body 1, an exhaust pipe 2, a slurry stopper 3, a connecting steel plate 4, a steel arch 5, a sleeper 6, a reinforcing steel bar 7, a connecting angle steel 8, a ball nut 9, a pad 10, etc., wherein:

[0023] (1) Design of the connection structure between the locking anchor rod and the steel arch frame

[0024] In previous structures, the connection method between the locking foot anchor pipe and the steel arch frame is to weld two L-shaped steel bars. This method has a small welding area and can withstand a small force. The weld is easy to split under the action of large force, resulting in the connection between the locking foot anchor pipe and the steel arch frame being disconnected, and it cannot play the role of supporting the steel arch frame.

[0025] In the present invention, a vertical rectangular hole is first opened at the web of the steel arch frame 5 close to the surrounding rock side, and the connecting steel plate 4 passes through the rectangular hole and is then welded to the steel arch frame 5. Figure 2 As shown, the rectangular hole is in the vertical direction, which is basically consistent with the main stress direction. It can also provide a radial constraint force on the steel arch frame 5 to reduce the clearance convergence.

[0026] The hollow rod body 1 and the steel arch frame 5 are welded together by connecting angle steel 8 to enhance the integrity of the hollow rod body 1 and the steel arch frame 5 .

[0027] (2) High-pressure grouting scheme design

[0028] In the previous grouting method, there is a dilemma: if the grouting pipe is removed after grouting, the mortar will flow back and the grouting fullness will decrease; if the grouting pipe is not removed and the mortar is waited for to solidify before being removed, the construction progress will be affected. In the present invention, a new grouting method and grouting device are designed to solve this dilemma.

[0029] The inner diameter of the grout stopper 3 makes it an interference fit with the anchor rod body, and has a "trumpet-shaped" opening with a front end size of 24 mm and a rear end size of 25.5 mm, with an interference allowance of 1 mm, thereby sealing the gap between the grout stopper 3 and the hollow rod body 1.

[0030] The raw material of the stop plug 3 is a rubber material with a Shore hardness of 65A, so that it has a certain degree of compressibility when it is rigid enough; the exhaust pipe 2 includes an exhaust hard pipe 22 (a metal exhaust pipe) installed in the exhaust hole of the stop plug and an exhaust hose 21 connected to both ends of the exhaust hard pipe 22; the stop plug 3 exhausts air through the metal exhaust pipe 22 to prevent the exhaust hole from being blocked when the stop plug is compressed. Figure 3 As shown, the use of a new type of grouting plug can maintain the grouting pressure during grouting, making the grouting fuller and filling more surrounding rock cracks with mortar, making the surrounding rock 11 more stable and more capable of bearing the locking anchor rod, and reducing the sinking of the steel arch frame.

[0031] In addition, the grout stopper is also used in conjunction with a grouting interface device, the structure of which is as follows: Figure 4 As shown, it includes: a connecting sleeve 12, a three-way valve 13, a hydraulic gauge 14, a quick connector 15, a two-way valve 16, a grouting pipe 17, etc., wherein:

[0032] One end of the connecting sleeve 12 is connected to the hollow rod body 1, and the other end is connected to the three-way valve 13. The three-way valve 13 is equipped with a hydraulic gauge 14, which can observe the grouting pressure in real time. The quick connector 15 is composed of two parts, one part is on the three-way valve 13, and the other part is on the two-way valve 16. In this way, the three-way valve 1 is connected to the two-way valve 16 through the quick connector 15, and the two-way valve 16 is connected to the grouting pipe 17 of the grouting machine.

[0033] Before grouting, first connect the three-way valve 13 to the hollow rod body 1, connect the two-way valve 16 to the grouting pipe 17 of the grouting machine, and then connect the quick connector 15. After the grouting is completed, close the three-way valve 13 to maintain the pressure. At the same time, the two-way valve 16 can be removed to grout the next foot anchor rod; the three-way valve 13 can be removed after the mortar is slightly solidified. This grouting interface device also solves the following problems: 1. The grouting is not full due to the grouting pipe being removed immediately after the grouting is completed; 2. After the grouting is completed, the grouting pipe is removed after the mortar is solidified, which prolongs the construction period.

[0034] (3) Other structural designs

[0035] The sleepers 6 are placed under the steel arch frame 5 to increase the force-bearing area between the steel arch frame 5 and the horizontal plane of the tunnel excavation, thereby reducing the initial settlement of the steel arch frame.

[0036] The reinforcing steel bar 7 is placed inside the hollow rod body after grouting is completed to enhance the bending resistance of the hollow rod body and improve the supporting effect of the rod body.

[0037] The specific support process is as follows:

[0038] (1) Install the steel arch frame 5. Place the sleepers 6 under the feet of the steel arch frame 5 before installation, and then weld the connecting steel plate 4 to the steel arch frame 5;

[0039] (2) The anchor hole is tilted downward by 15° to 20°;

[0040] (3) After the hole is formed, the anchoring agent is introduced, and then the hollow rod body 1 is introduced into the top of the anchor hole, and the hollow rod body is rotated to break the resin anchoring agent;

[0041] (4) After the resin anchoring agent solidifies, install the grouting plug 3, exhaust pipe 2, backing plate 10, ball nut 9 and apply prestress;

[0042] (5) Install the grouting interface device to carry out grouting. After the grouting is completed, install the reinforcing steel bars 7 and weld the connecting angle steels 8.

Claims

1. A locking foot anchor support system, characterized in that: It includes a hollow rod body, a grouting plug, a connecting steel plate, a steel arch frame, a connecting angle steel, a spherical nut and a pad, wherein: a rectangular hole is opened at the web of the steel arch frame close to the surrounding rock side, and the connecting steel plate is welded to the steel arch frame after passing through the rectangular hole; the hollow rod body and the steel arch frame are welded together through the connecting angle steel; an exhaust pipe is installed in the exhaust hole of the grouting plug; reinforcing steel bars are arranged in the hollow rod body; sleepers are padded under the steel arch frame; a grouting interface device is arranged between the hollow rod body and the grouting pipe of the grouting machine, and the grouting interface device includes a connecting sleeve, a three-way valve, a quick connector and a two-way valve connected in sequence; during support, sleepers are first padded on the horizontal plane of tunnel excavation and then the steel arch frame is installed, and then the connecting steel plate is welded to the steel arch frame. ; After the resin anchor solidifies, install the grouting plug and its exhaust pipe, pad, ball nut in sequence, and apply prestress; install the grouting interface device at the end of the hollow rod body for grouting, and after the grouting is completed, install reinforcing steel bars in the hollow rod body, and then use connecting angle steel to weld the hollow rod body and the steel arch frame into a whole; the installation and disassembly method of the grouting interface device is as follows: before grouting, first connect the three-way valve to the hollow rod body through the connecting sleeve, connect the two-way valve to the grouting pipe of the grouting machine, and then connect the two parts of the quick connector respectively arranged on the three-way valve and the two-way valve; after the grouting is completed, first close the three-way valve to maintain pressure, and then remove the two-way valve for grouting the next locking foot anchor rod; remove the three-way valve after the mortar is slightly solidified.

2. A locking foot anchor support system according to claim 1, characterized in that: The rectangular hole is in a vertical direction.

3. A locking foot anchor support system according to claim 1, characterized in that: A hydraulic pressure gauge is arranged on the three-way valve.

4. A support method based on the locking foot anchor support system according to claim 1, characterized in that: The steps include: Step 1: Place sleepers on the horizontal plane of tunnel excavation and then install the steel arch frame, and then weld the connecting steel plate to the steel arch frame; Step 2: Drill holes and ensure that the anchor hole angle is tilted downward by 15° to 20°; Step 3: After the hole is formed, the resin anchoring agent is introduced, and then the hollow rod body is introduced into the top of the anchor hole, and the hollow rod body is rotated to break the resin anchoring agent; Step 4: After the resin anchoring agent solidifies, install the grout stopper and its exhaust pipe, backing plate, and ball nut in sequence, and apply prestress; Step 5: Install the grouting interface device at the end of the hollow rod body for grouting. After the grouting is completed, install reinforcing steel bars into the hollow rod body, and then use connecting angle steel to weld the hollow rod body and the steel arch frame into a whole.

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