Prestressed anchor-grouting integrated device and construction method thereof

Abstract

The present invention provides a prestressed anchoring and grouting integrated device and a construction method thereof, which relate to the technical field of underground engineering of broken surrounding rock, including a hollow anchor rod, wherein the tail end of the hollow anchor rod is provided with a bursting disc and an end one-way valve, and the rod body of the hollow anchor rod is provided with a first slurry outlet hole and a second slurry outlet hole, the outer side of the first slurry outlet hole is provided with a first one-way valve, and the outer side of the first one-way valve is provided with a bag; the present invention performs grouting of the anchoring section through the bursting disc and the end one-way valve at the tail end of the hollow anchor rod, and uses the first slurry outlet hole, the first one-way valve and the bag in combination to grout and block the anchoring section space; uses the second slurry outlet hole and the second one-way valve for grouting reinforcement of the surrounding rock in the later stage; seals the hole through the sealing bag, and pre-tightens the hollow anchor rod multiple times through the tray and the nut; thereby performing multi-step grouting and anchoring to realize prestressed support, which can solve the problems of insufficient anchoring force and inability to apply prestress in conventional anchoring methods in broken surrounding rock areas.

Description

Technical Field

[0001] The present invention relates to the technical field of broken surrounding rock underground engineering, and in particular to a prestressed anchor-grouting integrated device and a construction method thereof. Background Art

[0002] In underground projects such as coal mines, metal mines, and tunnels, anchoring is required after drilling. Drilling anchoring belongs to foundation treatment, and its purposes can be roughly summarized as follows: improving the bearing capacity of the foundation; improving the shear characteristics of the foundation to prevent shear damage; improving the compression performance of the foundation, reducing uneven settlement, and improving the stability of the foundation; preventing the collapse of the surrounding rock of the underground cavern and the sliding of dangerous rocks on the slope and steep walls; setting up artificial foundation structures in the foundation so that they and the foundation can bear various loads together;

[0003] For the support of broken surrounding rock in underground projects, ordinary anchor rods (cables) are commonly used support materials, but due to the poor anchoring properties of broken surrounding rock, the anchoring effect is not ideal and the support quality is difficult to guarantee. Grouting anchor rods can be used as an effective support for broken areas and anchoring is achieved by full-hole grouting. However, this method is mostly full-length anchoring, which makes it difficult to apply prestress in advance and has a great impact on the support effect. Therefore, the present invention proposes a prestressed anchor-grouting integrated device and a construction method thereof to solve the problems existing in the prior art. Summary of the Invention

[0004] In response to the above problems, the present invention proposes a prestressed anchoring integrated device and a construction method thereof. The prestressed anchoring integrated device and the construction method thereof perform multi-step grouting anchoring to achieve prestressed support, which can solve the problems of insufficient anchoring force and inability to apply prestress in conventional anchoring methods in broken surrounding rock areas.

[0005] To achieve the purpose of the present invention, the present invention is implemented through the following technical solutions: a prestressed anchor-injection integrated device, comprising a hollow anchor rod, wherein the tail end of the hollow anchor rod is provided with a bursting disc and an end one-way valve, and the rod body of the hollow anchor rod is provided with a first slurry outlet hole and a second slurry outlet hole, a first one-way valve is provided on the outside of the first slurry outlet hole, and a bag is provided on the outside of the first one-way valve, and a second one-way valve is provided on the outside of the second slurry outlet hole, and the outer end of the hollow anchor rod is pre-tightened by a tray and a nut;

[0006] The outer end of the hollow anchor rod is sleeved with a hole sealing bag, and the hole sealing bag is provided with a grouting pipe.

[0007] A further improvement is that the hollow anchor rod is divided into an anchoring section and a free section for being inserted into a drill hole.

[0008] A further improvement is that the hollow anchor rod is a tube body with a spiral thread on the outside, the hollow anchor rod is used to achieve the grouting function, and the spiral on the outside of the hollow anchor rod is adapted to the nut.

[0009] A further improvement is that the bag is made of elastic material and is tightly attached to the wall of the hollow anchor rod before being filled with slurry. After being filled with slurry, it expands and contacts the borehole wall to achieve hole sealing.

[0010] Further improvements are: the first one-way valve is made of an annular rubber ring, which is tightly clamped on the hollow anchor rod to block the first slurry outlet. When the pressure inside the hollow anchor rod reaches a fixed value, the first one-way valve is pushed up and the slurry enters the bag. When the pressure decreases, the first one-way valve contracts and is tightly clamped on the hollow anchor rod again to prevent the slurry from flowing back.

[0011] A further improvement is that the bursting pressure value of the bursting disc is greater than the opening pressure of the first one-way valve. The bag is filled with slurry in the early stage, and the bursting disc opens after the pressure increases to grout and anchor the space where the anchoring section is located. The end one-way valve is used to prevent the slurry from flowing back.

[0012] A further improvement is that the first slurry outlet hole and the second slurry outlet hole are holes made on the hollow anchor rod, which are used to achieve communication between the interior of the hollow anchor rod and the external drilled hole.

[0013] Further improvements are: the second one-way valve is made of an annular rubber ring, which is tightly clamped on the hollow anchor rod to block the second slurry outlet. When the pressure in the hollow anchor rod reaches a set value, the second one-way valve is pushed up and the slurry enters the grouting space in the drill hole. The opening pressure of the second one-way valve is greater than the opening pressure of the bursting disc, and the opening pressure of the second one-way valve is greater than the opening pressure of the first one-way valve.

[0014] A further improvement is that the nut and the tray are a matching assembly of the hollow anchor rod, which is used to achieve pre-tightening and supporting functions.

[0015] A construction method for a prestressed anchor-grouting integrated device comprises the following steps:

[0016] Step 1: Use a drill bit that matches the size of the hollow anchor to drill a hole in the surrounding rock of the tunnel. The length of the hole should match the length of the hollow anchor.

[0017] Step 2: Place the hollow anchor rod into the borehole, connect the hole end of the hollow anchor rod to the grouting conduit, and inject slurry through the interior of the hollow anchor rod. When the slurry pressure exceeds the opening pressure of the first one-way valve, the bladder begins to fill. After the slurry is filled, the bladder begins to expand and contacts the borehole wall to seal the hole.

[0018] Step 3: Continue grouting. The pressure in the bag increases, and the pressure in the hollow anchor rod increases. When the pressure is greater than the opening pressure of the bursting disc, the bursting disc opens, and the slurry is injected into the space where the closed anchor section is located through the end one-way valve. When the grouting pressure rises to 80% of the opening pressure of the second one-way valve, the grouting of the anchor section is completed.

[0019] Step 4: Rinse the slurry inside the hollow anchor rod with clean water to avoid blockage inside the rod body;

[0020] Step 5: Install a sealing bag at the end of the hole mouth, and inject grout into the sealing bag through the grouting pipe to seal the hole mouth. After the slurry solidifies, install a tray and a nut at the end of the hollow anchor rod, and pre-tighten the rod body. After the pre-tightening is completed, reconnect the grouting pipe and grout the space between the sealing bag (11) and the bag (7) to reinforce the area. After the reinforcement is completed, pre-tighten the hollow anchor rod for the second time to complete the prestressed anchor reinforcement of the broken surrounding rock.

[0021] The beneficial effects of the present invention are:

[0022] 1. The present invention uses the bursting disc and the end one-way valve at the tail end of the hollow anchor rod to grout the space where the anchor section is located, and uses the first slurry outlet, the first one-way valve and the bag to grout and seal the anchor section space; the second slurry outlet and the second one-way valve are used for grouting and reinforcement of the surrounding rock in the later stage; the sealing bag is used to seal the hole, and the hollow anchor rod is pre-tightened multiple times by the tray and the nut; in this way, multi-step grouting and anchoring are carried out to realize prestressed support, which can solve the problems of insufficient anchoring force and inability to apply prestress in conventional anchoring methods in broken surrounding rock areas.

[0023] 2. The present invention can solve the problem that ordinary grouting anchor rods can only be anchored along the entire length and cannot apply prestress, and realize the integration of anchoring, applying prestress, and grouting reinforcement, effectively improving the support effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present invention;

[0025] Figure 2 A plan view of the sealed sac bag of the present invention;

[0026] Figure 3 is a cross-sectional view of the sealed pouch of the present invention;

[0027] Figure 4 This is a schematic diagram of the device of the present invention after being placed into a drill hole;

[0028] Figure 5 This is a schematic diagram of the anchoring section of the present invention;

[0029] Figure 6This is a schematic diagram after the first pre-tightening of the present invention;

[0030] Figure 7 This is a schematic diagram after grouting reinforcement according to the present invention.

[0031] Among them: 1. Hollow anchor rod; 2. Bursting disc; 3. End one-way valve; 4. First slurry outlet hole; 5. Second slurry outlet hole; 6. First one-way valve; 7. Bag; 8. Second one-way valve; 9. Tray; 10. Nut; 11. Sealing bag; 12. Grouting pipe; 13. Drill hole; 14. Anchoring section; 15. Free section. DETAILED DESCRIPTION

[0032] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the examples. The examples are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0033] Example 1

[0034] according to Figure 1 、 2 As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a prestressed anchor-injection integrated device, comprising a hollow anchor rod 1, a bursting disc 2 and an end check valve 3 being provided at the tail end of the hollow anchor rod 1, a first slurry outlet hole 4 and a second slurry outlet hole 5 being provided on the rod body of the hollow anchor rod 1, a first check valve 6 being provided on the outer side of the first slurry outlet hole 4, and a bag 7 being provided on the outer side of the first check valve 6, a second check valve 8 being provided on the outer side of the second slurry outlet hole 5, and the outer end of the hollow anchor rod 1 is pre-tightened by a tray 9 and a nut 10;

[0035] The outer end of the hollow anchor rod 1 is provided with a sealing bag 11, and the sealing bag 11 is provided with a grouting pipe 12. When in use, the anchoring section 14 is grouted under certain conditions through the bursting disc 2 and the end one-way valve 3 at the tail end of the hollow anchor rod 1. Two grouting holes are provided on the rod body, one is located at the starting end of the anchoring section 14, and the other is located at the free section 15. A first one-way valve 6 is provided on the outside of the first grouting hole 4 at the starting end of the anchoring section 14, which cooperates with the bag 7 to seal the space of the anchoring section 14; a second one-way valve 8 is provided on the outside of the second grouting hole 5 located in the free section 15 for grouting reinforcement of the surrounding rock in the later stage; a sealing bag 11 is provided at the hole mouth and is sleeved on the hollow anchor rod 1. After sealing, it does not affect the axial movement of the rod body; a tray 9 and a nut 10 are provided at the outer end of the hollow anchor rod 1 to pre-tighten the rod body multiple times.

[0036] The hollow anchor rod 1 is divided into an anchoring section 14 and a free section 15 , and is used for being inserted into a drill hole 13 .

[0037] The hollow anchor rod 1 is a tube body with a spiral thread on the outside. The hollow anchor rod 1 is used to realize the grouting function, and the spiral on the outside of the hollow anchor rod 1 is adapted to the nut 10. The hollow anchor rod 1 can realize the grouting function, and the tube body with a spiral on the outside can meet the pre-tightening requirements after anchoring.

[0038] The bladder 7 is made of an elastic material and is tightly attached to the wall of the hollow anchor rod 1 before slurry filling. After slurry filling, it expands and contacts the wall of the drilled hole 13 to seal the hole. The bladder 7 located outside the starting end of the anchoring section 14 is also made of an elastic material and is tightly attached to the wall of the hollow anchor rod 1 before slurry filling. After slurry filling, it expands and contacts the wall of the drilled hole 13 to seal the hole.

[0039] The first one-way valve 6 is made of an annular rubber ring and is tightly clamped on the hollow anchor rod 1, blocking the first slurry outlet 4. When the pressure in the hollow anchor rod 1 reaches a certain value, the first one-way valve 6 is pushed up and the slurry enters the bladder 7. When the pressure decreases, the first one-way valve 6 contracts and is tightly clamped on the hollow anchor rod 1 again, preventing the slurry from flowing back. The first one-way valve 6 located at the starting end of the anchoring section 14 is tightly clamped on the hollow anchor rod 1, blocking the slurry outlet. When the pressure in the rod reaches a certain value, the rubber ring is pushed up and the slurry enters the bladder 7. When the pressure decreases, the rubber ring contracts and is tightly clamped on the rod body again, preventing the slurry from flowing back.

[0040] The bursting pressure of the bursting disc 2 is greater than the opening pressure of the first one-way valve 6. During the initial grouting phase, the bladder 7 is filled. As pressure increases, the bursting disc 2 opens to grout the anchoring section 14. The end one-way valve 3 prevents slurry backflow. The bursting disc 2 has a bursting pressure greater than the first one-way valve 6, located outside the first grouting hole 4 at the starting end of the anchoring section 14. Initially, the bladder 7 outside the starting end of the anchoring section 14 is filled. As pressure increases, the bursting disc 2 opens to initiate grouting and anchoring of the anchoring section 14. The end one-way valve 3 prevents slurry backflow, improves the filling quality of the anchoring section 14, and ensures that the anchoring section 14 is fully filled with slurry.

[0041] The first slurry outlet hole 4 and the second slurry outlet hole 5 are holes made on the hollow anchor rod 1 and are used to achieve communication between the interior of the hollow anchor rod 1 and the external borehole 13 .

[0042] The second one-way valve 8 is made of an annular rubber ring and is tightly clamped on the hollow anchor rod 1, blocking the second grouting hole 5. When the pressure in the hollow anchor rod 1 reaches a certain value, the second one-way valve 8 is lifted, allowing slurry to enter the grouting space in the borehole 13. The opening pressure of the second one-way valve 8 is greater than the opening pressure of the bursting disc 2, and the opening pressure of the second one-way valve 8 is greater than the opening pressure of the first one-way valve 6. The second one-way valve 8, located outside the second grouting hole 5 in the free section 15, is used to block the grouting hole in the free section 15. When the pressure in the rod reaches a certain value, the second one-way valve 8 is lifted, allowing slurry to enter the grouting space. The opening pressure of the second one-way valve 8 in the free section 15 is greater than the opening pressure of the first one-way valve 6.

[0043] The sealing bag 11 provided at the hole opening is composed of a bag body and a grouting pipe 12. The sealing bag 11 is mainly used for grouting and sealing the hole in the later stage.

[0044] The nut 10 and tray 9 are a matching component of the hollow anchor rod 1, used to achieve pre-tightening and reinforcement. They solve the problem of insufficient anchoring force in conventional anchoring methods in broken rock areas and the problem that ordinary grouting anchor rods can only anchor along the entire length and cannot apply prestress, thus realizing the integration of anchoring, applying prestress, and grouting reinforcement.

[0045] Example 2

[0046] according to Figure 1 、 2 As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a construction method for a prestressed anchor-grouting integrated device, comprising the following steps:

[0047] Step 1: Use a drill bit that matches the size of the hollow anchor rod 1 to construct a borehole 13 in the surrounding rock of the tunnel. The length of the borehole 13 matches the length of the hollow anchor rod 1.

[0048] Step 2: Place the hollow anchor rod 1 into the borehole 13, connect the hole end of the hollow anchor rod 1 to the grouting catheter, and inject slurry through the interior of the hollow anchor rod 1. After the slurry pressure exceeds the opening pressure of the first one-way valve 6, start filling the bladder 7. After the slurry is filled, the bladder 7 begins to expand and contacts the wall of the borehole 13 to achieve hole sealing;

[0049] Step 3: Continue grouting. The pressure in the bag 7 increases, and the pressure in the hollow anchor rod 1 increases. When the pressure is greater than the opening pressure of the bursting disc 2, the bursting disc 2 opens, and the slurry is injected into the space where the closed anchor section 14 is located through the end check valve 3. When the grouting pressure rises to 80% of the opening pressure of the second check valve 8, the grouting of the space where the anchor section 14 is located is completed.

[0050] Step 4: Rinse the slurry inside the hollow anchor rod 1 with clean water to avoid blockage inside the rod;

[0051] Step 5: Install the sealing bag 11 at the end of the hole, and inject grout into the sealing bag 11 through the grouting pipe 12 to seal the hole. After the slurry solidifies, install the tray 9 and nut 10 at the end of the hollow anchor rod 1, and pre-tighten the rod body. After the pre-tightening is completed, grouting reinforcement is performed again on the free section 15 of the hollow anchor rod 1 to achieve regional reinforcement. After the reinforcement is completed, the hollow anchor rod 1 is pre-tightened a second time to complete the anchoring reinforcement of the broken surrounding rock. The multi-step grouting anchoring in this way can solve the problem of insufficient anchoring force in conventional anchoring methods in broken surrounding rock areas, and can solve the problem that ordinary grouting anchor rods can only be anchored along the entire length and cannot apply prestress. It can realize the integration of anchoring, applying prestress, and grouting reinforcement, and effectively improve the support effect.

[0052] The present invention uses the bursting disc 2 and the end check valve 3 at the tail end of the hollow anchor rod 1 to perform grouting of the anchoring section 14 under certain conditions. Two grouting holes are provided on the rod body, one at the starting end of the anchoring section 14 and the other at the free section 15. A first check valve 6 is provided outside the first grouting hole 4 at the starting end of the anchoring section 14, and cooperates with a bag 7 to seal the space of the anchoring section 14; a second check valve 8 is provided outside the second grouting hole 5 at the free section 15 for subsequent grouting reinforcement of the surrounding rock. A sealing bag 11 is provided at the hole mouth and is mounted on the hollow anchor rod 1. After the hole is sealed, the axial movement of the rod body is not affected. A tray 9 and a nut 10 are provided at the outer end of the hollow anchor rod 1 for multiple pre-tightening of the rod body. Multi-step grouting anchoring is carried out in this way, which can solve the problem of insufficient anchoring force in conventional anchoring methods in broken surrounding rock areas, and can solve the problem that ordinary grouting anchor rods can only be anchored along the entire length and cannot apply prestress, thereby realizing the integration of anchoring, applying prestress and grouting reinforcement, and effectively improving the support effect.

[0053] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A prestressed anchoring and grouting integrated device, comprising a hollow anchor rod (1), characterized in that: The tail end of the hollow anchor rod (1) is provided with a bursting disc (2) and an end one-way valve (3), and the rod body of the hollow anchor rod (1) is provided with a first slurry outlet hole (4) and a second slurry outlet hole (5), the outer side of the first slurry outlet hole (4) is provided with a first one-way valve (6), and the outer side of the first one-way valve (6) is provided with a bag (7), and the outer side of the second slurry outlet hole (5) is provided with a second one-way valve (8), and the outer end of the hollow anchor rod (1) is pre-tightened by a tray (9) and a nut (10); The hollow anchor rod (1) is divided into an anchoring section (14) and a free section (15); the outer end of the hollow anchor rod (1) is provided with a sealing bag (11), and the sealing bag (11) is provided with a grouting pipe (12); The hollow anchor rod (1) is a tube body with a spiral thread on the outside. The hollow anchor rod (1) is used to realize the grouting function, and the spiral on the outside of the hollow anchor rod (1) is adapted to the nut (10); the bag (7) is made of elastic material and is tightly attached to the wall of the hollow anchor rod (1) before filling with slurry. After filling with slurry, it expands and contacts the wall of the borehole (13) to achieve hole sealing; the first one-way valve (6) is made of an annular rubber ring and is tightly clamped on the hollow anchor rod (1) to block the first slurry outlet hole (4). When the hollow anchor rod ( 1) When the internal pressure reaches a fixed value, the first one-way valve (6) is lifted up and the slurry enters the bag (7); when the pressure decreases, the first one-way valve (6) contracts and is again clamped on the hollow anchor rod (1) to prevent the slurry from flowing back; the bursting pressure value of the bursting disc (2) is greater than the opening pressure of the first one-way valve (6); the slurry is filled into the bag (7) in the early stage; after the pressure increases, the bursting disc (2) opens and is used to grout and anchor the space where the anchor section (14) is located; the end one-way valve (3) is used to prevent the slurry from flowing back.

2. The prestressed anchor-grouting integrated device according to claim 1, characterized in that: The hollow anchor rod (1) is used for being inserted into a drill hole (13).

3. The prestressed anchor-grouting integrated device according to claim 2, characterized in that: The first slurry outlet hole (4) and the second slurry outlet hole (5) are holes made on the hollow anchor rod (1) and are used to achieve communication between the interior of the hollow anchor rod (1) and the external drill hole (13).

4. The prestressed anchor-grouting integrated device according to claim 3, characterized in that: The second one-way valve (8) is made of an annular rubber ring and is tightly clamped on the hollow anchor rod (1) to block the second slurry outlet (5). When the pressure in the hollow anchor rod (1) reaches a fixed value, the second one-way valve (8) is lifted up and the slurry enters the grouting space in the borehole (13). The opening pressure of the second one-way valve (8) is greater than the opening pressure of the bursting disc (2), and the opening pressure of the second one-way valve (8) is greater than the opening pressure of the first one-way valve (6).

5. The prestressed anchor-grouting integrated device according to claim 4, characterized in that: The nut (10) and the tray (9) are matching components of the hollow anchor rod (1) and are used to achieve pre-tightening and supporting functions.

6. A construction method of a prestressed anchor-grouting integrated device, using the prestressed anchor-grouting integrated device according to claim 5, characterized in that: The following steps are involved: Step 1: using a drill bit that matches the size of the hollow anchor rod (1) to construct a borehole (13) in the surrounding rock of the tunnel, wherein the length of the borehole (13) matches the length of the hollow anchor rod (1); Step 2: Place the hollow anchor rod (1) into the borehole (13), connect the hole end of the hollow anchor rod (1) to the grouting conduit, inject slurry into the hollow anchor rod (1), and start filling the bag (7) after the slurry pressure is greater than the opening pressure of the first one-way valve (6). After the bag (7) is filled with the slurry, it begins to expand and contacts the wall of the borehole (13), thereby sealing the hole; Step 3: Continuing grouting, the pressure in the bag (7) increases, and the pressure in the hollow anchor rod (1) increases. When the pressure is greater than the opening pressure of the bursting disc (2), the bursting disc (2) opens, and the slurry is grouted into the space where the closed anchoring section (14) is located through the end one-way valve (3). When the grouting pressure increases to 80% of the opening pressure of the second one-way valve (8), the grouting of the space where the anchoring section (14) is located is completed. Step 4: Rinse the slurry inside the hollow anchor rod (1) with clean water to avoid blockage inside the rod; Step 5: Install a sealing bag (11) at the hole end, and inject grout into the sealing bag (11) through the grouting pipe (12) to seal the hole. After the slurry solidifies, install a tray (9) and a nut (10) at the end of the hollow anchor rod (1), and pre-tighten the rod body. After the pre-tightening is completed, reconnect the grouting pipe and grout the space between the sealing bag (11) and the bag (7) to reinforce the area. After the reinforcement is completed, pre-tighten the hollow anchor rod (1) for the second time to complete the prestressed anchor reinforcement of the broken surrounding rock.

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