A method for positioning anchor rod grouting for tunnel
By using the positioning anchor grouting method, the inner wall of the anchor hole is supported by the limiting rod and the self-expanding mechanism, which solves the problem of traditional anchors falling off easily and improves tunnel construction efficiency and surrounding rock stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA RAILWAY NO 9 GRP NO 7 ENG CO LTD
- Filing Date
- 2023-06-16
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional hollow radial anchors are prone to falling off or shifting during tunnel construction, affecting the grouting reinforcement effect and resulting in low construction efficiency.
The positioning anchor grouting method is adopted. The self-expanding mechanism is driven by the limiting rod, so that the end of the first self-expanding part and the second self-expanding part connected to each other extends outward or retracts into the strip hole, which supports and limits the inner wall of the anchor hole to ensure the stability of the anchor. The grout is then injected into the soil layer by the grouting machine.
It effectively prevents anchor bolts from falling off before grouting, improves construction efficiency, ensures grouting effect, and enhances the stability and support of the surrounding rock.
Smart Images
Figure CN116906094B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of tunnel anchor support technology, specifically relating to a grouting method for positioning anchors in tunnels. Background Technology
[0002] Initial anchor bolt support is the core of the New Austrian Tunneling Method (NATM) tunnel lining in mountain tunnels. Hollow grouting anchor bolt technology can maximize the integrity and stability of the surrounding rock, effectively control rock deformation, displacement, and crack development, and fully utilize the supporting role of the surrounding rock itself. It is particularly effective in stabilizing fractured rock masses in karst topography. However, traditional hollow radial anchor bolts are difficult to install, especially during tunnel arch construction. Hollow anchor bolts inserted into the anchor holes often fall off or shift before or during grouting, severely affecting the effectiveness of hollow anchor bolt grouting in reinforcing the rock mass and significantly reducing construction efficiency.
[0003] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art described above. This invention provides a method for grouting positioning anchor bolts for tunnels.
[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for grouting positioning anchor bolts in tunnels includes the following steps: Step S1: Measure and lay out the anchor hole ring according to its longitudinal design parameters; Step S2: Drill holes in the inner wall of the tunnel, and clean the holes after drilling them to a preset depth. Step S3: Insert the anchor rod into the anchor hole and drive the limiting rod threaded to the outside of the anchor pipe. This causes the limiting rod to push the non-hinged end of the second self-expanding component of the self-expanding mechanism closer to the non-hinged end of the first self-expanding component. The end of the first self-expanding component and the second self-expanding component that are connected to each other extends outward or retracts into the strip hole and supports and limits the inner wall of the anchor hole. Step S4: Install the grouting pad and use a grouting machine to press the mortar into the anchor pipe, so that the mortar seeps into the soil layer after passing through the limiting port and the strip hole in sequence. Step S5: After filling the anchor hole with mortar, seal the grouting port.
[0006] Preferably, in step S2, a preliminary hole is first made, the depth of which is one-third to one-quarter of the preset depth of the anchor hole.
[0007] Preferably, after the initial drilling is completed, the anchor hole angle is checked, then the orifice pipe is installed, the orifice pipe is fixed at the opening of the anchor hole, and the gap between the orifice pipe and the inner wall of the anchor hole is sealed with mortar.
[0008] Preferably, the diameter of the anchor hole is 15mm larger than the diameter of the outer tube.
[0009] Preferably, a flexible hose is inserted into the grouting port of the grouting pad, so that the hose reaches the anchor head, and air in the anchor hole is discharged through the hose during the grouting process.
[0010] Preferably, the anchor pipe is provided with scale lines, and the position of the limiting rod is determined by the scale lines, thereby determining the opening state of the self-expanding mechanism.
[0011] Beneficial effects: After the anchor rod is inserted into the anchor hole, the limiting rod pushes the second self-expanding component of the self-expanding mechanism, causing the end of the first and second self-expanding components connected to each other to extend outward through the strip hole, supporting and limiting the inner wall of the anchor hole, thereby maintaining the stability of the anchor pipe. This can prevent the anchor rod from falling off before grouting and avoid the problem of low construction efficiency caused by repeated installation of anchor rods. Attached Figure Description
[0012] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein: Figure 1 This is a simplified structural diagram of the grouting anchor in a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the extension plate in the open state in a specific embodiment of the present invention.
[0013] In the figure: 1. Anchor head; 2. Outer tube; 3. Anchor pipe; 4. First self-expanding component; 5. Extension plate; 6. Second self-expanding component; 7. Annular baffle; 8. Limiting tube; 9. Strip hole; 10. Limiting hole; 11. Scale line; 12. First constraint component; 13. Second constraint component. Detailed Implementation
[0014] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.
[0015] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," 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 do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected" and "linked" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; they can refer to a direct connection or an indirect connection through intermediate components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0016] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.
[0017] like Figure 1-2 As shown, a method for grouting positioning anchor bolts in tunnels requires prior preparation of work conditions and technology. The work conditions include on-site labor organization, various construction machinery, materials and components, and the completion and acceptance of the previous process by the supervising engineer, who agrees to proceed with the current process.
[0018] The specific grouting includes the following steps: Step S1, measure and lay out according to the longitudinal design parameters of the anchor ring, lay out the holes according to the longitudinal design parameters of the anchor ring of the construction site, lay out the outline of the working face and the hole position in advance, and mark them with red paint. At the same time, lay out the centerline of the tunnel as the basis for controlling the drilling angle.
[0019] Step S2: Drill holes in the inner wall of the tunnel. After drilling the anchor holes to the preset depth, clean the holes. The holes can be cleaned by high-pressure air and high-pressure water to remove rock debris and dust.
[0020] Step S3: Insert the anchor rod into the anchor hole. When the anchor rod head 1 reaches the predetermined position, rotate the limiting tube 8 so that the limiting rod thread pushes the self-expanding mechanism. This causes the non-hinged end of the second self-expanding member 6 of the self-expanding mechanism to approach the non-hinged end of the first self-expanding member 4. The end of the first self-expanding member 4 and the second self-expanding member 6 that are connected to each other extends outward or retracts into the strip hole 9 and supports and limits the inner wall of the anchor hole. Step S4: Install the grouting pad and use a grouting machine to press the mortar into the anchor pipe 3, so that the mortar can seep into the soil layer after passing through the limiting port and the strip hole 9 in sequence. Step S5: After filling the anchor hole with mortar, seal the grouting port.
[0021] In an optional embodiment, in step S4, when the anchor bolt is installed, if the anchor bolt head 1 is at a horizontal height higher than the bottom of the anchor bolt, a hose should be inserted into the grouting port of the grouting pad so that the hose reaches the anchor bolt head 1, and the air in the anchor hole is discharged through the hose during the grouting process.
[0022] In an optional embodiment, in step S4, the grouting pad is provided with a grouting port and a grouting outlet. The grouting pressure is greater than 1.0 MPa. After the mortar reaches the design strength, the anchoring pad is installed and the anchoring nut is tightened to make the anchor pad fit tightly against the shotcrete surface to ensure that the anchor is under good stress. Then the excavation of the face can be completed, and the above steps are repeated to advance the length.
[0023] In one optional embodiment, the anchor bolt lengths are 3m, 3.5m, and 4m. The anchor holes are drilled in two stages using an anchor bolt trolley. In step S2, preliminary drilling is first performed, with the depth of the preliminary drilling being one-third to one-quarter of the preset depth of the anchor hole. After the preliminary drilling is completed, the anchor hole angle is checked, and then the orifice pipe is installed, fixed at the opening of the anchor hole, and the gap between the orifice pipe and the inner wall of the anchor hole is sealed with mortar.
[0024] Taking a 3m anchor rod as an example, the initial drilling is carried out to a depth of 1m using a large drill bit. The borehole pipe is made of seamless steel pipe with an inner diameter larger than that of the grouting anchor rod. The borehole pipe is wrapped with cotton yarn for 30-40cm to seal the hole. The gap between the borehole pipe and the hole is sealed with grout. Two threaded steel anchor rods are installed around the perimeter and welded firmly to the borehole pipe. The pull-out resistance of each anchor rod is determined according to the actual situation, and is generally not less than 50KN.
[0025] Use a pneumatic drill to make a hole at the designated location. The diameter of the anchor hole should be 15mm larger than the diameter of the outer tube 2.
[0026] The above grouting method uses tunnel grouting anchor bolts for grouting, including anchor bolt head 1, anchor pipe 3, limiting pipe 8 and self-expanding mechanism. Anchor bolt head 1 has a conical structure, preferably a bottomless conical shell. An outer pipe 2 is connected to the larger section of anchor bolt head 1. The outer pipe 2 is only used to protect the self-expanding mechanism when the anchor pipe 3 is inserted into the anchor hole. Therefore, the length of the outer pipe 2 can be matched with the axial length of the self-expanding mechanism. Specifically, it can completely cover the self-expanding mechanism. No further restrictions are made here.
[0027] Anchor pipe 3 extends axially into outer pipe 2 and is correspondingly connected to anchor head 1. This connection can be achieved through welding, threaded connection, or other methods. Limiting pipe 8 is fitted onto the outer wall of anchor pipe 3 and threadedly assembled with it. Limiting pipe 8 can rotate relative to anchor pipe 3, and through this rotation, it can reciprocate along the axial direction of anchor pipe 3 under the action of the thread. Two self-expanding mechanisms are distributed on both sides of anchor pipe 3. Each self-expanding mechanism includes a first self-expanding component 4 and a second self-expanding component 6. The first self-expanding component 4... One end is hinged to the end of the anchor pipe 3 near the anchor head 1, and the other end is constrained to one end of the second self-expanding member 6 in the form of a hinge. The other end of the second self-expanding member 6 abuts against the end of the limiting tube 8 corresponding to the anchor head 1. The anchor pipe 3 and the non-hinged section of the second self-expanding member 6 are driven by the limiting tube 8. When the non-hinged ends of the first self-expanding member 4 and the second self-expanding member 6 approach each other, the hinged ends of the first self-expanding member 4 and the second self-expanding member 6 extend outward through the strip hole 9, so as to lock and position the outer wall of the anchor hole.
[0028] There are two strip holes 9. The two strip holes 9 are provided with two self-expanding mechanisms facing each other on the side wall of the outer tube 2. In response to the limiting tube 8 pressing the self-expanding mechanism towards one end of the anchor head 1, the end of the first self-expanding member 4 and the second self-expanding member 6 connected to each other extends outward or retracts into the strip hole 9.
[0029] In another optional embodiment, the anchor pipe 3 is provided with limiting holes 10 corresponding to the self-expanding mechanism on both sides. The limiting holes 10 can discharge the mortar in the anchor pipe 3 during grouting, so that the mortar passes through the strip hole 9 and the limiting holes 10 and enters the anchor hole.
[0030] In this embodiment, multiple grout outlets are provided on the side of the anchor pipe 3, corresponding to the position of the strip hole 9 in the axial direction, to ensure that the grout is quickly discharged.
[0031] The limiting hole 10 is also a strip hole 9, and the width of the limiting hole 10 is adapted to the self-expanding mechanism.
[0032] In another optional embodiment, a constraint mechanism is provided between the two self-expanding mechanisms. Limiting holes 10 corresponding to the self-expanding mechanisms are provided on both sides of the anchor pipe 3. The constraint mechanism passes through the two limiting holes 10 and connects to the two self-expanding mechanisms. The constraint mechanism limits the self-expanding paths of the first self-expanding member 4 and the second self-expanding member 6, ensuring that the first self-expanding member 4 and the second self-expanding member 6 will not deviate when they rotate relative to each other, thus guaranteeing that the first self-expanding member 4 and the second self-expanding member 6 can smoothly pass through the strip hole 9.
[0033] In another embodiment, the constraint mechanism includes a first constraint member 12 and a second constraint member 13. One end of the first constraint member 12 is hinged to the middle of the first self-expanding member 4 of one of the self-expanding mechanisms, and the other end is slidably assembled with one end of the second constraint member 13. The other end of the second constraint member 13 is correspondingly hinged to the middle of the second self-expanding member 6 of the other self-expanding mechanism, so that the two self-expanding mechanisms open in the same plane.
[0034] In another embodiment, the first constraint member 12 and the second constraint member 13 are both grooved tubes, specifically directional tubes or round tubes, whose width or diameter is not greater than the width of the limiting hole 10. The second constraint member 13 extends into the first constraint member 12, thereby restricting the path of the first self-expanding member 4 or the second self-expanding member 6.
[0035] Furthermore, a return spring is provided between the end of the second constraint member 13 and the first constraint member 12. The return spring provides tension to keep the first self-expanding member 4 and the second self-expanding member 6 tending to retract, so that when the second self-expanding member 6 is not driven by the limiting tube 8 (e.g. during the process of inserting the anchor rod into the anchor hole), the first self-expanding member 4 and the second self-expanding member 6 are close to the anchor tube 3.
[0036] In another alternative embodiment, the second self-expanding member 6 abuts against the limiting tube 8 through an annular baffle 7 sleeved on the outside of the anchor tube 3. The annular baffle 7 is slidably fitted on the outer wall of the anchor tube 3, so that when the second self-expanding member 6 is driven, the rotation of the limiting tube 8 will not affect the second self-expanding member 6, thus preventing the second self-expanding member 6 from shifting due to force.
[0037] To further ensure stability, at least one convex strip extending axially is provided on the inner wall of the outer tube 2, and a notch corresponding to the convex strip is provided on the outer edge of the annular baffle 7. The convex strip further limits the movement and ensures that the annular baffle 7 will not rotate.
[0038] In another alternative embodiment, the first self-expanding component 4 is hinged to the limiting ring, and the limiting ring is threaded onto the anchor pipe 3, making the self-expanding mechanism a detachable structure, which can be selected for installation according to the actual situation, while reducing the production difficulty of the anchor pipe 3.
[0039] Furthermore, the limit ring is adjustable, allowing the axial position of the self-expanding mechanism to be adjusted according to actual conditions.
[0040] In another optional embodiment, the outer tube 2 is provided with a tongue and groove joint with an external thread at the tongue and groove joint. The larger end of the anchor head 1 has a receiving interface with an internal thread at the receiving interface. The outer tube 2 is assembled in this way. During the assembly process, the self-expanding mechanism is installed first, and then the outer tube 2 is installed.
[0041] In another optional embodiment, at least one end of the first self-expanding member 4 corresponding to the second self-expanding member 6 is a groove structure. The groove structure can provide a hinge position for the second self-expanding member 6. At the same time, when the self-expanding mechanism retracts, the second self-expanding member 6 can be retracted into the groove structure, so that the first self-expanding member 4 and the second self-expanding member 6 are closer to the anchor pipe 3. The end of the second self-expanding member 6 is provided with a hinge shaft that is correspondingly hinged inside the first self-expanding member 4. The two ends of the hinge shaft pass through the first self-expanding member 4 and are riveted together.
[0042] In another optional embodiment, in order to improve the locking ability to the inner wall of the anchor hole, an extension plate 5 is hinged to the end of the first self-expanding member 4. The extension plate 5 extends along the length direction of the first self-expanding member 4, and the length is selected according to the anchor hole. It should not be greater than one-half of the length of the first self-expanding member 4, and preferably one-third or one-quarter of the length of the first self-expanding member 4.
[0043] The thickness of the extension plate 5 is not greater than the wall thickness of the grooved portion of the first self-expanding member 4. One end of the extension plate 5 is hinged to the end of the first self-expanding member 4, and the other end is rotated and limited in both directions of the first self-expanding member 4. Thus, after the self-expanding mechanism opens, the extension plate 5 further supports the inner wall of the anchor hole, increases the point of force, and ensures stability.
[0044] In another alternative embodiment, a thrust spring is provided between the two extension plates 5 to provide driving force, thereby forming circumferential support and ensuring stability.
[0045] In another optional embodiment, the end of the extension plate 5 away from the first self-expanding member 4 is provided with a protrusion extending perpendicularly to the extension plate 5, and the thrust spring is located between the two protrusions, so as to make way for the second self-expanding member 6 and ensure that the second self-expanding member 6 will not interfere with the thrust spring during rotation.
[0046] In this embodiment, the tension spring has a greater elastic force than the thrust spring. In the free state, the extension plate can be pulled to overcome the elastic force of the thrust spring and then retract.
[0047] Alternatively, the slotted hole is not limited to a slit shape and can be adapted to the open state of the extension plate.
[0048] To better ensure that the self-expanding mechanism can pass smoothly through the strip hole 9, the protrusion is located inside the strip hole 9 when the self-expanding mechanism is retracted. The protrusion can be partially protruding, or the width of the extension plate 5 can be greater than the width of the first self-expanding member 4, so that part of it can be located inside the strip hole 9.
[0049] In another optional embodiment, the end of the anchor pipe 3 away from the anchor head 1 extends out of the limiting pipe 8. The anchor pipe 3 is provided with a scale line 11 corresponding to the limiting pipe 8, which can determine the opening state of the self-expanding mechanism according to the scale line 11, so as to ensure that it is engaged with the inner wall of the anchor hole.
[0050] In this embodiment, the limiting tube 8 can be disassembled or left in the anchor hole with the grouting. It is preferable to disassemble it. Before grouting, the limiting rod is rotated to make the limiting rod exit the anchor hole, and then the grouting pad is installed for grouting. At this time, due to the thrust spring pushing the extension plate 5 to open, the anchor tube 3 remains in a state of being clamped to the inner wall of the anchor hole, and the limiting tube 8 can be recycled, thereby reducing production costs.
[0051] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention shall be within the scope of protection of the pending claims of the present invention.
Claims
1. A method for grouting positioning anchor bolts in tunnels, characterized in that, Includes the following steps: Step S1: Measure and lay out the anchor hole ring according to its longitudinal design parameters; Step S2: Drill holes in the inner wall of the tunnel, and clean the holes after drilling them to a preset depth. Step S3: Insert the anchor rod into the anchor hole and drive the limiting rod threaded to the outside of the anchor pipe. This causes the limiting rod to push the non-hinged end of the second self-expanding component of the self-expanding mechanism closer to the non-hinged end of the first self-expanding component. The end of the first self-expanding component and the second self-expanding component that are connected to each other extends outward or retracts into the strip hole and supports and limits the inner wall of the anchor hole. The first self-expanding component has a groove-shaped structure at one end corresponding to the second self-expanding component. The end of the second self-expanding component is provided with a hinge shaft that is hinged to the inside of the first self-expanding component. The two ends of the hinge shaft pass through the first self-expanding component and are riveted together. An extension plate is hinged to the end of the first self-expanding component. The extension plate extends along the length of the first self-expanding component. One end of the extension plate is hinged to the end of the first self-expanding component, and the other end is rotated and limited in the direction of both sides of the first self-expanding component. Thus, after the self-expanding mechanism opens, the extension plate further supports the inner wall of the anchor hole. A thrust spring is provided between the two extension plates. The thrust spring provides driving force to form circumferential support. Step S4: Install the grouting pad and use a grouting machine to press the mortar into the anchor pipe, so that the mortar seeps into the soil layer after passing through the limiting port and the strip hole in sequence. Step S5: After filling the anchor hole with mortar, seal the grouting port.
2. The method for grouting positioning anchor bolts for tunnels according to claim 1, characterized in that, In step S2, a preliminary hole is first made, with the depth of the preliminary hole being one-third to one-quarter of the preset depth of the anchor hole.
3. The method for grouting positioning anchor bolts for tunnels according to claim 2, characterized in that, After the initial drilling is completed, the anchor hole angle is checked, and then the orifice pipe is installed. The orifice pipe is fixed at the opening of the anchor hole, and the gap between the orifice pipe and the inner wall of the anchor hole is sealed with mortar.
4. The method for grouting positioning anchor bolts for tunnels according to claim 3, characterized in that, The diameter of the anchor hole is 15mm larger than the diameter of the outer tube.
5. The method for grouting positioning anchor bolts for tunnels according to claim 1, characterized in that, A flexible hose is inserted into the grouting port of the grouting pad, so that the hose reaches the anchor head, and air in the anchor hole is discharged through the hose during the grouting process.
6. The method for grouting positioning anchor bolts for tunnels according to claim 1, characterized in that, The anchor pipe is marked with scale lines, and the position of the limiting rod is determined by the scale lines, thereby determining the opening state of the self-expanding mechanism.