Anchoring enhancement type self-drilling grouting anchor rod with telescopic grouting hole and using method of anchoring enhancement type self-drilling grouting anchor rod

Abstract

The invention discloses an anchoring enhancement type self-drilling grouting anchor rod with telescopic grouting holes and a using method of the anchoring enhancement type self-drilling grouting anchor rod, and relates to the technical field of roadway supporting, the anchoring enhancement type self-drilling grouting anchor rod comprises a hollow grouting anchor rod body, and a plurality of anchoring grouting assemblies are installed in the length direction of the grouting anchor rod body; each anchoring and grouting assembly comprises a plurality of guide holes formed in the circumferential direction of the grouting anchor rod, the guide holes penetrate through the side wall of the grouting anchor rod, grouting anchoring nails with the tips close to the outside are slidably installed in the guide holes, and the total length of the grouting anchoring nails is larger than the thickness of the side wall of the grouting anchor rod and smaller than the radius of the outer wall of the grouting anchor rod. A pushing ball is installed in an inner cavity of the grouting anchor rod in a rolling mode, and a gap is formed between the pushing ball and the wall of the inner cavity of the grouting anchor rod. Through the innovative telescopic grouting anchoring nail structure, the grouting anchoring nail is inserted into the broken surrounding rock of the roadway under the action of pressure during grouting, so that the friction force between the grouting anchor rod and the surrounding rock is remarkably enhanced, the anchoring effect is improved, and meanwhile, the risk that the grouting anchor rod pops up due to the fact that the grouting pressure is too large is effectively prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel support, and particularly relates to an anchoring-enhanced self-drilling grouting anchor rod with a retractable grouting hole and a use method thereof. Background Art

[0002] In mining projects, tunnel support is an important part of ensuring construction safety and project quality. However, when the project passes through broken soft rock formations such as faults, traditional support technology faces many challenges. Broken soft rock is prone to collapse and large deformation during excavation due to its loose structure, low strength, and large deformation, which significantly increases the difficulty and risk of support. This geological condition not only leads to poor stability of the surrounding rock, but may also cause serious safety hazards, such as sudden collapse of the surrounding rock, deformation and instability of the tunnel, and failure of the support structure. Therefore, more effective technical means are needed for reinforcement, and grouting technology is widely used in this context.

[0003] However, due to the loose structure of broken soft rock, traditional grouting anchors face the problem of not being able to make close contact with the rock mass when used, resulting in insufficient anchoring force and inability to effectively support the surrounding rock. During the grouting process, excessive grouting pressure may cause the anchor to be ejected, causing construction risks and safety hazards. Not only does it affect the support effect, it may also cause secondary disasters, increasing the danger and complexity of construction. In view of the technical difficulties of grouting anchors in broken soft rock support, it is urgent to design a safe, efficient and easy-to-construct support structure. Summary of the invention

[0004] In view of the problems mentioned in the background technology, the purpose of the present invention is to provide an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole and a method of using the same, so as to solve the problems mentioned in the background technology.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] An anchor-enhanced self-drilling grouting anchor with a retractable grouting hole comprises a hollow grouting anchor. A plurality of anchor grouting assemblies are installed in the extension direction of the grouting anchor. Each anchor grouting assembly comprises a plurality of guide holes opened along the circumference of the grouting anchor and the guide holes penetrate the side wall of the grouting anchor. A grouting anchor nail with a tip facing outward is slidably installed in the guide hole. The total length of the grouting anchor nail is greater than the thickness of the side wall of the grouting anchor and less than the radius of the outer wall of the grouting anchor. A pushing ball is rotoscopically installed in the inner cavity of the grouting anchor, and a gap is provided between the pushing ball and the inner cavity wall of the grouting anchor.

[0007] As an optimal technical solution, the outer end of the grouting anchor nail is conical and the cone radius is larger than the cylindrical radius of the inner side of the grouting anchor nail. The corresponding guide hole cross-section is T-shaped, and the grouting anchor nail cylinder, the small radius of the guide hole, the grouting anchor nail cone radius and the large radius of the guide hole increase successively.

[0008] As a preferred technical solution, the cone height of the grouting anchor nail is not greater than the height of the large diameter end of the guide hole.

[0009] As a preferred technical solution, the inner side of the grouting anchor nail is an inclined surface that gradually approaches the axis of the grouting anchor rod close to the drilling end.

[0010] As an optimal technical solution, a limit baffle is installed at the front end of the grouting anchor nail close to the inner slope, and the limit baffle is perpendicular to the length direction of the grouting anchor nail. When the limit baffle contacts the inner cavity wall of the grouting anchor rod, the distance between the limit baffle and the axis of the grouting anchor rod is greater than the radius of the pushing ball.

[0011] As a preferred technical solution, a grouting hole is opened through the grouting anchor nail, and the connection point between the grouting hole and the outside is located on the conical side wall of the grouting anchor nail.

[0012] As a preferred technical solution, a self-drilling bit is installed at the front end of the grouting anchor rod.

[0013] As a preferred technical solution, the inner cavity of the grouting anchor rod on the side where the push ball is away from the drilling end is sequentially provided with an inner diameter gradient structure, a check ball and a baffle bar. The inner wall of the inner diameter gradient structure is a smooth inclined surface which gradually approaches the axis of the grouting anchor rod near the drilling end. The check ball is rollingly installed between the inner diameter gradient structure and the baffle bar. The diameter of the check ball is larger than the minimum diameter of the inner diameter gradient structure and smaller than the maximum diameter of the inner diameter gradient structure.

[0014] As a preferred technical solution, the end of the grouting anchor rod away from the drilling end is sleeved with a grout stopper, a tray and a fastening nut in sequence from front to back.

[0015] A method for using an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole comprises the following steps:

[0016] Step 1: Push the grouting anchor nail into the guide hole and remove the fastening nut, tray and grout stopper at the end;

[0017] Step 2: Install the self-drilling bit at the front end of the grouting anchor rod, install the grouting anchor rod on the anchor drilling rig, start the anchor drilling rig, drill the self-drilling bit to the designated position of the tunnel, and remove the anchor drilling rig after the drilling is completed;

[0018] Step 3: Install the stopper and tray at the end of the grouting anchor rod in sequence, and finally tighten the nut;

[0019] Step 4: Connect the tail of the grouting anchor rod to the grouting pump for grouting. The grouting liquid pushes the ball forward to squeeze the grouting anchor nail out of the guide hole. After the grouting anchor nail is inserted into the surrounding rock, the grouting liquid diffuses into the surrounding rock through the grouting hole.

[0020] Step 5: After the grouting is completed, seal the tail of the grouting anchor.

[0021] The present invention designs an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole. Through the innovative retractable grouting anchor nail structure, the grouting anchor nail is inserted into the broken surrounding rock of the tunnel under pressure during grouting, which significantly enhances the friction between the grouting anchor rod and the surrounding rock, thereby improving the anchoring effect, and effectively preventing the risk of the grouting anchor rod being ejected due to excessive grouting pressure. In addition, the design ensures that the grouting slurry can fully penetrate into the cracks of the surrounding rock to form a stable reinforced support structure. The self-drilling drill bit installed on the top of the grouting anchor rod realizes grouting immediately after drilling, overcoming the problem of difficulty in drilling holes in broken surrounding rock tunnels. The check structure inside the grouting anchor rod effectively solves the problem of leakage of the grouting slurry before solidification, further improving the support effect and construction efficiency.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic cross-sectional view of an anchor-enhanced self-drilling grouting anchor rod of a retractable grouting hole proposed by the present invention before grouting;

[0024] Figure 2 A schematic cross-sectional view of an anchor-enhanced self-drilling grouting anchor rod of a retractable grouting hole proposed by the present invention after grouting;

[0025] Figure 3 A cross-sectional view of an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole proposed by the present invention;

[0026] Figure 4 A schematic diagram of the grouting anchor nail structure of an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole proposed by the present invention.

[0027] Figure numerals: 1-grouting anchor rod; 2-fastening nut; 3-tray; 4-grouting plug; 5-check structure; 51-inner diameter gradient structure; 52-check ball; 53-blocking bar; 6-pushing ball; 7-grouting anchor nail; 8-guide hole; 9-self-drilling bit; 10-grouting hole; 11-limit baffle. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar symbols throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] Example 1

[0030] refer to Figures 1 to 4 The embodiment of the present invention provides an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole, including a grouting anchor rod 1. The grouting anchor rod 1 is a hollow tube, and a self-drilling bit 9 is installed at the front end of the grouting anchor rod 1, so that grouting can be performed immediately after drilling, thereby overcoming the difficulty of drilling holes in broken surrounding rock tunnels.

[0031] Preferably, the self-drilling bit 9 is detachably connected via an internal thread on the self-drilling bit 9 and an external thread at the front end of the grouting anchor rod 1 .

[0032] The rear end of the grouting anchor rod 1 is sleeved with a grout stopper 4, a tray 3 and a fastening nut 2 in sequence from front to back. It is used to seal the hole after grouting is completed to prevent slurry from flowing out of the grouting anchor rod 1.

[0033] Multiple groups of anchor grouting components are installed in the extension direction of the grouting anchor rod 1. A pushing ball 6 is installed in the inner cavity of the grouting anchor rod 1 for rolling. Each group of anchor grouting components includes multiple groups of guide holes 8 opened along the circumference of the grouting anchor rod 1, and the guide holes 8 penetrate the grouting anchor rod 1, that is, the guide holes 8 connect the outside and the inner cavity of the grouting anchor rod 1. A group of grouting anchor nails 7 with the tip facing outward are slidably installed in each group of guide holes 8. During grouting, the pushing ball 6 rolls forward under the pressure, and pushes each group of grouting anchor nails 7 out of the guide holes 8 and inserts into the broken surrounding rock of the tunnel in turn, until all the grouting anchor nails 7 are inserted into the broken surrounding rock, which significantly enhances the friction between the grouting anchor rod 1 and the surrounding rock, thereby improving the anchoring effect, and effectively preventing the risk of the anchor rod popping out due to excessive grouting pressure.

[0034] Preferably, the guide holes 8 are arranged in four groups, and the distances between any two adjacent groups of guide holes 8 are equal.

[0035] Preferably, the outer end of the grouting anchor nail 7 is conical and the radius of the cone is larger than the cylindrical radius of the inner side of the grouting anchor nail 7, and the corresponding guide hole 8 cross-section is T-shaped, that is, the radius of the guide hole 8 facing outward is larger than the radius facing inward, the cylinder of the grouting anchor nail 7, the small radius of the guide hole 8, the cone radius of the grouting anchor nail 7 and the large radius of the guide hole 8 increase successively, the cone height of the grouting anchor nail 7 is not larger than the height of the large diameter end of the guide hole 8, the cylindrical end of the grouting anchor nail 7 slides in the small diameter end of the guide hole 8, and the cone end of the grouting anchor nail 7 slides in the large diameter end of the guide hole 8, and the guide hole 8 is segmented to prevent the grouting anchor nail 7 from sliding into the inner cavity of the grouting anchor rod 1.

[0036] Preferably, the inner side of the grouting anchor nail 7 is an inclined surface which gradually approaches the axis of the grouting anchor rod 1 from the back to the front, so as to facilitate the pushing ball 6 to push the grouting anchor nail 7 out of the guide hole 8.

[0037] Preferably, a limit baffle 11 is installed at the front end of the grouting anchor nail 7 close to the inner slope, and the limit baffle 11 is perpendicular to the length direction of the grouting anchor nail 7. When the grouting anchor nail 7 extends out of the guide hole 8, the limit baffle 11 contacts the inner cavity wall of the grouting anchor rod 1 to prevent the grouting anchor nail 7 from being thrown out of the guide hole 8 during drilling.

[0038] It is worth noting that the diameter of the pushing ball 6 is smaller than the diameter of the inner cavity of the grouting anchor 1 and smaller than the distance between the limit baffles 11 on both sides during grouting. Therefore, preferably, a groove for accommodating the limit baffle 11 can also be opened on the inner wall of the grouting anchor 1. At this time, it is only necessary to ensure that there is a gap between the pushing ball 6 and the inner cavity wall of the grouting anchor 1.

[0039] It is worth noting that the total length of the grouting anchor nail 7 is smaller than the radius of the outer wall of the grouting anchor rod 1, so as to avoid the grouting anchor nail 7 extending out of the guide hole 8 after the two relative groups of grouting anchor nails 7 abut against each other, thereby affecting the drilling; at the same time, the total length of the grouting anchor nail 7 is greater than the thickness of the side wall of the grouting anchor rod 1, leaving a telescopic distance.

[0040] Preferably, a grouting hole 10 is opened through the grouting anchor nail 7. It is worth noting that the grouting hole 10 does not damage the tip of the cone of the grouting anchor nail 7. The grouting hole 10 connects the outside and the inner cavity of the grouting anchor rod 1. After the grouting anchor nail 7 is driven into the surrounding rock, the slurry is injected into the surrounding rock from the grouting hole 10 to ensure that the grouting slurry can fully penetrate into the cracks in the surrounding rock and expand the grouting range to form a stable reinforced support structure.

[0041] After grouting is completed, the slurry is likely to flow back along the grouting hole 10 and the inner cavity of the grouting anchor rod 1, resulting in slurry leakage. Therefore, a check structure 5 is provided at the rear end of the inner cavity of the grouting anchor rod 1. The check structure 5 includes an inner diameter gradient structure 51, a check ball 52 and a baffle 53. The inner diameter gradient structure 51 and at least two groups of baffles 53 are fixedly installed on the inner wall of the grouting anchor 1, and the inner diameter gradient structure 51 is a tubular structure with an inclined inner wall. The inner wall of the inner diameter gradient structure 51 is a smooth inclined surface that gradually approaches the axis of the grouting anchor 1 from front to back. The two groups of baffles 53 are positioned relative to each other. The check ball 52 is rollingly installed between the inner diameter gradient structure 51 and the baffle 53. The push ball 6 is located between the baffle 53 and the anchor grouting assembly. The distance between the two groups of baffles 53 is smaller than the diameter of the check ball 52. The diameter of the check ball 52 is larger than the rear end diameter of the inner diameter gradient structure 51 and smaller than the front end diameter of the inner diameter gradient structure 51. The minimum distance between the baffle 53 and the inner diameter gradient structure 51 is larger than the diameter of the check ball 52. When the slurry flows downstream, the slurry pushes the check ball 52 close to the baffle 53, and the slurry flows through the gap between the check ball 52, the baffle 53 and the inner cavity of the grouting anchor 1. When the slurry flows upstream, the slurry pushes the check ball 52 close to the inner diameter gradient structure 51 until the check ball 52 fits tightly against the inner diameter gradient structure 51, preventing the slurry from flowing out of the inner cavity of the grouting anchor 1, effectively solving the problem of leakage of the grouting slurry before solidification, and further improving the support effect and construction efficiency.

[0042] Example 2

[0043] refer to Figures 1 to 4 The method for using the anchor-enhanced self-drilling grouting anchor rod of the retractable grouting hole described in this embodiment comprises the following steps:

[0044] Step 1: Push the grouting anchor nail 7 into the guide hole 8, and remove the fastening nut 2, tray 3 and grout stopper 4 at the end;

[0045] Step 2: Install the self-drilling bit 9 at the front end of the grouting anchor 1, install the grouting anchor 1 on the anchor drilling rig, start the anchor drilling rig, drill the self-drilling bit 9 to the designated position of the tunnel, and remove the anchor drilling rig after the drilling is completed;

[0046] Step 3: Install the stopper 4 and the tray 3 at the end of the grouting anchor rod 1 in sequence, and finally tighten the nut 2;

[0047] Step 4: Connect the tail of the grouting anchor rod 1 to the grouting pump for grouting. The slurry pushes the ball forward to squeeze the grouting anchor nail 7 out of the guide hole 8, and insert the tip of the grouting anchor nail into the surrounding rock to play an anchoring role. After the grouting anchor nail 7 is inserted into the surrounding rock, the slurry diffuses into the surrounding rock through the grouting hole 10, thereby achieving the grouting reinforcement effect of the tunnel surrounding rock.

[0048] Step 5: After the grouting is completed, the tail of the grouting anchor is closed to complete the installation and use process of the anchor-enhanced self-drilling grouting anchor of the retractable grouting hole.

[0049] It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0053] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An anchor-enhanced self-drilling grouting anchor with a retractable grouting hole, comprising a hollow grouting anchor (1), characterized in that: A plurality of anchor grouting components are installed in the extension direction of the grouting anchor rod (1), each of which comprises a plurality of guide holes (8) opened along the circumference of the grouting anchor rod (1), and the guide holes (8) penetrate the side wall of the grouting anchor rod (1), a grouting anchor nail (7) with a tip facing outward is slidably installed in the guide hole (8), the total length of the grouting anchor nail (7) is greater than the thickness of the side wall of the grouting anchor rod (1) and less than the radius of the outer wall of the grouting anchor rod (1), a pushing ball (6) is rotatably installed in the inner cavity of the grouting anchor rod (1), and a gap is provided between the pushing ball (6) and the inner cavity wall of the grouting anchor rod (1).

2. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 1, characterized in that: The outer end of the grouting anchor nail (7) is conical and the radius of the cone is greater than the radius of the cylinder on the inner side of the grouting anchor nail (7); the corresponding guide hole (8) has a T-shaped cross section; the cylinder of the grouting anchor nail (7), the small radius of the guide hole (8), the cone radius of the grouting anchor nail (7) and the large radius of the guide hole (8) increase in sequence.

3. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 2 is characterized in that: The cone height of the grouting anchor nail (7) is not greater than the height of the large diameter end of the guide hole (8).

4. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 1, characterized in that: The inner side of the grouting anchor nail (7) is an inclined surface which is close to the drilling end and gradually approaches the axis of the grouting anchor rod (1).

5. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 4, characterized in that: A limit baffle (11) is installed at the front end of the grouting anchor nail (7) close to the inner inclined surface. The limit baffle (11) is perpendicular to the length direction of the grouting anchor nail (7). When the limit baffle (11) contacts the inner cavity wall of the grouting anchor rod (1), the distance between the limit baffle (11) and the axis of the grouting anchor rod (1) is greater than the radius of the pushing ball (6).

6. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 5, characterized in that: A grouting hole (10) is formed through the grouting anchor nail (7), and the connection point between the grouting hole (10) and the outside is located on the conical side wall of the grouting anchor nail (7).

7. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 1, characterized in that: A self-drilling bit (9) is installed at the front end of the grouting anchor rod (1).

8. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 1, characterized in that: The inner cavity of the grouting anchor rod (1) on the side of the pushing ball (6) away from the drilling end is provided with an inner diameter gradual change structure (51), a check ball (52) and a stop bar (53) in sequence away from the drilling end. The inner wall of the inner diameter gradual change structure (51) is a smooth inclined surface which gradually approaches the axis of the grouting anchor rod (1) near the drilling end. The check ball (52) is rollingly installed between the inner diameter gradual change structure (51) and the stop bar (53). The diameter of the check ball (52) is larger than the minimum diameter of the inner diameter gradual change structure (51) and smaller than the maximum diameter of the inner diameter gradual change structure (51).

9. The anchor-enhanced self-drilling grouting anchor rod of the telescopic grouting hole according to claim 1, characterized in that: The end of the grouting anchor rod (1) away from the drilling end is sleeved with a grout stopper (4), a tray (3) and a fastening nut (2) in sequence from front to back.

10. A method for using an anchor-enhanced self-drilling grouting anchor rod with a retractable grouting hole, comprising the following steps: Step 1: Push the grouting anchor nail (7) into the guide hole (8), and remove the fastening nut (2), tray (3) and grouting stopper (4) at the end; Step 2: Install the self-drilling bit (9) at the front end of the grouting anchor (1), install the grouting anchor (1) on the anchor drilling machine, start the anchor drilling machine, drill the self-drilling bit (9) to the designated position of the tunnel, and remove the anchor drilling machine after the drilling is completed; Step 3: Install the grout stopper (4) and the tray (3) at the end of the grouting anchor rod (1) in sequence, and finally tighten the nut (2); Step 4: Connect the tail of the grouting anchor rod (1) to the grouting pump for grouting. The grouting liquid pushes the pushing ball forward to squeeze the grouting anchor nail (7) out of the guide hole (8). After the grouting anchor nail (7) is inserted into the surrounding rock, the grouting liquid diffuses into the surrounding rock through the grouting hole (10); Step 5: After the grouting is completed, seal the tail of the grouting anchor.

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