A sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor

Abstract

The present invention discloses a sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod. It includes an anchoring agent, an inner rod body, a middle sleeve, a hydraulic expansion shell, a tray, and a detachable propulsion rod; the hydraulic expansion shell is formed by radially bending a steel pipe; an anchoring agent is provided at one end of the inner rod body, and the other end is located in the middle sleeve; a conical structure is provided at the end of the inner rod body; grouting holes are provided on the inner rod body and the detachable propulsion rod; one end of the detachable propulsion rod is provided in the middle sleeve and docked with the conical structure; both ends of the hydraulic expansion shell are welded to the middle sleeve; the water injection hole is arranged on the middle sleeve; the anchoring agent, inner rod body, and hydraulic expansion shell are all located in a borehole; one end of the middle sleeve is located in the borehole, and the other end is fixed to the rock mass by a nut and a tray. The present invention has the advantages of simple structure, easy use, and the functions of simultaneously applying axial and radial prestress to the rod body, large deformation, and grouting, and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of rock and soil anchoring, and specifically refers to a sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod, and in particular refers to a large deformation anchor rod that can simultaneously apply axial and radial prestress to the rod body, and perform grouting reinforcement on the surrounding rock. When the surrounding rock undergoes plate cracking, spalling or rock burst, resulting in the separation of the tray and the surrounding rock surface, the anchor rod still has a certain supporting effect. Background Art

[0002] As an active support method, prestressed anchors have the outstanding feature of providing support force quickly compared to ordinary bonded anchors. By applying active prestress, it is beneficial to improve the stress state of the rock mass, alleviate the stress concentration of the surrounding rock, promote the closure of cracks in the surrounding rock, and timely inhibit the expansion and penetration of cracks. Prestressed anchors rely on pads to apply a surface support force to the surrounding rock, providing a certain support pressure to the surrounding rock, and thus effectively inhibiting the damage of the surrounding rock. As an economical and effective support method, prestressed anchors can significantly improve the deformation of the surrounding rock of the roadway / tunnel. However, in some roadways, due to plate cracking, spalling and rock bursts, the tray and the surrounding rock surface are separated, resulting in the loss of prestress in the anchor rods, causing the anchor rods to fail and unable to meet the support requirements of rock engineering excavation.

[0003] Therefore, it is necessary to develop an anchor rod that still has supporting force when the tray is separated from the surrounding rock surface. Summary of the Invention

[0004] The purpose of the present invention is to provide a sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod, which has a simple structure, is easy to use, has the functions of simultaneously applying axial and radial prestressing and large deformation to the rod body, and has a wide range of applications. After the tray and the surrounding rock are emptied, the hydraulic expansion shell expands and adheres tightly to the hole wall, exerting a certain friction force, so that the rod body still has axial pretightening force. It provides continuous support force to the surrounding rock, overcomes the shortcomings of existing anchor rods that cannot simultaneously apply axial and radial prestressing, large deformation and grouting to the rod body, and solves the problem of anchoring force failure after the tray and the surrounding rock surface are emptied.

[0005] In order to achieve the above object, the technical solution of the present invention is: a sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod, characterized in that it includes an anchoring agent, an inner rod body, a middle sleeve, a hydraulic expansion shell, a tray and a detachable propulsion rod;

[0006] The anchor, inner rod and hydraulic expansion shell are all located in the borehole;

[0007] The hydraulic expansion shell is formed by radially bending a steel pipe. The hydraulic expansion shell is sleeved on the outer periphery of the middle sleeve and both ends are welded to the middle sleeve. The water injection hole is arranged on the middle sleeve and is connected to the hydraulic expansion shell.

[0008] One end of the inner rod is fixed in the drill hole by an anchoring agent, and the other end is located in the middle sleeve;

[0009] One end of the detachable propulsion rod is arranged in the middle sleeve and docked with the conical structure, and the other end extends out of the middle sleeve;

[0010] One end of the middle sleeve is located in the drill hole, and the other end extends out of the drill hole and is fixed to the rock mass through a nut and a tray;

[0011] Grouting holes are provided on the inner rod body and the detachable propulsion rod;

[0012] The tapered structure is located at the end of the rod;

[0013] A through-hole structure is provided in the middle sleeve, and the through-hole structure includes a first through-hole structure, a second through-hole structure, and a third through-hole structure; the first through-hole structure, the second through-hole structure, and the third through-hole structure are connected in sequence; the inner diameter of the first through-hole structure is smaller than the inner diameter of the third through-hole structure; the second through-hole structure is an expanded diameter structure; the inner diameter of one end of the second through-hole structure is equal to the inner diameter of the first through-hole structure, and the inner diameter of the other end is equal to the inner diameter of the third through-hole structure;

[0014] A tapered structure is provided at the end of the inner rod body; the inner rod body is located in the first through-hole structure; the tapered structure is located in the second through-hole structure and the third through-hole structure;

[0015] The inner diameter of the first through-hole structure is greater than or equal to the outer diameter of the inner rod body and smaller than the outer diameter of the tapered structure; the outer diameter of the tapered structure is smaller than or equal to the inner diameter of the third through-hole structure.

[0016] In the above technical solution, the docking groove is provided on the conical structure;

[0017] One end of the detachable propulsion rod is located in the docking groove and docked with the inner rod body, and the other end extends out of the middle sleeve.

[0018] In the above technical solution, the hydraulic expansion shell is installed in the drilled hole after being compressed.

[0019] In the above technical solution, the hydraulic expansion shell is compressed into a flower shape or a wave shape and then installed in the drilled hole and sleeved on the outer periphery of the middle sleeve.

[0020] In the above technical solution, the damping pad is arranged between the tray and the rock mass and covers the drill hole;

[0021] The outer diameter of the damping washer is larger than the outer diameter of the drilled hole.

[0022] In the above technical solution, the grouting holes are arranged inside the inner rod body and the detachable propulsion rod.

[0023] In the above technical solution, the grouting holes include main grouting holes and branch grouting holes;

[0024] The main grouting hole is a through-hole structure;

[0025] One end of the grouting branch hole is communicated with the grouting main hole, and the other end is arranged on the outer wall of the inner rod body.

[0026] In the above technical solution, the main grouting hole passes through the inner rod body; the length of the main grouting hole is greater than the length of the inner rod body;

[0027] There are multiple grouting branch holes, and the multiple grouting branch holes are staggered.

[0028] The present invention has the following advantages:

[0029] The present invention provides anchoring force with an anchoring agent (that is, one end of the inner rod body is anchored in the drill hole by the anchoring agent), provides axial pre-tightening force of the rod body by means of a damping gasket, a tray and a nut, provides radial pre-tightening force of the rod body by means of a hydraulic expansion shell after water injection and expansion, realizes simultaneous application of axial and radial pre-tightening force on the rod body, provides friction force by the relative sliding of the inner rod body in the middle sleeve and expansion of the middle sleeve by the cone head, realizes the function of large deformation of the anchor rod structure; after the tray and the surrounding rock are emptied, the hydraulic expansion shell is tightly attached to the hole wall after expansion, and has a certain friction force, so that the rod body of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod still has axial pre-tightening force, realizes providing continuous support force to the surrounding rock; overcomes the shortcomings of the existing anchor rod in which the axial and radial prestress and large deformation of the rod body cannot be applied simultaneously, and solves the problem of anchoring force failure after the tray and the surrounding rock surface are emptied.

[0030] After the surrounding rock is deformed, the anchor rod structure in the present invention is elongated. During the elongation process, the inner rod body slides relative to the middle sleeve and the middle sleeve is expanded by the conical structure to provide friction. The anchor rod as a whole still has prestress, thereby providing continuous support force to the surrounding rock and achieving large deformation at the same time.

[0031] A large number of cracks will be generated during the large deformation of the surrounding rock. Grouting is carried out through the grouting holes to reinforce the surrounding rock and improve its integrity and bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the axial structure of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention.

[0033] Figure 2 This is a schematic diagram of the radial structure of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention.

[0034] Figure 3 It is an enlarged schematic diagram of the relative dislocation position of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention.

[0035] Figure 4This is a schematic diagram of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention before and after water injection and expansion.

[0036] Figure 5 This is a schematic diagram of the axial structure after water injection and expansion of the present invention.

[0037] Figure 6 This is a schematic diagram of the radial structure of the present invention after water injection and expansion.

[0038] Figure 7 It is a schematic diagram of the working structure of the present invention after major deformation.

[0039] Figure 8 This is a schematic diagram of the working structure of the present invention when the connection between the tray and the surrounding rock surface is empty.

[0040] Figure 9 It is a schematic diagram of the working structure when there are cracks in the surrounding rock and the connection between the tray of the present invention and the surface of the surrounding rock is empty.

[0041] exist Figure 4 In FIG. 1 , C represents the hydraulic expansion shell after compression and before deformation; D represents the hydraulic expansion shell after expansion and deformation.

[0042] exist Figure 8 In the figure, B represents the hollow part at the connection between the tray and the surrounding rock surface.

[0043] exist Figure 9 In the figure, A represents the crack; B represents the hollow part at the connection between the tray and the surrounding rock surface.

[0044] In the figure, 1-anchor, 2-inner rod, 2.1-conical structure, 2.2-docking groove, 3-drill hole, 4-middle sleeve, 4.1-first through-hole structure, 4.2-second through-hole structure, 4.3-third through-hole structure, 5-hydraulic expansion shell, 6-rock mass, 7-damping gasket, 8-nut, 9-water injection hole, 10-tray, 11-detachable push rod, 12-water, 13-grouting hole, 13.1-grouting main hole, 13.2-grouting branch hole. DETAILED DESCRIPTION

[0045] The following detailed description of the embodiments of the present invention is given in conjunction with the accompanying drawings, which do not limit the present invention but are merely examples. The description makes the advantages of the present invention clearer and easier to understand.

[0046] The existing publication number is CN113123817. A large deformation prestressed hydraulic expansion anchor rod is a patent application applied for by the applicant of this application on April 29, 2021. In subsequent research, the applicant found that the patent application with publication number CN113123817 fixes the anchor rod as a whole in the borehole through a nut during operation, which serves as an axial fixing force to prevent the anchor rod from falling out of the borehole; through the friction between the inner push head and the hydraulic expansion inner shell, and the deformation of the hydraulic expansion inner shell, the two provide axial fixing force at the same time; after water injection, the expansion of the hydraulic expansion outer shell, the deformation of the hydraulic expansion inner shell, and the pressure of the injected water are simultaneously applied to the inner wall of the borehole to provide radial fixing force; but the ends of the hydraulic expansion inner and outer shells are not bonded to the bottom of the borehole. When the tray is detached from the surrounding rock surface, when the tray and the nut fall off, the anchor rod and the nut have no fulcrum after the tray is detached from the surrounding rock surface, and the anchoring force fails. The present invention addresses the problem of anchoring failure after the tray and surrounding rock surface become detached, as previously mentioned in patent application CN113123817. The present invention secures the entire anchor rod within the borehole using a nut. The inner rod is bonded to the bottom of the hole with an adhesive, providing axial securing force to prevent the anchor rod from falling out of the hole. After water injection, the middle sleeve 4, under the action of the water, presses against the inner rod 2, providing axial securing force. After water injection, the hydraulic expansion shell 5 deforms and expands, exerting radial securing force on the inner wall of the borehole. When the tray and surrounding rock surface become detached, the anchoring agent and water force the inner rod 2, middle sleeve 4, and hydraulic expansion shell 5 into a single, integrated unit. Even if the nut 8 loosens, the integrated inner rod 2, middle sleeve 4, and hydraulic expansion shell 5 remain intact, maintaining axial and radial forces on the borehole. Furthermore, cracks generated during large deformation of the surrounding rock can be reinforced with grouting, improving the integrity and bearing capacity of the surrounding rock.

[0047] The present invention provides radial prestressing of the rod body to the drill hole through the radial expansion of the hydraulic expansion shell 5, and completes the application of axial prestressing of the rod body through the damping gasket 7, tray 10 and nut 8, thereby achieving axial and radial prestressing of the anchor rod body.

[0048] Referring to the accompanying drawings, it can be seen that: a sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod, comprising an anchoring agent 1, an inner rod body 2, a middle sleeve 4, a hydraulic expansion shell 5, a tray 10 and a detachable propulsion rod 11;

[0049] The anchoring agent 1, the inner rod 2 and the hydraulic expansion shell 5 are all located in the borehole 3;

[0050] The hydraulic expansion shell 5 is formed by radially bending a steel pipe to reduce its diameter. The hydraulic expansion shell 5 is sleeved on the outer periphery of the middle sleeve 4 and both ends are welded to the middle sleeve 4. The ends of the steel pipe are welded to the middle sleeve 4 to ensure airtightness.

[0051] The water injection hole 9 is arranged on the middle sleeve 4 and is connected to the hydraulic expansion shell 5; the water injection hole 9 is arranged inside the middle sleeve 4, and external water enters the hydraulic expansion shell 5 through the water injection hole 9;

[0052] Water is injected into the cavity of the hydraulic expansion shell 5 through the water injection hole 9 to expand the hydraulic expansion shell 5. Under the pressure of the water in the cavity of the hydraulic expansion shell 5, the outer shell of the hydraulic expansion shell 5 is tightly attached to the wall of the borehole 3, and the inner shell is tightly attached to the inner rod 2, thereby fixing one end of the inner rod 2 to the orifice end of the borehole 3. At the same time, before and after the surrounding rock is damaged, and when part of the tunnel is separated from the surrounding rock surface due to plate cracking, spalling and rock burst, the radial anchoring force is continuously provided;

[0053] One end of the inner rod 2 is fixed in the borehole 3 by the anchor 1, and the other end is located in the middle sleeve 4. The other end of the inner rod 2 is fixed to the bottom of the borehole 3 by the anchor 1, which continuously provides axial anchoring force before and after the surrounding rock is damaged, and when part of the roadway is separated from the surrounding rock surface due to plate cracking, spalling and rock burst.

[0054] One end of the detachable propulsion rod 11 is disposed in the middle sleeve 4 and docked with the conical structure 2.1, and the other end extends out of the middle sleeve 4;

[0055] One end of the middle sleeve 4 is located in the borehole 3, and the other end extends out of the borehole 3 and is fixed to the rock mass 6 through a nut 8 and a tray 10;

[0056] Grouting holes 13 are provided on the inner rod body 2 and the detachable propulsion rod 11;

[0057] The tapered structure 2.1 is located at the end of the rod body 2.1;

[0058] A through-hole structure is provided in the middle sleeve 4, and the through-hole structure includes a first through-hole structure 4.1, a second through-hole structure 4.2, and a third through-hole structure 4.3; the first through-hole structure 4.1, the second through-hole structure 4.2, and the third through-hole structure 4.3 are sequentially connected; the inner diameter of the first through-hole structure 4.1 is smaller than the inner diameter of the third through-hole structure 4.3; the second through-hole structure 4.2 is an expanded diameter structure; the inner diameter of one end of the second through-hole structure 4.2 is equal to the inner diameter of the first through-hole structure 4.1, and the inner diameter of the other end is equal to the inner diameter of the third through-hole structure 4.3;

[0059] A tapered structure 2.1 is provided at the end of the inner rod body 2; the inner rod body 2 is located in the first through-hole structure 4.1; the tapered structure 2.1 is located in the second through-hole structure 4.2 and the third through-hole structure 4.3;

[0060] The inner diameter of the first through-hole structure 4.1 is greater than or equal to the outer diameter of the inner rod 2 and smaller than the outer diameter of the conical structure 2.1; the outer diameter of the conical structure 2.1 is smaller than or equal to the inner diameter of the third through-hole structure 4.3.

[0061] Furthermore, the docking groove 2.2 is provided on the conical structure 2.1;

[0062] One end of the detachable propulsion rod 11 is located in the docking groove 2.2 and docked with the inner rod body 2, and the other end extends out of the middle sleeve 4. The inner rod body 2 is fixed to the bottom of the drill hole 3 through the detachable propulsion rod 11 and the anchoring agent 1.

[0063] Furthermore, the hydraulic expansion shell 5 is compressed and installed in the borehole 3. Water is injected 12 through the water injection port 9 to expand and deform the hydraulic expansion shell 5, and radial anchoring force is continuously applied before and after the tray is separated from the surrounding rock surface.

[0064] Furthermore, the hydraulic expansion shell 5 is compressed into a special shape (such as a flower shape or a wave shape, etc.) and then installed in the borehole 3 and sleeved on the outer periphery of the middle sleeve 4. The hydraulic expansion shell 5 has the function of large structural deformation. Due to the expansion and deformation of the hydraulic expansion shell, close contact with the hole wall and the presence of radial anchoring force of the rod body, when the tray is detached from the surrounding rock surface, the anchor rod still has a certain supporting effect on the surrounding rock. The hydraulic expansion shell 5 in the present invention is a round steel pipe before expansion, which is pressed into a special shape (such as a flower shape, a wave shape, etc., in order to reduce the size of the hydraulic expansion shell, thereby reducing the outer diameter of the whole formed by the hydraulic expansion shell 5, the middle sleeve 4 and the inner rod body 2). After compression, the size of the hydraulic expansion shell is reduced, making it easier to place in the borehole.

[0065] Furthermore, the inner rod body 2 is cylindrical; the conical structure 2.1 is a frustum-shaped structure;

[0066] One end of the middle sleeve 4 is cylindrical, and the other end is a frustum-shaped structure.

[0067] Furthermore, the damping pad 7 is arranged between the tray 10 and the rock mass 6 and covers the drill hole 3;

[0068] The outer diameter of the damping washer 7 is larger than the outer diameter of the bore 3 .

[0069] Furthermore, grouting holes 13 are provided inside the inner rod body 2 and the detachable propulsion rod 11. When necessary, the surrounding rock is reinforced by grouting. Grouting through the grouting holes has an inhibitory effect on cracking, spalling and rock burst of the surrounding rock plate.

[0070] Furthermore, the grouting hole 13 includes a main grouting hole 13.1 and a branch grouting hole 13.2;

[0071] The main grouting hole 13.1 is a through-hole structure; both ends of the main grouting hole 13.1 are flush with both ends of the rod body 3;

[0072] One end of the grouting branch hole 13.2 is connected to the grouting main hole 13.1, and the other end is set on the outer wall of the rod body 3. The grouting slurry flows into the borehole 2 through the grouting main hole 13.1 and the grouting branch hole 13.2 in sequence, reinforcing the surrounding rock and suppressing cracking, spalling and rock burst of the surrounding rock plate.

[0073] Furthermore, the main grouting hole 13.1 passes through the inner rod body 2; the length of the main grouting hole 13.1 is greater than the length of the inner rod body 2;

[0074] Multiple branch grouting holes 13.2 are arranged in a staggered pattern. The multiple branch grouting holes 13.2 are arranged on the main grouting hole 13.1 to improve grouting efficiency and cover the entire length of the borehole, enhancing the grouting effect. The grouting liquid flows sequentially through the main grouting holes 13.1 and the branch grouting holes 13.2 into the gap between the rod body 3 and the borehole and into the surrounding rock cracks, bonding the rod body 3 to the borehole.

[0075] The anchoring agent in the present invention is epoxy resin glue, which is used to bond the rod body and the displacement into one body.

[0076] The method for using the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention is characterized by comprising the following steps:

[0077] Step 1: Install the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod;

[0078] The inner rod body 2 is anchored in the rock mass 6 by the anchoring agent 1, and the middle sleeve 4 is fixed to the rock mass 6 by the damping gasket 7, the tray 10 and the nut 8, so as to realize the axial anchoring force application of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod body;

[0079] Water is injected through the water injection hole 9 to expand and deform the hydraulic expansion shell 5, increase its inner diameter, and cling to the hole wall of the borehole 3 (the water injection hole is set on the hole wall of the sleeve 4, and water is injected into the water injection hole by a high-pressure water injection pump, and the water enters the hydraulic expansion shell 5 to achieve the expansion of the hydraulic expansion shell 5), thereby achieving the application of radial anchoring force to the rod body of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod. At this point, the installation of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod is completed;

[0080] Step 2: Anchor support;

[0081] When the surrounding rock deforms, the inner rod body 2 slides relatively in the middle sleeve 4 and the conical structure 2.1 expands the middle sleeve 4 to provide friction, thus realizing the large deformation function of the sleeve expansion type prestressed hydraulic expansion grouting anchor structure (such as Figure 4 (as shown), to support the surrounding rock and improve its bearing capacity;

[0082] When the tray is detached from the surface of the surrounding rock, the inner rod body 2 is fixed in the borehole by the anchoring agent 1 to provide axial anchoring force, and the axial anchoring force is provided by the friction force generated by the relative movement and deformation of the inner rod body 2 and the middle sleeve 4; the radial anchoring force is provided by the expansion and deformation of the hydraulic expansion shell 5 and the close contact between the hydraulic expansion shell 5 and the wall of the borehole 3; at this time, the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod as a whole still has prestress, so as to provide continuous support force to the surrounding rock, and the surrounding rock continues to be supported by the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod.

[0083] exist Figure 4 This is the state before the hydraulic expansion shell 5 of the present invention expands. After the hydraulic expansion shell 5 expands, the sleeve 4 is expanded during the overall elongation process of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod. After expansion, the diameter of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod becomes larger.

[0084] When the surrounding rock cannot be prevented from plate cracking, spalling or rock bursting, resulting in the tray being detached from the surrounding rock surface, the present invention still has a certain supporting effect due to the close contact between the hydraulic expansion shell 5 and the hole wall and the existence of radial anchoring force of the rod body, as well as the existence of axial anchoring force (one end of the inner rod body 2 is fixed to the bottom end of the borehole 3 by the anchoring agent 1, and the axial anchoring force is continuously provided before and after the surrounding rock is damaged and when the tray is detached from the surrounding rock surface due to plate cracking, spalling and rock bursting in some tunnels). The purpose of the large deformation of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention is to adapt to the deformation of the surrounding rock while continuously providing anchoring force; it overcomes the defects of the existing anchor rods that cannot adapt to the deformation of the surrounding rock and will be broken during the deformation of the surrounding rock, making it unable to play a supporting role.

[0085] Furthermore, in step 2, grouting is performed to reinforce the surrounding rock as needed. The grouting liquid flows into the gap between the inner rod body 2 and the drill hole 3 through the grouting main hole 13.1 and the grouting branch hole 13.2 in sequence, bonding the inner rod body 2 and the drill hole 3, and at the same time sealing the cracks that will be generated during the large deformation of the surrounding rock, thereby reinforcing the surrounding rock and improving the integrity and bearing capacity of the surrounding rock.

[0086] In order to more clearly illustrate the advantages of the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor rod described in the present invention compared with the existing technology, the staff compared the two technical solutions, and the comparison results are shown in the following table:

[0087]

[0088] It can be seen from the above table that, compared with the prior art, the sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor described in the present invention provides pre-tightening force through the friction between the hydraulic expansion shell and the borehole wall. It can still provide three-dimensional stress to the surrounding rock after the surrounding rock and the tray are emptied, and grouting can be performed to reinforce the surrounding rock at the same time. It has strong applicability and is not only suitable for general rock mass surrounding rock support, but can also provide support when the surrounding rock and the tray are emptied.

[0089] Other parts not described belong to the prior art.

Claims

1. A sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor, characterized by: It comprises an anchoring agent (1), an inner rod body (2), a middle sleeve (4), a hydraulic expansion shell (5), a tray (10) and a detachable propulsion rod (11); The anchoring agent (1), the inner rod (2) and the hydraulic expansion shell (5) are all located in the borehole (3); The hydraulic expansion shell (5) is formed by radially bending a steel pipe; the hydraulic expansion shell (5) is sleeved on the outer periphery of the middle sleeve (4), and both ends are welded to the middle sleeve (4); the water injection hole (9) is arranged on the middle sleeve (4) and is connected to the hydraulic expansion shell (5); One end of the inner rod body (2) is fixed in the borehole (3) through an anchoring agent (1), and the other end is located in the middle sleeve (4); One end of the detachable propulsion rod (11) is arranged in the middle sleeve (4) and docked with the conical structure (2.1), and the other end extends out of the middle sleeve (4); One end of the middle sleeve (4) is located in the borehole (3), and the other end extends out of the borehole (3) and is fixed to the rock mass (6) through a nut (8) and a tray (10); Grouting holes (13) are provided on the inner rod body (2) and the detachable propulsion rod (11); The conical structure (2.1) is located at the end of the rod body (2.1); A through-hole structure is provided in the middle sleeve (4), and the through-hole structure comprises a first through-hole structure (4.1), a second through-hole structure (4.2), and a third through-hole structure (4.3); the first through-hole structure (4.1), the second through-hole structure (4.2), and the third through-hole structure (4.3) are connected in sequence; the inner diameter of the first through-hole structure (4.1) is smaller than the inner diameter of the third through-hole structure (4.3); the second through-hole structure (4.2) is an expanded diameter structure; the inner diameter of one end of the second through-hole structure (4.2) is equal to the inner diameter of the first through-hole structure (4.1), and the inner diameter of the other end is equal to the inner diameter of the third through-hole structure (4.3); A conical structure (2.1) is provided at the end of the inner rod body (2); the inner rod body (2) is located in the first through-hole structure (4.1); the conical structure (2.1) is located in the second through-hole structure (4.2) and the third through-hole structure (4.3); The inner diameter of the first through-hole structure (4.1) is greater than or equal to the outer diameter of the inner rod body (2) and smaller than the outer diameter of the tapered structure (2.1); the outer diameter of the tapered structure (2.1) is smaller than or equal to the inner diameter of the third through-hole structure (4.3); The docking groove (2.2) is arranged on the conical structure (2.1); One end of the detachable propulsion rod (11) is located in the docking groove (2.2) and docked with the inner rod body (2), and the other end extends out of the middle sleeve (4); The hydraulic expansion shell (5) is compressed and installed in the drill hole (3); The hydraulic expansion shell (5) is compressed into a flower shape or a corrugated shape and then installed in the drill hole (3) and sleeved on the outer periphery of the middle sleeve (4); The grouting hole (13) is provided inside the inner rod body (2) and the detachable propulsion rod (11); The grouting holes (13) include a main grouting hole (13.1) and a branch grouting hole (13.2).

2. The sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor according to claim 1 is characterized in that: The main grouting hole (13.1) is a through-hole structure; One end of the grouting branch hole (13.2) is connected to the grouting main hole (13.1), and the other end is arranged on the outer wall of the inner rod body (2).

3. The sleeve expansion type large deformation prestressed hydraulic expansion grouting anchor according to claim 2 is characterized in that: The main grouting hole (13.1) passes through the inner rod body (2); the length of the main grouting hole (13.1) is greater than the length of the inner rod body (2); There are a plurality of grouting branch holes (13.2), and the plurality of grouting branch holes (13.2) are arranged in a staggered manner.

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