A rod cutting type large deformation prestressed hydraulic expansion grouting anchor

Abstract

The present invention discloses a rod cutting 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, and a tray; the inner rod body is a grouting anchor rod; the hydraulic expansion shell is formed by radial bending of a steel pipe; an anchoring agent is arranged at one end of the inner rod body, and the other end is located in the middle sleeve; a rib is arranged on the inner rod body; both ends of the hydraulic expansion shell are welded to the middle sleeve; a water injection hole is arranged on the middle sleeve; the anchoring agent and the hydraulic expansion shell are both located in a borehole; one end of the inner rod body and 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, convenient use, simultaneous application of axial and radial prestressing of 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 rod cutting 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 tray being detached from 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 with ordinary bonded anchors. By applying active prestress, it is beneficial to improve the stress state of the rock mass, relieve 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, provide a certain support confining pressure to the surrounding rock, and then effectively inhibit the destruction 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, due to plate cracking, spalling and rock burst in some roadways, the tray and the surrounding rock surface are detached, resulting in the loss of prestress of the anchor, causing the anchor 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 rod-cutting 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 prestress, large deformation and grouting to the rod body, and has a wide range of applications; after the tray and the surrounding rock are emptied, the hydraulic expansion shell is expanded and tightly attached to the hole wall, which has a certain friction force, so that the axial direction of the rod body of the rod-cutting large deformation prestressed hydraulic expansion grouting anchor rod still has a pretightening force, thereby providing continuous supporting force to the surrounding rock; the disadvantage of the existing anchor rods that cannot apply axial and radial prestress, large deformation and grouting to the rod body at the same time is overcome, and the problem of anchoring force failure after the tray and the surrounding rock surface are emptied is solved.

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

[0006] The anchor and hydraulic expansion shell are both located in the borehole;

[0007] One end of the middle sleeve is located in the borehole, and the other end extends out of the borehole and is fixed to the rock mass through a nut and a tray;

[0008] The inner rod body is a grouting anchor rod;

[0009] One end of the inner rod body is fixed to the bottom of the drilled hole by an anchor, and the other end passes through the middle sleeve; a rib is arranged on the inner rod body; and the rib is located in the middle sleeve;

[0010] The hydraulic expansion shell is formed by radially bending a steel pipe; the hydraulic expansion shell is located in the drilled hole; the hydraulic expansion shell is sleeved on the outer periphery of the middle sleeve, and both ends of the hydraulic expansion shell are welded to the middle sleeve;

[0011] The water injection hole is arranged on the middle sleeve and is communicated with the hydraulic expansion shell;

[0012] A through hole structure is arranged inside the middle sleeve; the through hole structure comprises 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 third through hole structure is larger than the inner diameter of the first 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;

[0013] The inner rod body is located in the first through-hole structure; the ribs are located in the second through-hole structure and the third through-hole structure; 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 ribs;

[0014] The outer diameter of the rib is smaller than the inner diameter of the second through hole structure and smaller than the inner diameter of the third through hole structure.

[0015] In the above technical solution, the hydraulic expansion shell is installed in the drilled hole after being compressed.

[0016] 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.

[0017] In the above technical solution, the damping pad is arranged between the tray and the rock mass and covers the drill hole;

[0018] The outer diameter of the damping spacer is larger than the outer diameter of the drilled hole.

[0019] In the above technical solution, the grouting hole is arranged inside the inner rod body.

[0020] In the above technical solution, the grouting holes include a main grouting hole and a branch grouting hole;

[0021] The main grouting hole is a through-hole structure;

[0022] The main grouting hole is arranged inside the inner rod body;

[0023] One end of the grouting branch hole is connected with the grouting main hole, and the other end is arranged on the outer wall of the inner rod body.

[0024] In the above technical solution, the main grouting hole passes through the inner rod body; the length of the main grouting hole is equal to the length of the inner rod body;

[0025] There are multiple grouting branch holes, and the multiple grouting branch holes are arranged in a staggered manner.

[0026] The present invention has the following advantages:

[0027] (1) The present invention provides anchoring force with an anchoring agent (i.e., one end of the inner rod body is anchored in the borehole with the anchoring agent), provides axial pre-tightening force for the rod body with a damping gasket, a tray and a nut, and provides radial pre-tightening force for the rod body with a hydraulic expansion shell after water injection and expansion, thereby realizing simultaneous axial and radial pre-tightening force on the rod body, and realizing large deformation function of the anchor rod structure through relative sliding of the middle sleeve and the inner rod body and cutting of the ribs on the inner rod body; after the tray is emptied from the surrounding rock, 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 rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod still has axial pre-tightening force, thereby realizing continuous support force for the surrounding rock; the disadvantages of the existing anchor rod that cannot simultaneously apply axial and radial pre-stress and large deformation to the rod body are overcome, and the problem of anchoring force failure after the tray is emptied from the surrounding rock surface is solved;

[0028] (2) After the surrounding rock is deformed, the anchor rod structure of the present invention is elongated, and during the elongation process, the ribs are cut off by the middle sleeve; during the cutting process, the anchor rod as a whole still has prestress, providing continuous support force to the surrounding rock, while achieving large deformation;

[0029] (3) During the large deformation of the surrounding rock, a large number of cracks will be generated. 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

[0030] Figure 1 It is a schematic diagram of the axial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention before water injection and expansion.

[0031] Figure 2 It is a schematic diagram of the radial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention before water injection and expansion.

[0032] Figure 3 It is a schematic diagram of the connection structure of the middle sleeve, ribs, inner rod body and hydraulic expansion shell in the present invention.

[0033] Figure 4 It is a schematic diagram of the axial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention after being expanded and deformed greatly by water injection.

[0034] Figure 5 It is a schematic diagram of the radial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention after large deformation due to water injection expansion.

[0035] Figure 6 It is a schematic diagram of the axial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod after water injection expansion and large deformation when the surrounding rock surface is hollowed out.

[0036] Figure 7 It is a schematic diagram of the axial structure of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod after water injection expansion and large deformation when there are cracks on the surrounding rock surface and it is hollow.

[0037] exist Figure 6 In the figure, B indicates that the surrounding rock surface is hollow.

[0038] exist Figure 7 In the figure, A represents cracks; B represents hollowing out of the surrounding rock surface.

[0039] In the figure, 1-anchor, 2-inner rod, 3-drilled hole, 4-middle sleeve, 4.1-through hole structure, 4.11-first through hole structure, 4.12-second through hole structure, 4.13-third through hole structure, 5-hydraulic expansion shell, 6-rock mass, 7-damping gasket, 8-nut, 9-water injection hole, 10-tray, 11-rib, 12-water, 13-grouting hole, 13.1-grouting main hole, 13.2-grouting branch hole. DETAILED DESCRIPTION

[0040] The following is a detailed description of the implementation of the present invention in conjunction with the accompanying drawings, but they do not constitute a limitation of the present invention and are only given as examples. At the same time, the advantages of the present invention are made clearer and easier to understand through the description.

[0041] The existing publication number is CN113123817. A large deformation prestressed hydraulic expansion anchor 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 as a whole in the borehole through a nut during operation, which serves as an axial fixing force to prevent the anchor 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 all applied to the inner wall of the borehole at the same time 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 and the nut have no fulcrum after the tray is detached from the surrounding rock surface, and the anchoring force fails. The present invention is to solve the problem of anchoring force failure after the tray and the surrounding rock surface are emptied in the patent application with publication number CN113123817. The present invention fixes the anchor rod as a whole in the borehole through a nut, and at the same time, the inner rod is bonded to the bottom of the hole through an adhesive as an axial fixing force to prevent the anchor rod from falling out of the borehole; after water injection, under the action of water, the middle sleeve 4 is close to the inner rod body 2 to provide an axial fixing force; after water injection, the hydraulic expansion shell 5 is deformed and expanded to be applied to the inner wall of the borehole to provide a radial fixing force. When the tray and the surrounding rock surface are emptied, under the action of the anchor and water, the inner rod body 2, the middle sleeve 4, the hydraulic expansion shell 5 and the borehole form a whole. Even if the nut 8 is loose, the inner rod body 2, the middle sleeve 4, and the hydraulic expansion shell 5 as a whole will not loosen, and still have axial and radial forces on the borehole. At the same time, the cracks generated during the large deformation of the surrounding rock can be grouting reinforced to improve the integrity and bearing capacity of the surrounding rock.

[0042] Referring to the attached drawings, it can be seen that: a rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod comprises an anchoring agent 1, an inner rod body 2, a middle sleeve 4, a hydraulic expansion shell 5 and a tray 10;

[0043] The anchoring agent 1 and the hydraulic expansion shell 5 are both located in the borehole 3;

[0044] 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 on the rock mass 6 through the nut 8 and the tray 10; the axial prestress of the rod body is applied through the tray 10 and the nut 8, and the axial and radial prestress of the anchor rod body is applied at the same time;

[0045] The inner rod body 2 is a grouting anchor rod;

[0046] One end of the inner rod body 2 is fixed to the bottom of the borehole 3 by means of an anchor 1, and the other end passes through the middle sleeve 4; a rib 11 is arranged on the inner rod body 2; the rib 11 is located in the middle sleeve 4; one end of the inner rod body 2 is fixed to the bottom of the borehole 3 by means of the anchor 1, and an 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 burst in some tunnels;

[0047] The hydraulic expansion shell 5 is formed by radially bending a steel pipe, the purpose of which is to reduce the diameter of the hydraulic expansion shell 5; 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 two ends of the steel pipe of the hydraulic expansion shell 5 are welded to the middle sleeve 4 to ensure air tightness; due to the radial expansion of the hydraulic expansion shell 5, the radial prestress of the rod body is applied to the drill hole;

[0048] 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 the external water 12 enters the hydraulic expansion shell 5 through the water injection hole 9;

[0049] 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 12 in the cavity of the hydraulic expansion shell 5, the outer shell of the hydraulic expansion shell 5 is closely attached to the wall of the borehole, and the inner shell is closely attached to the inner rod body 2, so that the other end of the inner rod body 2 is fixed to the hole end of the borehole 3. At the same time, before and after the surrounding rock is damaged and when part of the tunnel is detached from the surrounding rock surface due to plate cracking, spalling and rock burst, the radial anchoring force is continuously provided;

[0050] A through hole structure 4.1 is arranged inside the middle sleeve 4; the through hole structure 4.1 comprises a first through hole structure 4.11, a second through hole structure 4.12 and a third through hole structure 4.13; the first through hole structure 4.11, the second through hole structure 4.12 and the third through hole structure 4.13 are connected in sequence; the inner diameter of the third through hole structure 4.13 is larger than the inner diameter of the first through hole structure 4.11; the second through hole structure 4.12 is an expanded diameter structure; the inner diameter of one end of the second through hole structure 4.12 is equal to the inner diameter of the first through hole structure 4.11, and the inner diameter of the other end is equal to the inner diameter of the third through hole structure 4.13;

[0051] The inner rod body 2 is located in the first through hole structure 4.11; the rib 11 is located in the second through hole structure 4.12 and the third through hole structure 4.13; the inner diameter of the first through hole structure 4.11 is greater than or equal to the outer diameter of the inner rod body 2 and smaller than the outer diameter of the rib 11;

[0052] The outer diameter of the rib 11 is smaller than the inner diameter of the second through hole structure 4.12 and smaller than the inner diameter of the third through hole structure 4.13.

[0053] 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 emptied from the surrounding rock surface.

[0054] Furthermore, the hydraulic expansion shell 5 is compressed into a special shape (such as a flower shape, 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 is a round steel pipe before expansion. The purpose of compressing it into a special shape (such as a flower shape, a wave shape, etc.) is to reduce the diameter and facilitate placement into the borehole.

[0055] Further, the damping pad 7 is arranged between the tray 10 and the rock mass 6 and covers the borehole 3;

[0056] The outer diameter of the damping washer 7 is larger than the outer diameter of the borehole 3; the axial prestress of the rod body is applied through the damping washer 7, the tray 10 and the nut 8, and the axial and radial prestress of the anchor rod body is applied at the same time.

[0057] Furthermore, the grouting hole 13 is arranged inside the inner rod body 2 .

[0058] Further, the grouting hole 13 includes a main grouting hole 13.1 and a branch grouting hole 13.2;

[0059] The main grouting hole 13.1 is a through-hole structure; the main grouting hole 13.1 is arranged inside the inner rod body 2, and when necessary, the surrounding rock is reinforced by grouting, and the grouting through the grouting hole has an inhibitory effect on the cracking, spalling and rock burst of the surrounding rock plate;

[0060] The two ends of the grouting main hole 13.1 are flush with the two ends of the inner rod body 2 respectively;

[0061] 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. The grouting slurry flows into the borehole 2 through the grouting main hole 13.1 and the grouting branch hole 13.2 in sequence, so as to reinforce the surrounding rock and inhibit cracking, spalling and rock burst of the surrounding rock plate.

[0062] Furthermore, the main grouting hole 13.1 passes through the inner rod body 2; the length of the main grouting hole 13.1 is equal to the length of the inner rod body 2;

[0063] There are multiple grouting branch holes 13.2, which are arranged in a staggered manner to improve grouting efficiency and cover the entire borehole, thereby improving grouting effect. The grouting liquid flows into the gap between the inner rod body 2 and the borehole and the surrounding rock cracks through the grouting main hole 13.1 and the grouting branch holes 13.2 in sequence, and bonds the inner rod body 2 to the borehole.

[0064] The anchoring agent in the present invention is epoxy resin glue, which is used to bond the bonding rod body and the surrounding rock into one body.

[0065] The method for using the rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod of the present invention comprises the following steps:

[0066] Step 1: Install the rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod;

[0067] The inner rod body 2 is anchored in the rock mass 6 by the anchoring agent 1, and the middle sleeve 4 is fixed on the rock mass 6 by the damping gasket 7, the tray 10 and the nut 8, so as to realize the application of the axial anchoring force of the rod body of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod;

[0068] Water is injected 12 through the water injection port 9 to expand and deform the hydraulic expansion shell 5, increase its outer diameter, and cling to the hole wall of the borehole 3 (the water injection hole is on the hole wall of the middle sleeve 4, and water 12 is injected into the water injection hole by a high-pressure water injection pump, and the water 12 enters the hydraulic expansion shell 5 to achieve the expansion of the hydraulic expansion shell 5), so as to achieve the application of the radial anchoring force of the rod body of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod; at this point, the installation of the anchor rod is completed;

[0069] Step 2: Anchor support;

[0070] When the surrounding rock is deformed, the middle sleeve 4 and the inner rod body 2 slide relative to each other and cut the ribs 11 on the inner rod body, thus achieving the function of large deformation of the anchor structure.

[0071] When the tray is detached from the surface of the surrounding rock, the inner rod body 2 is fixed in the borehole by the anchor 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 anchor rod still has prestress as a whole, so as to provide continuous support force to the surrounding rock, and the surrounding rock is continued to be supported by the sleeve expansion type large deformation prestressed hydraulic expansion anchor rod.

[0072] like Figure 4 As shown, Figure 4 This is the state before cutting. Before cutting, there are many ribs 11. The rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod as a whole stretches as the surrounding rock deforms. During the overall elongation of the anchor rod, the ribs 11 on the inner rod body are cut off one by one. After cutting, the ribs of the rod body cutting type large deformation prestressed hydraulic expansion grouting anchor rod are reduced, and other structures remain unchanged. While the ribs 11 on the inner rod body are cut off (i.e., the present invention is deformed), the present invention adapts to the deformation of the surrounding rock and continues to provide anchoring force. The large deformation of the structure of the present invention is to adapt to the deformation of the surrounding rock and continue to provide anchoring force; it overcomes the shortcomings of the anchor rods in the prior art that cannot adapt to the deformation of the surrounding rock, the anchor rods are broken as the surrounding rock deforms, and cannot play a supporting role.

[0073] 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 anchor rod described in 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 of the borehole 3 by the anchoring agent layer 1, and the axial anchoring force is continuously provided before and after the surrounding rock is destroyed and when the tray is detached from the surrounding rock surface due to plate cracking, spalling and rock bursting in some tunnels).

[0074] Furthermore, in step 2, grouting is performed as needed to reinforce the surrounding rock. The grouting slurry flows into the gap between the inner rod body 2 and the borehole through the grouting main hole 13.1 and the grouting branch hole 13.2 in sequence, bonding the inner rod body 2 to the wall of the borehole 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. When the tray is emptied from the surface of the surrounding rock, due to the close contact between the hydraulic expansion shell 5 and the wall of the borehole 3 and the existence of the radial anchoring force of the rod body, the anchor rod still has a certain supporting effect, and the surrounding rock continues to be supported by the anchor rod.

[0075] In order to more clearly illustrate the advantages of the rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod described in the present invention compared with the prior art, the staff compared the two technical solutions, and the comparison results are shown in the following table:

[0076]

[0077] It can be seen from the above table that, compared with the prior art, the rod-cutting large-deformation prestressed hydraulic expansion grouting anchor described in the present invention provides preload 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.

[0078] Other parts not described belong to the prior art.

Claims

1. A rod cutting type large deformation prestressed hydraulic expansion grouting anchor, characterized in that: It comprises an anchoring agent (1), an inner rod body (2), a middle sleeve (4), a hydraulic expansion shell (5) and a tray (10); The anchoring agent (1) and the hydraulic expansion shell (5) are both located in the borehole (3); One end of the middle sleeve (4) is located in the borehole (3), and the other end thereof extends out of the borehole (3) and is fixed on the rock mass (6) through a nut (8) and a tray (10); The inner rod body (2) is a grouting anchor rod; One end of the inner rod body (2) is fixed to the bottom of the borehole (3) through an anchor (1), and the other end passes through the middle sleeve (4); a rib (11) is provided on the inner rod body (2); and the rib (11) is located inside the middle sleeve (4); The hydraulic expansion shell (5) is formed by radially bending a steel pipe; the hydraulic expansion shell (5) is located in the borehole (3); the hydraulic expansion shell (5) is sleeved on the outer periphery of the middle sleeve (4), and both ends of the hydraulic expansion shell (5) 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); A through hole structure (4.1) is arranged inside the middle sleeve (4); the through hole structure (4.1) comprises a first through hole structure (4.11), a second through hole structure (4.12) and a third through hole structure (4.13); the first through hole structure (4.11), the second through hole structure (4.12) and the third through hole structure (4.13) are connected in sequence; the inner diameter of the third through hole structure (4.13) is larger than the inner diameter of the first through hole structure (4.11); the second through hole structure (4.12) is an expanded diameter structure; the inner diameter of one end of the second through hole structure (4.12) is equal to the inner diameter of the first through hole structure (4.11), and the inner diameter of the other end is equal to the inner diameter of the third through hole structure (4.13); The inner rod body (2) is located in the first through-hole structure (4.11); the rib (11) is located in the second through-hole structure (4.12) and the third through-hole structure (4.13); the inner diameter of the first through-hole structure (4.11) is greater than or equal to the outer diameter of the inner rod body (2) and smaller than the outer diameter of the rib (11); The outer diameter of the rib (11) is smaller than the inner diameter of the second through hole structure (4.12); The hydraulic expansion shell (5) is compressed into a flower shape or a wave shape and then installed in the drill hole (3) and sleeved on the outer circumference of the middle sleeve (4); The damping pad (7) is arranged between the tray (10) and the rock mass (6) and covers the drill hole (3).

2. The rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod according to claim 1 is characterized in that: The grouting hole (13) is arranged inside the inner rod body (2).

3. The rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod according to claim 2 is characterized in that: The grouting holes (13) include a main grouting hole (13.1) and a branch grouting hole (13.2); The main grouting hole (13.1) is a through hole structure; The main grouting hole (13.1) is arranged inside the inner rod body (2); 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).

4. The rod cutting type large deformation prestressed hydraulic expansion grouting anchor rod according to claim 3 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 equal to 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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