Hollow grouting bolt structure and grouting method

Abstract

The present invention provides a hollow grouting bolt structure and a grouting method. The hollow grouting bolt structure includes: a rod body, the center of the rod body has a grouting hole, and the side wall of the rod body has multiple groups of limiting structures, and the multiple groups of limiting structures are arranged at intervals along the axial direction of the rod body; a stop sleeve, the stop sleeve is arranged on the inner wall of the grouting hole, the stop sleeve has multiple groups of communication hole groups, and the multiple groups of communication hole groups and the multiple groups of limiting structures are arranged in one-to-one correspondence, and the grouting hole is communicated with the limiting structure through the communication hole group; multiple groups of strengthening structures, the strengthening structures are movably arranged in the limiting structures, and at least a part of the strengthening structures penetrates out of the limiting structures, and the multiple groups of strengthening structures and the multiple groups of limiting structures are arranged in one-to-one correspondence, and both ends of the strengthening structures are respectively in stop cooperation with the stop sleeve and the limiting structure in two directions in the radial direction of the rod body, and the strengthening structures are used for penetrating into the inner wall of the drilling hole. Through this technical solution, the problem that the hollow grouting bolt structure in the prior art is prone to slipping can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal mine roadway support, and more specifically, to a hollow grouting bolt structure and a grouting method. Background Art

[0002] With the increase in the depth and intensity of coal resource mining, geological conditions, the properties of coal and rock masses, mining layouts, etc. have become more complex. Subsequently, the phenomenon of large roadway deformation has become more obvious, and roadway support work has become extremely important. As a commonly used device in support engineering, bolts connect broken rock blocks into a whole, enabling the broken rock mass to be in a stable and safe state. They have the advantages of low cost, good support effect, simple operation, flexible use, and less occupation of construction clearance. However, problems such as "bolt deviation", "bolt pull-out", and "inadequate grouting" seriously affect the anchoring effect in coal and rock roadways.

[0003] In the prior art, there has been a relatively systematic study on the design and construction method of hollow bolts, but there are still deficiencies in the following aspects: 1. Although the rod body of the existing grouting bolt uses a spiral structure, which increases the friction with the hole wall, with the influence of factors such as mining disturbance and overlying pressure, the surrounding rock of the roadway will deform, and it is extremely easy to cause the pull-out or sliding of the roof bolts; 2. The existing grouting method of grouting bolts is not conducive to the filling of the surrounding rock fissures, especially for some broken soft rock roadways. The construction method of grouting bolts is to grout into the gap between the bolt and the borehole after the bolt is installed in place, so that the grout fills into the surrounding rock fissures, thereby achieving the purpose of improving the strength of the surrounding rock. However, in actual roadway support work, the "from outside to inside" grouting method requires extremely high grouting pressure on the grouting pump. Excessive pressure will cause spraying and overflowing of the grout, while too low pressure cannot completely fill the fissures. Moreover, the grouting channel is extremely easy to be blocked by the crushed stones in the borehole, resulting in the interruption of the grouting process and unable to ensure the complete filling of the surrounding rock fissures. Summary of the Invention

[0004] The present invention provides a hollow grouting bolt structure and a grouting method to solve the problem that the existing hollow grouting bolt structure is prone to sliding.

[0005] In order to solve the above problems, according to one aspect of the present invention, there is provided a hollow grouting anchor structure, comprising: a rod body, a grouting hole is provided at the center of the rod body, a side wall of the rod body has a plurality of limiting structures, and the plurality of limiting structures are arranged at intervals along the axial direction of the rod body; a stop sleeve, the stop sleeve is arranged on the inner wall of the grouting hole, the stop sleeve has a plurality of connecting hole groups, the plurality of connecting hole groups and the plurality of limiting structures are arranged in one-to-one correspondence, and the grouting hole is connected with the limiting structure through the connecting hole groups; a plurality of reinforcing structures, the reinforcing structure is movably arranged in the limiting structure, and at least a part of the reinforcing structure passes through the limiting structure, the plurality of reinforcing structures and the plurality of limiting structures are arranged in one-to-one correspondence, and the two ends of the reinforcing structure are respectively cooperated with the stop sleeve and the limiting structure in two radial directions of the rod body, and the reinforcing structure is used to penetrate into the inner wall of the drilled hole.

[0006] Furthermore, the limiting structure includes a plurality of limiting holes distributed along the circumference of the rod body, the connecting hole group includes a plurality of sub-through holes, the reinforcing structure includes a plurality of reinforcing cones, the reinforcing cones are movably arranged in the limiting holes, the grouting holes are connected with the limiting holes through the sub-through holes, the end face of the reinforcing cone facing the grouting hole and the outer wall stopper of the stop sleeve are matched, the side wall of the reinforcing cone and the inner wall stopper of the limiting hole are matched, and the end of the reinforcing cone away from the grouting hole passes through the limiting hole, the plurality of limiting holes and the plurality of sub-through holes are arranged in a one-to-one correspondence, and the plurality of reinforcing cones and the plurality of limiting holes are arranged in a one-to-one correspondence.

[0007] Furthermore, the reinforcing cone is a cone, and the limiting hole has a first opening and a second opening which are interconnected, the aperture of the first opening is smaller than the aperture of the second opening, the aperture of the sub-through hole is smaller than the aperture of the second opening, the aperture of the sub-through hole is larger than the diameter of the bottom surface of the cone, the aperture of the first opening is smaller than the diameter of the bottom surface of the cone, and the end of the cone with a smaller diameter passes through the first opening.

[0008] Furthermore, along the circumference of the rod body, the angle between any two adjacent limiting holes is 90°.

[0009] Furthermore, the outer diameter of the rod body is 25-32 mm, and the diameter of the grouting hole is 10-15 mm.

[0010] Furthermore, the hollow grouting anchor structure also includes an anchor head and a grouting plug, wherein the anchor head is connected to one end of the rod body, and the grouting plug is sleeved on the other end of the rod body, and the grouting plug is used to seal the gap formed between the rod body and the inner wall of the borehole.

[0011] Furthermore, the hollow grouting anchor structure also includes an anchor tray and a nut. The anchor tray is sleeved on the other end of the rod body, the anchor tray abuts against the grouting plug, and the nut is connected to the threaded part on the outer wall of the rod body to fix the anchor tray.

[0012] Further, the reinforcement structure is made of steel material.

[0013] According to another aspect of the present invention, a grouting method is provided. The grouting method is applied to the above hollow grouting bolt structure and includes:

[0014] Drill a hole in the surrounding rock and clean the hole;

[0015] Insert the rod body in the hollow grouting bolt structure into the hole, and block the gap formed between the rod body and the inner wall of the hole through the grout plug in the hollow grouting bolt structure;

[0016] Insert the grouting pipe into the grouting hole in the hollow grouting bolt structure, and grout between the rod body and the inner wall of the hole, with the grouting pressure being P1;

[0017] After the grout fills the gap between the rod body and the inner wall of the hole, grout into the grouting hole through the grouting pipe, with the grouting pressure being P2, P2 > P1. The strengthening structure in the hollow grouting bolt structure is pressed out, and one end of the strengthening structure penetrates into the inner wall of the hole;

[0018] After the grout fills the grouting hole, stop grouting and block the grouting hole;

[0019] Install the bolt tray and nut in the hollow grouting bolt structure.

[0020] Furthermore, it includes: before inserting the rod body into the hole, bond the side wall of the strengthening structure to the inner wall of the limiting hole in the hollow grouting bolt structure.

[0021] By applying the technical solution of the present invention, a hollow grouting anchor structure is provided, comprising: a rod body, a grouting hole is provided at the center of the rod body, a side wall of the rod body has a plurality of limiting structures, the plurality of limiting structures are arranged at intervals along the axial direction of the rod body; a stop sleeve, the stop sleeve is arranged on the inner wall of the grouting hole, the stop sleeve has a plurality of connecting hole groups, the plurality of connecting hole groups and the plurality of limiting structures are arranged in one-to-one correspondence, and the grouting hole is connected with the limiting structure through the connecting hole groups; a plurality of reinforcing structures, the reinforcing structures are movably arranged in the limiting structures, and at least a part of the reinforcing structures passes through the limiting structures, the plurality of reinforcing structures and the plurality of limiting structures are arranged in one-to-one correspondence, the two ends of the reinforcing structures are respectively stopped and cooperated with the stop sleeve and the limiting structure in two radial directions of the rod body, and the reinforcing structures are used to penetrate into the inner wall of the drilled hole. With this solution, the two ends of the reinforcing structure are respectively matched with the stop sleeve and the limit structure in the two radial directions of the rod body, so that it can not only ensure that the reinforcing structure will not fall into the grouting hole, but also ensure that when grouting into the grouting hole, the reinforcing structure will not be separated from the limit structure and can penetrate into the inner wall of the borehole, thereby strengthening the connection strength between the rod body and the borehole, and effectively solving the problem that the hollow grouting anchor structure in the prior art is prone to slipping. Multiple groups of limit structures, multiple groups of connecting hole groups and multiple groups of reinforcing structures are set, and the multiple groups of connecting hole groups and the multiple groups of limit structures are set one by one, and the multiple groups of reinforcing structures and the multiple groups of limit structures are set one by one, so as to further enhance the connection strength between the rod body and the borehole. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 A cross-sectional view of a hollow grouting anchor structure provided by an embodiment of the present invention is shown;

[0024] Figure 2 Shows Figure 1 A partial enlarged view of the middle A;

[0025] Figure 3 Shows Figure 1 Top view of the hollow grouting anchor structure;

[0026] Figure 4 Shows Figure 1 Cross-sectional view of the hollow grouting anchor structure after grouting;

[0027] Figure 5 Shows Figure 4 Top view of the hollow grouting anchor structure after grouting is completed.

[0028] The above drawings include the following reference numerals:

[0029] 10. Rod body; 11. Grouting hole; 12. Limiting structure; 121. Limiting hole;

[0030] 20. Stop sleeve; 21. Communication hole group; 211. Sub-communication hole;

[0031] 30. Reinforcing structure; 31. Reinforcing cone;

[0032] 40. Anchor head;

[0033] 50. Grout plug;

[0034] 60. Anchor bolt tray;

[0035] 70. Nut;

[0036] 80. Borehole. Detailed implementation manner

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0038] As Figures 1 to 5 shown, the embodiment of the present invention provides a hollow grouting anchor bolt structure, including: a rod body 10, the center of the rod body 10 has a grouting hole 11, the side wall of the rod body 10 has multiple groups of limiting structures 12, and the multiple groups of limiting structures 12 are arranged at intervals along the axial direction of the rod body 10; a stop sleeve 20, the stop sleeve 20 is arranged on the inner wall of the grouting hole 11, the stop sleeve 20 has multiple groups of communication hole groups 21, the multiple groups of communication hole groups 21 and the multiple groups of limiting structures 12 are arranged in one-to-one correspondence, and the grouting hole 11 is communicated with the limiting structures 12 through the communication hole groups 21; multiple groups of reinforcing structures 30, the reinforcing structures 30 are movably arranged in the limiting structures 12, and at least a part of the reinforcing structures 30 penetrates out of the limiting structures 12, the multiple groups of reinforcing structures 30 and the multiple groups of limiting structures 12 are arranged in one-to-one correspondence, and both ends of the reinforcing structures 30 are respectively in stop cooperation with the stop sleeve 20 and the limiting structures 12 in two directions in the radial direction of the rod body 10, and the reinforcing structures 30 are used for penetrating into the inner wall of the borehole 80.

[0039] By adopting this solution, the two ends of the reinforcing structure 30 are respectively stopped and matched with the stop sleeve 20 and the limiting structure 12 in the two radial directions of the rod body 10, so that it can not only ensure that the reinforcing structure 30 will not fall into the grouting hole 11, but also ensure that when grouting into the grouting hole 11, the reinforcing structure 30 will not be separated from the limiting structure 12, and can penetrate into the inner wall of the borehole 80, thereby strengthening the connection strength between the rod body 10 and the borehole 80, and effectively solving the problem that the hollow grouting anchor structure in the prior art is prone to slipping. A plurality of groups of limiting structures 12, a plurality of groups of connecting hole groups 21 and a plurality of groups of reinforcing structures 30 are set, and the plurality of groups of connecting hole groups 21 and the plurality of groups of limiting structures 12 are set one by one, and the plurality of groups of reinforcing structures 30 and the plurality of groups of limiting structures 12 are set one by one, so that the connection strength between the rod body 10 and the borehole 80 is further enhanced.

[0040] Among them, the limiting structure 12 includes a plurality of limiting holes 121 distributed along the circumference of the rod body 10, the connecting hole group 21 includes a plurality of sub-through holes 211, the reinforcing structure 30 includes a plurality of reinforcing cones 31, the reinforcing cones 31 are movably arranged in the limiting hole 121, the grouting hole 11 is connected with the limiting hole 121 through the sub-through hole 211, the reinforcing cone 31 faces the end face of the grouting hole 11 and cooperates with the outer wall stop of the stop sleeve 20, the side wall of the reinforcing cone 31 cooperates with the inner wall stop of the limiting hole 121, and the end of the reinforcing cone 31 away from the grouting hole 11 passes through the limiting hole 121, the plurality of limiting holes 121 and the plurality of sub-through holes 211 are arranged one-to-one, and the plurality of reinforcing cones 31 and the plurality of limiting holes 121 are arranged one-to-one. By adopting the above-mentioned setting mode, the end face of the reinforcing cone 31 facing the grouting hole 11 is matched with the outer wall stopper of the stop sleeve 20, and the side wall of the reinforcing cone 31 is matched with the inner wall stopper of the limiting hole 121, so that when grouting into the grouting hole 11, the slurry will push the reinforcing cone 31 to move toward the inner wall direction of the borehole 80, and because the end of the reinforcing cone 31 away from the grouting hole 11 passes through the limiting hole 121, the reinforcing cone 31 can penetrate into the inner wall of the borehole 80. In addition, the plurality of limiting holes 121 and the plurality of sub-through holes 211 are set in one-to-one correspondence, and the plurality of reinforcing cones 31 and the plurality of limiting holes 121 are set in one-to-one correspondence, which further enhances the connection strength between the rod body 10 and the borehole 80.

[0041] Furthermore, the reinforcing cone 31 is a circular cone. The limiting hole 121 has a first opening and a second opening that are interconnected. The aperture of the first opening is smaller than that of the second opening. The aperture of the sub-through hole 211 is smaller than that of the second opening, and the aperture of the sub-through hole 211 is larger than the diameter of the bottom surface of the circular cone. The aperture of the first opening is smaller than the diameter of the bottom surface of the circular cone. The smaller-diameter end of the circular cone passes through the first opening. Setting the aperture of the sub-through hole 211 to be smaller than that of the second opening and the aperture of the sub-through hole 211 to be larger than the diameter of the bottom surface of the circular cone can block the end face of the reinforcing cone 31 and prevent the reinforcing cone 31 from falling into the grouting hole 11. Setting the aperture of the first opening to be smaller than the diameter of the bottom surface of the circular cone can block the reinforcing cone 31 and prevent the reinforcing cone 31 from passing through the limiting hole 121.

[0042] In this embodiment, in the circumferential direction of the rod body 10, the angle between any two adjacent limiting holes 121 is 90°. Setting the angle between any two adjacent limiting holes 121 to be 90° can enable the rod body 10 to receive uniform horizontal pressure and ensure that the rod body 10 will not affect the grouting effect due to deviation during the grouting process.

[0043] Specifically, the outer diameter of the rod body 10 is 25 - 32 mm, and the diameter of the grouting hole 11 is 10 - 15 mm. Setting the outer diameter of the rod body 10 to be 25 - 32 mm and the diameter of the grouting hole 11 to be 10 - 15 mm can adjust the sizes of the rod body 10 and the grouting hole 11 according to the actual situation while ensuring the self-structural strength of the rod body 10.

[0044] In this embodiment, the hollow grouting anchor structure further includes an anchor head 40 and a grout stopper 50. The anchor head 40 is connected to one end of the rod body 10, and the grout stopper 50 is sleeved on the other end of the rod body 10. The grout stopper 50 is used to block the gap formed between the rod body 10 and the inner wall of the drilling hole 80. Setting the grout stopper 50 can block the gap formed between the rod body 10 and the inner wall of the drilling hole 80 and ensure that the grout will not leak out. Setting the anchor head 40 facilitates inserting the rod body 10 into the drilling hole 80.

[0045] Among them, the hollow grouting anchor structure further includes an anchor tray 60 and a nut 70. The anchor tray 60 is sleeved on the other end of the rod body 10. The anchor tray 60 abuts against the grout stopper 50, and the nut 70 is connected to the threaded part on the outer wall of the rod body 10 to fix the anchor tray 60. Setting the anchor tray 60 can abut against the grout stopper 50 to ensure that the grout stopper 50 will not fall off. Connecting the nut 70 to the threaded part on the outer wall of the rod body 10 can fix the anchor tray 60.

[0046] Specifically, the reinforcing structure 30 is made of steel material. Making the reinforcing structure 30 of steel material has the advantages of high strength and strong anti-bending property.

[0047] Another embodiment of the present invention provides a grouting method, which is applied to the above hollow grouting bolt structure and includes: drilling a hole 80 in the surrounding rock and cleaning the hole 80; inserting the rod body 10 in the hollow grouting bolt structure into the hole 80, and sealing the gap formed between the rod body 10 and the inner wall of the hole 80 through the grout plug 50 in the hollow grouting bolt structure; inserting a grouting pipe into the grouting hole 11 in the hollow grouting bolt structure, and grouting between the rod body 10 and the inner wall of the hole 80, with the grouting pressure being P1; after the grout fills the gap between the rod body 10 and the inner wall of the hole 80, grouting into the grouting hole 11 through the grouting pipe, with the grouting pressure being P2, P2 > P1, the strengthening structure 30 in the hollow grouting bolt structure is pressed out, and one end of the strengthening structure 30 penetrates into the inner wall of the hole 80; after the grout fills the grouting hole 11, stop grouting and block the grouting hole 11; install the bolt tray 60 and nut 70 in the hollow grouting bolt structure.

[0048] Adopting this solution, the two ends of the strengthening structure 30 are respectively in stop cooperation with the stop sleeve 20 and the limiting structure 12 in two directions in the radial direction of the rod body 10, which can not only ensure that the strengthening structure 30 will not fall into the grouting hole 11, but also ensure that the strengthening structure 30 will not break away from the limiting structure 12 when grouting into the grouting hole 11, and can penetrate into the inner wall of the hole 80, thereby strengthening the connection strength between the rod body 10 and the hole 80, and effectively solving the problem that the hollow grouting bolt structure in the prior art is prone to slipping. Multiple groups of limiting structures 12, multiple groups of communication hole groups 21 and multiple groups of strengthening structures 30 are provided, and the multiple groups of communication hole groups 21 and the multiple groups of limiting structures 12 are arranged in one-to-one correspondence, and the multiple groups of strengthening structures 30 and the multiple groups of limiting structures 12 are arranged in one-to-one correspondence, which further enhances the connection strength between the rod body 10 and the hole 80.

[0049] Among them, it includes: before inserting the rod body 10 into the hole 80, bonding the side wall of the strengthening structure 30 to the inner wall of the limiting hole 121 in the hollow grouting bolt structure. With this setting, it can be ensured that when grouting into the grouting hole 11, the strengthening structure 30 will not shift and affect the grouting effect.

[0050] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hollow grouting anchor structure, It is characterized in that include: A rod body (10), wherein the center of the rod body (10) has a grouting hole (11), and the side wall of the rod body (10) has multiple groups of limiting structures (12), and the multiple groups of limiting structures (12) are arranged at intervals along the axial direction of the rod body (10); A stop sleeve (20), the stop sleeve (20) being arranged on the inner wall of the grouting hole (11), the stop sleeve (20) having a plurality of groups of connecting hole groups (21), the plurality of groups of connecting hole groups (21) and the plurality of groups of limiting structures (12) being arranged in a one-to-one correspondence, and the grouting hole (11) being connected to the limiting structure (12) via the connecting hole groups (21); A plurality of groups of reinforcing structures (30), wherein the reinforcing structures (30) are movably arranged in the limiting structure (12), and at least a portion of the reinforcing structures (30) passes through the limiting structure (12), the plurality of groups of reinforcing structures (30) and the plurality of groups of limiting structures (12) are arranged in a one-to-one correspondence, and the two ends of the reinforcing structures (30) are respectively engaged with the stop sleeve (20) and the limiting structure (12) in two radial directions of the rod body (10), and the reinforcing structures (30) are used to pass through the inner wall of the drill hole (80); The limiting structure (12) comprises a plurality of limiting holes (121) distributed along the circumference of the rod body (10); the connecting hole group (21) comprises a plurality of sub-through holes (211); the reinforcing structure (30) comprises a plurality of reinforcing cones (31); the reinforcing cones (31) are movably arranged in the limiting holes (121); the grouting hole (11) is connected to the limiting hole (121) via the sub-through holes (211); the reinforcing cones (31) are oriented toward the grouting hole (11); The end surface of the grout hole (11) and the outer wall of the stop sleeve (20) are stop-matched, the side wall of the reinforcing cone (31) and the inner wall of the limiting hole (121) are stop-matched, and one end of the reinforcing cone (31) that is away from the grouting hole (11) passes through the limiting hole (121), a plurality of limiting holes (121) and a plurality of sub-through holes (211) are arranged in a one-to-one correspondence, and a plurality of reinforcing cones (31) and a plurality of limiting holes (121) are arranged in a one-to-one correspondence; The reinforcing cone (31) is a cone, the limiting hole (121) has a first opening and a second opening which are connected to each other, the aperture of the first opening is smaller than the aperture of the second opening, the aperture of the sub-through hole (211) is smaller than the aperture of the second opening, the aperture of the sub-through hole (211) is larger than the diameter of the bottom surface of the cone, the aperture of the first opening is smaller than the diameter of the bottom surface of the cone, and the end of the cone with a smaller diameter passes through the first opening.

2. The hollow grouting anchor structure according to claim 1, It is characterized in that Along the circumference of the rod body (10), the included angle between any two adjacent limiting holes (121) is 90°.

3. The hollow grouting anchor structure according to claim 1, It is characterized in that The outer diameter of the rod body (10) is 25 - 32 mm, and the diameter of the grouting hole (11) is 10 - 15 mm.

4. The hollow grouting anchor structure according to claim 1, wherein, the hollow grouting anchor structure further includes an anchor head (40) and a grout stopper (50). The anchor head (40) is connected to one end of the rod body (10), and the grout stopper (50) is sleeved on the other end of the rod body (10). The grout stopper (50) is used to block the gap formed between the rod body (10) and the inner wall of the drilling hole (80).

5. The hollow grouting anchor structure according to claim 4, wherein, the hollow grouting anchor structure further includes an anchor tray (60) and a nut (70). The anchor tray (60) is sleeved on the other end of the rod body (10), the anchor tray (60) abuts against the grout stopper (50), and the nut (70) is connected to the threaded part on the outer wall of the rod body (10) to fix the anchor tray (60).

6. The hollow grouting anchor structure according to claim 1, wherein, the strengthening structure (30) is made of steel material.

7. A grouting method, wherein, the grouting method is applied to the hollow grouting anchor structure according to any one of claims 1 to 6, and includes: drilling a hole (80) in the surrounding rock and cleaning the hole (80); inserting the rod body (10) in the hollow grouting anchor structure into the hole (80), and blocking the gap formed between the rod body (10) and the inner wall of the hole (80) through the grout stopper (50) in the hollow grouting anchor structure; inserting a grouting pipe into the grouting hole (11) in the hollow grouting anchor structure, and grouting between the rod body (10) and the inner wall of the hole (80), with the grouting pressure being P1; after the grout fills the gap between the rod body (10) and the inner wall of the hole (80), grouting into the grouting hole (11) through the grouting pipe, with the grouting pressure being P2, P2 > P1. The strengthening structure (30) in the hollow grouting anchor structure is pressed out, and one end of the strengthening structure (30) penetrates into the inner wall of the hole (80); after the grout fills the grouting hole (11), stop grouting and block the grouting hole (11); install the anchor tray (60) and the nut (70) in the hollow grouting anchor structure.

8. The grouting method according to claim 7, wherein, it includes: before inserting the rod body (10) into the hole (80), bonding the side wall of the strengthening structure (30) to the inner wall of the limiting hole (121) in the hollow grouting anchor structure.

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