Tension and compression integrated mixed anchoring anchor rod and construction method thereof

Abstract

The invention discloses a tension and compression integrated mixed anchoring anchor rod and a construction method thereof in the field of anchoring construction, the tension and compression integrated mixed anchoring anchor rod comprises an anchor rod body and ground anchors evenly fixed on the anchor rod body at intervals, and the diameter of the anchor rod body section with the ground anchors is larger than that of a drill hole. Meanwhile, the problems that an existing self-propelled anchor rod is low in construction efficiency and low in supporting force are solved, the structure is simple, construction procedures are reduced, and supporting timeliness is improved.

Description

Technical Field

[0001] The present invention relates to the field of anchoring construction, and particularly to a tension-compression integrated hybrid anchoring bolt and its construction method. Background Art

[0002] In underground projects such as tunnels, when the surrounding rock is soft, broken, and has poor self-stability, it is difficult to form stable drill holes. In response to the above problems, the commonly used bolt type in the prior art is the self-advancing (post-grouting) bolt, which solves a series of problems such as bolt hole formation and installation in soft and broken surrounding rock, but there are also two obvious deficiencies:

[0003] First, the self-advancing (post-grouting) bolt belongs to the bonded bolt, and the rod body contacts the surrounding rock through the slurry. The complete solidification time of the commonly used cement slurry is generally more than 7 days. Therefore, before the cement slurry is completely solidified, the rod body cannot support the surrounding rock, making it difficult to achieve the due support effect in the rock mass with rapid deformation.

[0004] Second, the self-advancing (post-grouting) bolt belongs to the tension-type bolt, and the anchoring force depends on the shear stress between the surface of the grouting body and the drill hole wall. Due to the soft and broken rock mass, the anchoring force is also relatively low.

[0005] In the patent with the application number CN201620956111.4, a multi-section variable-section grouting bolt is disclosed. By adding a tension rod inside the grouting bolt body, the conical anchor is connected to the tension rod through a rotating shaft, and the conical anchor passes through the arc-shaped opening groove. When the tension rod is subjected to an outward pulling force, the conical anchor will expand outward as the rotating shaft rotates and penetrate into the cement slurry and soil around the periphery of the grouting bolt body. This structure can play a better role in bolt support.

[0006] However, the above patent belongs to the type of drilling first and then installation, and cannot solve the problem of easy hole collapse in soft rock, and cannot provide timely support for soft rock.

[0007] Therefore, how to achieve rapid support while enhancing the support force on the basis of realizing the self-advancing construction of the bolt in the surrounding rock that is difficult to form holes has become an urgent problem to be solved in the field of anchoring tools and anchoring construction. Summary of the Invention

[0008] The purpose of the present invention is to provide a tension-compression integrated hybrid anchoring bolt and its construction method. For the soft and broken rock mass with poor self-stability, on the basis of the traditional self-advancing grouting tension-type bolt, the bolt body is set as a variable-section rod body with a diameter larger than the drill hole diameter at one end exposed from the drill hole, and at the same time, the rod body opening with the anchor is larger than the drill hole diameter, so that the self-advancing bolt integrates friction and bonding, and is both subjected to tension and pressure, overcoming the problem that the existing bolt cannot achieve rapid support while enhancing the support force in the soft and broken rock mass.

[0009] Due to the low mechanical strength of soft rock, the impact of the drill bit during drilling can easily change the original short-term stability of the rock mass, making the rock mass structure loose and prone to hole collapse. It is difficult to implement the conventional anchoring form of first forming the hole and then installing. Moreover, due to the poor water stability and significant creep characteristics of soft rock, the deformation of soft rock will gradually increase with the passage of time, and the longer the time, the more likely it is to produce large subsidence or uneven deformation. The self-advancing bolt belongs to the tension-type bolt, and the magnitude of its anchoring force depends on the shear stress between the surface of the grouting body and the borehole wall. Due to the poor stability of soft rock, the anchoring force generated is also low. At the same time, the long setting time of the slurry makes it difficult to support the rock mass immediately.

[0010] The object of the present invention is mainly achieved through the following technical solutions:

[0011] A tension-compression integrated hybrid anchoring bolt, comprising a bolt body, the bolt body is a variable cross-section rod body, and the diameter of the bolt body increases from small to large along the direction from inside the borehole to outside the borehole. The diameter of the part of the bolt body exposed outside the borehole is larger than the borehole diameter;

[0012] The bolt body on the side exposed outside the borehole can be squeezed with the hole wall to generate frictional force, which can support the borehole in time after the bolt is drilled. At the same time, it can replace the grout plug in the traditional self-advancing bolt to block the borehole opening, simplify the bolt structure, reduce the construction process, and speed up the construction progress and support time;

[0013] A number of wedge-shaped studs with a right trapezoidal cross-section are provided on the bolt body, and the studs can be nailed into the rock and soil layer from the borehole;

[0014] Since the setting time of the slurry of the self-advancing grouting bolt is long, and the soft and broken rock mass is easy to deform, it is easy to deform before the slurry solidifies to generate the supporting force, making it difficult for the bolt to achieve a good supporting effect. In this technology, by making the diameter of the rod body of the bolt body connecting the studs larger than the borehole diameter, the bolt can be squeezed into the rock mass to reduce the stress-bearing surface of the rock mass, cause stress concentration, and generate immediate frictional force under the extrusion of the hole wall, thereby generating an anchoring force to achieve rapid support. At the same time, the natural solidification process of the slurry between the rod body and the hole wall can be unaffected, enabling this application to generate rapid and timely support before the slurry solidifies. After the slurry solidifies, combined with the friction of the slurry, studs and rock mass, a greater anchoring force is generated;

[0015] The stud adopts a wedge-shaped structure, which can fully squeeze the stud with the rock mass and slurry, can transmit axial force and torque, improve the overall stability of the structure, and effectively prevent the deformation of the rock mass;

[0016] And the wedge shape is a right trapezoid. Due to the large angle of the trapezoidal inclined surface, the contact area with the slurry and rock mass can be increased, and the connection strength can be improved. Compared with the ordinary structure, the trapezoidal structure is more firm, can withstand greater tensile force and torque, and makes the overall structure of the anchor solid more stable, further increasing the anchoring force;

[0017] Based on the self-advancing bolt, this application adopts a variable-section bolt, increasing the diameter of some rod segments of the bolt body to be larger than the borehole diameter, so that the bolt can generate immediate support by frictional contact with the hole wall when drilling into the rock mass, preventing borehole collapse and deformation in the first place. Moreover, in this technology, anchor studs are arranged at intervals along the bolt body, making the bolt diameter connecting the anchor studs larger than the borehole diameter. The anchor solid is simultaneously subjected to tension and pressure, which can increase the anchoring force of the bolt;

[0018] In summary, this application is for soft rock, integrating mechanical and bonded anchoring methods on the basis of self-advancing anchoring. For rock and soil masses that cannot form holes by themselves and have poor bonded anchoring performance, such as soft and broken ones, the structure of this application can achieve the effect of rapid support and improved anchoring performance. At the same time, after the bonding slurry solidifies, its bonding anchoring force is higher, which can better solve the problem of significant creep characteristics of soft rock.

[0019] Furthermore, the bolt body includes a concave variable-section rod segment, a concave-section rod segment, a transition rod segment, and an open-section rod segment, which are distributed in sequence from inside the borehole to outside the borehole;

[0020] From front to back, the cross-section of the bolt body becomes larger from small at the concave variable-section rod segment and is always smaller than the borehole diameter, remains unchanged at the concave-section rod segment, gradually becomes larger than the borehole diameter at the transition rod segment, and finally remains unchanged at the open-section rod segment, making the cross-section of this bolt body smaller at the front and larger at the back, facilitating the initial drilling. At the same time, the diameters of the tail of the transition rod segment and the open-section rod segment are larger than the borehole diameter, which can immediately support the rock mass during drilling, prevent borehole collapse, and wait for the normal coagulation of the slurry to play a major supporting role for the rock mass;

[0021] The diameters of both the concave variable-section rod segment and the transition rod segment increase from small to large along the direction from inside the borehole to outside the borehole;

[0022] Taking the drilling direction of the bolt as the front and the direction of the bolt outside the borehole wall as the back, the cross-section of the concave variable-section rod segment is smaller at the front and larger at the back. During the drilling process of the bolt, it can reduce the sway of the rod body and is also convenient for better clamping the drill bit to separate the drill rod and the drill bit when pulling the drill rod backward;

[0023] Openings are provided on the rod body of the open-section rod segment along the rod body direction, and the openings can be closed;

[0024] The open-section rod segment is a split-tube rod body. After entering the hole wall, it frictional contacts with the entire cross-section of the hole wall, and the openings are gradually closed under extrusion, which can prevent the slurry from overflowing from the inside of the bolt body. At the same time, because the diameter of the open-section rod segment is larger than the hole wall diameter, it can also prevent the slurry from seeping out from the gap between the bolt body and the rock mass, making the slurry maintain a certain pressure in the bonding area to fully fill the surrounding rock voids, replacing the grout plug in the traditional bolt, simplifying the bolt structure, facilitating production, and saving costs.

[0025] Furthermore, the anchor bolts are evenly spaced along the rod body of the concave cross-section rod segment. The part of the concave cross-section rod segment connected with the anchor bolts is the concave cross-section rod segment with anchor bolts.

[0026] The anchor bolts are evenly distributed along the circumferential direction of the rod body, automatically meeting the requirement of the rod body being centered. There is no need to set a centering device, and the spaced arrangement will also reduce the resistance when the rod body is driven in.

[0027] The anchor bolts are spaced along the rod body of the concave cross-section rod segment. After the slurry is solidified, when the anchor rod is subjected to tension, the anchor bolts will squeeze the anchor body, generating compressive stress, so that the anchor body generates a compressive stress, achieving the effect of improving the anchoring effect by combining tension and compression.

[0028] The anchor bolts are fixed equidistantly on the concave cross-section rod segment. Since the anchor bolts are equidistantly distributed on the concave cross-section rod segment and the diameter of the front part of the transition rod segment is smaller than the diameter of the hole wall, the cross-sectional diameter of the anchor rod body is larger than the diameter of the hole wall section and smaller than the hole wall. Description of the Drawings

[0029] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0030] Figure 1 is the anchoring use diagram of the anchor rod of this application;

[0031] Figure 2 is the schematic diagram of the anchor rod of this application;

[0032] Figure 3 is this application Figure 2 schematic diagram of part A in;

[0033] Figure 4 is the cross-sectional diagram of the open cross-section rod segment of this application that is not extruded with the hole wall;

[0034] Figure 5 is the cross-sectional diagram of the open cross-section rod segment of this application that is extruded with the hole wall;

[0035] Figure 6 is the schematic diagram of the anchor rod body of this application;

[0036] Figure 7 is the cross-sectional diagram of the concave cross-section rod segment of this application;

[0037] Figure 8 is the cross-sectional diagram of the concave cross-section rod segment with anchor bolts of this application;

[0038] Figure 9 is the schematic diagram of the drill bit, drill pipe and connector of this application;

[0039] Figure 10Perspective view of the backing plate of the present application;

[0040] The names corresponding to the reference numerals are: 1, anchor rod body; 101, concave variable cross-section rod segment; 102, anchor bolt; 103, concave cross-section rod segment; 104, concave cross-section rod segment with anchor bolt; 105, concave structure; 106, transition rod segment; 107, open cross-section rod segment; 108, bearing ring; 2, backing plate; 201, wedge-shaped hole; 3, drill bit; 4, drill pipe; 401, threaded connection segment; 402, impact ring; 403, large hexagonal prism segment; 404, small hexagonal prism segment; 5, connector. Detailed implementation mode

[0041] In order to make the purpose, technical solution and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0042] Embodiment:

[0043] As Figures 1-10 shown,

[0044] A tension and compression integrated hybrid anchor bolt includes an anchor rod body 1. The anchor rod body 1 is a rod body with a variable cross-section. The diameter of the anchor rod body 1 increases from small to large along the direction from the inside of the drill hole to the outside of the drill hole. The diameter of the part of the anchor rod body 1 exposed outside the drill hole is larger than the diameter of the drill hole;

[0045] The anchor rod body 1 of this section can be squeezed with the hole wall to generate frictional force, and the drill hole can be timely supported after the anchor rod is drilled. At the same time, it can replace the grout stopper in the traditional self-advancing anchor bolt to block the drill hole opening, simplify the anchor bolt structure, reduce the construction process, and speed up the construction progress and support time;

[0046] A number of wedge-shaped anchor bolts 102 with a right trapezoidal cross-section are provided on the anchor rod body 1, and the connecting anchor bolts 102 can be nailed into the rock and soil layer from the drill hole;

[0047] Since the grout of the self-advancing grouting anchor bolt has a long setting time, and the soft and broken rock mass is easy to deform, it is easy to deform before the grout solidifies to generate support force, making it difficult for the anchor bolt to achieve a good support effect. In this technology, by making the rod body diameter of the anchor rod body 1 connecting the anchor bolt 102 larger than the diameter of the drill hole, the anchor bolt can be squeezed into the rock mass to reduce the stress-bearing surface of the rock mass, cause stress concentration, and generate immediate frictional force by being squeezed by the hole wall, thereby generating anchoring force and realizing rapid support. At the same time, the natural setting process of the grout between the rod body and the hole wall can be unaffected, enabling the present application to generate rapid and timely support before the grout solidifies. After the grout solidifies, combined with the friction of the grout, the anchor bolt 102 and the rock mass, a greater anchoring force is generated;

[0048] The anchor bolt 102 adopts a wedge-shaped structure, which can fully extrude the anchor bolt 102 with the rock mass and mud, transfer axial force and torque, improve the overall stability of the structure, and effectively prevent the deformation of the rock mass;

[0049] And the wedge-shaped body is a right trapezoid. Due to the large angle of the trapezoidal inclined plane, the contact area with the mud and the rock mass can be increased, and the connection strength can be improved. Compared with the ordinary structure, the trapezoidal structure is more firm, can withstand greater tensile force and torque, and makes the overall structure of the anchor solid more stable, further increasing the anchoring force;

[0050] As an implementable manner of the present application, the anchor bolt 102 is welded on the rod body of the anchor rod body 1;

[0051] As a preferred implementation manner of the above implementation manner, the anchor bolt 102 and the rod body can be integrally arranged, directly eliminating the risk of unstable connection;

[0052] Based on the self-advancing anchor rod, the present application adopts a variable-section anchor rod, increasing the diameter of some rod sections of the anchor rod body 1 to be larger than the borehole diameter, so that the anchor rod can generate immediate support by frictional contact with the hole wall when drilling into the rock mass, preventing cave-in and deformation in the first time. And in this technology, the anchor bolts 102 are arranged at intervals on the rod body of the anchor rod, making the diameter of the anchor rod connecting the anchor bolts 102 larger than the borehole diameter. The anchor solid is subjected to both tensile force and pressure, which can increase the anchoring force of the anchor rod;

[0053] To sum up, the present application integrates mechanical and bonding anchoring methods on the basis of self-advancing anchoring for soft rock. For rock and soil masses that cannot form holes by themselves and have poor bonding anchoring performance such as soft and broken ones, the structure of the present application can achieve the effect of rapid support and improved anchoring performance. At the same time, after the bonding slurry solidifies, its bonding anchoring force is higher, which can better solve the problem of significant creep characteristics of soft rock.

[0054] Furthermore, the anchor rod body 1 includes a concave variable-section rod section 101, a concave-section rod section 103, a transition rod section 106, and an open-section rod section 107 that are distributed in sequence from inside the borehole to outside the borehole;

[0055] The cross-section of the anchor rod body 1 changes from small to large and is smaller than the borehole diameter at the concave variable-section rod section 101, remains unchanged at the concave-section rod section 103, gradually becomes larger than the borehole diameter at the transition rod section 106, and finally remains unchanged at the open-section rod section 107, making the cross-section of the anchor rod body 1 smaller at the front and larger at the back, which is convenient for early drilling. At the same time, the diameter of the tail of the transition rod section 106 and the open-section rod section 107 is larger than the borehole diameter, which can immediately support the rock mass during drilling, prevent cave-in, and wait for the normal coagulation of the mud to play a major supporting role in the rock mass;

[0056] The diameters of the concave variable-section rod section 101 and the transition rod section 106 both increase from inside the borehole to outside the borehole;

[0057] As an alternative to the above technology, the concave variable cross-section rod segment 101, the concave cross-section rod segment 103, and the transition rod segment 106 are provided as an integral conical rod;

[0058] With the drilling direction of the anchor rod as the front and the direction of the anchor rod outside the borehole wall as the rear, the cross-section of the concave variable cross-section rod segment 101 is smaller at the front and larger at the rear. During the drilling process of the anchor rod, it can reduce the sway of the rod body and facilitate better clamping of the drill bit 3 when pulling the drill rod 4 backward, so that the drill rod 4 and the drill bit 3 are separated;

[0059] Openings are provided on the rod body of the open cross-section rod segment 107 and are distributed along the rod body direction, and the openings can be closed;

[0060] As a preferred solution of the present technology, the perimeter of the cross-section of the rod body of the open cross-section rod segment 107 is equal to the outer arc length of the drill bit 3. After the drill bit 3 drills in, the diameter of the anchor rod body 1 connected behind it is not greater than the hole diameter, and the anchor rod body 1 can directly enter the hole without being restricted by the rock mass resistance;

[0061] As an implementable solution of the above solution, the length of the open cross-section rod segment 107 is 30 - 50 cm to prevent the too short rod body of the open cross-section rod segment 107 from reducing the grout stopping effect, and too long will reduce the length of the anchoring section; the arc length of the opening part is 1 / 10 - 1 / 5 of the perimeter of the rod body cross-section to prevent the poor rebound extrusion effect caused by too small deformation, and too large will cause the rod body to be easily distorted, making it difficult to fit well to the hole wall and resulting in poor grout stopping effect at the back;

[0062] The open cross-section rod segment 107 is a pipe-slot type rod body. After entering the hole wall, it frictions with the entire cross-section of the hole wall, and the opening is gradually closed under extrusion, which can prevent the slurry from overflowing from the inside of the anchor rod body. At the same time, because the diameter of the open cross-section rod segment 107 is larger than the hole wall diameter, it can also prevent the slurry from seeping out from the gap between the anchor rod body 1 and the rock mass, so that the slurry maintains a certain pressure in the bonding area to fully fill the surrounding rock voids, replacing the grout stopper in the traditional anchor rod, simplifying the anchor rod structure, facilitating production, and saving costs.

[0063] Furthermore, the anchor nails 102 are evenly spaced along the rod body of the concave cross-section rod segment 103, and the part of the concave cross-section rod segment 103 connected with the anchor nails 102 is the concave cross-section rod segment 104 with anchor nails;

[0064] The anchor nails 102 are evenly distributed along the circumferential direction of the rod body, automatically meeting the requirement of the rod body being centered. There is no need to set a centering device, and the spaced arrangement will also reduce the resistance when the rod body is driven in;

[0065] The anchor nails 102 are spaced along the rod body of the concave cross-section rod segment 103. After the slurry solidifies, when the anchor rod is subjected to tension, the anchor nails 102 will squeeze the anchor solid, generating compressive stress.

[0066] The specific embodiments described above further elaborate on the object, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only for the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tension-compression hybrid anchor bolt, comprising an anchor bolt body (1), characterized in that: The anchor rod body (1) is a rod body with a variable cross-section, the diameter of the anchor rod body (1) increases from small to large along the direction from inside the borehole to outside the borehole, and the diameter of the portion of the anchor rod body (1) exposed from the borehole is larger than the borehole diameter; The anchor rod body (1) is provided with a plurality of wedge-shaped anchor nails (102) with a right-angle trapezoidal cross section, and the anchor nails (102) can be driven into the rock and soil layer through a drill hole.

2. A tension-compression integrated anchor bolt as claimed in claim 1, characterized in that: The anchor rod body (1) comprises an inwardly concave variable cross-section rod segment (101), an inwardly concave cross-section rod segment (103), a transition rod segment (106) and an open cross-section rod segment (107) which are sequentially distributed from the inside of the borehole to the outside of the borehole; The diameter of the inwardly concave variable cross-section rod segment (101) and the diameter of the transition rod segment (106) both increase from small to large along the direction from inside the borehole to outside the borehole; The shaft of the open cross-section shaft section (107) is provided with openings distributed along the shaft direction, and the openings are closable.

3. A tension-compression integrated anchor bolt as claimed in claim 2, characterized in that: The anchors (102) are evenly spaced on the rod body of the concave cross-section rod segment (103), and the portion of the concave cross-section rod segment (103) connected to the anchors (102) is the concave cross-section rod segment (104) with anchors.

4. A tension-compression integrated anchor bolt as claimed in claim 3, characterized in that: The surfaces of the rod shafts of the inwardly concave variable cross-section rod segments (101) and the inwardly concave cross-section rod segments (103) are provided with inwardly concave structures (105) along the rod shaft direction, and the inwardly concave structures (105) are distributed away from the anchor nails (102); The concave structure (105) is U-shaped or V-shaped.

5. The tension-compression integrated anchor bolt according to claim 1, characterized in that: It also includes a backing plate (2), wherein the backing plate (2) is provided with a wedge-shaped hole (201); The anchor rod body (1) passes through a wedge-shaped hole (201) on the backing plate (2), and the backing plate (2) is located outside the drilled hole.

6. A tension-compression integrated anchor bolt as claimed in claim 5, characterized in that: The end of the anchor rod body (1) close to the pad (2) is provided with a load ring (108) with an outwardly convex wedge-shaped structure, the inner side of the load ring (108) is a conical structure, the outer side of the load ring (108) is a cylindrical structure and the outer surface is a threaded structure; The carrying ring (108) and the wedge-shaped hole (201) can be interlocked.

7. A tension-compression integrated anchor bolt as claimed in claim 6, characterized in that: A drill rod (4) passes through the anchor rod body (1), one end of the drill rod (4) is connected to the bearing ring (108), and the other end of the drill rod (4) is connected to a detachable drill bit (3); The drill rod (4) is a hexagonal prism rod, the side of the drill rod (4) connected to the drill bit (3) is a small hexagonal prism section (404), the side of the drill rod (4) away from the drill bit (3) is a threaded connection section (401), the portion between the threaded connection section (401) and the small hexagonal prism section (404) is a large hexagonal prism section (403), and the radius of the circumscribed circle of the cross section of the large hexagonal prism section (403) is greater than the radius of the circumscribed circle of the cross section of the small hexagonal prism section (404).

8. The tension-compression integrated anchor bolt according to claim 7, characterized in that: An impact ring (402) is provided between the threaded connection section (401) and the large hexagonal prism section (42); The impact ring (402) is an inwardly concave structure, and the inner side of the impact ring (402) can be interlocked with the outer side of the supporting ring (108).

9. A tension-compression integrated anchor bolt as claimed in claim 8, characterized in that: The threaded connection section (401) is provided with a connector (5), and the connector (5) is spirally connected to the threaded connection section (401).

10. A construction method for a tension-compression integrated hybrid anchor bolt, characterized in that: The construction method of the tension-compression integrated hybrid anchor bolt is based on the tension-compression integrated hybrid anchor bolt according to any one of claims 1 to 9, comprising the following steps: S1. Assembly of anchor rod and drilling rig: The anchor rod body (1) is inserted into the backing plate (2) through the wedge-shaped hole (201) and the wedge-shaped hole (201) and the bearing ring (108) are engaged with each other; Inserting the drill rod (4) into the anchor rod body (1) and making the impact ring (402) and the bearing ring (108) engage with each other; Connecting the drill bit (3) to the small hexagonal prism segment (404); Connecting one end of the connector (5) to the threaded connection section (401), and connecting the other end of the connector (5) to a rotary impact drill; S2. After the assembly of the anchor rod and the drilling rig is completed, the anchor rod is driven into the target rock mass: After aligning the drill bit (30) of the anchor rod with the drilling position of the target rock mass, the rotary impact drill is started to drive the anchor rod into the target rock mass; S3. After the anchor is fully driven in, inject grouting liquid into the anchor: After the anchor rod is completely driven in, the rotary impact drill is separated from the connector (5); Applying a pulling force at the connection point between the connector (5) and the threaded connection section (401) to separate the drill rod (4) from the drill bit (3), and pulling out the drill rod (4); The grouting conduit is connected to the bearing ring (108) and the grouting liquid is injected into the anchor rod.

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