Mechanical tension anchor rod and supporting method

Abstract

The invention provides a mechanical tension anchor rod and a supporting method, and relates to the technical field of supporting anchor rods. According to the mechanical tension anchor rod and the supporting method, the steel strand is stretched outwards relative to the hollow rod body to drive the power arm and the friction block to expand outwards, so that the friction block abuts against the inner wall of a drill hole, huge anchoring force is applied through the steel strand, and it is ensured that the anchor rod forms a stable supporting structure in a rock-soil body; by controlling the stretching length of the steel strand, corresponding prestress is applied to the steel strand, a prestress anchor rod is formed, and the stability and the bearing capacity of building supporting are enhanced; in the supporting process, when the steel strand is loosened, the prestress lost due to loosening of the steel strand can be compensated through springback of the spring, and when a rock-soil body suddenly deforms greatly or rock burst disturbance occurs, yielding buffering of the anchor rod is achieved, and permanent failure caused by direct fracture of the anchor rod is avoided; when the structure needs to be dismantled, the anchor rod can be conveniently dismantled from the rock-soil body to be recycled.

Description

Technical Field

[0001] The present invention relates to the technical field of supporting anchor rods, and in particular to a mechanical tension anchor rod and a supporting method. Background Art

[0002] Anchor rods are frequently used in slope support, tunnel support, mine support and other fields. Anchor rods used in support structures are mostly disposable and cannot be recycled, which easily leads to material waste. When the structure is demolished after its service life, the anchor rods still remain in the rock and soil, affecting the subsequent demolition and excavation construction, and even damaging the excavation machinery. Furthermore, the anchor rods will suffer varying degrees of damage over time during the support process. In the event of sudden large deformation of the rock and soil or impact ground pressure disturbance, the anchor rods may break directly and fail permanently, losing their anchoring effect and posing a safety hazard to the structure. In addition, ordinary anchor rods cannot apply prestress, resulting in the stability and bearing capacity of the support structure often failing to meet expectations. Summary of the Invention

[0003] The purpose of the present invention is to provide a mechanical tension anchor rod and support method to achieve the recycling of the anchor rod, extend the effective anchoring life of the anchor rod, and apply prestress to improve the stability and bearing capacity of the support structure.

[0004] In order to achieve the above objectives, the technical solutions adopted by the present invention are as follows:

[0005] A mechanical tension anchor, comprising:

[0006] The hollow rod body has a hollow structure inside;

[0007] The steel strand passes through the interior of the hollow rod body, and the inner and outer ends of the steel strand are exposed from the hollow rod body;

[0008] Anchorage, connected to the inner end of the strand;

[0009] a friction block for abutting against the inner wall of the drill hole;

[0010] A plurality of first force arms are provided, one end of which is hinged to the inner end of the hollow rod body, and the other end of which is hinged to one end of the friction block;

[0011] The second lever arm has the same number as the first lever arm, one end of which is hinged to the other end of the friction block, and the other end of which is hinged to the anchor seat;

[0012] The anchoring assembly is arranged at the outer end of the hollow rod body and the steel strand, and is used to connect the outer end of the steel strand to maintain the extension and contraction length of the steel strand relative to the hollow rod body.

[0013] Furthermore, the anchoring assembly includes a gasket and an anchor, the outer end of the steel strand passes through the gasket, the outer end of the steel strand is connected to the anchor, the gasket abuts the outer end of the hollow rod body, and the anchor abuts the outer end of the gasket.

[0014] Furthermore, the anchor comprises an anchor sleeve and a pressure-bearing seat, the pressure-bearing seat is provided at the lower end of the anchor sleeve, and the outer end of the steel strand passes through the pressure-bearing seat and the anchor sleeve in sequence;

[0015] The inner wall of the anchor sleeve is provided with a plurality of compression lock buckles, which can abut the steel strand. The side wall of the anchor sleeve is provided with a threaded hole, and the threaded hole is threadedly connected with a compression bolt, and the end of the compression bolt can abut the compression lock buckle.

[0016] Furthermore, one end of the compression lock buckle is connected to the inner wall of the anchor sleeve, and the other end of the compression lock buckle extends toward the central axis of the anchor sleeve and downward.

[0017] Furthermore, the outer end of the other end of the tightening lock is provided with a platform for abutting against the end of the tightening bolt, and the inner end of the other end of the tightening lock is provided with a triangular limit block for abutting against the steel strand.

[0018] Furthermore, the lower end of the anchoring sleeve is slidably connected to the pressure-bearing seat, and a spring is connected between the anchoring sleeve and the pressure-bearing seat.

[0019] Furthermore, it also includes a hollow column, the interior of the hollow column is a hollow structure, a limit ring is provided at the upper end of the hollow column, and an external thread is provided at the lower end of the hollow column;

[0020] A guide hole is provided at the lower end of the anchoring sleeve, and a threaded hole is provided at the middle position of the pressure bearing seat;

[0021] The lower end of the hollow column passes through the guide hole and the spring in sequence, the lower end of the hollow column is threadedly connected to the threaded hole, and the two ends of the spring respectively abut against the pressure seat and the anchoring sleeve.

[0022] Furthermore, a groove is provided on the pressure-bearing seat at the edge of the threaded hole, and the spring is located in the groove.

[0023] Furthermore, the outer end surface of the friction block is provided with a plurality of protrusions.

[0024] A mechanical tension anchor support method, using the above-mentioned mechanical tension anchor, comprises the following steps:

[0025] S1. Drill a hole in the rock mass of the structure to be supported using a drilling rig, extend the portion of the mechanical tension anchor rod excluding the anchor assembly into the hole, and pass the outer end of the steel strand through the gasket, the pressure seat, and the anchor sleeve in sequence, so that the gasket contacts the outer wall of the rock mass;

[0026] S2. Use the drawing device to connect the outer end of the steel strand, extend the steel strand outward relative to the hollow rod body, and the steel strand drives the friction block to move away from the steel strand until the outer end surface of the friction block abuts the inner wall of the drilled hole. After the steel strand is extended outward by a set length relative to the hollow rod body to apply prestress to the steel strand, rotate the tightening bolt forward, and the tightening bolt drives the tightening lock buckle to abut the steel strand, maintaining the extended length of the steel strand relative to the hollow rod body and remove the drawing device. At this time, the spring is in a compressed state;

[0027] During the support process, when the steel strands relax, the spring rebounds to compensate for the prestress loss caused by the relaxation. When the rock mass suddenly undergoes large deformation or impact ground pressure disturbance, the compression lock on the anchor sleeve moves away from the rock mass relative to the steel strands to avoid direct fracture of the anchor rod and permanent failure.

[0028] S4. When the structure needs to be dismantled, rotate the compression bolt in the opposite direction to disengage the compression lock from the steel strand, move the hollow rod body away from the rock and soil, and retract the steel strand inward relative to the hollow rod body, so that the friction block moves toward the steel strand, and the outer end face of the friction block disengages from the inner wall of the borehole, and the anchor rod is removed from the rock and soil for recycling.

[0029] The beneficial technical effects of the present invention are:

[0030] The mechanical tension anchor and support method of the present invention stretches the steel strand outward relative to the hollow rod body to drive the power arm and the friction block to expand outward, so that the outer end surface of the friction block abuts the inner wall of the borehole, and relies on the steel strand to apply a huge anchoring force to ensure that the anchor forms a stable support structure in the rock and soil. By controlling the stretching length of the steel strand, corresponding prestress is applied to the steel strand to form a prestressed anchor, thereby enhancing the stability and bearing capacity of the structure support, controlling the deformation of the rock and soil, improving the stress distribution inside the structure, and reducing the possibility of local damage. During the anchoring process, no grouting or Instead of using materials such as anchoring agents for anchoring, some researchers continue to retain the drill holes. The retained drill holes can reduce the occurrence of rock bursts to a certain extent and reduce safety hazards. During the support process, when the steel strands relax, the spring rebound can compensate for the prestress of the steel strands lost due to relaxation. When the rock and soil mass suddenly undergoes a large deformation or impact ground pressure disturbance occurs, the compression lock on the anchor sleeve moves relative to the steel strand in the direction away from the rock and soil mass, realizing the pressure buffering of the anchor rod and avoiding the direct breakage of the anchor rod and permanent failure. When the structure needs to be demolished, the anchor rod can be easily removed from the rock and soil mass for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The structure of the mechanical tension anchor rod according to the embodiment of the present invention is shown in FIG. Figure 1 ;

[0032] Figure 2 This is a schematic diagram of the structure of the mechanical tension and compression anchor rod excluding the steel strands according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic structural diagram of a steel strand according to an embodiment of the present invention;

[0034] Figure 4 The structure of the mechanical tension anchor rod according to the embodiment of the present invention is shown in FIG. Figure 2 ;

[0035] Figure 5 Schematic diagram of anchoring construction performed by mechanical tension and compression anchor rods according to an embodiment of the present invention;

[0036] Figure 6 is a three-dimensional diagram of an anchor according to an embodiment of the present invention;

[0037] Figure 7 An exploded view of an anchor according to an embodiment of the present invention;

[0038] Figure 8 This is an exploded view of a half-section view of an anchor according to an embodiment of the present invention;

[0039] Figure 9 An exploded view of the anchor structure according to an embodiment of the present invention;

[0040] Figure 10 This is a front view of an anchor according to an embodiment of the present invention;

[0041] Figure 11 This is a schematic structural diagram of the anchor portion when the mechanical tension anchor rod is in a supporting state according to an embodiment of the present invention. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions, and beneficial effects of the present invention more clearly understood, the present invention is further described below in conjunction with specific embodiments and with reference to the accompanying drawings. Certain embodiments of the present invention will be more fully described below with reference to the accompanying drawings, some, but not all, of which are illustrated. The various embodiments of the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention satisfies applicable legal requirements.

[0043] In the description of the present invention, it should be noted that the terms "inner," "outer," "upper," "lower," "front," and "rear," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] In an embodiment of the present invention, a mechanical tension anchor and support method is provided. Please refer to Figures 1 to 11 shown.

[0045] A mechanical tension anchor comprises a hollow rod body 11, a steel strand 12, an anchor seat 2, a friction block 31, a first lever arm 32, a second lever arm 33 and an anchoring assembly.

[0046] The hollow rod body 11 is a cylindrical body with a hollow structure at both ends for the steel strand 12 to pass through the interior of the hollow rod body 11. Four first hinge seats 111 are arranged at equal intervals on the circumferential side wall of the inner end of the hollow rod body 11.

[0047] The steel strand 12 can pass through the interior of the hollow rod body 11 , and the inner and outer ends of the steel strand 12 are exposed from both ends of the hollow rod body 11 .

[0048] The anchor seat 2 is connected to the inner end of the steel strand 12 , and four second hinge seats 21 are arranged at equal intervals on the circumferential side wall of the anchor seat 2 .

[0049] The friction block 31 is used to abut against the inner wall of the bore hole 61 . The outer end surface of the friction block 31 is provided with a plurality of protrusions 311 so that the friction block 31 and the inner wall of the bore hole 61 can cooperate more firmly.

[0050] Four first force arms 32 are provided. One end of the first force arm 32 is hinged to the first hinge seat 111 at the inner end of the hollow rod body 11 , and the other end of the first force arm 32 is hinged to one end of the friction block 31 .

[0051] Four second force arms 33 are provided, one end of the second force arm 33 is hinged to the other end of the friction block 31 , and the other end of the second force arm 33 is hinged to the second hinge seat 21 on the anchor seat 2 .

[0052] The anchoring assembly is provided at the outer ends of the hollow rod body 11 and the steel strand 12 , and is used to connect the outer ends of the steel strand 12 to maintain the extension and contraction length of the steel strand 12 relative to the hollow rod body 11 .

[0053] The anchoring assembly includes a gasket 4 and an anchor 5. The outer end of the steel strand 12 passes through the gasket 4, the outer end of the steel strand 12 is connected to the anchor 5, the gasket 4 abuts the outer end of the hollow rod body 11, and the anchor 5 abuts the outer end of the gasket 4.

[0054] The anchor 5 includes an anchor sleeve 51 and a pressure seat 52. The pressure seat 52 is provided at the lower end of the anchor sleeve 51. The outer end of the steel strand 12 passes through the pressure seat 52 and the anchor sleeve 51 in sequence. The inner wall of the anchor sleeve 51 is provided with a plurality of compression locks 511. Three circles of compression locks 511 are arranged at equal intervals along the axial direction of the anchor sleeve 51, with four compression locks 511 per circle. The compression locks 511 can abut the steel strand 12. The side wall of the anchor sleeve 51 has a threaded hole 512, and a compression bolt 513 is threadedly connected to the threaded hole 512. The end of the compression bolt 513 can abut the compression lock 511.

[0055] By rotating the tightening bolt 513 in the forward direction, the tightening bolt 513 drives the tightening lock buckle 511 to abut against the steel strand 12 , so as to maintain the extended length of the steel strand 12 relative to the hollow rod body 11 .

[0056] One end of the compression buckle 511 is connected to the inner wall of the anchor sleeve 51, and the other end of the compression buckle 511 extends toward and below the central axis of the anchor sleeve 51. In this way, when the rock mass undergoes sudden and significant deformation or is disturbed by impact ground pressure, the compression buckle 511 on the anchor sleeve 51 can be moved away from the rock mass relative to the steel strand 12, thereby preventing the anchor rod from breaking and permanently failing.

[0057] The outer end of the other end of the compression lock buckle 511 is provided with a platform 5111, which is used to abut the end of the compression bolt 513. This ensures that the compression bolt 513 firmly abuts the outer end of the other end of the compression lock buckle 511. The inner end of the other end of the compression lock buckle 511 is provided with a triangular stopper 5112, which is used to abut the steel strand 12. This ensures that the inner end of the other end of the compression lock buckle 511 firmly abuts the steel strand 12.

[0058] The lower end of the anchor sleeve 51 is slidably connected to the pressure seat 52, and a spring 53 is connected between the anchor sleeve 51 and the pressure seat 52. During the support process, when the steel strand 12 relaxes, the spring 53 rebounds to compensate for the prestress of the steel strand 12 lost due to relaxation.

[0059] The hollow column 54 is cylindrical and hollow inside. A retaining ring 541 is provided at the upper end of the column, and external threads are provided at the lower end. A guide hole 514 is defined at the lower end of the anchor sleeve 51, and a threaded hole 521 is defined in the middle of the pressure seat 52. The lower end of the hollow column 54 first passes through the guide hole 514, then through the spring 53. The lower end of the hollow column 54 is threadedly connected to the threaded hole 521, with the ends of the spring 53 abutting the pressure seat 52 and the anchor sleeve 51, respectively.

[0060] The threaded hole 521 , the hollow column 54 , the guide hole 514 and the anchoring sleeve 51 are coaxially arranged. The hollow column 54 slides with the guide hole 514 , so that the anchoring sleeve 51 slides along the hollow column 54 , and the limiting ring 541 limits the sliding.

[0061] The pressure seat 52 is provided with a groove 522 at the edge of the threaded hole 521, and the spring 53 is located in the groove 522. In this way, during the compression and rebound process of the spring 53, the groove 522 and the hollow column 54 jointly guide the spring 53 to prevent the spring 53 from being skewed and deformed.

[0062] A mechanical tension anchor support method, using the mechanical tension anchor described above in this embodiment, comprises the following steps:

[0063] S1. Use a drilling rig to drill a hole 61 in the rock mass 6 of the structure to be supported, extend the part of the mechanical tension anchor rod except the anchoring component into the hole 61, and pass the outer end of the steel strand 12 through the gasket 4, the pressure seat 52 and the anchoring sleeve 51 in sequence, so that the gasket 4 abuts the outer wall of the rock mass 6.

[0064] Specifically, after the outer end of the steel strand 12 passes through the gasket 4 , the outer end of the steel strand 12 passes through the hollow column 54 and the anchor sleeve 51 . At this time, a gap is left between the steel strand 12 and the other end of the compression lock buckle 511 .

[0065] S2. Use the drawing device 7 to connect the outer end of the steel strand 12, and extend the steel strand 12 outward relative to the hollow rod body 11. The steel strand 12 drives the friction block 31 to move in the direction away from the steel strand 12 until the outer end face of the friction block 31 abuts the inner wall of the drill hole 61. After the steel strand 12 is extended outward by a set length relative to the hollow rod body 11 to apply prestress to the steel strand 12, the tightening bolt 513 is rotated forward. The tightening bolt 513 drives the tightening lock buckle 511 to abut against the steel strand 12, maintaining the extended length of the steel strand 12 relative to the hollow rod body 11 and removing the drawing device 7. At this time, the spring 53 is in a compressed state.

[0066] S3. During the support process, when the steel strand 12 relaxes, the spring 53 rebounds to compensate for the prestress of the steel strand 12 lost due to relaxation; when the rock mass 6 suddenly undergoes a large deformation or an impact ground pressure disturbance occurs, the compression lock buckle 511 on the anchor sleeve 51 moves relative to the steel strand 12 in the direction away from the rock mass 6 to avoid the anchor rod (mainly the steel strand 12) from directly breaking and permanently failing.

[0067] S4. When the structure needs to be dismantled, the tightening bolt 513 is rotated in the opposite direction, and the tightening lock buckle 511 is disengaged from the steel strand 12, and the hollow rod body 11 is moved in the direction away from the rock and soil 6. The steel strand 12 retracts inward relative to the hollow rod body 11, so that the friction block 31 moves in the direction close to the steel strand 12. The outer end face of the friction block 31 is disengaged from the contact with the inner wall of the borehole 61, and the anchor rod is removed from the rock and soil for recycling.

[0068] So far, the present embodiment has been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the mechanical tension anchor rod and support method of the present invention. The mechanical tension anchor rod and support method of the present invention stretches the steel strand 12 outward relative to the hollow rod body 11 to drive the power arm (first force arm 32, second force arm 33) and the friction block 31 to expand outward, so that the outer end face of the friction block 31 abuts against the inner wall of the borehole 61, and relies on the steel strand 12 to apply a huge anchoring force to ensure that the anchor rod forms a stable support structure in the rock mass 6; by controlling the stretching length of the steel strand 12, the corresponding prestress is applied to the steel strand 12 to form a prestressed anchor rod, thereby enhancing the stability and bearing capacity of the support for the structure, controlling the deformation of the rock mass 6, improving the stress distribution inside the structure, and reducing the possibility of local damage; during the anchoring process, there is no pressure on the drill hole. The hole 61 is not grouted or anchored with materials such as anchoring agents, but the drill hole 61 is retained. The retained drill hole 61 can reduce the occurrence of rock bursts to a certain extent and reduce safety hazards. During the support process, when the steel strand 12 is relaxed, the prestress of the steel strand 12 lost due to relaxation can be compensated by the rebound of the spring 53. When the rock mass 6 suddenly undergoes a large deformation or an impact ground pressure disturbance occurs, the pressing lock 511 on the anchor sleeve 51 moves relative to the steel strand 12 in a direction away from the rock mass 6, thereby achieving pressure relief and buffering of the anchor rod, avoiding direct breakage of the anchor rod and permanent failure. When the structure needs to be demolished, the anchor rod can be easily removed from the rock mass for recycling.

[0069] Of course, the specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A mechanical tension anchor, characterized in that: include: The hollow rod body has a hollow structure inside; The steel strand passes through the interior of the hollow rod body, and the inner and outer ends of the steel strand are exposed from the hollow rod body; Anchorage, connected to the inner end of the strand; a friction block for abutting against the inner wall of the drill hole; A plurality of first force arms are provided, one end of which is hinged to the inner end of the hollow rod body, and the other end of which is hinged to one end of the friction block; The second lever arm has the same number as the first lever arm, one end of which is hinged to the other end of the friction block, and the other end of which is hinged to the anchor seat; The anchoring assembly is arranged on the outer end of the hollow rod body and the steel strand, and is used to connect the outer end of the steel strand to maintain the extension and contraction length of the steel strand relative to the hollow rod body.

2. A mechanical tension anchor according to claim 1, characterized in that: The anchoring assembly includes a gasket and an anchor. The outer end of the steel strand passes through the gasket, the outer end of the steel strand is connected to the anchor, the gasket abuts the outer end of the hollow rod body, and the anchor abuts the outer end of the gasket.

3. A mechanical tension anchor according to claim 2, characterized in that: The anchor comprises an anchor sleeve and a pressure-bearing seat, the lower end of the anchor sleeve is provided with a pressure-bearing seat, and the outer end of the steel strand passes through the pressure-bearing seat and the anchor sleeve in sequence; The inner wall of the anchor sleeve is provided with a plurality of compression lock buckles, which can abut the steel strand. The side wall of the anchor sleeve is provided with a threaded hole, and the threaded hole is threadedly connected with a compression bolt, and the end of the compression bolt can abut the compression lock buckle.

4. A mechanical tension anchor according to claim 3, characterized in that: One end of the pressing lock buckle is connected to the inner wall of the anchoring sleeve, and the other end of the pressing lock buckle extends toward the central axis of the anchoring sleeve and downward.

5. A mechanical tension anchor according to claim 3 or 4, characterized in that: The outer end of the other end of the pressing lock is provided with a platform for abutting against the end of the pressing bolt, and the inner end of the other end of the pressing lock is provided with a triangular limit block for abutting against the steel strand.

6. The mechanical tension anchor according to claim 3, characterized in that: The lower end of the anchoring sleeve is slidably connected to the pressure-bearing seat, and a spring is connected between the anchoring sleeve and the pressure-bearing seat.

7. The mechanical tension anchor according to claim 6, characterized in that: It also includes a hollow column, the interior of the hollow column is a hollow structure, a limit ring is provided at the upper end of the hollow column, and an external thread is provided at the lower end of the hollow column; A guide hole is provided at the lower end of the anchoring sleeve, and a threaded hole is provided at the middle position of the pressure bearing seat; The lower end of the hollow column passes through the guide hole and the spring in sequence, the lower end of the hollow column is threadedly connected to the threaded hole, and the two ends of the spring respectively abut against the pressure seat and the anchoring sleeve.

8. The mechanical tension anchor according to claim 7, characterized in that: The pressure bearing seat is provided with a groove at the edge of the threaded hole, and the spring is located in the groove.

9. The mechanical tension anchor according to claim 1, characterized in that: The outer end surface of the friction block is provided with a plurality of protrusions.

10. A mechanical tension anchor support method, using the mechanical tension anchor according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: S1. Drill a hole in the rock mass of the structure to be supported using a drilling rig, extend the portion of the mechanical tension anchor rod excluding the anchor assembly into the hole, and pass the outer end of the steel strand through the gasket, the pressure seat, and the anchor sleeve in sequence, so that the gasket contacts the outer wall of the rock mass; S2. Use the drawing device to connect the outer end of the steel strand, extend the steel strand outward relative to the hollow rod body, and the steel strand drives the friction block to move away from the steel strand until the outer end surface of the friction block abuts the inner wall of the drilled hole. After the steel strand is extended outward by a set length relative to the hollow rod body to apply prestress to the steel strand, rotate the tightening bolt forward, and the tightening bolt drives the tightening lock buckle to abut the steel strand, maintaining the extended length of the steel strand relative to the hollow rod body and remove the drawing device. At this time, the spring is in a compressed state; During the support process, when the steel strands relax, the spring rebounds to compensate for the prestress loss caused by the relaxation. When the rock mass suddenly undergoes large deformation or impact ground pressure disturbance, the compression lock on the anchor sleeve moves away from the rock mass relative to the steel strands to avoid direct fracture of the anchor rod and permanent failure. S4. When the structure needs to be dismantled, rotate the compression bolt in the opposite direction to disengage the compression lock from the steel strand, move the hollow rod body away from the rock and soil, and retract the steel strand inward relative to the hollow rod body, so that the friction block moves toward the steel strand, and the outer end face of the friction block disengages from the inner wall of the borehole, and the anchor rod is removed from the rock and soil for recycling.

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