Hydraulic triggering type telescopic anchoring anchor rod and geotechnical engineering supporting method

Abstract

The invention discloses a hydraulic triggering type telescopic anchoring anchor rod and a geotechnical engineering supporting method, and belongs to the technical field of geotechnical engineering supporting. The anchor rod mainly comprises a blocking piece, a multi-stage rod body, an anchor head and a sliding block. The core is that the multiple stages of rod bodies are mutually overlapped and sleeved through the grooves and the bosses, so that great contraction can be realized; a sliding block mechanism is arranged in the rod body, a sliding block can move from an initial locking position to a final locking position under the hydraulic effect generated by grouting, in the process, the inner-layer rod body is pushed to extend inside and outside, telescopic inserting rods on the two sides of the inner-layer rod body are driven to pop out and be clamped in anchoring holes of the rod body, and an irreversible rigid mechanical anchoring point is formed. Grouting pressure is ingeniously used as trigger power, active stretching and final rigid locking of the anchor rod are achieved, the anchor rod has the comprehensive advantages of being convenient and fast to transport, efficient in installation, high in anchoring force and good in large-deformation adaptability, and the anchor rod is particularly suitable for supporting soft broken rock masses.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering and mine supporting equipment, in particular to a hydraulic trigger type telescopic anchoring anchor rod and a geotechnical engineering supporting method using the anchor rod. BACKGROUND

[0002] In the field of geotechnical engineering anchor rod supporting, especially in complex geological conditions such as mine roadway and deep tunnel, large deformation of surrounding rock has become the main threat leading to failure of the supporting system. The traditional anchor rods such as full-length bonded anchor rod widely used in current engineering face multiple challenges in practical application due to inherent limitations in design.

[0003] Firstly, these anchor rods adopt rigid rod body structure with fixed length, which is extremely difficult to transport and turnover in narrow underground space, not only significantly reducing the construction efficiency, but also having safety hazards such as bumping, jamming and even injury due to the overlong rod body, which seriously restricts the overall progress and safety of supporting operation.

[0004] Secondly, in terms of function triggering mechanism, the existing technology is generally in a passive and lagging state, and most so-called "yielding" or "telescopic" anchor rods must wait for the surrounding rock to deform significantly and press the rod body before starting to work. This "after-response" mode has inevitable lag, and the initial deformation of the surrounding rock has caused irreversible damage to the supporting system before the anchor rod starts to yield, and the triggering threshold has large dispersion and cannot be precisely controlled.

[0005] Thirdly, in terms of core anchoring performance, the traditional scheme has single and fragile risks, and the anchoring force of most commercially available anchor rods depends only on the bonding force between the grout and the geotechnical body. This single static anchoring mode is completely subject to the often unreliable rock strength and grout interface, and the stress path is single, and once the interface slips, the entire anchoring system collapses quickly, and the anti-pulling safety reserve is seriously insufficient.

[0006] Finally, in terms of the ability to deal with large deformation, existing products face the dilemma of "rigid fracture" and "flexible failure": traditional rigid anchor rods are brittle and break due to their inability to extend, while existing yielding anchor rods choose the technical route of "continuous slip" or "constant resistance deformation" to adapt to deformation, which leads to continuous decay of the supporting prestress during service, and finally cannot provide a strong and rigid ultimate supporting force to stabilize the surrounding rock for a long time.

[0007] These systematic defects jointly restrict the development of geotechnical supporting technology, and there is an urgent need for an innovative solution that can fundamentally solve these problems. SUMMARY

[0008] The technical problem solved by the present application is to overcome the systematic defects of traditional anchor rods in terms of inconvenient transportation and installation, single and weak anchoring force, passive and lagging trigger mechanism, and poor large deformation adaptability.

[0009] To solve the above problems, the present application adopts the following technical solutions: On the one hand, the present application provides a hydraulic trigger type telescopic anchoring anchor rod, characterized in that it comprises a baffle, a plurality of rod bodies, an anchor head, and a sliding block. The baffle is fixed to one end of the outermost rod body. The sidewall of each rod body is recessed from the outside to the inside, forming a groove and a boss on the outer surface and the inner wall of the rod body, respectively. The plurality of rod bodies are stacked through the groove and the boss, so that the anchor rod has a contraction and expansion state. Limiting holes and anchoring holes are provided on the rod body. The boss end forms an upper sliding channel, and the two sides form side sliding channels. The anchor head is fixed to the end of the innermost rod body, and the anchor head is provided with a plurality of grout outlets. The sliding block is accommodated in the rod body and is fixedly connected with the next level rod body. The sliding block comprises an upper sliding block nested in a lower sliding block, and a first spring is installed between the two. The lower sliding block is provided with a lower telescopic insertion rod and an upper telescopic insertion rod which are nested with each other, and a second spring is installed between the two. The sliding block is provided with a limiting rod and a hook block. The limiting rod cooperates with the upper sliding channel and the limiting hole, and the hook block cooperates with the side sliding channel. When the grouting pressure acts on the sliding block, the sliding block can move from the initial locking position to the final locking position, push the plurality of rod bodies to expand, and make the lower telescopic insertion rod and the upper telescopic insertion rod pop out and be locked through the anchoring hole.

[0010] As an optional implementation, the limiting hole comprises an upper limiting hole and a lower limiting hole, the depth of the lower limiting hole is greater than the depth of the upper limiting hole, so that the limiting rod can be separated from the upper limiting hole under the action of hydraulic pressure but cannot be separated from the lower limiting hole.

[0011] As an optional implementation, a one-way locking structure is provided between the mating surfaces of the lower telescopic insertion rod and the upper telescopic insertion rod, so that they can be locked after being popped out.

[0012] As an optional implementation, the end of the limiting rod is a ball head or a conical head, and the end of the hook block is a wedge-shaped head.

[0013] As an optional implementation, the baffle and the rod body are threadedly connected or welded.

[0014] As an optional implementation, the plurality of rod bodies are at least two levels of telescopic structure.

[0015] As an optional implementation, the sliding block is welded with the end face of the next stage rod body.

[0016] In another aspect, the present application also provides a geotechnical engineering supporting method using the hydraulic trigger type telescopic anchoring anchor rod described above, comprising the following steps: S1. The anchor rod in the contracted state is installed in the rock-soil body drill hole; S2. Grouting is injected into the drill hole, and the primary bonding anchoring of the anchor rod is completed through the grout outlet of the anchor head; S3. When the hydraulic pressure in the rod body reaches the preset value, the sliding block is triggered to move, so that the multi-stage rod body is stretched outward and forms an internal mechanical anchoring point.

[0017] The present application is based on the multi-stage telescopic sleeve structure, so that the anchor rod can be contracted to 30%-40% of the working length during transportation, which fundamentally solves the transportation and installation problems of long rod bodies in narrow tunnels, significantly improves the construction safety and efficiency. Secondly, by skillfully utilizing the energy contained in the grouting pressure, which is a construction link itself, the automatic triggering of the anchor rod without external energy is realized, breaking through the technical limitations of the passive response of traditional anchor rods, and ensuring the timely activation of the supporting system. More importantly, the present application creates a double anchoring mechanism of "grout bonding + internal mechanical interlocking", which improves the overall uplift resistance by 80%-150% through the rigid locking of the telescopic rod in the anchoring hole. In addition, the modular design concept makes all the sliding blocks and rod body structures uniform, greatly simplifying the manufacturing, inventory and assembly processes, and reducing the production and maintenance costs. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description.

[0019] Figure 1 is a structural schematic diagram of the working state of the present application; Figure 2 is a structural schematic diagram of the non-working state of the present application; Figure 3 is a structural schematic diagram of the anchor head assembly of the present application; Figure 4 is a partial structural schematic diagram of the rod body of the present application; Figure 5 is a structural schematic diagram of the cooperation between the driving and anchoring assembly and the rod body of the present application; Figure 6 is a structural schematic diagram of the driving and anchoring assembly of the present application.

[0020] In the figure: 1, baffle; 2, rod body; 201, upper limit hole; 202, anchoring hole; 203, lower limit hole; 204, groove; 205, boss; 206, upper slide; 207, side slide; 3, anchor head; 301, side slurry hole; 302, upper slurry hole; 303, front slurry hole; 4, sliding block; 401, limiting rod; 402, hook block; 403, lower telescopic rod; 404, upper telescopic rod; 405, first spring; 406, second spring. DETAILED DESCRIPTION

[0021] The following examples are intended to illustrate the present application but not to limit the scope of the present application.

[0022] Example 1 As shown in Figure 1 and Figure 6 , the present embodiment provides a hydraulic trigger type telescopic anchoring anchor rod, which ingeniously combines a multi-stage telescopic rod body structure with a hydraulic trigger mechanical anchoring mechanism. As shown in Figure 1 , in the working state, the anchor rod is fully stretched to form the maximum support length; and as shown in Figure 2 , in the non-working state, the anchor rod can be contracted to the minimum length, facilitating transportation and installation. The basic components of the anchor rod include four core components of baffle 1, multi-stage rod body 2, anchor head 3 and sliding block 4.

[0023] The baffle 1 can be fixed to one end of the outermost rod body 2 by threaded connection or welding, serving as the force basis of the entire anchor rod system, which transmits the load to the rock-soil surface during support. The multi-stage rod body 2 can adopt at least two hollow sleeve structures, and the side wall of each rod body 2 is recessed from the outside to the inside, forming a groove 204 and a boss 205 on the outer surface and the inner wall of the rod body 2 respectively. The groove 204 and the boss 205 are designed to realize mutual nesting. The boss 205 of the outer rod body and the groove 204 of the inner rod body form a sliding fit by mutual fitting, which restricts the relative rotation between the two adjacent rod bodies 2, and only allows the axial extension or contraction of the two rod bodies 2, which lays a foundation for the smooth ejection of the later-stage all-hole docking and rod insertion.

[0024] As shown in Figure 4As shown, a system of limiting holes is precisely formed along the axial direction on the wall of the rod 2, including a shallower upper limiting hole 201 and a deeper lower limiting hole 203 located at both ends of the rod 2. This depth difference design is a key point of this embodiment. The depth of the lower limiting hole 203 is about 30% to 50% deeper than that of the upper limiting hole 201, to ensure that the limiting rod 401 can break through the constraint of the upper limiting hole 201 under hydraulic action, but cannot disengage from the locking of the lower limiting hole 203. On both sides of the rod 2 near the lower limiting hole 203, anchoring holes 202 are symmetrically formed. The diameter of these anchoring holes 202 is slightly larger than the size of the telescopic insertion rod, providing a channel for mechanical anchoring. The rod 2 also has a boss 205 inside. The end of the boss 205 forms an upper slide rail 206, and the sides form side slide rails 207. These slide rails provide precise guidance for the movement of the slider 4. The anchor head 3 is fixed to the end of the innermost rod 2, and its structure is as follows. Figure 3 As shown, an upper grout outlet 302, a side grout outlet 301, and a front grout outlet 303 are respectively provided at the top, side, and front. This multi-directional grout outlet design ensures that the grout can fully fill all areas within the borehole, avoiding grouting dead zones and forming a uniform, full-length bonded initial anchor. Optionally, the number and size of the grout outlets can be adjusted according to specific geological conditions. For example, in highly permeable rock formations, the number of side grout outlets 301 can be increased; while in cases where priority grouting at the front end is required, the size of the front grout outlet 303 can be increased.

[0025] like Figure 5 and Figure 6 As shown, slider 4 is the core component of the anchor bolt hydraulic triggering and driving mechanism. It is housed inside rod 2 and can be welded to the end face of the next-level rod 2 to ensure effective transmission of thrust. Slider 4 adopts a split design, including an upper slider nested inside the lower slider, with a first spring 405 installed between them. The preload of the first spring 405 determines the hydraulic threshold for triggering rod 2 at that level. By selecting first springs 405 of different strengths, sequential triggering of each level of rod 2 can be achieved. This differentiated design ensures that rod 2 unfolds stably from the outside to the inside. Mechanical anchoring mechanisms are provided on both sides of the lower slider, including mutually nested lower telescopic rods 403 and upper telescopic rods 404, with a second spring 406 installed between them. A one-way locking structure is provided between the mating surfaces of the lower telescopic rod 403 and the upper telescopic rod 404. This one-way locking structure can be specifically referenced from existing ratchet rack structures (such as the self-locking structure on cable ties), or from the self-locking principle of the limiting rod 401 and the lower limiting hole 203 in this embodiment, which will not be elaborated further in this embodiment. This allows the upper telescopic rod 404 to be locked relative to the lower telescopic rod 403 after it is extended, forming an irreversible lock. To further enhance shear resistance, serrations or raised textures can also be provided on the outer surfaces of the lower telescopic rod 403 and the upper telescopic rod 404.

[0026] The slider 4 is also equipped with a limiting rod 401 and a hook block 402, as shown. Figure 6 The end of the limiting rod 401 is preferably designed as a ball head or a conical head to reduce the frictional resistance during movement in the upper slide 206; the end of the hook block 402 is designed as a wedge-shaped head to facilitate smooth sliding in the side slide 207. The limiting rod 401 cooperates with the upper slide 206 and the limiting holes 201 and 203, and the hook block 402 cooperates with the side slide 207, to jointly ensure the precise guided movement of the slider 4 under hydraulic action. The anchor rod of the present embodiment can adopt a telescopic structure of multiple stages, and the most basic is two stages, but according to actual engineering needs, it can be expanded to four stages, five stages or even more. The structures of the sliders and the rod body of all levels remain unified, and such a modular design greatly simplifies the manufacturing, inventory and assembly processes. In terms of material selection, the rod body 2 can be made of high-strength alloy steel with a tensile strength not less than 500 MPa; the sliders 4 and the upper telescopic insert rod 404 and the lower telescopic insert rod 403 can be made of tool steel with better wear resistance, and the surface is heat treated to improve the hardness; the springs 405 and 406 are made of high-strength spring steel to ensure that they will not fail due to fatigue during long-term service.

[0027] The use process of the present embodiment is as follows: in the initial fully retracted state, as shown in Figure 2As shown, all the rod bodies 2 are in a nested state, and the limiting rods 401 of the sliders 4 are clamped in the upper limiting holes 201 of the respective rod bodies 2, forming a preliminary fixation. The upper telescopic insertion rods 404 and the lower telescopic insertion rods 403 are in a retracted state. When the grouting begins, the pressure generated by the high-pressure slurry will simultaneously act on the end faces of all the sliders 4. When the pressure reaches the first-stage trigger threshold, the slider 4 in the first-stage rod body 2 (i.e., the outermost rod body 2) is started, and under the action of the slurry pressure, the limiting rods 401 at the upper and lower ends of the slider 4 will be separated from the upper limiting hole 201 by the contraction of the upper slider relative to the lower slider at the first spring 405, and the slider 4 that has been released from the limitation will slide along the boss 205 to the other end of the first-stage rod body 2 under the constraint of the upper slide 206 and the side slide 207, until the limiting rods 401 at the upper and lower ends of the slider 4 are clamped into the lower limiting hole 203 at the other end of the first-stage rod body 2. Since the end face of the first-stage rod body 2 is fixedly connected with the slider 4, when the slider 4 moves along the boss 205 inside the first-stage rod body 2, it will convert the kinetic energy of the high-pressure slurry impacting the surface of the slider 4 into the kinetic energy of the second-stage rod body 2 sliding relative to the first-stage rod body 1, until the limiting rods 401 on the slider 4 are clamped into the lower limiting hole 203 at the other end of the first-stage rod body 2. At this time, because the depth of the lower limiting hole 203 is deep, even if the upper slider reaches the maximum contraction stroke, the limiting rods 401 cannot be separated from the lower limiting hole 203, and thus the second-stage rod body 2 completes the process of sliding out of the first-stage rod body 1 and extending, and because the lower limiting hole 203 is locked with the limiting rods 401, the relative fixation process of the first-stage rod body 2 and the second-stage rod body 1 is also completed at the same time as the extension process of the second-stage rod body 2 is completed. During the impact process of the slider 4, the baffle 1 will play a role of reverse support, ensuring the stable extension of the second-stage rod body 1.

[0028] In addition, through precise size design, when the limiting rods 401 are clamped into the lower limiting hole 203 at the other end of the first-stage rod body 2, the upper telescopic insertion rods 404 at the two ends of the slider 4 will be aligned with the anchoring holes 202 on the side wall of the first-stage rod body 2, and will be ejected from the anchoring holes 202 under the action of the second spring 406 and inserted into the anchoring hole side wall.

[0029] The remaining rod bodies 2 are the same expansion process, until all the rod bodies 2 are completely expanded, the anchor head 3 is pushed to the final position, and the final locking is completed. When all the modules are completely expanded, the anchor rod reaches its maximum designed working length, and at the same time, the slurry fills the drill hole through the slurry outlet on the anchor head 3, forming the initial slurry bonding anchoring, and the upper telescopic insertion rods 404 in each stage rod body form a multiple internal anchoring system in the longitudinal direction inside the rod body 2.

[0030] In summary, the hydraulic triggerable telescopic anchoring anchor rod of the embodiment realizes the unification of convenient transportation, efficient installation and reliable anchoring through the multi-stage telescopic structure and the hydraulic trigger mechanical anchoring mechanism. The modular design facilitates manufacturing and maintenance, and the double anchoring system provides a safety reserve far beyond traditional anchor rods, especially suitable for supporting engineering in complex geological conditions such as soft and broken rock mass.

[0031] Embodiment two: The embodiment provides a geotechnical engineering supporting method using the hydraulic triggerable telescopic anchoring anchor rod described in embodiment one. The method cleverly utilizes the inherent hydraulic energy in the conventional grouting process, realizing the automatic triggering and expansion of the anchor rod without additional energy input, especially suitable for use in energy-limited underground environments. The method includes three core steps: anchor rod installation step S1, grouting anchoring step S2 and hydraulic triggering expansion step S3. In step S1, first determine the drilling parameters according to the geological survey results, including hole diameter, hole depth and inclination. Then use the drilling machine to form a drilling hole that meets the design requirements in the rock-soil body. Insert the hydraulic triggerable telescopic anchoring anchor rod in the fully contracted state into the drilling hole, ensuring that the baffle 1 is in close contact with the rock surface. At this stage, the contracted state of the anchor rod reduces its length to only 30% to 40% of the working length, greatly reducing the difficulty of transportation and installation, especially in space-limited mine tunnels. Step S2 starts grouting into the drilling hole, and through the upper grout outlet 302, side grout outlet 301 and front grout outlet 303 on the anchor head 3, the grout gradually fills the annular space between the anchor rod and the hole wall. The grout formula can be adjusted according to the rock mass conditions, for example, in soft rock strata, high-strength grout with low water-cement ratio can be used; while in the permeable fracture zone, a proper amount of expanding agent and thickening agent can be added. The grouting pressure needs to be accurately controlled, using lower pressure in the initial stage to ensure uniform filling of the grout, and then gradually increasing to the design pressure. The fluidity, setting time and final strength of the grout all need to meet the engineering specification requirements to ensure reliable primary bond anchoring.

[0032] Step S3 is the core part of the whole method, when the hydraulic pressure in the rod body 2 reaches the preset threshold, the slider 4 is triggered to start moving. This process is completely automatic and does not require manual intervention or external energy input. The hydraulic threshold is set by the pre-tightening force of the first spring 405, which can be differentiated according to the design requirements of each level of anchor rod. For example, for two-stage telescopic anchor rods, the first stage trigger pressure can be set to 2.0 MPa, the second stage to 1.6 MPa, and the second stage to 1.2 MPa. This step-by-step decreasing pressure setting ensures that the anchor rod expands in order from the outside to the inside. During the movement of the slider 4, on the one hand, it pushes the multi-stage rod body 2 to expand step by step, and on the other hand, it activates the mechanical anchoring mechanism when it reaches the designated position, causing the upper telescopic insert rod 404 and the lower telescopic insert rod 403 to pop out through the anchoring hole 202 and be locked, forming an internal mechanical anchoring point. One advantage of this method is its adaptive nature, as the grouting pressure not only forms a cohesive anchor but also serves as a hydraulic power source to trigger the expansion of the mechanical anchoring mechanism. This method eliminates the passive response lag problem commonly found in traditional anchor support, achieving synchronization of anchor installation and activation. In practical applications, the grouting pressure can be precisely adjusted by selecting different strengths of the first spring 405 to ensure that the mechanical anchoring point can be fully embedded in the rock mass.

[0033] To ensure the support effect, we conduct quality detection after grouting, including anchor rod pull-out test and length verification. Compared with traditional anchor rods, the anchor rod system implemented by this method has significantly higher pull-out resistance, with tests showing that it increases by 80% to 150% compared to traditional full-length cohesive anchor rods. This method is particularly suitable for supporting large-deformation rock masses, and its composite structure can safely adapt to 3-5 times the deformation of traditional anchor rods. In addition, the multiple anchoring system formed by this method creates a statically indeterminate structure with multiple force transmission paths, with high mechanical redundancy and a gradual failure mode instead of brittle fracture, providing the possibility for safety monitoring and early warning.

[0034] In summary, the geotechnical engineering support method of the present embodiment uses grouting pressure as a hydraulic trigger to achieve the integrated completion of anchor rod automatic expansion and mechanical anchoring. This method not only simplifies the construction process and improves work efficiency, but also significantly improves the reliability and safety reserve of the support system through the dual anchoring mechanism, providing an innovative solution for geotechnical engineering support in complex geological conditions.

Claims

1. Hydraulic triggerable retractable anchoring rod, characterized in that, The anchor rod comprises a baffle (1), a multi-stage rod body (2), an anchor head (3) and a sliding block (4); The baffle (1) is fixed to one end of the outermost rod body (2); The sidewall of each stage of the rod body (2) is concave from outside to inside, forming a groove (204) and a boss (205) on the outer surface and the inner wall of the rod body (2) respectively, and the two adjacent stages of the rod body (2) are stacked through the groove (204) and the boss (205), so that the anchor rod has a contraction and expansion state, and the rod body (2) is provided with a limiting hole and an anchoring hole (202); The end of the boss (205) forms an upper sliding channel (206), and the two sides form side sliding channels (207); The anchor head (3) is fixed to the end of the innermost rod body, and the anchor head (3) is provided with a plurality of grout outlets; The sliding block (4) is accommodated in the rod body (2) and is fixedly connected with the next stage of the rod body (2), the sliding block (4) comprises an upper sliding block nested in a lower sliding block, and a first spring (405) is arranged between the upper sliding block and the lower sliding block, the lower sliding block is provided with a lower telescopic inserting rod (403) and an upper telescopic inserting rod (404) which are nested with each other, and a second spring (406) is arranged between the lower telescopic inserting rod (403) and the upper telescopic inserting rod (404); The sliding block (4) is provided with a limiting rod (401) and a hook block (402), the limiting rod (401) is matched with the upper sliding channel (206) and the limiting hole, and the hook block (402) is matched with the side sliding channel (207); When the grouting pressure acts on the sliding block (4), the sliding block (4) can move from the initial locking position to the final locking position, push the next stage of the rod body (2) to expand, and make the lower telescopic inserting rod (403) and the upper telescopic inserting rod (404) pop out through the anchoring hole (202) and be stuck.

2. Hydraulic triggerable retractable anchoring rod according to claim 1, characterized in that The limiting hole comprises an upper limiting hole (201) and a lower limiting hole (203), the depth of the lower limiting hole (203) is greater than the depth of the upper limiting hole (201), so that the limiting rod (401) can be separated from the upper limiting hole (201) but cannot be separated from the lower limiting hole (203) under the action of hydraulic pressure.

3. Hydraulic triggerable retractable anchoring rod according to claim 1, characterized in that, A one-way locking structure is arranged between the matching surfaces of the lower telescopic inserting rod (403) and the upper telescopic inserting rod (404), so that the two can be stuck after being popped out.

4. The hydraulic trigger retractable anchor of claim 1, wherein: The end of the limiting rod (401) is a ball head or a conical head, and the end of the hook block (402) is a wedge-shaped head.

5. The hydraulic trigger retractable anchor of claim 1, wherein: The baffle (1) and the rod body (2) are threadedly connected or welded.

6. The hydraulic trigger retractable anchor of claim 1, wherein: The multi-stage rod body (2) has at least two telescopic structures.

7. The hydraulic trigger retractable anchor of claim 1, wherein: The sliding block (4) is welded with the end face of the next stage of the rod body.

8. A method of geotechnical engineering support using a hydraulic triggerable retractable anchoring anchor rod as claimed in any one of claims 1 to 7, characterised in that, The method comprises the following steps: S1. The anchor rod in the contraction state is installed in the rock-soil body drill hole; S2. Grouting is carried out in the drill hole, and the initial bonding anchoring of the anchor rod is completed through the grout outlets of the anchor head (3); S3. When the hydraulic pressure in the rod body reaches a preset value, the movement of the sliding block (4) is triggered, the multi-stage rod body (2) is expanded outward, and an internal mechanical anchoring point is formed.

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