Multi-stage anchoring type mechanical expansion self-locking combined anchor rod

Abstract

The invention relates to the technical field of geotechnical engineering anchoring, in particular to a multi-stage anchoring type mechanical expansion self-locking combined anchor rod. Comprising a hollow rod body; the fastening assembly is arranged at one end of the hollow rod body and is used for preventing slurry from overflowing from the drill hole; the grouting assembly is arranged at the other end of the hollow rod body and used for connecting the anchoring assembly to the end of the hollow rod body and guiding grout to flow; the anchoring assembly is provided with a plurality of anchoring pieces, and the multiple anchoring pieces expand in the radial direction under extrusion of the hollow rod body and the bottom wall of the drill hole and are self-locked with the grouting assembly through a clamping structure. After the anchoring pieces are expanded, mechanical anchoring is formed, and gaps between the anchoring pieces and the hole wall are filled through grouting to form a composite anchoring system. Through collaborative design of mechanical expansion, a self-locking structure and multi-stage grouting, the anchoring performance and construction efficiency of the anchor rod are remarkably improved, and the anchor rod is suitable for geotechnical engineering support under complex geological conditions and has wide market prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering anchoring, and particularly relates to a multi-stage anchoring type mechanical expansion self-locking combined bolt applicable to complex geological environments such as tunnels, mine roadways, and slope reinforcement. High-efficiency anchoring is achieved through the synergistic effect of mechanical expansion and grouting. Background Art

[0002] In various geotechnical engineering fields such as tunnels, slope reinforcement, and mine exploitation, bolts, as commonly used support members, play a crucial role in maintaining the stability of engineering structures. With the continuous development of geotechnical engineering, its scale has been continuously expanded, and the construction environment has become increasingly complex and diverse, posing more stringent requirements for the anchoring performance of bolts. However, current traditional bolts have exposed many problems in practical applications and are difficult to fully meet the diverse needs of projects.

[0003] High requirement for the length of the anchorage section: Traditional bolts rely on full-length bonding to achieve anchoring and require a relatively long anchorage section, usually 80% - 100% of the drilling depth. For example, in hard rock formations, the anchorage section length of traditional bolts needs to reach 2 - 3 meters to meet the uplift resistance requirements. This not only increases material costs but also limits their application in narrow spaces or rapid construction scenarios.

[0004] Insufficient uplift resistance: The uplift resistance of traditional bolts is limited by the frictional force of the anchorage section and the bonding force of the grout, and the value is usually relatively low. Taking hard rock formations as an example, the single-anchor uplift resistance of traditional bolts is generally only between 200 - 300 kN. In scenarios such as deep foundation pit support and large building foundation anchoring, it is difficult to resist high pulling forces, which is likely to cause bolt failure or structural instability.

[0005] Poor grouting uniformity: Traditional bolts have obvious defects. Due to the limitations of their structural design, the grout is prone to flow along a single channel during injection, resulting in uneven filling of the gap between the bolt and the hole wall. This makes it difficult to effectively improve the interfacial bonding strength of the anchoring system. During long-term use, local stress concentration is likely to occur, thereby reducing the anchoring effect and service life of the bolt.

[0006] Weak anti-floating performance: Traditional bolts rely on the passive force of the anchorage section to resist buoyancy. When the groundwater level fluctuates or the buoyancy suddenly increases, the anchorage section is prone to loosening. For example, in underground parking lot projects, the rising groundwater level may cause the anti-floating capacity of traditional bolts to decrease by 30% - 50%, threatening the structural safety.

[0007] In summary, the existing bolt technologies have many deficiencies in key aspects such as the length of the anchorage section, uplift resistance, grouting uniformity, and anti-floating performance, and are difficult to meet the requirements of complex and changeable geotechnical engineering. Therefore, developing a new type of bolt with significant improvements in the above performances has important practical significance for improving the safety, stability, and economy of geotechnical engineering. Summary of the Invention

[0008] The present invention aims to overcome the deficiencies of the prior art and provide a multi-stage anchoring type mechanical expansion self-locking combined anchor bolt. Through innovative structural design, the anchoring performance of the anchor bolt in complex geotechnical environments is significantly improved, and its stability and uplift resistance are enhanced. At the same time, the construction of the present invention is simple and has a wide range of applicability, providing a reliable and efficient solution for various geotechnical anchoring projects. The specific technical solutions are as follows:

[0009] The present invention provides a multi-stage anchoring type mechanical expansion self-locking combined anchor bolt, comprising:

[0010] A hollow rod body;

[0011] A fastening assembly, arranged at one end of the hollow rod body, for blocking the overflow of grout from the drill hole;

[0012] A grouting assembly, arranged at the other end of the hollow rod body, for connecting the anchoring assembly to the end of the hollow rod body and guiding the flow of grout;

[0013] The anchoring assembly is provided with a plurality of anchoring plates, and the plurality of anchoring plates radially expand under the extrusion between the hollow rod body and the bottom wall of the drill hole and are self-locked with the grouting assembly through a clamping structure;

[0014] Wherein, after the anchoring plates expand, mechanical anchoring is formed, and a composite anchoring system is formed by grouting to fill the gap between the anchoring plates and the hole wall.

[0015] As an implementation manner, the fastening assembly includes a grout plug made of an elastic material, and the inner wall of the grout plug is in interference fit with the hollow rod body.

[0016] As an implementation manner, the fastening assembly further includes a nut and a backing plate; the backing plate is located between the nut and the grout plug, and the nut is threadedly engaged with the outer wall of the hollow rod body.

[0017] As an implementation manner, the grouting assembly includes a flow splitting seat;

[0018] The flow splitting seat is fixedly installed at the end of the hollow rod body, and a cavity communicating with the hollow rod body is opened inside the flow splitting seat; a plurality of flow splitting channels extend horizontally outwards from the cavity, and the number of the flow splitting channels is the same as the number of the anchoring plates.

[0019] As an implementation manner, the anchoring assembly includes a mounting seat, a connecting rod and an anchoring plate;

[0020] The mounting base is coaxially installed at the lower end of the flow dividing base. A through hole is formed in the center of the mounting base, and the through hole communicates with the cavity of the flow dividing base. A plurality of mounting grooves are arranged in a circumferential array on the surface of the mounting base. On both side walls of each mounting groove, multiple groups of mounting holes are correspondingly formed. A pin is fixedly inserted into each group of mounting holes.

[0021] One end of the connecting rod is rotatably connected to the pin, and the other end is rotatably connected to the back surface of the anchoring piece.

[0022] As an implementation manner, the clamping structure includes a clamping block and a clamping ring.

[0023] The clamping block is vertically installed on the surface of the connecting rod in the mounting groove close to the flow dividing base.

[0024] The clamping ring is vertically installed on the outer side of the flow dividing base.

[0025] As an implementation manner, the front shape of the anchoring piece is adapted to the hole wall of the drilling hole.

[0026] As an implementation manner, a plurality of diversion grooves are uniformly formed on the front surface of the anchoring piece, and through holes connecting the front surface and the back surface of the anchoring piece are formed in the diversion grooves.

[0027] As an implementation manner, a fixing piece extends outward from the front surface of the anchoring piece.

[0028] Compared with traditional anchor bolts, the advantages of the present invention are as follows:

[0029] Through the innovative multi-stage anchoring structure and grouting strengthening system, the present invention has breakthroughly solved the bottleneck of the anchoring performance of traditional anchor bolts under complex geological conditions. Its core advantage lies in realizing the synergistic effect of mechanical expansion and grouting consolidation. Through the radial expansion of the anchoring piece to form an active embedded anchoring, combined with the biting mechanism of the fixing piece on the hole wall, the anchoring contact area is increased by 3-5 times compared with traditional full-length bonded anchor bolts. Thus, while shortening the length of the anchoring section, the anti-pulling performance is significantly enhanced. Verified by simulation experiments, the single-anchor anti-pulling force of this structure in hard rock formations can reach more than 400 kN, which is more than 50% higher than that of traditional anchor bolts, and a stable anchoring effect can still be maintained in soft rocks and fractured zones.

[0030] The diversion and diversion design of the grouting system completely overturns the defect of uneven grouting of traditional anchor rods. The multi-angle diversion channels in the diversion seat and the axial guide grooves on the anchor plate form a hierarchical grouting network, so that the slurry can evenly fill the tiny gap between the anchor rod and the hole wall in a spiral diffusion manner. This design not only eliminates the "blind spot" of traditional grouting, but also further enhances the bite force between the anchor plate and the hole wall through the micro-expansion effect after the slurry solidifies. Experimental data show that the grouting system can increase the interfacial bonding strength by 30%-50%, and form a stable anti-floating barrier under the condition of groundwater level fluctuation, effectively solving the buoyancy instability problem in underground engineering.

[0031] The snap-fit ​​structure automatically engages when the anchoring piece is unfolded to a critical angle, forming an irreversible mechanical lock. This design not only completely eliminates the risk of anchor failure caused by retraction of traditional anchor rods, but also absorbs overload energy through micro-yield deformation when the formation stress changes suddenly, thus avoiding the hole wall from rupturing. In actual applications, the self-locking mechanism can still maintain structural integrity when bearing 1.5 times the design load, significantly improving the reliability of the anchor rod under dynamic loads such as earthquakes and blasting.

[0032] In addition, the modular design of the present invention greatly simplifies the construction process. Through the quick-release bolt structure and adjustable connecting rod, construction workers can quickly complete the bolt assembly and grouting operations in a narrow space, and the overall construction efficiency is significantly improved compared with the traditional process. Especially in restricted environments such as mine tunnels and tunnel faces, its superior operability provides a strong guarantee for the progress of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] This specification includes the following drawings, which show the following contents:

[0034] Figure 1 It is a structural schematic diagram of the present invention in working state;

[0035] Figure 2 It is a structural schematic diagram of the present invention in a non-working state;

[0036] Figure 3 It is a schematic diagram of the structure of the mechanical expansion anchor head of the present invention;

[0037] Figure 4 It is a structural schematic diagram of the mounting seat of the present invention;

[0038] Figure 5 It is a schematic diagram of the structure of the anchoring sheet of the present invention;

[0039] Figure 6 It is a structural schematic diagram of the connecting rod of the present invention;

[0040] In the figure: 1. Hollow rod body; 2. Anchor piece; 201. Flow guiding groove; 202. Through hole; 203. Fixing piece; 3. Grout plug; 4. Nut; 5. Base plate; 6. Flow dividing seat; 601. Flow dividing hole passage; 7. Mounting seat; 701. Mounting groove; 702. Through hole; 703. Mounting hole; 8. Connecting rod; 9. Pin; 10. Block; 11. Snap ring. Specific embodiments

[0041] The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0042] Taking a tunnel support application as an example, the drilling depth is 3.2 meters and the hole diameter is 42 ± 1 mm.

[0043] As Figures 1 - 6 As shown, the present invention provides a multi-stage anchoring type mechanical expansion self-locking combined bolt, including: a hollow rod body 1; a fastening assembly arranged at one end of the hollow rod body 1 for blocking the overflow of grout from the drill hole; a grouting assembly arranged at the other end of the hollow rod body 1 for connecting the anchoring assembly to the end of the hollow rod body 1 and guiding the flow of grout; the anchoring assembly is provided with a plurality of anchor pieces 2, and the plurality of anchor pieces 2 radially expand under the extrusion of the hollow rod body 1 and the bottom wall of the drill hole and are self-locked with the grouting assembly through a clamping structure; wherein, after the anchor pieces 2 expand, mechanical anchoring is formed, and the gap between the anchor pieces 2 and the hole wall is filled with grout to form a composite anchoring system.

[0044] Specifically, select a combined bolt with a suitable specification according to the engineering parameters of the above drill hole. The outer diameter of the hollow rod body 1 is 25 mm, and the diameter after the anchor piece 2 is unfolded is 45 mm. Then check the integrity of each part of the combined bolt, confirm whether the anchor piece 2 is deformed, and whether the clamping structure is flexible. After checking without errors, then carry out the bolt insertion work. At the same time, before inserting the hollow rod body 1, the debris in the drill hole can be cleaned by blowing air to ensure that the hole wall and the hole bottom are smooth, and to avoid interfering with the expansion and anchoring of the anchor piece 2.

[0045] After the above preparations are completed, insert the end of the hollow rod body 1 with the anchoring assembly along the hole into the drill hole. At this time, the anchor piece 2 has not yet touched the bottom and enters the drill hole in its initial unfolded state. At this time, the overall diameter of the closed anchoring assembly is smaller than the drill hole diameter, so the engineering personnel can insert the anchoring assembly into the drill hole without any obstacle. After the anchoring assembly touches the bottom, the continuous axial push of the hollow rod body 1 will bidirectionally extrude the anchoring assembly with the hole bottom, causing the anchor piece 2 in the anchoring assembly to radially expand. The combined diameter of the expanded anchor pieces 2 can reach 45 mm, exceeding the drill hole diameter of 42 mm. Therefore, it will inevitably be squeezed against the drill hole wall, so that the front surface of the anchor piece 2 can be closely attached to the hole wall.

[0046] After the anchoring piece 2 is unfolded, the clamping structure can automatically lock the anchoring piece 2 to maintain its unfolded state, preventing the anchoring piece 2 from loosening under the reverse push of the hole wall after the axial pressure of the hollow rod 1 is lost.

[0047] After the anchoring piece 2 is unfolded, the fastening assembly just plugs the drilling opening. At this time, the whole drilling will form a closed grouting space. Connect one end of the hollow rod 1 exposed outside the drilling to the slurry pipeline, and inject the slurry into the hollow rod 1 at a pressure of 0.5 - 0.8 MPa and a grouting volume of 0.8 m³. Under the guidance of the hollow rod 1, the slurry is led into the grouting assembly at the other end of the hollow rod 1. The grouting assembly guides the slurry towards the anchoring piece 2, enabling the slurry to evenly fill the gap between the anchoring piece 2 and the hole wall. After the slurry solidifies, a multi-stage composite anchoring system of mechanical anchoring and slurry anchoring is formed to achieve the purpose of strengthening the anchoring strength.

[0048] As Figures 1 - 2 shown, among them, the fastening assembly may include a grout plug 3 made of elastic material. The inner wall of the grout plug 3 is in interference fit with the hollow rod 1. The grout plug 3 can be generally conical with the cone tip facing the drilling side to meet the sealing requirements of drillings with different hole diameters. After the anchoring piece 2 is unfolded, the grout plug 3 will be inserted into the opening end of the drilling. The grout plug 3 can be manually pushed along the length direction of the hollow rod 1 towards the drilling opening until the drilling is completely blocked, preventing the slurry from overflowing during the grouting process. Specifically, nitrile rubber can be used as the material for making the grout plug 3. Utilizing its wear-resistant and elastic physical properties, the grout plug 3 can fully adapt to the sealing requirements of drillings with different diameters and the sleeving requirements of the hollow rod 1, and when inserted into the hole opening, it can ensure the sealing effect of the hole opening by the extrusion of the hole opening and its own sufficient deformation.

[0049] As Figures 1 - 2 shown, further, the above-mentioned grout plug 3 relies only on the binding force of the hole opening on it and the friction force between the inner hole of the grout plug 3 and the hollow rod 1 to maintain its own stability at the hole opening. When the grouting pressure is relatively high, the sealing stability of the grout plug 3 will face a more severe test. To completely avoid this hidden danger, when the grouting pressure is relatively high, a nut 4 and a backing plate 5 can be additionally provided at the upper end of the grout plug 3. The backing plate 5 is located between the nut 4 and the grout plug 3, and the nut 4 is threadedly engaged with the outer surface of the hollow rod 1. Therefore, when the nut 4 is screwed, the nut 4 will drive the backing plate 5 to continuously approach and squeeze the grout plug 3 through threaded engagement transmission, and push the grout plug 3 into the drilling along the hollow rod 1. The flat surface of the backing plate 5 can apply a uniform thrust to the grout plug 3, ensuring that the grout plug 3 is uniformly stressed circumferentially. Thus, by utilizing the self-locking characteristic of the threaded engagement between the nut 4 and the hollow rod 1, an additional layer of insurance is added to the grout plug 3, enabling it to still ensure the sealing stability of the hole opening when facing a relatively high grouting pressure.

[0050] In this embodiment, whether it is the grout plug 3 or the radially deployed anchoring piece 2, they are both centered on the hollow rod body 1. That is to say, after the grout plug 3 seals the borehole opening and the anchoring piece 2 expands and mechanically anchors the bottom wall of the borehole, the grout plug 3 and the anchoring piece 2 can correct the attitude of the hollow rod body 1 relative to the borehole at both ends of the hollow rod body 1, ensuring that the hollow rod body 1 is coaxially assembled with the borehole. This assembly process will be automatically completed as the grout plug 3 and the anchoring piece 2 are installed in place, without manual adjustment. The hollow rod body 1 coaxially assembled with the borehole will ensure that the slurry filling gaps around the hollow rod body 1 are uniform and equal in size, which can maximize the grasping force of the slurry after solidification on the hollow rod body 1 in addition to laying the foundation for uniform slurry filling.

[0051] In addition, the deployment of the anchoring piece 2 at the bottom of the borehole will form a pre-fixation for the entire hollow anchor bolt, and this pre-fixation will be the basis for the grout plug 3 to be squeezed by the nut 4. When the nut 4 drives the backing plate 5 to squeeze the grout plug 3 through threaded meshing transmission, the nut 4 will inevitably give a reaction force to the hollow rod body 1 to pull out the hollow rod body 1 from the borehole. However, due to the extrusion and anchoring of the anchoring piece 2 on the inner wall of the hole bottom, this pulling force cannot pull out the hollow rod body 1. Therefore, the nut 4 can smoothly squeeze the backing plate 5 towards the grout plug 3. Conversely, the grout plug 3 locked and squeezed by the nut 4 and the backing plate 5 will seal the borehole opening, and this seal can maintain the grouting pressure after the borehole is filled with slurry, enabling the slurry to be forced to penetrate and spread into those unfilled gaps to improve the adequacy of the combination of the hollow rod body 1 and the anchoring piece 2 with the slurry.

[0052] That is to say, the pre-fixation of the anchoring piece 2 can provide support for the nut 4 to squeeze and fix the grout plug 3; and the seal of the grout plug 3 can provide support for the full combination of the anchoring piece 2 and the slurry. The two cooperate with each other to jointly improve the anchoring performance.

[0053] As Figure 3 shown, the grouting assembly may include a flow dividing seat 6; the flow dividing seat 6 is fixedly installed at the end of the hollow rod body 1, and a cavity communicating with the hollow rod body 1 is formed inside the flow dividing seat 6; a number of flow dividing channels 601 extend horizontally outward from the cavity, and the number of the flow dividing channels 601 is the same as the number of the anchoring pieces 2.

[0054] In this embodiment, taking three anchoring pieces 2 as an example, the three anchoring pieces 2 can correspond to three flow dividing channels 601. Combining Figure 3, the flow dividing seat 6 can be a three - leaf structure. The area between the leaves is the outlet of the flow dividing channel 601, and the outlet is located on the circumferential side of the flow dividing seat 6. Specifically, when the external quick - setting slurry is injected into the hollow rod body 1, it will directly reach the cavity inside the bottom flow dividing seat 6 along the hollow rod body 1, and then be ejected from three directions of the flow dividing seat 6 through the diversion of the three flow dividing channels 601. This optimization of the slurry flow field distribution enables the slurry to enter the expansion area of the anchoring piece 2 from multiple directions, forming the effect of multi - point injection. This multi - point injection method can significantly improve the diffusion range and uniformity of the slurry, ensuring that the slurry can evenly cover the inner wall of the anchoring piece 2.

[0055] As Figure 5 shown, further, in order to strengthen the guiding effect on the slurry, a plurality of guiding grooves 201 and through - holes 202 can be axially opened on the front surface of the anchoring piece 2. In order to adapt to the circular inner wall of the drilling hole, the front surface of the anchoring piece 2 can also be designed as an arc shape to ensure that the anchoring piece 2 can fully fit with the inner wall of the drilling hole. Specifically, when the slurry in the flow dividing channel 601 is ejected, the slurry just sprays onto the hole wall between two adjacent anchoring pieces 2. The splashing slurry will be guided from the back surface of the anchoring piece 2 to the guiding grooves 201 opened on the front surface of the anchoring piece 2 through the through - holes 202, so as to assist the diffusion and filling of the slurry between the anchoring piece 2 and the inner wall of the drilling hole, and fully ensure the uniform distribution of the slurry in the drilling hole.

[0056] In addition, a fixing piece 203 can be extended outward on the front surface of the anchoring piece 2. The fixing piece 203 can be in the shape of a barbed hook. During the radial expansion of the anchoring piece 2, it can be obliquely inserted into the hole wall from bottom to top along with the deflection action of the connecting rod 8, so as to strengthen the grasping force between the anchoring piece 2 and the hole wall and improve the anchoring effect.

[0057] As Figure 4 and Figure 6 shown, the anchoring assembly can include a mounting seat 7, a connecting rod 8 and an anchoring piece 2; the mounting seat 7 is coaxially installed at the lower end of the flow dividing seat 6, a through - hole 702 is opened in the center of the mounting seat 7 and the through - hole 702 is communicated with the cavity of the flow dividing seat 6; a plurality of mounting grooves 701 are arranged in a circumferential array on the surface of the mounting seat 7; a plurality of groups of mounting holes 703 are correspondingly opened on both side walls of each mounting groove 701; a pin 9 is fixedly inserted into each group of mounting holes 703; one end of the connecting rod 8 is rotatably connected with the pin 9, and the other end is rotatably connected with the back surface of the anchoring piece 2.

[0058] The mounting base 7 is coaxially installed at the lower end of the flow splitting base 6 and extends downward along the three-lobe structure contour of the flow splitting base 6, so as to avoid interfering with the slurry spraying path of the flow splitting channels 601. Specifically, when the hollow rod body 1 is inserted into the bottom of the hole, the three anchoring pieces 2 will first contact the bottom of the hole, and with the axial force applied by the hollow rod body 1, the connecting rod 8 between the anchoring piece 2 and the hollow rod body 1 will deflect due to the bi-directional extrusion of the flow splitting base 6 and the bottom of the hole, and then the anchoring piece 2 will move radially. When the connecting rod 8 close to the flow splitting base 6 rotates to fit with the lower end face of the flow splitting base 6, the rotation of the connecting rod 8 terminates, and the anchoring piece 2 is fully deployed. At this time, the connecting rod 8 is perpendicular to the hollow rod body 1. At this special point, with the rotation of the connecting rod 8, the clamping block 10 fixedly installed on the upper surface of the connecting rod 8 close to the flow splitting base 6 will continuously approach the clamping ring 11 vertically installed on the outside of the flow splitting base 6. When the connecting rod 8 is perpendicular to the hollow rod body 1, the clamping block 10 and the clamping ring 11 are exactly docked. At this time, the connecting rod 8 will no longer be able to rotate freely due to the docking constraint of the clamping block 10 and the clamping ring 11. Even if the engineering personnel no longer apply continuous pressure to the hollow rod body 1, the deployed anchoring piece 2 can maintain the stability of the existing deployed posture due to the self-locking of the clamping block 10 and the clamping ring 11.

[0059] Whether it is the clamping of the clamping ring 11 and the clamping block 10 or the position constraint of the lower surface of the flow splitting base 6 on the connecting rod 8, it can buffer the impact force on the hole wall caused by overload to a certain extent, avoiding the situation where the engineering personnel blindly apply force in the visual blind area, resulting in the over-extrusion of the anchoring piece 2 against the hole wall and causing damage to it, and significantly improving the adaptability of the anchor bolt to different stratum conditions and construction working conditions.

[0060] Index Traditional anchor bolt Combined anchor bolt of this embodiment Anchorage section length 2 - 3 m 0.5 - 0.8 m (60% - 70% shorter) Single - anchor pull - out resistance 200 - 300 kN Above 400 kN (100% - 150% increase) Grouting filling uniformity ≤70% ≥90% (30% - 50% increase) Anti - floating capacity Vulnerable to groundwater influence 50% - 70% increase

[0061] Table 1. Performance comparison table of the combined anchor bolt of this embodiment and the traditional anchor bolt

[0062] As can be seen from Table 1 above, the present invention is superior to the traditional anchor bolt in terms of the anchoring section length, pull-out resistance, grouting uniformity, and anti-floating performance, etc., providing a reliable and efficient solution for the geotechnical engineering field.

[0063] The multi-stage anchoring type mechanical expansion self-locking combined anchor bolt of the present invention significantly improves the anchoring performance of the anchor bolt, enhances its stability and pull-out resistance through innovative mechanical expansion and grouting strengthening designs. At the same time, the anchor bolt is convenient for construction and has a wide applicability, and can effectively meet the high-efficiency support requirements in complex geological environments such as tunnels, mine roadways, and slope reinforcement.

[0064] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. Multi-stage anchoring mechanical expansion self-locking combined anchor, characterized in that: include: Hollow rod body (1); A fastening assembly, arranged at one end of the hollow rod body (1), and used to prevent slurry from overflowing from the drill hole; A grouting assembly, arranged at the other end of the hollow rod body (1), used to connect the anchoring assembly to the end of the hollow rod body (1) and guide the flow of slurry; The anchoring assembly is provided with a plurality of anchoring sheets (2), and the plurality of anchoring sheets (2) radially expand under the squeezing of the hollow rod body (1) and the bottom wall of the borehole and are self-locked with the grouting assembly through a snap-fit ​​structure; The anchoring sheet (2) forms a mechanical anchor after expansion, and a composite anchoring system is formed by grouting to fill the gap between the anchoring sheet (2) and the hole wall.

2. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 1 is characterized in that: The fastening assembly comprises a slurry stopping plug (3) made of elastic material, the inner wall of the slurry stopping plug (3) being in interference fit with the hollow rod body (1).

3. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 2 is characterized in that: The fastening assembly further comprises a nut (4) and a gasket (5); the gasket (5) is located between the nut (4) and the slurry stopper (3), and the nut (4) is threadedly engaged with the outer wall of the hollow rod body (1).

4. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 1, characterized in that: The grouting assembly comprises a diverter seat (6); The flow diverter seat (6) is fixedly mounted on the end of the hollow rod body (1), and a cavity communicating with the hollow rod body (1) is provided inside the flow diverter seat (6); a plurality of flow diverter channels (601) are horizontally extended outward from the cavity, and the number of the flow diverter channels (601) is the same as the number of the anchoring sheets (2).

5. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 4 is characterized in that: The anchoring assembly comprises a mounting seat (7), a connecting rod (8) and an anchoring sheet (2); The mounting seat (7) is coaxially mounted on the lower end of the diverter seat (6); a through hole (702) is provided at the center of the mounting seat (7) and the through hole (702) is communicated with the cavity of the diverter seat (6); a plurality of mounting grooves (701) are arranged in a circular array on the surface of the mounting seat (7); a plurality of groups of mounting holes (703) are correspondingly provided on the groove walls on both sides of each mounting groove (701); a latch (9) is fixedly inserted in each group of mounting holes (703); One end of the connecting rod (8) is rotatably connected to the latch pin (9), and the other end is rotatably connected to the back side of the anchor plate (2).

6. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 5, characterized in that: The snap-fit ​​structure comprises a snap block (10) and a snap ring (11); The clamping block (10) is vertically mounted on the surface of the connecting rod (8) close to the diverter seat (6) in the mounting groove (701); The clamping ring (11) is vertically mounted on the outer side of the diverter seat (6).

7. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 1, characterized in that: The front shape of the anchoring sheet (2) is adapted to the wall of the drilled hole.

8. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 7 is characterized in that: A plurality of guide grooves (201) are evenly arranged on the front side of the anchoring sheet (2), and a through hole (202) connecting the front side and the back side of the anchoring sheet (2) is arranged in the guide groove (201).

9. The multi-stage anchoring mechanical expansion self-locking combined anchor bolt according to claim 1, characterized in that: A fixing piece (203) extends outwardly from the front side of the anchoring sheet (2).

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