Anchor rod for slope reinforcement and multi-stage variable-pressure grouting method

Abstract

The anchor rod comprises a hollow rod body, a grouting channel is formed in the hollow rod body, and multiple sets of through grooves are evenly distributed in the peripheral side of the hollow rod body; the driving unit comprises a top shaft movably arranged in the hollow rod body, the axis of the top shaft is overlapped with the axis of the hollow rod body, the clamping arms are movably arranged in the corresponding through grooves, a top plate is fixedly arranged at one end of the top shaft, and the end, away from the top shaft, of the top plate is located on the outer side of the end of the hollow rod body; wedge-shaped blocks with the number corresponding to that of the multiple sets of clamping arms are fixedly arranged on the peripheral side of the top shaft, and the multiple sets of clamping arms extend out of the hollow rod body under the action of the corresponding wedge-shaped blocks. The through grooves evenly distributed in the peripheral side of the hollow rod body are matched with the clamping arms, when the anchor rod is installed, the clamping arms extend out of the hollow rod body under the action of the wedge-shaped blocks, the clamping arms can disperse and resist external force from different angles, and compared with a traditional anchor rod with the single anchoring direction, pulling resistance can be more effectively provided, and the stability of the anchor rod under the complex stress condition is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of slope protection, and in particular to an anchor rod for slope reinforcement and a multi-stage variable pressure grouting method. Background Art

[0002] In civil engineering construction, slope stability reinforcement is a significant technical challenge. Due to low soil cohesion, slopes are prone to geological disasters such as landslides and collapses, posing a serious threat to project safety and the safety of people and property. Currently, anchor bolting is a commonly used slope reinforcement method. By anchoring bolts into stable rock and soil layers, the pullout resistance of the bolts is utilized to improve slope stability.

[0003] However, the existing anchor rods have problems in slope applications. Due to the slope soil, the anchoring force between the anchor rod and the slope is mainly determined by the bonding force of the slurry material. The anchoring force has a single source and it is difficult to provide sufficient pull-out resistance, which makes the anchor rod easy to loosen or even pull out. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide an anchor rod and a multi-stage variable pressure grouting method for slope reinforcement, so as to solve the problem that the traditional anchor rod in the existing technology has a single source of anchoring force and is difficult to provide sufficient pull-out resistance, which causes the anchor rod to loosen easily or even be pulled out.

[0005] According to an embodiment of the present invention, an anchor rod for slope reinforcement includes a hollow rod body with a grouting channel formed inside, and multiple groups of through grooves are distributed around the circumference of the hollow rod body; a driving unit includes a top shaft movably arranged inside the hollow rod body, the axis of the top shaft overlaps with the axis of the hollow rod body, and a clamping arm movably arranged in the corresponding through groove, a top plate is fixedly provided at one end of the top shaft, and an end of the top plate away from the top shaft is located outside the end of the hollow rod body, wherein wedge blocks corresponding to the number of the multiple groups of clamping arms are fixedly provided on the circumference of the top shaft, and the multiple groups of clamping arms extend outside the hollow rod body under the action of the corresponding wedge blocks.

[0006] Compared to existing technologies, the present invention offers the following advantages: Through slots uniformly distributed around the hollow rod body, the clamping arms are coupled to the wedge-shaped blocks, allowing the clamping arms to extend beyond the hollow rod body during anchor installation. Multiple sets of clamping arms extend beyond the hollow rod body, tightly engaging the soil from multiple directions. This eliminates the need for anchoring forces limited to the axial direction of the rod body, forming a multi-dimensional force system. When the slope soil exerts forces on the anchor rod, the clamping arms can disperse and resist external forces from different angles. Compared to the single anchoring direction of traditional anchor rods, this design provides more effective pullout resistance and enhances the stability of the anchor rod under complex load conditions.

[0007] Preferably, a limit block is mirror-imaged inside one end of the hollow rod body close to the top plate, and limit slots are provided on both sides of the top plate. Each limit block is located in a corresponding limit slot and is slidable.

[0008] Preferably, a duckbill groove is mirrored at one end of the limit block of the hollow rod body, a first inclined surface is provided on the bottom wall of each limit groove, a slot is provided at the end of each first inclined surface, and teeth are provided on the opposite surfaces of the two limit blocks, and each tooth corresponds to each slot one by one.

[0009] Preferably, a limiting plate for limiting the clamping arm from being pushed out of the through slot is provided at the bottom of each clamping arm, and the limiting plate is located in the hollow rod body.

[0010] Preferably, a second wedge surface and a second plane are provided on a side of each limiting plate facing away from the corresponding clamping arm, a first wedge surface and a first plane are provided on each wedge block, and each first wedge surface abuts against the corresponding second wedge surface.

[0011] Preferably, a spike portion is provided on one end of each clamping arm away from the corresponding limiting plate.

[0012] Preferably, a spiral groove is provided on the outer wall of the hollow rod.

[0013] Preferably, a thread is formed on one end of the hollow rod body away from the top plate, and a pad and a nut are provided on the threaded section.

[0014] On the other hand, according to an embodiment of the present invention, the present invention also provides a multi-stage variable pressure grouting method for anchor rods for slope reinforcement, comprising the following steps:

[0015] S1, anchor bolt and grouting preparation: Drill anchor bolt holes on the slope according to the design requirements. After the drilling is completed, insert the hollow rod body into the drilled hole;

[0016] S2, initial low-pressure grouting stage: initial low-pressure grouting is performed through the hollow rod channel, and the grouting pressure is set to P1, and the value range of P1 is 0.2~0.6MPa;

[0017] S3, medium pressure grouting stage: the grouting pressure is increased to P2, which is 1.5 to 2 times of P1, and medium pressure grouting is performed;

[0018] S4, high-pressure grouting stage: the grouting pressure is increased to P3, which is 1.2 to 1.5 times that of P2, and high-pressure grouting is performed;

[0019] Preferably, in step S1: after the hollow rod body is inserted into the drill hole, external force is continuously applied to the hollow rod body so that the top plate and the bottom of the hole are squeezed against each other, the top plate is pushed into the hollow rod body, and the wedge block synchronously squeezes the clamping arm so that it extends out of the hollow rod body and inserts into the hole wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0021] Figure 2 Schematic diagram of the end structure of the hollow rod in an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the three-dimensional structure of the positioning unit in an embodiment of the present invention.

[0023] Figure 4 Schematic diagram of the three-dimensional structure of the driving unit in an embodiment of the present invention.

[0024] Figure 5 for Figure 4 Magnified view of area A in center.

[0025] Figure 6 Schematic diagram of the internal structure of the hollow rod body in an embodiment of the present invention.

[0026] Figure 7 for Figure 6 Magnified view of area B.

[0027] The figure marks in the drawings of the specification include: 10, hollow rod body; 11, spiral groove; 12, pad; 13, nut; 15, duckbill groove; 16, through groove; 17, limit block; 171, latch tooth; 20, latch arm; 21, limit plate; 211, second wedge surface; 212, second plane; 22, spike portion; 30, top plate; 31, limit groove; 311, first inclined surface; 312, latch groove; 40, top shaft; 50, wedge block; 501, first wedge surface; 502, first plane. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0029] like Figures 1 to 7 As shown, an embodiment of the present invention proposes an anchor rod for slope reinforcement, which includes a hollow rod body 10 with a grouting channel formed inside, and multiple groups of through grooves 16 are evenly distributed around the hollow rod body 10; a driving unit includes a top shaft 40 movably arranged inside the hollow rod body 10, the axis of the top shaft 40 overlaps with the axis of the hollow rod body 10, and a clamping arm 20 movably arranged in the corresponding through groove 16, a top plate 30 is fixedly provided at one end of the top shaft 40, and the end of the top plate 30 away from the top shaft 40 is located outside the end of the hollow rod body 10, wherein wedge blocks 50 corresponding to the number of the multiple groups of clamping arms 20 are fixedly provided around the top shaft 40, and the multiple groups of clamping arms 20 extend to the outside of the hollow rod body 10 under the action of the corresponding wedge blocks 50.

[0030] The detailed working process of this embodiment is as follows: Through slots 16 evenly distributed around the hollow rod body 10, the clamping arms 20 engage with the wedge blocks 50 during anchor installation, extending beyond the hollow rod body 10. Multiple groups of clamping arms 20 extend beyond the hollow rod body 10 and penetrate the soil, tightly engaging with the soil from multiple directions. This eliminates the need for anchoring forces limited to the rod's axial direction, forming a multi-dimensional force-bearing system. When the slope soil exerts forces on the anchor, the clamping arms 20 disperse and resist external forces from various angles. Compared to the single anchoring direction of traditional anchors, this provides more effective pullout resistance and enhances the anchor's stability under complex load conditions.

[0031] Multiple groups of clamping arms 20 can greatly increase the contact area between the anchor rod and the slope soil, so that the anchor rod can obtain more friction and bite force in the soil, thereby improving the anchoring force and reducing the risk of loosening or pulling out.

[0032] like Figures 2 to 5 As shown, a limit block 17 is mirror-imaged inside one end of the hollow rod body 10 close to the top plate 30 , and limit slots 31 are provided on both sides of the top plate 30 . Each limit block 17 is located in a corresponding limit slot 31 and is slidable.

[0033] The detailed working process of this embodiment is as follows: through the cooperation between the limit block 17 and the limit groove 31, the movement of the top plate 30 in the radial direction of the rod body is limited, ensuring that the top plate 30 will not shake or shift at will during the operation of the anchor rod, and ensuring that each wedge block 50 is in contact with the corresponding clamping arm 20. When the driving unit is working, the movement of the top plate 30 can be precisely reinforced by the sliding of the limit block 17 in the limit groove 31, thereby ensuring that the clamping arm 20 is unfolded in the expected manner and realizing the reliable operation of the anchoring function of the anchor rod.

[0034] During the installation of the anchor rod, the top plate 30 can slide smoothly along the limiting groove 31, pushing the wedge block 50 and other structures to act on the clamping arm 20, so that the clamping arm 20 is accurately extended.

[0035] like Figure 4 and Figure 5 As shown, the hollow rod body 10 is provided with a duckbill groove 15 at one end of the limit block 17, and the bottom wall of each limit groove 31 is provided with a first inclined surface 311. A card slot 312 is provided at the end of each first inclined surface 311. The opposite surfaces of the two limit blocks 17 are provided with cards 171, and each card tooth 171 corresponds to each card slot 312 one by one.

[0036] The detailed working process of this embodiment is as follows: through the coordinated action of the duckbill groove 15, the first inclined surface 311, the latching groove 312, and the latching teeth 171, the mirrored groove at the end of the hollow rod body 10 enables the rod end to be elastically deformable. When the top plate 30 is subjected to stress, the rod end can expand outward through the duckbill groove 15 to relieve stress. The inclined surface structure of the bottom wall of the limiting groove 31 guides the latching teeth 171 along a specific path, ensuring that the latching teeth 171 accurately enter the latching groove 312. The latching groove 312 provides a locking position for the latching teeth 171. The combination of the two forms a mechanical locking structure to prevent the top plate 30 from accidentally retracting.

[0037] When the top plate 30 is pushed by an external force, the latching teeth 171 slide along the first inclined surface 311 and gradually compress the rod material on both sides of the duckbill slot 15. When the latching teeth 171 reach the latching slot 312, the rod material elastically recovers, and the latching teeth 171 engage the latching slot 312, forming a rigid lock. The engagement between the latching slot 312 and the latching teeth 171 provides reverse resistance, effectively preventing the top plate 30 from being forced back, ensuring the stability of the anchor rod during long-term use.

[0038] like Figure 6 As shown, a limiting plate 21 is provided at the bottom of each clamping arm 20 for limiting the clamping arm 20 from being pushed out of the through slot 16 , and the limiting plate 21 is located in the hollow rod body 10 .

[0039] The detailed working process of this embodiment is as follows: under the setting of the limit plate 21, when the clamping arm 20 is pushed out of the through slot 16 by the wedge block 41, the limit plate 21 will eventually contact the inner edge of the through slot 16, preventing the clamping arm 20 from moving further outward, thereby limiting the maximum travel of the clamping arm 20. During the anchor bolt installation process, the wedge block 41 pushes the clamping arm 20 to expand outward.

[0040] The presence of the limiting plate 21 prevents the clamping arm 20 from completely separating from the through slot 16 due to excessive force, ensuring that the clamping arm 20 and the rod body remain connected at all times, maintaining the overall structural integrity of the anchor rod.

[0041] like Figure 5 and Figure 6 As shown, each limiting plate 21 is provided with a second wedge surface 211 and a second plane 212 on a side facing away from the corresponding clamping arm 20 , and each wedge block 50 is provided with a first wedge surface 501 and a first plane 502 , and each first wedge surface 501 abuts against the corresponding second wedge surface 211 .

[0042] The detailed working process of this embodiment is as follows: through the interaction between the first wedge surface 501 and the second wedge surface 211, as well as the first plane 502 and the second plane 212, when the top shaft 40 pushes the wedge block 50 forward, the contact between the first wedge surface 501 and the second wedge surface 211 causes the clamping arm 20 to gradually expand outward. After the clamping arm 20 is fully extended, the first plane 502 and the second plane 212 mate, forming a surface contact support that prevents the wedge block 50 from retreating, thereby achieving mechanical self-locking. Even if the grouting material is not fully solidified or the soil undergoes slight deformation, the clamping arm 20 will not retract, ensuring the long-term stability of the anchoring force.

[0043] During the grouting process, the self-locking structure of the wedge surface prevents the clamping arm 20 from retracting due to the grouting pressure, ensuring that the grouting liquid fully fills the space formed by the expansion structure. The solidified grouting liquid and the mechanical locking structure work together to further enhance the anchor bolt's pullout resistance.

[0044] like Figure 6 As shown, each clamping arm 20 is provided with a spike portion 22 at one end away from the corresponding limiting plate 21 .

[0045] The detailed working process of this embodiment is as follows: under the setting of the spike portion 22, during the expansion of the clamping arm 20, the spike portion 22 can first cut into the soil, especially when encountering gravel or hard interlayers in the soil, it can effectively break the obstacles, reduce the expansion resistance of the clamping arm 20, and ensure that the clamping arm 20 can smoothly expand to the predetermined position.

[0046] like Figure 2 As shown, a spiral groove 11 is formed on the outer wall of the hollow rod body 10 .

[0047] The detailed working process of this embodiment is as follows: With the spiral groove 11, it increases the contact area between the rod, the grouting material, and the soil, creating a thread-like interlocking effect. During grouting, the slurry fills the spiral groove 11 and, after solidification, forms a tight fit like a "screw and nut." This significantly increases the friction and adhesion between the anchor rod and the surrounding medium, improving its pullout resistance and effectively preventing the anchor rod from loosening or being pulled out of the slope.

[0048] like Figure 2 As shown, one end of the hollow rod body 10 away from the top plate 30 is provided with a thread, and a backing plate 12 and a nut 13 are provided on the threaded section.

[0049] The detailed working process of this embodiment is as follows: The thread at the end of the hollow rod 10 is used to cooperate with the nut 13, pressing the backing plate 12 against the slope surface to form an anchoring reaction force device. The pitch and tooth profile of the thread should be selected according to the design load of the anchor rod to ensure sufficient thread strength and self-locking performance.

[0050] The pad 12 is usually a circular or square steel plate, and its function is to disperse the concentrated load of the nut 13 to prevent the slope soil from being damaged due to excessive local pressure. By tightening the nut 13, prestress can be applied to the anchor rod, so that the anchor rod is in a tensile state before being subjected to force, thereby improving the anchor rod's active restraint ability on the slope.

[0051] like Figures 1 to 7 As shown, a multi-stage variable pressure grouting method for anchor rods for slope reinforcement is also provided, comprising the following steps:

[0052] S1, anchor bolt and grouting preparation: Drill anchor bolt holes on the slope according to design requirements. After the drilling is completed, insert the hollow rod body 10 into the drilled hole;

[0053] S2, initial low-pressure grouting stage: initial low-pressure grouting is performed through the 10 channels of the hollow rod body, and the grouting pressure is set to P1, and the value range of P1 is 0.2-0.6MPa;

[0054] S3, medium pressure grouting stage: the grouting pressure is increased to P2, which is 1.5 to 2 times of P1, and medium pressure grouting is performed;

[0055] S4, high-pressure grouting stage: increase the grouting pressure to P3, which is 1.2 to 1.5 times that of P2, and perform high-pressure grouting.

[0056] The detailed working process of this embodiment is as follows: in the initial low-pressure grouting stage S2, initial low-pressure grouting is carried out through the hollow channel of the anchor rod, and the grouting pressure is set to P1 (P1 is pre-set to 0.2-0.6MPa based on the characteristics of the slope soil). In the initial low-pressure grouting stage, the slurry slowly penetrates into the pores of the soil under relatively low pressure, fills larger pores and cracks, and forms a preliminary anchoring foundation. During the grouting process, the changes in the grouting volume and grouting pressure are continuously monitored. When the grouting volume reaches 30%-50% of the designed grouting volume or the grouting pressure rises to a value close to the upper limit of P1, the next stage is entered.

[0057] During grouting, the external grouting equipment is connected to the end of the hollow rod body 10, and grouting is performed through the internal channel of the hollow rod body 10. The concrete slurry flows out from the other end of the hollow rod body 10 and the duckbill groove 15 and spreads to the hole mouth until the anchor hole is filled.

[0058] During the S3 medium-pressure grouting phase, the grouting pressure is increased to P2 (P2>P1) and medium-pressure grouting is performed. This allows the slurry to penetrate further into smaller pores and cracks in the soil, expanding its diffusion range and strengthening the bond between the anchor and the soil. During the medium-pressure grouting process, the grouting volume and pressure are also closely monitored. When the grouting volume reaches 70%-80% of the designed grouting volume or the grouting pressure rises close to the upper limit of P2, the high-pressure grouting phase begins.

[0059] During the S4 high-pressure grouting stage, the grouting pressure is increased to P3 (P3>P2) and high-pressure grouting is performed. High-pressure grouting allows the grout to fully fill the fine pores and cracks in the soil, forming a denser grouting mass around the anchor, significantly increasing the anchoring strength. Grouting is stopped when the grouting volume reaches the designed grouting volume or the grouting pressure reaches P3 and stabilizes for a certain period of time (generally 3-5 minutes).

[0060] The problem is that single pressure grouting in the soil can easily lead to uneven diffusion of the slurry, which cannot fully fill the soil pores, resulting in insufficient anchoring force between the anchor rod and the soil, reducing the reinforcement effect of the anchor rod; on the other hand, the problem is that excessive grouting pressure may cause adverse phenomena such as soil splitting and surface uplift, destroying the original stability of the slope.

[0061] like Figure 1 As shown, in step S1: after the hollow rod body 10 is inserted into the drill hole, external force is continuously applied to the hollow rod body 10 so that the top plate 30 and the bottom of the hole are squeezed against each other, and the top plate 30 is pushed into the hollow rod body 10. The wedge block 50 synchronously squeezes the clamping arm 20 so that it extends out of the hollow rod body 10 and inserts into the hole wall.

[0062] The detailed operating process of this embodiment is as follows: After the hollow rod 10 is inserted into the drilled hole, an external force pushes the top plate 30 toward the bottom of the hole. Because the top plate 30 is connected to the top shaft 40 and the wedge block 50, the displacement of the top plate 30 drives the wedge block 50 forward synchronously. The inclined surface of the wedge block 50 interacts with the second wedge surface 211 of the bottom stop plate 21 of the clamping arm 20. As the wedge block 50 moves forward, the clamping arm 20 is gradually pushed out of the through slot 16, and the spike portion 22 penetrates the soil at the hole wall. This creates a multi-point anchoring structure, significantly enhancing the engagement with the soil.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An anchor rod for slope reinforcement, characterized in that: include: A hollow rod body (10) is provided with a grouting channel formed therein, and a plurality of through grooves (16) are evenly distributed around the circumference of the hollow rod body (10); The driving unit comprises a top shaft (40) movably arranged inside the hollow rod body (10), the axis of the top shaft (40) overlapping with the axis of the hollow rod body (10), and a clamping arm (20) movably arranged in the corresponding through groove (16), a top plate (30) fixedly arranged at one end of the top shaft (40), and an end of the top plate (30) away from the top shaft (40) being located outside the end of the hollow rod body (10), wherein wedge blocks (50) corresponding in number to the plurality of groups of clamping arms (20) are fixedly arranged on the circumference of the top shaft (40), and the plurality of groups of clamping arms (20) extend to the outside of the hollow rod body (10) under the action of the corresponding wedge blocks (50).

2. The anchor rod for slope reinforcement according to claim 1, characterized in that: A limiting block (17) is mirror-imaged inside one end of the hollow rod body (10) close to the top plate (30), and limiting grooves (31) are provided on both sides of the top plate (30). Each limiting block (17) is located in a corresponding limiting groove (31) and is slidable.

3. The anchor rod for slope reinforcement according to claim 2, characterized in that: The hollow rod body (10) is provided with a limit block (17) at one end thereof, and a duckbill groove (15) is provided in a mirror image. The bottom wall of each limit groove (31) is provided with a first inclined surface (311). The end of each first inclined surface (311) is provided with a clamping groove (312). The opposing surfaces of the two limit blocks (17) are provided with clamping teeth (171), and each clamping tooth (171) corresponds to each clamping groove (312) in a one-to-one manner.

4. The anchor rod for slope reinforcement according to claim 1, characterized in that: A limiting plate (21) for limiting the clamping arm (20) from being pushed out of the through slot (16) is provided at the bottom of each clamping arm (20), and the limiting plate (21) is located inside the hollow rod body (10).

5. The anchor rod for slope reinforcement according to claim 4, characterized in that: A second wedge surface (211) and a second plane (212) are provided on a side of each of the limiting plates (21) facing away from the corresponding clamping arm (20), and a first wedge surface (501) and a first plane (502) are provided on each of the wedge blocks (50), and each of the first wedge surfaces (501) abuts against the corresponding second wedge surface (211).

6. The anchor rod for slope reinforcement according to claim 1, characterized in that: Each of the clamping arms (20) is provided with a spike portion (22) at one end away from the corresponding limiting plate (21).

7. The anchor rod for slope reinforcement according to claim 1, characterized in that: The outer wall of the hollow rod body (10) is provided with a spiral groove (11).

8. The anchor rod for slope reinforcement according to claim 1, characterized in that: One end of the hollow rod body (10) away from the top plate (30) is provided with a thread, and the threaded section is provided with a backing plate (12) and a nut (13).

9. The multi-stage variable pressure grouting method for anchor rods for slope reinforcement according to any one of claims 1 to 7, characterized in that: The following steps are included: S1, anchor rod and grouting preparation: anchor rod holes are drilled on the slope according to the design requirements. After the drilling is completed, the hollow rod body (10) is inserted into the drill hole; S2, initial low-pressure grouting stage: initial low-pressure grouting is performed through the hollow rod (10) channel, and the grouting pressure is set to P1, and the value range of P1 is 0.2 to 0.6 MPa; S3, medium pressure grouting stage: the grouting pressure is increased to P2, which is 1.5 to 2 times of P1, and medium pressure grouting is performed; S4, high-pressure grouting stage: increase the grouting pressure to P3, which is 1.2 to 1.5 times that of P2, and perform high-pressure grouting.

10. The multi-stage variable pressure grouting method according to claim 9, characterized in that: In step S1: after the hollow rod body (10) is inserted into the drill hole, an external force is continuously applied to the hollow rod body (10) so that the top plate (30) and the bottom of the hole are squeezed against each other, and the top plate (30) is pushed into the hollow rod body (10). The wedge block (50) simultaneously squeezes the clamping arm (20) so that it extends out of the hollow rod body 10 and is inserted into the hole wall.

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