A self-recovering yielding anchor rod

Abstract

The present invention discloses a deformable and self-restoring pressure-yielding anchor rod, comprising a tendon body, a sleeve and a pressure-bearing box arranged at the bottom of the tendon body, the tendon body is sleeved with the sleeve from the head thereof to the pressure-bearing box, the pressure-bearing box comprises a pressure-bearing steel plate, a guide rod, a high-strength steel spring, an extruded steel plate and a cylinder, the pressure-bearing steel plate is sleeved on the tendon body, at least two guide rods are vertically arranged on the lower side of the pressure-bearing steel plate, the guide rod is screwed on the pressure-bearing steel plate, the high-strength spring sleeve is arranged on the outside of all the guide rods, the extruded steel plate is arranged at the bottom of the high-strength spring, the extruded steel plate is provided with a rod through hole matched with the guide rod and a tendon through hole matched with the tendon body, a limiting nut is arranged on the guide rod located at the bottom of the extruded steel plate, a clamp is arranged on the tendon body located at the bottom of the extruded steel plate, and the cylinder is fixed on the pressure-bearing steel plate.

Description

Technical Field

[0001] The invention relates to the field of anchoring engineering, and in particular to a self-deforming and self-restoring yielding anchor rod, which is suitable for supporting projects such as coal mine tunnels, tunnels and highway embankment slopes. Background Art

[0002] At present, rock and soil anchoring technology is widely used in coal mine tunnels, tunnel projects, highway slopes, construction foundation pits, water conservancy dams, structural anti-floating and other projects. The force transmission method of traditional tension anchors is to use the anchor head to directly transmit the tension to the grouting body of the anchoring section through the tendon body, and then transmit it to the soil through the interface between the grouting body and the soil; the force transmission method of traditional pressure anchors is to directly transmit the tension to the bottom of the anchoring section through the anchor head, and squeeze the grouting body through the pressure plate connected to the tendon body, and then further transmit it to the soil through the interface between the grouting body and the soil.

[0003] In actual projects, a large number of engineering anchors are subjected to more complex loads. For example, the anchors supporting the slopes of highway embankments are subjected to reciprocating traffic loads from heavy-duty vehicles for a long time, and the vibrations generated cause the loads on the anchors to fluctuate back and forth; when the urban foundation pit is close to the traffic road, the supporting structure of the foundation pit is inevitably subjected to the impact of heavy vehicles on the road, heavy lifting machinery on the top of the foundation pit slope, and concrete transport vehicles on the supporting structure; when anti-floating anchors are used in underground structural projects, they will be subjected to the reciprocating rise and fall of the groundwater level; when an earthquake occurs, the slope projects supported by anchors will be subjected to a large impact instantaneously; and when supporting the surrounding rock of coal mine lanes and tunnels, rock bursts will be generated due to the release of surrounding rock stress, which will have different degrees of impact on the supporting structure, and then the impact force will be transmitted to the anchors supporting the surrounding rock. These reciprocating loads and instantaneous impacts will cause irreversible plastic deformation of the anchors, which will gradually accumulate, eventually leading to an increase in the displacement of the anchor head, bringing serious risks to the supporting structure. Moreover, when the anchor rod is subjected to impact load, the energy cannot be consumed, and the anchor rod reinforcement, the interface between the reinforcement and the grouting body, and the interface between the grouting body and the soil body will be damaged to varying degrees, thus endangering the safe operation of the anchoring project in the later stage.

[0004] Therefore, traditional anchor rods have serious safety hazards and durability problems when subjected to reciprocating loads and impacts. If the anchor rod structure can be deformed synchronously with the reciprocating load, absorb the impact energy when subjected to load impact, and recover the anchor rod deformation by self-release of the absorbed impact energy when the impact dissipates, the deformation self-recovery will greatly improve the anchoring performance of the anchor rod, ensure the bearing capacity of the anchor rod, and increase the service life of the anchor rod.

[0005] There are a small number of anchor rod devices with pressure-yielding deformation function on the market, but these devices are difficult to apply to actual projects. The main reasons are as follows: (1) To achieve the pressure-yielding function, the pressure-yielding spring must be able to freely expand and contract. When the anchor rod is used in projects, especially permanent anchoring projects, the anchor head must be strictly encapsulated and protected. The pressure-yielding device is set on the anchor head, which is not conducive to the encapsulation and protection construction of the anchor head. (2) To achieve the support function, the anchor rod must transmit the force of the rock layer to the anchor head through the retaining structure. For projects such as tunnels and coal mine tunnels, the space requirements are relatively high. The pressure-yielding device installed outside the retaining structure will inevitably occupy a large amount of excavation space, which will seriously increase the thickness of the tunnel lining and seriously reduce the clearance size of the coal mine tunnel, resulting in extremely inconvenient construction or a significant increase in project cost. (3) The pressure-yielding device is set on the anchor head. During construction, it is easy to be damaged by collision with construction machinery, especially earth excavation machinery, which is very easy to hit the anchor head during construction.

[0006] In view of this, the inventor conducted in-depth research on the anchor rod structure, and thus the present invention was produced. Summary of the invention

[0007] The purpose of the present invention is to provide a self-recovering yielding anchor rod, so as to overcome the shortcomings of traditional anchor rods in dealing with reciprocating loads and impact effects, and solve the safety and durability problems of the anchor rod.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] A deformable and self-restoring pressure-yielding anchor rod comprises a tendon body, a sleeve and a pressure box arranged at the bottom of the tendon body, the tendon body is sleeved with the sleeve from its head to the pressure box, the pressure box comprises a pressure-bearing steel plate, a guide rod, a high-strength steel spring, an extruded steel plate and a cylinder, the pressure-bearing steel plate is sleeved on the tendon body, at least two guide rods are vertically arranged on the lower side of the pressure-bearing steel plate, the guide rod is screwed on the pressure-bearing steel plate, the high-strength spring sleeve is arranged on the outside of all the guide rods, the extruded steel plate is arranged at the bottom of the high-strength spring, the extruded steel plate is provided with a rod through hole cooperating with the guide rod and a tendon through hole cooperating with the tendon body, a limiting nut is arranged on the guide rod located at the bottom of the extruded steel plate, a clamp is arranged on the tendon body located at the bottom of the extruded steel plate, and the cylinder is fixed on the pressure-bearing steel plate.

[0010] Furthermore, the sleeve is screwed and fixed on the pressure-bearing steel plate.

[0011] Furthermore, the pressure-bearing steel plate is a circular plate, the cylinder is a cylindrical cylinder with an opening at one end, the inner side of the opening is provided with an internal cylinder thread, the outer side of the pressure-bearing steel plate is provided with an external plate thread, the cylinder is fixed to the pressure-bearing steel plate by threaded cooperation between the internal cylinder thread and the external plate thread, and the guide rod, the high-strength steel spring, the extrusion steel plate and the clamp are all arranged in the cylinder.

[0012] Furthermore, a guide groove for screwing the upper end of each guide rod is correspondingly opened on the lower side of the pressure-bearing steel plate.

[0013] Furthermore, an inner thread is provided in the guide groove, and the depth of the guide groove is 10-20 mm.

[0014] Furthermore, the guide grooves are symmetrically distributed on the pressure-bearing steel plate.

[0015] Furthermore, a through hole is correspondingly opened at the center of the pressure-bearing steel plate for the reinforcement to penetrate.

[0016] Furthermore, the through hole is provided with an inner plate thread.

[0017] Furthermore, a first rod end wire and a second rod end wire are respectively provided at both ends of the guide rod, the length of the first rod end wire is 15-25 mm, the length of the second rod end wire is 30-60 mm, and the length of the guide rod is 60-150 mm longer than the height of the high-strength steel spring.

[0018] Furthermore, the high-strength steel spring is a helical cylindrical spring.

[0019] Furthermore, the cylindrical inner diameter of the high-strength steel spring is 5-10 mm larger than the outer diameter of the circumscribed circle of the guide rod.

[0020] Furthermore, the extruded steel plate is a circular steel plate, a rib-penetrating hole for the rib body to penetrate is arranged at the center of the extruded steel plate, and a rod-penetrating hole for the guide rod to penetrate is arranged in a corresponding ring on the extruded steel plate.

[0021] Furthermore, after the bottom end of the rib body passes through the rib hole, a matching clamp is installed.

[0022] Furthermore, the extruded steel plate is mounted on the guide rod via a limit nut.

[0023] Furthermore, the bottom end of the rib body and the bottom end of the guide rod are at a net distance of 10-20 mm from the bottom of the cylinder.

[0024] By adopting the above technical scheme, a self-deforming and self-recovering yielding anchor rod of the present invention is provided with a pressure box at the bottom of the tendon body, so that the anchor rod of the present invention has the following advantages: (1) By adjusting the stiffness of the high-strength steel spring, when the anchor rod is subjected to reciprocating loads, the compression and rebound synergistic load of the high-strength steel spring can be relied on to realize the self-recovery of the anchor head deformation, thereby greatly improving the stress state of the anchor rod. (2) When the anchor rod is subjected to impact loads or earthquakes, the compression energy of the high-strength steel spring consumes the impact energy, thereby greatly reducing the damage to the anchor rod and the supporting structure. When the impact load disappears or the earthquake ends, the high-strength steel spring automatically rebounds and stretches, and the anchor head deforms and recovers. (3) The pressure box is provided at the bottom of the tendon body, which is convenient for construction and installation, and the grouting body outside the pressure box has a good protective effect on the pressure box. (4) Since the pressure box is located at the bottom of the reinforcement, its anchor head can be directly connected to the surrounding structure according to the construction method of the traditional anchor bolt anchor head. When used in coal mine roadways and tunnel projects, it can minimize the thickness of the tunnel lining and increase the clearance size of the coal mine roadways. It can also effectively protect the anchor head during construction and prevent damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the present invention disposed in the soil layer;

[0026] Figure 2 For the present invention Figure 1 Schematic diagram of the cross-sectional structure at AA;

[0027] Figure 3 It is a schematic diagram of the cylindrical cross-section structure of the present invention;

[0028] Figure 4 It is a schematic diagram of the cross-sectional structure of the pressure-bearing steel plate of the present invention;

[0029] Figure 5 It is a schematic diagram of the top view of the pressure-bearing steel plate of the present invention;

[0030] Figure 6 It is a bottom view of the structure of the pressure bearing steel plate of the present invention;

[0031] Figure 7 It is a schematic diagram of the cross-sectional structure of an extruded steel plate of the present invention;

[0032] Figure 8 It is a schematic structural diagram of an extruded steel plate of the present invention;

[0033] Fig. 9 It is a schematic diagram of the guide rod structure of the present invention;

[0034] Fig.10 It is a schematic diagram of the casing structure of the present invention.

[0035] Explanation of labels and symbols

[0036] Muscle 11 Casing 12

[0037] Screw-in wire 121 Anchor 21

[0038] Anchor plate 22 Pressure box 3

[0039] Pressure steel plate 31 plate external thread 311

[0040] Perforation 312 Plate internal thread 313

[0041] Guide groove 314 Groove internal thread 315

[0042] Guide rod 32 First rod end wire 321

[0043] Second rod end wire 322 Limit nut 323

[0044] High strength steel spring 33 Extruded steel plate 34

[0045] Rebar hole 341 Rod hole 342

[0046] Clamp 35 Cylinder 36

[0047] Internal thread of cylinder 361 Grouting body 4

[0048] Soil 5 Drilling 6 DETAILED DESCRIPTION

[0049] See also Figure 1-Figure 10 The present invention discloses a self-recovering pressure-yielding anchor rod, comprising a tendon 11, a sleeve 12, an anchor 21, an anchor pad 22 and a pressure box 3 arranged at the bottom of the tendon 11.

[0050] For the convenience of describing this specification Figure 1 The up and down directions shown are up and down directions.

[0051] The tendon 11 is sleeved with a sleeve 12 from its head to the pressure box 3. The pressure box 3 includes a pressure steel plate 31, a guide rod 32, a high-strength steel spring 33, an extrusion steel plate 34 and a cylinder 36. The pressure steel plate 31 is sleeved on the tendon 11. At least two guide rods 32 are vertically arranged on the lower side of the pressure steel plate 31. The guide rods 32 are screwed on the pressure steel plate 31. The high-strength springs 33 are sleeved on the outside of all the guide rods 32. An extrusion steel plate 34 is arranged at the bottom of the high-strength spring 33. The extrusion steel plate 34 is provided with a rod through hole 342 cooperating with the guide rod 32 and a tendon through hole 341 cooperating with the tendon 11. A limiting nut 323 is arranged on the guide rod 32 located at the bottom of the extrusion steel plate 34, and a clamp 35 is arranged on the tendon 11 located at the bottom of the extrusion steel plate 34.

[0052] The pressure-bearing steel plate 31 is a circular plate, and the cylinder 36 is a cylindrical cylinder with one end open. The inner side of the open end is provided with an internal cylinder thread 361, and the outer side surface of the pressure-bearing steel plate 31 is provided with an external plate thread 311. The cylinder 36 is fixed on the pressure-bearing steel plate 31 by the cooperation of the internal cylinder thread 361 and the external plate thread 311. The guide rod 32, the limit nut 323, the high-strength steel spring 33, the extrusion steel plate 34 and the clamp 35 are all arranged in the cylinder 36.

[0053] The lower side of the pressure bearing steel plate 31 is correspondingly provided with a guide groove 314 for screwing the upper end of each guide rod 32. The guide groove 314 is provided with an inner groove thread 315, and the depth of the guide groove 314 is 10-20mm.

[0054] The guide grooves 314 are symmetrically distributed on the pressure-bearing steel plate 31. A through hole 312 is correspondingly provided at the center of the pressure-bearing steel plate 31 for the reinforcement body 11 to penetrate. The through hole 312 of the pressure-bearing steel plate 31 is provided with a plate inner thread 313. A screw thread 121 is provided at the bottom end of the sleeve 12, and the sleeve 12 is fixed to the pressure-bearing steel plate 31 through the cooperation of the screw thread 121 and the plate inner thread 313.

[0055] The first rod end thread 321 and the second rod end thread 322 are respectively provided at both ends of the guide rod 32. The first rod end thread 321 is screwed with the inner thread 315 of the groove, and the second rod end thread 322 passes through the rod hole 342 of the extruded steel plate 34 and is screwed with the limit nut 323. The length of the first rod end thread 321 is 15-25 mm, and the length of the second rod end thread 322 is 30-60 mm. The length of the guide rod 32 is 60-150 mm longer than the height of the high-strength steel spring 33. The high-strength spring 33 is a spiral cylindrical spring. The cylindrical inner diameter of the high-strength spring 33 is 5-10 mm larger than the outer diameter of the circumscribed circle of the guide rod 32.

[0056] The extruded steel plate 34 is a circular steel plate, and a through-rib hole 341 for the rib body 11 to pass through is provided at the center of the extruded steel plate 34, and a through-rib hole 342 for the guide rod 32 to pass through is provided on the extruded steel plate 34. The extruded steel plate 34 is installed on the guide rod 32 through a limit nut 323. After the rib body 11 passes through the through-rib hole 341 of the extruded steel plate 34, a matching clamp 35 is installed at the end. After the rib body 11 and the guide rod 32 are installed, the bottom end of the rib body 11 and the bottom end of the guide rod 32 are 10-20 mm away from the bottom of the cylinder 36.

[0057] As a preferred solution, the end of the cylinder 36 is hemispherical, which helps the pressure box 3 to be placed in the borehole 6. The cylinder 36 is made of synthetic resin material or steel.

[0058] The invention discloses a self-recovering yielding anchor rod, and the construction steps thereof are as follows:

[0059] (1) Process the reinforcement body 11 and the sleeve 12 according to the designed length, and make the screw thread 121; screw the guide rod 32 into the guide groove 314 of the pressure-bearing steel plate 31;

[0060] (2) Insert the reinforcement 11 into the pressure-bearing steel plate 31 from the smooth side of the pressure-bearing steel plate 31 (the side facing away from the cylinder 36), with the end protruding about 100 mm from the end of the guide rod 32. Insert the sleeve 12 onto the reinforcement 11 from the anchor head toward the pressure-bearing steel plate 31, and screw the screw thread 121 at the end of the sleeve 12 into the inner thread 313 of the pressure-bearing steel plate 31 until it is tight.

[0061] (3) Insert the high-strength steel spring 33 onto the guide rod 32; align the rib holes 341 of the extruded steel plate 34 with the rib body 11 and the rod holes 342 with the guide rod 32, and then insert the extruded steel plate 34 onto the rib body 11 and the guide rod 32;

[0062] (4) Screw the limit nut 323 from the end of the guide rod 32 until the extrusion steel plate 34 gently squeezes the high-strength steel spring 33; install the clamp 35 from the end of the tendon 11; then screw the cylinder 36 from the guide rod 32 to the pressure-bearing steel plate 31 and into the pressure-bearing steel plate 31, thus completing the production of the tendon 11 and the pressure-bearing box 3;

[0063] (5) Place the pressure box 3 into the borehole 6, and then inject grout into the borehole 6 to make the grouting body 4 wrap around the pressure box 3. After the strength of the grouting body 4 reaches the design requirement, install the anchor plate 22 at the hole mouth, and lock the tendon 11 with the anchor 21, thus completing the construction of the anchor rod.

[0064] Due to the application of the technical solution, compared with the traditional anchor technology, the present invention has the following significant advantages:

[0065] (1) When using a self-recovering yielding anchor rod of the present invention, when the anchor rod is set in the soil layer in a normal state, under the action of the anchor rod preload, the tendon 11 pushes the extrusion steel plate 34 through the clamp 35 to appropriately compress the high-strength steel spring 33. When the anchor rod is impacted, the tendon 11 directly transmits the tension to the extrusion steel plate 34 in the pressure box 3. When the extrusion steel plate 34 moves toward the head of the tendon 11 along the guide rod 32, the extrusion steel plate 34 compresses the high-strength steel spring 33. In this process, the high-strength steel spring 33 stores and absorbs the impact energy through the "yielding" deformation. When the impact is over, the high-strength steel spring 33 rebounds and pushes the extrusion steel plate 34 to reset the tendon 11. At this time, the energy is released through the "deformation self-recovery" in the pressure box 3. Since the high-strength steel spring 33 can rely on its own elastic compression and elongation to control the absorption and release of energy and realize the function of self-recovery of the anchor head deformation, it can avoid the impact effect directly acting on the grouting body 4 through the tendon 11, greatly reducing the damage or even destruction of the bonding performance of the interface between the grouting body 4 and the soil 5; it can even avoid the fracture accident caused by excessive deformation of the tendon 11 when the tendon 11 is directly subjected to the impact.

[0066] (2) When the anchor rod is subjected to reciprocating loads, a high-strength steel spring 33 with different stiffness can be designed according to the stress conditions of the anchor rod to match different stress conditions. In the process of reciprocating increase and decrease of the load, the high-strength steel spring 33 can coordinate the load through repeated compression and elongation of its length. The "pressure-releasing" phenomenon caused by the compression of the high-strength steel spring 33 can make the anchor head "actively" deform, greatly improve the stress state of the anchor body, and avoid the irreversible plastic deformation accumulation of the tendon 11. The elongation of the high-strength steel spring 33 can make the anchor head "passively" deform, realizing the "deformation self-recovery" function. It is not only beneficial to the deformation control of the anchor support structure and optimize the overall stress of the structure, but also beneficial to reduce the shear deformation damage accumulation of the grouting body 4 and the soil 5 interface caused by the grouting body 4 under reciprocating loads, thereby greatly improving the service life of the anchor rod.

[0067] (3) The pressure box 3 is arranged at the bottom of the reinforcement body 11, which is convenient for construction and installation, and the grouting body 4 outside the pressure box 3 has a good protective effect on the pressure box 3.

[0068] (4) Since the pressure box 3 is arranged at the bottom of the reinforcement body 11, its anchor head can be directly connected to the surrounding structure according to the construction method of the traditional anchor bolt anchor head. The anchor head located outside the soil layer occupies a small space. When applied to coal mine roadways and tunnel projects, it can minimize the thickness of the tunnel lining and increase the clearance size of the coal mine roadways. It can also effectively protect the anchor head during construction and prevent damage.

[0069] The present invention is described in detail above with reference to the accompanying drawings, but the embodiments of the present invention are not limited to the above embodiments. Those skilled in the art can make various modifications to the present invention based on the prior art, all of which belong to the protection scope of the present invention.

Claims

1. A self-recovering yielding anchor rod, characterized in that: It includes a tendon body, a sleeve and a pressure-bearing box arranged at the bottom of the tendon body, the tendon body is sleeved with the sleeve from its head to the pressure-bearing box, the pressure-bearing box includes a pressure-bearing steel plate, a guide rod, a high-strength steel spring, an extruded steel plate and a cylinder, the pressure-bearing steel plate is sleeved on the tendon body, at least two guide rods are vertically arranged on the lower side of the pressure-bearing steel plate, the guide rods are screwed on the pressure-bearing steel plate, the high-strength steel spring sleeve is on the outside of all the guide rods, the extruded steel plate is arranged at the bottom of the high-strength steel spring, the extruded steel plate is provided with a rod through hole matching the guide rod and a tendon through hole matching the tendon body, a limiting nut is arranged on the guide rod located at the bottom of the extruded steel plate, a clamp is arranged on the tendon body located at the bottom of the extruded steel plate, the cylinder is fixed on the pressure-bearing steel plate, and the end of the cylinder is hemispherical.

2. The self-recovering yielding anchor rod according to claim 1, characterized in that: The sleeve is screwed and fixed on the pressure-bearing steel plate.

3. The self-recovering yielding anchor rod according to claim 1, characterized in that: The pressure-bearing steel plate is a circular plate, the cylinder is a cylindrical cylinder with an opening at one end, the inner side of the opening is provided with an internal cylinder thread, the outer side of the pressure-bearing steel plate is provided with an external plate thread, the cylinder is fixed to the pressure-bearing steel plate by threaded cooperation between the internal cylinder thread and the external plate thread, and the guide rod, the limit nut, the high-strength steel spring, the extrusion steel plate and the clamp are all arranged in the cylinder.

4. The self-recovering yielding anchor rod according to claim 1, characterized in that: The lower side of the pressure-bearing steel plate is correspondingly provided with a guide groove for screwing the upper end of each guide rod.

5. The self-recovering yielding anchor rod according to claim 4, characterized in that: The guide groove is provided with an inner groove thread, and the depth of the guide groove is 10-20 mm.

6. The self-recovering yielding anchor rod according to claim 4, characterized in that: The guide grooves are symmetrically distributed on the pressure-bearing steel plate.

7. The self-recovering yielding anchor rod according to claim 1, characterized in that: A through hole is correspondingly opened at the center of the pressure-bearing steel plate for the reinforcement to penetrate.

8. The self-recovering yielding anchor rod according to claim 7, characterized in that: The through hole is provided with an inner plate thread.

9. The self-recovering yielding anchor rod according to claim 1, characterized in that: The guide rod is provided with a first rod end wire and a second rod end wire at both ends, the length of the first rod end wire is 15-25 mm, the length of the second rod end wire is 30-60 mm, and the length of the guide rod is 60-150 mm longer than the height of the high-strength steel spring.

10. The self-recovering yielding anchor rod according to claim 1, characterized in that: The high-strength steel spring is a helical cylindrical spring.

11. The self-recovering yielding anchor rod according to claim 1, characterized in that: The cylindrical inner diameter of the high-strength steel spring is 5-10 mm larger than the outer diameter of the circumscribed circle of the guide rod.

12. The self-recovering yielding anchor rod according to claim 1, characterized in that: The extruded steel plate is a circular steel plate, the center of the extruded steel plate is provided with a rib hole for the rib body to penetrate, and the extruded steel plate is provided with a corresponding ring with a rod hole for the guide rod to penetrate.

13. The self-recovering yielding anchor rod according to claim 12, characterized in that: After the bottom end of the rib body passes through the rib hole, a matching clamp is installed.

14. The self-recovering yielding anchor rod according to claim 1, characterized in that: The extruded steel plate is mounted on the guide rod via a limit nut.

15. The self-recovering yielding anchor rod according to claim 1, characterized in that: The bottom end of the rib body and the bottom end of the guide rod are at a net distance of 10-20 mm from the bottom of the cylinder.

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