Resistance-increasing multi-stage energy-absorbing anchor cable suitable for deep engineering time-lag rockburst

Abstract

The resistance-increasing multistage energy-absorbing anchor cable comprises an anchor cable main body, a tray, a lockset, an anchorage device, an expansion anchor head, a rigid sleeve, a reducing energy-absorbing circular pipe, an expanding energy-absorbing polygonal pipe and an elastic compression reducing energy-absorbing spring, the expansion shell anchor head is fixedly arranged at the head end of the anchor cable main body; the anchorage device is fixedly arranged at the tail end of the anchor cable main body; the head end of the rigid sleeve is inserted into the surrounding rock anchoring hole, and the tail end of the rigid sleeve extends out of the surrounding rock anchoring hole. The lockset is fixedly arranged at the tail end of the rigid sleeve; the tray sleeves the tail end of the rigid sleeve and is positioned between the lockset and the wall surface of the surrounding rock; an annular blocking edge is arranged at a sleeve opening at the head end of the rigid sleeve; the anchorage device is positioned in the rigid sleeve; and the reducing energy-absorbing circular pipe, the expanding energy-absorbing polygonal pipe and the elastic compression reducing energy-absorbing spring are sequentially sleeved on the anchor cable main body between the anchorage device and the annular blocking edge. The device has the advantages of being simple in structure, large in energy absorption and long in energy absorption duration, and the stability of surrounding rock can be better enhanced when time-lag rock burst occurs.

Description

Technical Field

[0001] The present invention belongs to the technical field of deep mine support safety, and particularly relates to a resistance-increasing multi-stage energy-absorbing anchor cable applicable to time-delay rock bursts in deep engineering. Background Art

[0002] Deep engineering construction generally faces a complex environment of "four highs and one disturbance". Especially under the condition of high ground stress, due to strong unloading during excavation and strong disturbance during blasting, it will cause a violent release of the stored strain energy inside the rock mass at the excavation boundary, thus easily inducing strong dynamic engineering disasters such as rock bursts, seriously affecting the safe and efficient construction of deep engineering. Therefore, how to effectively and actively prevent and control strong dynamic engineering disasters such as rock bursts has become a technical problem that urgently needs to be solved in deep engineering construction.

[0003] According to the time and space characteristics of its occurrence, rock bursts can be divided into instant rock bursts and time-delay rock bursts. Instant rock bursts mostly occur during the process of excavation unloading effect, showing the instantaneous release of elastic strain energy concentration. Time-delay rock bursts usually occur several days or months later, and are mostly seen in areas where the stress adjustment caused by excavation unloading has basically reached equilibrium and there are hard structural planes and bands.

[0004] Under the action of strong external disturbances, the activation of hard structural planes and bands will cause the stored energy of deep engineering rock mass to be released in a secondary or multiple stepped manner, thus inducing time-delay rock bursts and intermittent rock bursts. Compared with instant rock bursts, time-delay rock bursts have stronger time randomness and greater harmfulness. Due to the multiple releases of energy, it is more difficult to actively prevent and control them.

[0005] At present, through the slip energy-absorbing structure and large-deformation extension materials of energy-absorbing anchor cables, they can play a key role in rock burst prevention and control. The core mechanism lies in actively absorbing the kinetic energy released by the surrounding rock and delaying the energy release rate to achieve the active prevention and control of rock bursts in deep engineering rock mass.

[0006] However, the energy-absorbing and impact-preventing capabilities of most energy-absorbing anchor cables are generally weak, and they can only meet the support requirements for instant rock bursts and are difficult to adapt to the multiple stepped releases of energy in time-delay rock bursts. Although some energy-absorbing anchor cables are also designed according to the multi-stage energy-absorbing requirements, the effect of dealing with the multiple stepped releases of energy in time-delay rock bursts is not ideal enough.

[0007] The Chinese patent application with the publication number CN112431623A discloses a multi-stage energy-absorbing anchor and its construction method, and the Chinese patent application with the publication number CN208057139U discloses a tension-compression coupling deformation anchor. Although multi-stage energy absorption is achieved in the design, the effect of its energy-absorbing components in dealing with the multiple stepped releases of energy in time-delay rock bursts is still poor, and there are problems such as complex structure, small energy absorption, and short energy absorption duration. Summary of the Invention

[0008] Aiming at the problems existing in the prior art, the present invention provides a resistance-increasing multi-stage energy-absorbing anchor cable applicable to time-delay rock bursts in deep engineering, which has the characteristics of simple structure, large energy absorption capacity, and long energy absorption duration, and can better enhance the stability of surrounding rock when a time-delay rock burst occurs.

[0009] To achieve the above object, the present invention adopts the following technical solution: A resistance-increasing multi-stage energy-absorbing anchor cable applicable to time-delay rock bursts in deep engineering, comprising an anchor cable main body, a tray, a locking device, an anchoring device, an expanding shell anchor head, a rigid sleeve, a reduced-diameter energy-absorbing round tube, an expanded-diameter energy-absorbing polygonal tube, and an elastic compression variable-diameter energy-absorbing spring; the expanding shell anchor head is fixedly installed at the head end of the anchor cable main body; the anchoring device is fixedly installed at the tail end of the anchor cable main body; the head end of the rigid sleeve is inserted into the surrounding rock anchoring hole, and the tail end of the rigid sleeve extends outside the surrounding rock anchoring hole; the locking device is fixedly installed at the tail end of the rigid sleeve; the tray is sleeved on the tail end of the rigid sleeve, and the tray is located between the locking device and the surrounding rock wall surface; a circumferential retaining edge is provided at the head end opening of the rigid sleeve; the anchoring device is located inside the rigid sleeve; the reduced-diameter energy-absorbing round tube, the expanded-diameter energy-absorbing polygonal tube, and the elastic compression variable-diameter energy-absorbing spring are sequentially sleeved on the anchor cable main body between the anchoring device and the circumferential retaining edge.

[0010] The anchoring device and the inner surface of the rigid sleeve are in clearance fit.

[0011] The reduced-diameter energy-absorbing round tube and the inner surface of the rigid sleeve are in clearance fit.

[0012] The outer surface of the expanded-diameter energy-absorbing polygonal tube at its maximum diameter is in clearance fit with the inner surface of the rigid sleeve.

[0013] The end face of the tail end opening of the reduced-diameter energy-absorbing round tube is a plane, and the end face of the tail end opening of the reduced-diameter energy-absorbing round tube abuts against the anchoring device.

[0014] A tapered chamfer is provided at the end face of the head end opening of the reduced-diameter energy-absorbing round tube, and a flared tapered chamfer is provided at the end face of the tail end opening of the expanded-diameter energy-absorbing polygonal tube, and the flared tapered chamfer abuts against the tapered chamfer.

[0015] The end face of the head end opening of the expanded-diameter energy-absorbing polygonal tube is a plane, and the end face of the head end opening of the expanded-diameter energy-absorbing polygonal tube abuts against the tail end of the elastic compression variable-diameter energy-absorbing spring, and the head end of the elastic compression variable-diameter energy-absorbing spring abuts against the circumferential retaining edge.

[0016] The strength relationship of the rigid sleeve, the reduced-diameter energy-absorbing round tube, the expanded-diameter energy-absorbing polygonal tube, and the elastic compression variable-diameter energy-absorbing spring is: the strength of the rigid sleeve > the plastic deformation strength of the elastic compression variable-diameter energy-absorbing spring > the plastic deformation strength of the expanded-diameter energy-absorbing polygonal tube > the plastic deformation strength of the reduced-diameter energy-absorbing round tube > the elastic deformation strength of the elastic compression variable-diameter energy-absorbing spring.

[0017] Advantages of the present invention:

[0018] The resistance-increasing multi-stage energy-absorbing anchor cable applicable to the time-delay rockburst in deep engineering of the present invention has the characteristics of simple structure, large energy absorption, and long energy absorption duration, and can better enhance the stability of the surrounding rock when the time-delay rockburst occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of a resistance-increasing multi-stage energy-absorbing anchor cable (initial state) applicable to the time-delay rockburst in deep engineering of the present invention;

[0020] Figure 2 It is a schematic structural diagram of a resistance-increasing multi-stage energy-absorbing anchor cable (primary energy-absorbing state) applicable to the time-delay rockburst in deep engineering of the present invention;

[0021] Figure 3 It is a schematic structural diagram of a resistance-increasing multi-stage energy-absorbing anchor cable (secondary energy-absorbing state) applicable to the time-delay rockburst in deep engineering of the present invention;

[0022] Figure 4 It is a schematic structural diagram of a resistance-increasing multi-stage energy-absorbing anchor cable (tertiary energy-absorbing state) applicable to the time-delay rockburst in deep engineering of the present invention;

[0023] Figure 5 It is a schematic structural diagram of a resistance-increasing multi-stage energy-absorbing anchor cable (quaternary energy-absorbing state) applicable to the time-delay rockburst in deep engineering of the present invention;

[0024] In the figure, 1 - anchor cable main body, 2 - tray, 3 - locking device, 4 - anchor fitting, 5 - expanding shell anchor head, 6 - rigid sleeve, 7 - reduced-diameter energy-absorbing round tube, 8 - expanded-diameter energy-absorbing polygonal tube, 9 - elastic compression variable-diameter energy-absorbing spring, 10 - circumferential retaining edge. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] As Figures 1 to 5As shown in the figure, a resistance-increasing multi-stage energy-absorbing anchor cable applicable to time-delay rock bursts in deep engineering includes an anchor cable body 1, a tray 2, a locking device 3, an anchor fitting 4, an expanding shell anchor head 5, a rigid sleeve 6, a reduced-diameter energy-absorbing circular tube 7, an expanded-diameter energy-absorbing polygonal tube 8, and an elastic compression variable-diameter energy-absorbing spring 9. The expanding shell anchor head 5 is fixedly installed at the head end of the anchor cable body 1. The anchor fitting 4 is fixedly installed at the tail end of the anchor cable body 1. The head end of the rigid sleeve 6 is inserted into the surrounding rock anchoring hole, and the tail end of the rigid sleeve 6 extends to the outside of the surrounding rock anchoring hole. The locking device 3 is fixedly installed at the tail end of the rigid sleeve 6. The tray 2 is sleeved on the tail end of the rigid sleeve 6, and the tray 2 is located between the locking device 3 and the surrounding rock wall surface. A circumferential retaining edge 10 is provided at the head end opening of the rigid sleeve 6. The anchor fitting 4 is located inside the rigid sleeve 6. The reduced-diameter energy-absorbing circular tube 7, the expanded-diameter energy-absorbing polygonal tube 8, and the elastic compression variable-diameter energy-absorbing spring 9 are sequentially sleeved on the anchor cable body 1 between the anchor fitting 4 and the circumferential retaining edge 10.

[0027] The anchor fitting 4 and the inner surface of the rigid sleeve 6 are in clearance fit.

[0028] The reduced-diameter energy-absorbing circular tube 7 and the inner surface of the rigid sleeve 6 are in clearance fit.

[0029] The outer surface of the expanded-diameter energy-absorbing polygonal tube 8 at its maximum diameter is in clearance fit with the inner surface of the rigid sleeve 6.

[0030] The end face of the tail end opening of the reduced-diameter energy-absorbing circular tube 7 is a plane, and the end face of the tail end opening of the reduced-diameter energy-absorbing circular tube 7 abuts against the anchor fitting 4.

[0031] The end face of the head end opening of the reduced-diameter energy-absorbing circular tube 7 is provided with a pointed conical chamfer, and the end face of the tail end opening of the expanded-diameter energy-absorbing polygonal tube 8 is provided with an expanded conical chamfer, and the expanded conical chamfer abuts against the pointed conical chamfer.

[0032] The end face of the head end opening of the expanded-diameter energy-absorbing polygonal tube 8 is a plane, and the end face of the head end opening of the expanded-diameter energy-absorbing polygonal tube 8 abuts against the tail end of the elastic compression variable-diameter energy-absorbing spring 9, and the head end of the elastic compression variable-diameter energy-absorbing spring 9 abuts against the circumferential retaining edge 10.

[0033] The strength relationship among the rigid sleeve 6, the reduced-diameter energy-absorbing circular tube 7, the expanded-diameter energy-absorbing polygonal tube 8, and the elastic compression variable-diameter energy-absorbing spring 9 is: the strength of the rigid sleeve 6 > the plastic deformation strength of the elastic compression variable-diameter energy-absorbing spring 9 > the plastic deformation strength of the expanded-diameter energy-absorbing polygonal tube 8 > the plastic deformation strength of the reduced-diameter energy-absorbing circular tube 7 > the elastic deformation strength of the elastic compression variable-diameter energy-absorbing spring 9.

[0034] In this embodiment, the diameter of the anchor cable body 1 is 22 mm; the inner diameter of the circumferential retaining edge 10 is 26 mm, and the anchor cable body 1 passes through the inner hole of the circumferential retaining edge 10; the outer diameter of the rigid sleeve 6 is 42 mm, the wall thickness of the rigid sleeve 6 is 4.9 mm, and the inner diameter of the rigid sleeve 6 is 32.2 mm; the outer diameter of the anchor 4 is 30 mm; the outer diameter of the reduced-diameter energy-absorbing circular tube 7 is 32 mm, the wall thickness of the reduced-diameter energy-absorbing circular tube 7 is 2 mm, and the length of the reduced-diameter energy-absorbing circular tube 7 is 400 mm; the cross-sectional shape of the expanded-diameter energy-absorbing polygonal tube 8 is a regular octagon, the circumscribed circle diameter of the expanded-diameter energy-absorbing polygonal tube 8 is 32 mm, the wall thickness of the expanded-diameter energy-absorbing polygonal tube 8 is 2 mm, and the length of the expanded-diameter energy-absorbing polygonal tube 8 is 500 mm; the outer diameter of the elastic compression variable-diameter energy-absorbing spring 9 is 32 mm, the inner diameter of the elastic compression variable-diameter energy-absorbing spring 9 is 26 mm, the non-loaded length of the elastic compression variable-diameter energy-absorbing spring 9 is 400 mm, and the maximum elastic compression amount of the elastic compression variable-diameter energy-absorbing spring 9 is 200 mm.

[0035] The following describes the first use process of the present invention with reference to the accompanying drawings:

[0036] First, the head end of the anchor cable body 1 is fixed to the bottom side of the surrounding rock anchoring hole through the swelled shell anchor head 5, then the circumferential retaining edge 10 of the rigid sleeve 6 is oriented towards the surrounding rock anchoring hole and inserted into the hole, and at the same time, the tail end of the anchor cable body 1 is inserted into the rigid sleeve 6, and then the tray 2 and the locking device 3 are successively installed on the rigid sleeve 6. Next, the elastic compression variable-diameter energy-absorbing spring 9 is first sleeved from the tail end of the anchor cable body 1 and sent into the rigid sleeve 6, and then the expanded-diameter energy-absorbing polygonal tube 8 and the reduced-diameter energy-absorbing circular tube 7 are successively sleeved from the tail end of the anchor cable body 1 and sent into the rigid sleeve 6, and then the anchor 4 is fixed at the tail end of the anchor cable body 1, and finally the pulling pre-tightening fixation of the anchor cable body 1 is completed.

[0037] When the time-delay rock burst occurs, the surrounding rock will undergo deformation and displacement. At this time, the tray 2, the locking device 3 and the rigid sleeve 6 are relatively stationary with respect to the surrounding rock wall surface at the orifice of the surrounding rock anchoring hole, while the surrounding rock where the swelled shell anchor head 5 is located moves relative to the surrounding rock wall surface at the orifice of the surrounding rock anchoring hole. At this time, a displacement also occurs between the anchor 4 at the tail end of the anchor cable body 1 and the rigid sleeve 6.

[0038] In the initial stage, the distance between the anchor 4 and the circumferential retaining edge 10 at the head end of the rigid sleeve 6 becomes smaller, which first forces the elastic compression variable-diameter energy-absorbing spring 9 to be compressed and elastically deformed to achieve the first-stage energy absorption until the elastic compression variable-diameter energy-absorbing spring 9 reaches the maximum elastic compression amount, and the first-stage energy absorption ends.

[0039] In the second stage, as the distance between the anchor 4 and the circumferential retaining edge 10 continues to decrease, the front end of the diameter-reducing energy-absorbing circular tube 7 is engaged with the flared conical chamfer of the diameter-increasing energy-absorbing polygonal tube 8 through the tapered chamfer structure. The diameter-reducing energy-absorbing circular tube 7 will be gradually pressed into the diameter-increasing energy-absorbing polygonal tube 8. The diameter-reducing energy-absorbing circular tube 7 begins to absorb energy through plastic deformation of radial compression. At the same time, the frictional resistance between the diameter-reducing energy-absorbing circular tube 7 and the diameter-increasing energy-absorbing polygonal tube 8 also cooperates to absorb energy, ultimately achieving the second-stage energy absorption until the diameter-reducing energy-absorbing circular tube 7 is completely pressed into the diameter-increasing energy-absorbing polygonal tube 8, and the second-stage energy absorption ends.

[0040] In the third stage, as the distance between the anchor 4 and the circumferential retaining edge 10 continues to decrease, the anchor 4 is squeezed into the diameter-increasing energy-absorbing polygonal tube 8 by means of the flared conical chamfer structure of the diameter-increasing energy-absorbing polygonal tube 8. At this time, the diameter-increasing energy-absorbing polygonal tube 8 begins to absorb energy through plastic deformation of radial expansion. The cross-sectional shape of the diameter-increasing energy-absorbing polygonal tube 8 gradually expands from a polygon to a circle, and the wall thickness of the diameter-increasing energy-absorbing polygonal tube 8 also decreases during the radial expansion process. The frictional resistance between the anchor 4 and the diameter-increasing energy-absorbing polygonal tube 8 also cooperates to absorb energy. At the same time, the diameter-reducing energy-absorbing circular tube 7 is further pressed into the elastic compression variable-diameter energy-absorbing spring 9 at the maximum elastic compression amount. The frictional resistance between the diameter-reducing energy-absorbing circular tube 7 and the elastic compression variable-diameter energy-absorbing spring 9 and the cable anchor body 1 synchronously cooperates to absorb energy, ultimately achieving the third-stage energy absorption until the diameter-increasing energy-absorbing polygonal tube 8 is completely expanded radially in the length direction, and the anchor 4 abuts against the end of the elastic compression variable-diameter energy-absorbing spring 9 at the maximum elastic compression amount, and the third-stage energy absorption ends.

[0041] In the fourth stage, as the distance between the anchor 4 and the circumferential retaining edge 10 continues to decrease, the elastic compression variable-diameter energy-absorbing spring 9 begins to undergo plastic deformation under the extrusion force, causing the elastic compression variable-diameter energy-absorbing spring 9 to become thicker and wider radially. At the same time, the frictional resistance between the diameter-reducing energy-absorbing circular tube 7 and the elastic compression variable-diameter energy-absorbing spring 9 and the cable anchor body 1 continues to cooperate to absorb energy until the elastic compression variable-diameter energy-absorbing spring 9 reaches the maximum plastic deformation amount, and the fourth-stage energy absorption ends. After that, the entire cable anchor enters the rigid support state.

[0042] The solutions in the embodiments are not intended to limit the protection scope of the present invention. Any equivalent implementation or modification without departing from the present invention is included in the protection scope of the present invention.

Claims

1. A multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rock burst in deep engineering, characterized by: It includes an anchor cable body, a tray, a lock, an anchor, an expansion shell anchor head, a rigid sleeve, a reduced diameter energy absorbing circular tube, an expanded diameter energy absorbing polygonal tube and an elastic compression variable diameter energy absorbing spring; the expansion shell anchor head is fixedly installed at the head end of the anchor cable body; the anchor is fixedly installed at the tail end of the anchor cable body; the head end of the rigid sleeve is inserted into the surrounding rock anchor hole, and the tail end of the rigid sleeve extends to the outside of the surrounding rock anchor hole; the lock is fixedly installed at the tail end of the rigid sleeve; the tray is sleeved on the tail end of the rigid sleeve, and the tray is located between the lock and the surrounding rock wall; an annular retaining edge is provided at the head end of the rigid sleeve; the anchor is located in the rigid sleeve; the reduced diameter energy absorbing circular tube, the expanded diameter energy absorbing polygonal tube and the elastic compression variable diameter energy absorbing spring are sequentially sleeved on the anchor cable body between the anchor and the annular retaining edge.

2. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The anchor is clearance-matched with the inner surface of the rigid sleeve.

3. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The energy-absorbing circular tube with reduced diameter is clearance-matched with the inner surface of the rigid sleeve.

4. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The outer surface of the tube body at the maximum diameter of the expanded energy-absorbing polygonal tube and the inner surface of the rigid sleeve are clearance-matched.

5. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The end surface of the tail end of the energy-absorbing circular tube with reduced diameter is a plane, and the end surface of the tail end of the energy-absorbing circular tube with reduced diameter is in abutment contact with the anchor.

6. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The front end of the energy-absorbing circular tube with reduced diameter is provided with a sharp conical chamfer, and the rear end of the energy-absorbing polygonal tube with expanded diameter is provided with a flared conical chamfer, and the flared conical chamfer is in contact with the sharp conical chamfer.

7. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The end face of the first end of the expanding energy absorbing polygonal tube is a plane, and the end face of the first end of the expanding energy absorbing polygonal tube abuts against the tail end of the elastic compression variable diameter energy absorbing spring, and the first end of the elastic compression variable diameter energy absorbing spring abuts against the annular retaining edge.

8. The multi-stage energy-absorbing anchor cable with increased resistance suitable for time-delay rockburst in deep engineering according to claim 1, characterized in that: The strength relationship among the rigid sleeve, the energy-absorbing circular tube with reduced diameter, the energy-absorbing polygonal tube with expanded diameter and the elastic compression variable diameter energy-absorbing spring is as follows: the strength of the rigid sleeve>the plastic deformation strength of the elastic compression variable diameter energy-absorbing spring>the plastic deformation strength of the energy-absorbing polygonal tube with expanded diameter>the plastic deformation strength of the energy-absorbing circular tube with reduced diameter>the elastic deformation strength of the elastic compression variable diameter energy-absorbing spring.

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