A multi-segment anchored energy-dissipating support device and support method for rockburst prevention

Abstract

This invention discloses a multi-segment anchored energy-dissipating support device and method for preventing rockbursts. The device includes a rod, a pre-tightening device, a pressure-relief sleeve, an energy-dissipating anchoring assembly, and a fastening assembly. The rod penetrates the front and rear ends of the pressure-relief sleeve. The pre-tightening device is located at the rear end of the pressure-relief sleeve. The anchoring assembly is located inside the pressure-relief sleeve and connected to the inner walls of the rod and the sleeve. The fastening assembly is located at the connection points between the rod and both ends of the pressure-relief sleeve. A ring-shaped toothed cutter is provided on the outer wall of the pressure-relief sleeve, and the cutter is integrally connected to the sleeve. This invention can release the elastic energy of the surrounding rock, preventing rockbursts and other disasters. It effectively avoids problems such as anchor bolts failing to adapt to surrounding rock deformation and becoming dislodged, or anchor bolts being pulled out or broken, thus improving the stability of the tunnel surrounding rock and ensuring construction safety.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a multi-segment anchored energy-dissipating support device and support method for preventing rockbursts. Background Technology

[0002] In recent years, with the rapid development of my country's transportation infrastructure construction, the characteristics of underground engineering projects—"long, large, deep, and clustered"—have become increasingly prominent. A large number of long railway, highway, and hydraulic tunnels traversing high ground stress conditions have emerged, bringing with them many deep rock mechanics problems, among which rockburst is the most prominent. Rockburst is generally considered a dynamic geological hazard that occurs during the excavation of underground engineering projects under high ground stress conditions. The stress differentiation in the tunnel walls due to excavation unloading causes the elastic strain energy stored in the rock mass to be suddenly released, resulting in explosive loosening, spalling, ejection, or even throwing. Since the first report of rockburst phenomena in British tin mines, rockbursts have been recorded in many countries worldwide, spanning transportation, hydraulic engineering, and mining fields. Rockburst hazards not only seriously threaten construction safety and affect construction progress but also cause over-excavation, initial support failure, and in severe cases, even induce earthquakes. It has become one of the important issues that must be considered in the design and construction of deep-buried hard rock tunnels.

[0003] Tunnel excavation in complex, high-stress rockburst environments results in intense mining disturbances, leading to severe deformation of the surrounding rock and a high concentration of secondary stress. Current rockburst control methods primarily rely on fixed rockburst-type support structures and conventional prevention measures. The parameters for various control measures also vary significantly, and rockburst prevention largely depends on construction experience, resulting in considerable subjectivity and randomness. Research on systematic rockburst-proof support structures is limited. Therefore, designing effective rockburst-proof support structures for extra-long railway tunnels is a pressing issue that needs to be addressed.

[0004] In high-stress environments, rock bolts are the most effective reinforcement method. However, ordinary rock bolts currently used for surrounding rock reinforcement have limited deformation capacity and low energy consumption. When anchoring surrounding rock in high-stress environments, they are prone to exceeding strain and stress limits, leading to problems such as anchor detachment, pull-out, and breakage. In rockburst areas, conventional anchor bolts cannot effectively suppress rockbursts because they cannot release the energy stored within the surrounding rock. Therefore, they are unsuitable for supporting deep and complex tunnel excavations. Summary of the Invention

[0005] This invention aims to provide a multi-segment anchored energy-dissipating support device and method for preventing rockbursts. It can release the elastic energy of the surrounding rock, avoid the occurrence of disasters such as rockbursts, and effectively prevent problems such as anchor rods being unable to adapt to the deformation of the surrounding rock and becoming dislodged, or anchor rods being pulled out or broken. It improves the stability of the tunnel surrounding rock and ensures the safety of construction.

[0006] To achieve the above objectives, the present invention provides a multi-segment anchored energy-dissipating support device for rockburst prevention, comprising a rod, a pre-tightening device, a pressure-relief sleeve, an energy-dissipating anchoring assembly, and a fastening assembly. The rod penetrates the front and rear ends of the pressure-relief sleeve. The pre-tightening device is located at the rear end of the pressure-relief sleeve. The anchoring assembly is located inside the pressure-relief sleeve and connected to the inner wall of the rod and the pressure-relief sleeve. The fastening assembly is located at the connection points between the rod and both ends of the pressure-relief sleeve. An annular toothed cutter is provided on the outer wall of the pressure-relief sleeve, and the annular toothed cutter is integrally connected to the pressure-relief sleeve.

[0007] Preferably, the pre-tightening device includes a tray and a locking nut. The tray is sleeved on the rear end of the pressure relief sleeve. The surface of the rod is provided with threads. The locking nut is located at the rear end of the tray and is threadedly connected to the rod.

[0008] Preferably, the energy-dissipating anchoring component includes a first anchoring block, a second anchoring block, a third anchoring block, and an elastic component. The first anchoring block, the second anchoring block, and the third anchoring block are all located inside the pressure-relief sleeve and are sleeved on the rod body and connected to the inner wall of the rod body and the pressure-relief sleeve. The first anchoring block and the second anchoring block are connected by the elastic component, and the second anchoring block and the third anchoring block are connected by the elastic component.

[0009] Furthermore, the first anchor block, the second anchor block, and the third anchor block are ring-shaped blocks with a triangular cross-section.

[0010] Furthermore, the elastic component is a high-strength spring.

[0011] Preferably, there is at least one energy-dissipating anchoring component.

[0012] Preferably, the fastening component is a rubber ring.

[0013] Preferably, there are several annular toothed cutters, which are spaced apart on the pressure relief sleeve.

[0014] Preferably, there is at least one pressure sleeve.

[0015] The preferred support method is:

[0016] S1. Deepen the blast holes, add no less than 15 blast holes in each cycle step, and spray high-pressure water on the tunnel face and tunnel wall after tunnel excavation, blasting, hazard removal and slag removal.

[0017] S2. Steel mesh is installed on the excavation face and initial shotcrete is sprayed to form an initial shotcrete layer (11) for timely support.

[0018] S3. Preparation of multi-segment anchoring energy-dissipating anchor rod: Weld the ring-shaped toothed cutter onto the pressure relief sleeve, weld the anchoring assembly to the rod body and the pressure relief sleeve, connect the first anchoring block and the second anchoring block of the anchoring assembly through an elastic component, connect the second anchoring block and the third anchoring block through an elastic component, and fasten the two ends of the pressure relief sleeve to the rod body through a fastening component.

[0019] S4. Drill stress relief holes. Open stress relief holes in the surrounding rock. The diameter of the stress relief hole is slightly larger than the diameter of the pressure relief sleeve with ring toothed cutter. The depth of the stress relief hole is greater than the length of the rod. At the same time as opening the stress relief hole, water is injected to soften the surrounding rock and release the strain energy deep in the surrounding rock.

[0020] S5. Support installation: Send the rod to the stress relief hole drilled in step 4, then inject cement grout and stir evenly to fill the stress relief hole. After the cement grout solidifies, install the pre-tightening component and apply the pre-tightening force.

[0021] S6. Erect a steel frame and spray concrete to seal the excavation face, and set a reserved deformation amount between the sprayed concrete layer and the secondary lining.

[0022] Compared with existing technologies, the present invention has the following technical effects:

[0023] 1. This invention can release the elastic energy of the surrounding rock, preventing disasters such as rock bursts;

[0024] 2. The multi-segment anchoring design on the anchor rod of the present invention can effectively avoid problems such as the anchor rod being unable to adapt to the deformation of the surrounding rock and thus becoming dislodged, or the anchor rod being pulled out or broken.

[0025] 3. This invention can improve the stability of the surrounding rock of the tunnel and ensure the safety of construction. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a single section of the multi-section anchoring energy dissipation support device in an embodiment;

[0028] Figure 2 This is a schematic diagram of the structure of the anchoring components inside the multi-segment anchoring energy dissipation support device in an embodiment.

[0029] Figure 3 This is a schematic diagram of a partial construction cross-section.

[0030] Icons: 1-rod body, 2-pallet, 3-locking nut, 4-pressure relief sleeve, 5-tooth cutter, 6-elastic component, 7-first anchor block, 8-second anchor block, 9-third anchor block, 10-fastening component, 11-initial shotcrete layer, 12-steel frame, 13-re-shotcrete layer, 14-reserved deformation amount, 15-secondary lining. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of the embodiments of this application, it should be noted that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, or the orientation or positional relationship commonly understood by those skilled in the art, and is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In addition, the terms "first," "second," "third," etc. are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] In the description of the embodiments of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] Example

[0038] A multi-segment anchored energy-dissipating support device for rockburst prevention includes a rod 1, a pre-tightening device, a pressure-relief sleeve 4, an energy-dissipating anchoring assembly, and a fastening assembly 10. The rod 1 passes through the front and rear ends of the pressure-relief sleeve 4. The pre-tightening device is located at the rear end of the pressure-relief sleeve 4. The anchoring assembly is located inside the pressure-relief sleeve 4 and connected to the inner wall of the rod 1 and the pressure-relief sleeve 4. The fastening assembly 10 is located at the connection points of the rod 1 and the pressure-relief sleeve 4 at both ends. The outer wall of the pressure-relief sleeve 4 is provided with an annular toothed cutter 5, which is integrated with the pressure-relief sleeve 4. The annular toothed cutter 5 can reduce the deformation and damage of the surrounding rock of the tunnel, inhibit the fracturing of the rock mass, and effectively improve the stability of the tunnel rock mass.

[0039] The pre-tightening device includes a tray 2 and a locking nut 3. The tray 2 is sleeved on the rear end of the pressure relief sleeve 4. The surface of the rod body 1 is provided with threads. The locking nut 3 is located at the rear end of the tray 2 and is threadedly connected to the rod body 1.

[0040] The energy-dissipating anchoring assembly includes a first anchoring block 7, a second anchoring block 8, a third anchoring block 9, and an elastic component 6. The first anchoring block 7, the second anchoring block 8, and the third anchoring block 9 are all located inside the pressure-relief sleeve 4 and are sleeved on the rod body 1, connected to the inner wall of the rod body 1 and the pressure-relief sleeve 4. The first anchoring block 7 and the second anchoring block 8 are connected by the elastic component 6, and the second anchoring block 8 and the third anchoring block 9 are connected by the elastic component 6.

[0041] The first anchor block 7, the second anchor block 8, and the third anchor block 9 are ring-shaped blocks with a triangular cross-section.

[0042] Elastic component 6 is a high-strength spring.

[0043] There must be at least one energy-dissipating anchoring component.

[0044] Fastening component 10 is a rubber ring.

[0045] There are several annular toothed cutters 5, which are distributed at intervals on the pressure sleeve 4.

[0046] Make sure there is at least one pressure sleeve 4.

[0047] The support method is as follows:

[0048] S1. Deepen the blast holes. Add no less than 15 blast holes per cycle step. After tunnel excavation, blasting, hazard removal and slag removal, spray high-pressure water on the tunnel face and tunnel wall to soften the surface layer and play a role in partially releasing the strain energy of the surrounding rock.

[0049] S2. A steel mesh is installed on the excavation face and initial shotcrete is applied to form an initial shotcrete layer 11 for timely support. The initial shotcrete should be 8cm thick C30 early high-strength shotcrete.

[0050] S3. Preparation of multi-segment anchoring energy-dissipating anchor rod: Weld the annular toothed cutter 5 onto the pressure relief sleeve 4, weld the anchoring assembly to the rod body 1 and the pressure relief sleeve 4, connect the first anchoring block 7 and the second anchoring block 8 of the anchoring assembly through the elastic component 6, connect the second anchoring block 8 and the third anchoring block 9 through the elastic component 6, and fasten the two ends of the pressure relief sleeve 4 to the rod body 1 through the fastening component 10.

[0051] S4. Drill stress relief holes. Open stress relief holes in the surrounding rock. The diameter of the stress relief hole is slightly larger than the diameter of the pressure relief sleeve 4 with ring toothed cutter 5. The depth of the stress relief hole is greater than the length of the rod 1. At the same time as opening the stress relief hole, water is injected to soften the surrounding rock and release the strain energy in the deep part of the surrounding rock. The stress relief hole can actively guide the release of some energy of the surrounding rock with rock burst tendency under high ground stress environment, which can reduce the stress concentration of the support structure after excavation.

[0052] S5. Support installation: Send rod 1 to the stress relief hole drilled in step 4, then inject cement grout and stir evenly to fill the stress relief hole. After the cement grout solidifies, install the pre-tightening component and apply pre-tightening force.

[0053] S6. Erect a steel frame 12 and spray concrete to seal the excavation face. Set a reserved deformation amount 14 between the sprayed concrete layer 13 and the secondary lining 15. Use full-ring I18 steel frame for reinforcement support. The steel frame spacing is 1.2m / frame. The thickness of the sprayed concrete is 25cm.

[0054] Compared to ordinary anchor bolts, this application possesses the ability to absorb and compressive deformation. Under extremely high stress conditions, when the surrounding rock cracks, the pressure-relieving sleeve 4 moves due to tensile and shear stresses. The first anchor block 7 and the second anchor block 8 of the anchoring assembly are connected by an elastic component 6, and the second anchor block 8 and the third anchor block 9 are connected by the elastic component 6. The two ends of the pressure-relieving sleeve 4 are securely connected to the rod body 1 by the fastening component 10, which also connects the pressure-relieving sleeve 4 and the rod body 1. The anchoring assembly can dissipate the elastic strain energy generated by the deformation of the surrounding rock, suppressing the tendency for further cracking by absorbing elastic strain energy. During the rockburst incubation stage, it inhibits tensile and shear damage, suppresses the development of rock mass cracking, and prevents rockbursts. The entire support process is clearly layered and highly practical, effectively improving the stability of the tunnel surrounding rock in high-stress environments and ensuring construction safety.

[0055] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A support method for a multi-segment anchored energy-dissipating support device for rockburst prevention, characterized in that: The rockburst prevention multi-segment anchored energy dissipation support device includes: a rod (1), a pre-tightening device, a pressure relief sleeve (4), an energy dissipation anchoring component, and a fastening component (10). The rod (1) passes through the front and rear ends of the pressure relief sleeve (4). The pre-tightening device is set at the rear end of the pressure relief sleeve (4). The energy dissipation anchoring component is set inside the pressure relief sleeve (4) and connected to the inner wall of the rod (1) and the pressure relief sleeve (4). The fastening component (10) is set at the connection between the rod (1) and the pressure relief sleeve (4). The outer wall of the pressure relief sleeve (4) is provided with an annular toothed cutter (5), and the annular toothed cutter (5) is connected to the pressure relief sleeve (4) as a whole. The energy-dissipating anchoring assembly includes a first anchoring block (7), a second anchoring block (8), a third anchoring block (9), and an elastic component (6). The first anchoring block (7), the second anchoring block (8), and the third anchoring block (9) are all located inside the pressure-relief sleeve (4) and are sleeved on the rod body (1) and connected to the inner wall of the rod body (1) and the pressure-relief sleeve (4). The first anchoring block (7) and the second anchoring block (8) are connected by the elastic component (6), and the second anchoring block (8) and the third anchoring block (9) are connected by the elastic component (6). There are several annular toothed cutters (5), and several annular toothed cutters (5) are distributed at intervals on the pressure-relief sleeve (4). The support method is as follows: S1. Deepen the blast holes, add no less than 15 blast holes in each cycle step, and spray high-pressure water on the tunnel face and tunnel wall after tunnel excavation, blasting, hazard removal and slag removal. S2. Steel mesh is installed on the excavation face and initial shotcrete is sprayed to form an initial shotcrete layer (11) for timely support. S3. Preparation of multi-segment anchoring energy-dissipating anchor rod: Weld the ring toothed cutter (5) onto the pressure relief sleeve (4), weld the anchoring assembly to the rod body (1) and the pressure relief sleeve (4), connect the first anchoring block (7) and the second anchoring block (8) of the anchoring assembly through the elastic component (6), connect the second anchoring block (8) and the third anchoring block (9) through the elastic component (6), and fasten the two ends of the pressure relief sleeve (4) to the rod body (1) through the fastening component (10); S4. Drill stress relief holes. Open stress relief holes on the surrounding rock. The diameter of the stress relief hole is slightly larger than the diameter of the pressure relief sleeve (4) with the ring toothed cutter (5). The depth of the stress relief hole is greater than the length of the rod (1). At the same time as opening the stress relief hole, water is injected to soften the surrounding rock and release the strain energy deep in the surrounding rock. S5. Support installation: Send the rod (1) to the stress relief hole drilled in step 4, then inject cement grout and stir evenly to fill the stress relief hole. After the cement grout solidifies, install the pre-tightening component and apply the pre-tightening force. S6. Erect a steel frame (12) and spray concrete to seal the excavation face. Set a reserved deformation amount (14) between the sprayed concrete layer (13) and the secondary lining (15).

2. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: The pre-tightening device includes a tray (2) and a locking nut (3). The tray (2) is sleeved on the rear end of the pressure relief sleeve (4). The surface of the rod (1) is provided with threads. The locking nut (3) is located at the rear end of the tray (2) and is threadedly connected to the rod (1).

3. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: The first anchor block (7), the second anchor block (8), and the third anchor block (9) are ring-shaped blocks with a triangular cross-section.

4. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: The elastic component (6) is a high-strength spring.

5. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: There is at least one energy-dissipating anchoring component.

6. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: The fastening component (10) is a rubber ring.

7. The support method for a multi-segment anchored energy-dissipating support device for rockburst prevention according to claim 1, characterized in that: There is at least one pressure relief sleeve (4).

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