Tunnel anti-seismic energy-dissipation anchor rod and installation method

Abstract

The application discloses a tunnel anti-seismic energy-dissipation anchor rod and a mounting method, and belongs to the technical field of tunnel engineering anti-seismic technology. The anchor rod comprises an anchor rod body and a viscous damper. The viscous damper comprises a steel sleeve shell, a push rod piston, a high-strength spring and viscous damping liquid. The push rod piston is arranged in the steel sleeve shell, and the push rod passes through the tail of the shell and is threadedly connected with the anchor rod body. The high-strength spring is sleeved on the push rod and connected with the piston. The head of the shell is connected with a bolt, the bolt passes through a tray and is fixed on a tunnel lining structure. During an earthquake, the high-strength spring and the viscous damping liquid can absorb energy, reduce the deformation and deformation rate of the tunnel structure, and gradually reset after the earthquake. The application is suitable for reinforcing new and existing tunnels, and has the advantages of good anti-seismic performance, flexible installation and convenient transportation.

Description

Technical Field

[0001] This invention relates to the field of seismic resistance technology in tunnel engineering, and in particular to a seismic energy dissipation anchor bolt for tunnels and its installation method. Background Technology

[0002] The Yunnan, Guizhou, and Sichuan regions are mountainous areas prone to high-intensity earthquakes. The soil and rock structures in these areas are frequently threatened by natural disasters, especially earthquakes. These disasters can easily trigger soil and rock instability, causing not only large deformations in tunnel structures but also, in extreme cases, structural damage or even collapse, posing a serious threat to people's lives and property.

[0003] While traditional anchor systems can provide some support and stability under dynamic loads such as earthquakes, they have significant limitations. Specifically, traditional anchors often lack effective energy dissipation mechanisms or suffer from complex structures and high costs. This means that during an earthquake, traditional anchors cannot efficiently absorb and dissipate seismic energy, making them prone to failure under significant deformation, thus affecting the long-term stability and seismic performance of the structure. Furthermore, many existing highway tunnels, after long-term use, gradually age and become unable to withstand sudden earthquakes, urgently requiring safe and non-invasive reinforcement to improve their seismic resilience. Therefore, the application of traditional anchor systems in areas prone to high-intensity earthquakes is limited, necessitating a new type of anchor system to improve the seismic performance and ease of maintenance of tunnel structures. Summary of the Invention

[0004] The purpose of this invention is to provide a tunnel seismic energy dissipation anchor and its installation method, which can greatly reduce the deformation of the tunnel structure and absorb seismic energy, while having the advantages of convenient transportation, flexible installation and low cost.

[0005] To achieve the above objectives, this invention provides a tunnel seismic energy dissipation anchor bolt, comprising an anchor bolt body and a viscous damper. The viscous damper includes a push rod piston, a high-strength spring, a viscous damping fluid, and a steel sleeve shell. A bolt is pre-attached to the head steel plate of the steel sleeve shell, passing through a tray. The distance between the tray and the damper head is adjusted by a nut, and the tray and damper are fixed to the tunnel concrete lining structure by fasteners (such as expansion bolts or embedded parts). The push rod piston moves axially within the viscous damper, the inner cavity of which is filled with viscous damping fluid. The push rod extends out of the tail of the steel sleeve shell and is screwed to the anchor bolt body. A high-strength spring is fitted onto the push rod, and one end of the spring is fixedly connected to the push rod piston, used to dissipate seismic energy to reduce large deformations in the tunnel lining structure. The viscous damping fluid is preferably a non-Newtonian fluid, used to absorb the instantaneous energy of an earthquake to reduce the deformation rate of the tunnel lining structure, and the deformation gradually recovers after the earthquake, reducing the impact of the earthquake on the tunnel structure. The push rod piston is provided with multiple holes for the flow of viscous damping fluid.

[0006] Preferably, the anchor head of the anchor rod body is provided with a tapered thread for embedding into the stable surrounding rock at the far end; the interior of the anchor rod body is hollow, and the anchor head is reinforced by injecting anchoring grout.

[0007] Preferably, a rubber waterstop is provided between the steel sleeve shell and the tunnel lining structure to prevent water leakage.

[0008] Preferably, the tray serves as a fixed damper and buffers the impact of seismic loads, and prestress can be applied by adjusting the nut.

[0009] Preferably, the viscous damper and the anchor rod body are detachable and separable structures, both of which are modularly manufactured, and different models are selected for combination and assembly according to actual engineering and geological conditions.

[0010] This invention also provides a method for installing seismic-resistant energy dissipation anchors in tunnels, comprising the following steps: S1. The tail of the viscous damper is tightened to the anchor rod body with bolts; S2. Drill and enlarge the hole, insert rubber water-stop gaskets, dampers and anchor rods, embed the anchor head into the stable original rock and soil at the far end, and reinforce the anchor rod and anchor head by injecting anchoring grout; S3. The pre-connected screw at the head of the viscous damper passes through the tray, the spacing is adjusted and tightened, and prestress is applied as needed to provide better reinforcement performance. For existing tunnels, the tray is fixed to the reinforced concrete structure with expansion bolts; for new tunnels, pre-embedded connectors fix the tray and the damper is cast into the concrete structure.

[0011] Therefore, the tunnel seismic energy dissipation anchor bolt and its installation method using the above-described structure have the following beneficial effects: (1) When an earthquake occurs, the anchor bolts rely on the high-strength springs and viscous damping fluid in the viscous damper to absorb the earthquake energy, which greatly reduces the deformation and deformation rate of the tunnel structure. (2) The seismic energy dissipation anchor provided by the present invention can be used not only in newly built tunnels, but also for the reinforcement of existing tunnels to improve their seismic toughness; (3) The installation method of the anchor rod in this invention can also provide prestress, which can adapt to soft rock tunnel conditions and improve reinforcement performance; (4) In this invention, the viscous damper and the anchor rod are detachable and separable structures, which are convenient to transport and flexible to install, reduce costs and improve their applicability.

[0012] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0013] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention; Figure 2 This is a working cross-sectional view of a specific embodiment of the present invention during an earthquake; Figure Labels 1-Viscous damper; 2-Anchor bolt; 3-Anchoring grout; 4-Anchor head; 5-Piston rod with hole; 6-High-strength spring; 7-Viscous damping fluid; 8-Steel sleeve shell; 9-Bolt; 10-Nut; 11-Plate; 12-Rubber waterstop; 13-Tunnel lining structure; 14-Threaded joint; 15-Expansion bolt. Detailed Implementation

[0014] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0016] Example like Figure 1 As shown, this invention provides a tunnel seismic energy dissipation anchor bolt, comprising a viscous damper 1 and an anchor bolt 2. The viscous damper 1 includes a perforated push rod piston 5, a high-strength spring 6, viscous damping fluid 7, and a steel sleeve shell 8. A bolt 9 is pre-attached to the head steel plate of the steel sleeve shell 8, passing through a tray 11, and the viscous damper 1 is fixed to the tunnel concrete lining structure 13 by a nut 10. The perforated push rod piston 5 moves axially within the viscous damper 1, and the viscous damping fluid 7 flows within the cavity of the viscous damper 1. The push rod extends out of the tail of the steel sleeve shell 8 and is screwed to the anchor bolt 2. The high-strength spring 6 is sleeved on the push rod, and one end of the high-strength spring 6 is fixedly connected to the push rod piston 5, dissipating seismic energy to reduce large deformations in the tunnel lining structure 13. The viscous damping fluid 7 is a non-Newtonian fluid used to absorb the instantaneous energy of an earthquake to reduce the deformation rate of the tunnel lining structure 13. The deformation gradually recovers after the earthquake, reducing the impact of the earthquake on the tunnel structure. Holes are provided on the piston to allow the damping fluid to flow, thus providing damping force.

[0017] The anchor head 4 of anchor bolt 2 is equipped with a tapered thread for penetrating into stable surrounding rock at a distance. The anchor bolt 2 is hollow inside, and the anchor head 4 is reinforced by injecting anchoring grout 3 to ensure anchoring force.

[0018] A rubber waterstop 12 is installed between the steel sleeve shell 8 and the tunnel concrete lining structure 13 to prevent water leakage from affecting the performance of the damper and the safety of the tunnel.

[0019] In this embodiment, the viscous damper 1 and the anchor bolt 2 are detachable and modularly manufactured. In practical applications, appropriate anchor bolt length, diameter, and spring stiffness parameters are selected based on actual engineering and geological conditions, and then the components are assembled.

[0020] Specifically, for different geological conditions, the present invention provides the following preferred implementation parameters: In soft rock tunnels with large deformation, anchorage lengths of 4.5m to 6.0m are used to enhance the bond with the deep, stable surrounding rock; the anchor diameter is selected as 32mm to improve tensile bearing capacity; the spring stiffness is selected as medium to low stiffness, with a value range of 80kN / m to 100kN / m, to ensure that the gradual pressure relief does not hinder the deformation of the surrounding rock; the damping coefficient is selected as 150kN·s / m to 200kN·s / m to dissipate the energy of large deformation and avoid overloading of the support structure.

[0021] In hard rock tunnels in high seismic intensity zones, a medium anchorage length, ranging from 2m to 3m, is adopted to meet the anchorage requirements of hard rock. The anchor diameter is selected as 28mm to balance strength and ease of construction. High spring stiffness, ranging from 180kN / m to 220kN / m, is selected to provide strong support resistance against seismic impact. The damping coefficient is selected as 200kN·s / m to 250kN·s / m to quickly dissipate seismic energy and to allow for elastic recovery after the earthquake via the spring.

[0022] This invention also provides a method for installing seismic-resistant energy dissipation anchors in tunnels, the specific steps of which are as follows: For new tunnel construction projects: First, holes are drilled and enlarged in the exposed surrounding rock, and the anchor head 4 of the anchor rod 2 is embedded into the stable surrounding rock at the far end. The anchor rod 2 and anchor head 4 are reinforced by injecting anchoring grout 3 to stabilize them and form the initial lining support of the tunnel.

[0023] Then, the viscous damper 1 and the anchor rod 2 are tightened together by threaded connection, the rubber waterstop 12 is wrapped around the steel sleeve shell 8, and the tunnel lining structure 13 is poured.

[0024] Finally, insert the tray 11 into the screw 9 and tighten the nut 10 to adjust the preload. Then, use the embedded parts or bolts 15 to fix the tray 11 onto the tunnel lining structure 13. At this point, the viscous damper 1 is fixed to the tunnel structure, the tunnel structure is coupled with the anchor displacement, and the viscous damper is coordinated with the deformation of the tunnel structure.

[0025] For existing tunnel reinforcement projects: First, holes are drilled, enlarged, and cleaned in the tunnel and the surrounding rock behind it.

[0026] Then, the viscous damper 1 is combined with the anchor rod 2, wrapped with rubber waterstop 12, and then placed together into the hole in the tunnel lining structure 13. The anchor rod 2 and anchor head 4 are reinforced by injecting anchoring grout 3 to make their anchoring stable.

[0027] Finally, expansion bolts 15 are driven into the tunnel, and tray 11 is installed. Prestress can be applied by adjusting nuts 10 to improve anchoring performance.

[0028] like Figure 2As shown, during an earthquake, the anchor bolt 2 drives the perforated push rod piston 5 and the high-strength spring 6 within the viscous damper 1 to move axially. The push rod piston 5 moves within the steel sleeve housing 8, forcing the viscous damping fluid 7 to flow through the holes in the piston, generating damping force, and simultaneously compressing or stretching the high-strength spring 6. The high-strength spring 6 and the viscous damping fluid 7 absorb seismic energy, reducing the dynamic effect of the seismic load on the tunnel lining structure 13, decreasing the deformation of the tunnel lining structure 13, and lowering the deformation rate of the structure. After the earthquake, under the action of the high-strength spring 6, the push rod piston 5 gradually returns to its original position, reducing the permanent impact of the earthquake on the structure.

[0029] Therefore, when an earthquake occurs, the anchor rod absorbs seismic energy by relying on the high-strength spring and viscous damping fluid inside the viscous damper, which greatly reduces the deformation and deformation rate of the tunnel structure. The anchor rod can be used in newly built tunnels or to reinforce existing tunnels and improve their seismic toughness.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A tunnel seismic energy dissipation anchor, characterized in that, The device includes an anchor bolt body and a viscous damper. The viscous damper includes a steel sleeve shell, a push rod piston, a high-strength spring, and a viscous damping fluid. The push rod piston is slidably disposed inside the steel sleeve shell, and the viscous damping fluid fills the inner cavity of the steel sleeve shell. The push rod of the push rod piston extends out of the tail of the steel sleeve shell and is threadedly connected to one end of the anchor bolt body. The high-strength spring is sleeved on the push rod, and one end of the high-strength spring is fixedly connected to the push rod piston. A bolt is fixedly connected to the head of the steel sleeve shell, and a tray is passed through the bolt. The tray is configured to be fixed to the tunnel concrete lining structure by fasteners.

2. The tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, The viscous damping fluid is a non-Newtonian fluid.

3. The tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, The push rod piston has multiple holes for the flow of the viscous damping fluid.

4. The tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, The anchor head of the anchor rod body is provided with a tapered thread, and the anchor head is configured to be embedded in the stable surrounding rock at the far end.

5. A tunnel seismic energy dissipation anchor bolt according to claim 4, characterized in that, The anchor body is hollow inside, and the anchor body is configured to reinforce the anchor head by injecting anchoring grout.

6. A tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, A rubber waterstop is installed between the steel sleeve shell and the tunnel concrete lining structure.

7. A tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, A nut is also threaded onto the bolt. The nut is located on the side of the tray away from the outer shell of the steel sleeve. Prestress is applied to the tray by adjusting the position of the nut on the bolt.

8. A tunnel seismic energy dissipation anchor bolt according to claim 1, characterized in that, The viscous damper and the anchor body are detachable.

9. A method for installing a tunnel seismic energy dissipation anchor, applied to the tunnel seismic energy dissipation anchor as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Tighten the tail end of the viscous damper to the anchor rod body via threaded connection; S2. Drill and enlarge holes in the surrounding rock, insert rubber water-stop gaskets, viscous dampers and anchor rods, embed the anchor head of the anchor rod into the original rock and soil, and inject anchoring grout into the anchor rod to reinforce the anchor head; S3. Pass the pre-connected bolts of the viscous damper head through the tray, adjust the spacing and tighten the nuts to fix the tray to the tunnel lining structure.

10. The method for installing a tunnel seismic energy dissipation anchor according to claim 9, characterized in that, In step S3, for existing tunnels, the tray is fixed to the reinforced concrete structure by expansion bolts; for newly built tunnels, the tray is fixed by pre-embedded connectors, and the viscous damper is cast into the concrete structure.

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