Tunnel shock absorption anchor rod and construction method thereof

Abstract

The invention relates to the technical field of tunnel construction, in particular to a tunnel shock absorption anchor rod and a construction method thereof. The tunnel shock absorption anchor rod is of a hollow structure, a plurality of protruding parts are arranged on the rod wall of the anchor rod, grouting holes are formed between the adjacent protruding parts, and the grouting holes penetrate through the rod wall. The multiple protruding parts are arranged on the rod wall of the anchor rod, and the influence of seismic waves on a tunnel is effectively reduced through the waveguide effect and an energy absorption and dispersion mechanism. For longitudinal waves, the projection changes the propagation path of the longitudinal waves through reflection and refraction, so that the wave energy is gradually dissipated, and the impact of longitudinal vibration on the tunnel is reduced. And for transverse waves, shear vibration of the transverse waves is scattered and dispersed on the surfaces of the protruding parts, so that the amplitude and the propagation speed of the transverse waves are reduced, and the influence of transverse deformation on the tunnel wall is reduced. According to the design, the anti-seismic capacity of the tunnel structure is greatly improved, structural stress concentration is reduced, and the stability and safety of the tunnel in an earthquake are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a tunnel seismic anchor rod and a construction method thereof. Background Art

[0002] Tunnel structures in areas with frequent seismic activity are often exposed to severe seismic wave effects, especially longitudinal waves (P waves) and transverse waves (S waves). The longitudinal wave is the fastest type of seismic wave, and its vibration direction is consistent with the wave propagation direction. The longitudinal wave is usually the first wave in the seismic wave, and it has the strongest compression and expansion effect on the rock and soil structure. The energy transmitted by the longitudinal wave is relatively concentrated. If it is not effectively attenuated, it may cause initial damage to the tunnel structure. The propagation mode of the transverse wave is different from that of the longitudinal wave. Its vibration direction is perpendicular to the direction of wave propagation. The propagation speed of the transverse wave is slower, but it is more destructive to the tunnel structure. These waves can propagate in the tunnel structure, causing deformation, cracks and even collapse of the tunnel wall, seriously affecting the safety and stability of the tunnel. Existing tunnel seismic design mostly adopts reinforcement measures, such as anchor reinforcement, grouting and other methods, but these methods are often not specially designed for the propagation characteristics of seismic waves, so the seismic effect is limited.

[0003] In the prior art, anchor rods usually adopt a simple rigid structure, the purpose of which is to increase the contact area between the anchor rod and the rock and soil layer to improve the anchoring force. However, this design only focuses on improving the pull-out and tensile strength of the anchor rod, and lacks targeted design for the propagation characteristics of seismic waves and the absorption and attenuation of vibration energy. Therefore, the shock absorption effect in the prior art is not satisfactory, and it cannot effectively slow down the propagation of seismic waves in the tunnel, nor can it effectively reduce the damage of seismic waves to the tunnel structure. Summary of the invention

[0004] To solve the above problems, the present invention provides a tunnel shock-absorbing anchor rod, which is a hollow structure. The rod wall of the anchor rod is provided with multiple protrusions, and grouting holes are provided between adjacent protrusions, and the grouting holes penetrate the rod wall.

[0005] The present invention changes the propagation path of the longitudinal wave by providing a protrusion and forming a waveguide structure with the anchor rod. When the longitudinal wave encounters the protrusion, the wave will be reflected, refracted or scattered, resulting in the dispersion and absorption of the wave energy. Since the propagation mode of the longitudinal wave is compression and expansion along the wave propagation direction, the design of the protrusion can guide the energy of the longitudinal wave along the direction of the anchor rod, thereby reducing its propagation in the tunnel structure. In addition, since the vibration direction of the transverse wave is vertical, providing multiple protrusions can effectively change the propagation direction of the transverse wave. When the transverse wave encounters the protrusion, reflection and refraction will occur, causing the vibration direction of the transverse wave to change, thereby reducing the direct impact of the wave on the tunnel structure.

[0006] Furthermore, the anchor rod of the present invention also includes an anchor head, which is arranged at one end of the anchor rod and is connected to the anchor rod by threads to ensure the convenience of installation and maintenance, while providing reliable mechanical fixing. The shape of the anchor head can be designed to be conical, umbrella-shaped or expansion-shaped to adapt to different geological conditions and anchoring requirements. Among them, the conical anchor head can reduce the resistance during installation, making it easier for the anchor rod to be inserted into the rock formation, while enhancing its stability under earthquake action; the umbrella-shaped anchor head expands the contact area with the surrounding rock, improves the pull-out resistance and lateral support capacity, and is suitable for loose formations or soft rock environments; the expansion anchor head can be closely attached to the rock formation by mechanical expansion or grouting expansion after installation, thereby improving the anchoring effect, and is particularly suitable for high vibration environments or uneven geological conditions. The setting of the anchor head not only provides additional anchoring force, but also enhances the force distribution of the anchor rod when an earthquake occurs, reduces the possibility of the anchor rod loosening or failing due to the action of seismic waves, and thus improves the overall seismic resistance and long-term stability of the tunnel.

[0007] Furthermore, the anchor rod of the present invention also includes a grouting plug, which is arranged at one end of the anchor rod away from the anchor head, and is mainly used to control the flow of slurry, prevent leakage of slurry during grouting, and ensure that the slurry can evenly fill the gap around the anchor rod, thereby improving the anchoring effect. The structure of the grouting plug can be elastic sealing, mechanical locking or adjustable expansion to adapt to different construction environments. Among them, the elastic sealing grouting plug uses highly elastic materials (such as rubber or polyurethane) to fit tightly to the inner wall of the anchor rod, effectively blocking the overflow of slurry; the mechanical locking grouting plug is fixed to the end of the anchor rod by a threaded or snap-on structure to ensure that it will not loosen during high-pressure grouting; the adjustable expansion grouting plug can expand after grouting, so that it forms a closer combination with the inner wall of the anchor rod, enhances the sealing effect, and provides additional support after curing. In addition, the grouting plug can also integrate an exhaust channel to allow the gas generated during the grouting process to be discharged smoothly, avoiding bubbles from affecting the uniform distribution of the slurry. In short, the grouting plug not only ensures the effectiveness of grouting, but also improves the overall stability of the anchor bolt, enhances its seismic performance, and prevents anchor failure caused by uneven slurry distribution, thereby improving the safety and durability of the tunnel structure under earthquake action.

[0008] Furthermore, the anchor rod of the present invention also includes a damping inner layer, which is arranged inside the hollow structure of the anchor rod and is closely attached to the rod wall of the anchor rod, and is mainly used to absorb and attenuate the energy of seismic waves to improve the seismic performance of the anchor rod. The damping inner layer can be made of high-damping elastic materials (such as rubber, polyurethane, viscoelastic composite materials or shape memory alloys, etc.), which can effectively absorb vibration energy under the action of seismic waves and convert it into heat energy or internal dispersed energy, thereby reducing the impact of seismic waves on the anchor rod. The thickness and material of the damping inner layer can be optimized according to the frequency and propagation characteristics of the seismic waves to achieve effective attenuation of longitudinal waves and transverse waves. Specifically, for longitudinal waves, the damping inner layer can reduce the vibration response of the anchor rod in the compression and tension directions, reduce the transmission efficiency of longitudinal vibration, and thus reduce the structural deformation of the tunnel during earthquakes. For transverse waves, the damping inner layer can reduce the lateral amplitude by increasing shear damping, so that the deformation amplitude of the anchor rod under shear is reduced, thereby improving the stability of the tunnel structure. In addition, the damping inner layer can effectively reduce the reflection and resonance effects of seismic waves, and prevent the superposition of seismic waves inside the anchor rod, which leads to amplitude amplification. During the construction process, the damping inner layer can be formed by prefabricated coating or injection curing, so that it is closely attached to the anchor rod wall and ensures that it will not peel off or age during long-term use.

[0009] Furthermore, the anchor rod of the present invention is provided with protrusions distributed in an axial spiral on the rod wall, so as to improve the seismic resistance of the tunnel through waveguide effect, shear absorption, energy dispersion and enhanced anchoring force. Specifically, for longitudinal waves, the spiral protrusion forms a non-uniform waveguide path, so that the longitudinal waves are reflected, refracted and scattered multiple times on the anchor rod, and the propagation direction is constantly changed, thereby extending the energy transfer path, and reducing the amplitude by gradual absorption, thereby reducing the axial impact of the longitudinal wave on the tunnel. For transverse waves, the spiral protrusion provides multiple shear interfaces, so that the transverse waves are tangentially decomposed at different angles, resulting in energy being dispersed in multiple directions, thereby reducing the shear amplitude of the transverse waves and reducing the destructive effect of lateral deformation. In addition, the spiral protrusion increases the contact area between the anchor rod and the surrounding rock, improves friction and adhesion, makes the anchor rod more stable in a vibrating environment, and prevents slippage and loosening caused by vibration. At the same time, the structure can also optimize the grouting effect. The spiral path can guide the slurry to spread evenly along the spiral channel, avoid local insufficient grouting or slurry leakage, improve the adhesion strength between the anchor rod and the rock formation, and enhance the pull-out resistance, making it more suitable for complex geological environments.

[0010] Furthermore, a thread is provided at the top of the protrusion. The thread structure increases the contact area between the anchor rod and the surrounding rock, making it have stronger mechanical bite force and shear resistance in a vibration environment, thereby improving the pull-out resistance and preventing the anchor rod from slipping or loosening under the action of an earthquake. At the same time, the multi-level interface formed on the thread surface can effectively disperse the energy of seismic waves, so that the longitudinal wave gradually attenuates due to multiple reflections, refractions and scattering during the propagation process, and the transverse wave is further weakened due to the shear effect, thereby reducing the impact on the tunnel structure. In addition, the groove channel formed on the thread surface optimizes the grouting effect, allowing the slurry to penetrate and wrap the anchor rod more evenly, enhancing the bonding strength between the anchor rod and the rock formation, and forming a stronger mechanical locking effect after the slurry solidifies, thereby improving long-term stability. At the same time, the thread structure improves the ability of the anchor rod to screw in during the construction process, making it easier to adjust the angle and depth in the borehole, reducing the difficulty of construction and improving engineering efficiency.

[0011] Furthermore, the anchor rod of the present invention also includes a damping outer layer, which is arranged between adjacent protrusions, and the grouting holes penetrate the damping outer layer, aiming to enhance the attenuation effect of seismic waves, while optimizing the grouting effect and improving the overall anchoring performance of the anchor rod and the surrounding rock. The damping outer layer adopts high damping materials, such as rubber, polyurethane, composite polymer materials or shape memory alloys, etc. These materials can absorb part of the vibration energy during the propagation of seismic waves and convert it into heat energy or internal dispersed energy, thereby reducing the transmission of vibration. For longitudinal waves, the damping outer layer can undergo microscopic deformation under the action of compression and tension, effectively absorb wave energy, reduce its amplitude, and reduce the intensity of longitudinal vibration; for transverse waves, the flexible characteristics of the damping outer layer can buffer shear deformation, so that the transverse waves gradually decay during propagation, and reduce the damage of shear force to the tunnel structure. In addition, the setting of the damping outer layer can also optimize the grouting effect. Since the grouting holes penetrate the damping outer layer, the slurry can be evenly diffused along the gaps of the damping outer layer during the injection process, so that the slurry can fully wrap the anchor rod, improve the bonding force between the anchor rod and the surrounding rock, reduce the loss of slurry, and improve the overall anchoring strength after the slurry solidifies. The existence of the damping outer layer can also prevent the slurry from excessive diffusion during high-pressure injection, so that it is evenly distributed inside the surrounding rock, forming a more stable anchoring structure.

[0012] On the other hand, the present invention provides a method for constructing a tunnel seismic anchor, comprising the following steps: Step 1: Fix the anchor rod in the tunnel surrounding rock, and the direction of the anchor rod is consistent with the design direction of the tunnel structure; Step 2: Inject slurry into the anchor rod, and the slurry overflows from the grouting hole.

[0013] Longitudinal waves propagate along the tunnel direction, causing compression and tension effects, resulting in axial deformation of the tunnel structure. Transverse waves propagate perpendicular to the tunnel direction, causing shear deformation, which can easily lead to distortion, dislocation or local cracking of the tunnel wall. The direction of the anchor rod of the present invention is consistent with the axial direction of the tunnel, which helps to form a waveguide effect, thereby effectively regulating the impact of seismic waves on the tunnel in different directions. Longitudinal waves mainly propagate along the tunnel direction. When passing through the anchor rod, the spiral protrusion and the damping layer cause it to be reflected, refracted and scattered multiple times, extending the wave propagation path, and gradually absorbing its energy through the damping material, reducing the amplitude, reducing the axial compression and tensile impact caused by the longitudinal wave, and reducing damage to the tunnel structure. Transverse waves propagate perpendicular to the tunnel direction. When its shear vibration contacts the spiral protrusion, it will be sheared and decomposed due to the action of the shear interface, so that the wave energy can be diffused in multiple directions, weakening the amplitude of the shear wave, thereby reducing the dislocation, shear cracking and local deformation of the tunnel structure caused by the transverse wave.

[0014] Beneficial effects of the present invention: (1) The present invention arranges a plurality of protrusions on the wall of the anchor rod, and utilizes the waveguide effect, energy absorption and dispersion mechanism to effectively reduce the impact of seismic waves on the tunnel. For longitudinal waves, the protrusions change their propagation path through reflection and refraction, so that the wave energy is gradually dissipated and the impact of longitudinal vibration on the tunnel is reduced. For transverse waves, their shear vibrations are scattered and dispersed on the surface of the protrusions, thereby reducing their amplitude and propagation speed, and reducing the impact of lateral deformation on the tunnel wall. In addition, the damping effect of the protrusions can absorb part of the seismic wave energy, convert the vibration into heat energy, and gradually attenuate the seismic waves around the anchor rod. This design greatly improves the seismic resistance of the tunnel structure, reduces structural stress concentration, and enhances the stability and safety of the tunnel during earthquakes.

[0015] (2) The provision of the protrusion of the present invention increases the contact area between the anchor rod and the surrounding rock or soil, thereby significantly improving the adhesion and anchoring effect. Under the action of seismic waves, the larger contact area can enhance the friction and embedding force between the anchor rod and the surrounding rock, making it more stably embedded in the rock layer and reducing the displacement caused by vibration.

[0016] (3) The protrusion of the present invention optimizes the grouting effect, allowing the slurry to more evenly fill the gaps around the anchor rod, thereby improving the bonding strength and reducing slurry loss.

[0017] (4) Compared with traditional smooth anchor rods, the protrusion can increase the contact area with the surrounding rock, improve the friction and mechanical embedding force, and make the anchor rod more difficult to be pulled out or sheared when the surrounding rock deforms. In addition, when the surrounding rock expands, shears or contracts under the action of an earthquake, the protrusion can serve as a deformation buffer zone, forming additional support in the area with greater local stress, reducing the squeezing effect of the surrounding rock on the anchor rod, and delaying the damage of the anchor rod. In other words, the protrusion of the present invention can resist the deformation of the surrounding rock, improve the bearing capacity of the anchor rod, and enhance the long-term stability and earthquake resistance of the tunnel structure.

[0018] Based on the above beneficial effects, the present invention has good application prospects in the field of tunnel construction technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of a tunnel seismic anchor.

[0020] In the figure: 1. Rod wall; 2. Protrusion; 3. Grouting hole. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0022] Example 1 The present invention provides a tunnel shock absorbing anchor rod, such as Figure 1 As shown, it has a hollow structure. The whole is composed of an anchor body, a protrusion 2, a grouting hole 3, an anchor head, a grouting plug, a damping inner layer and a damping outer layer. The anchor body is made of high-strength steel, and a plurality of protrusions 2 are evenly arranged on its outer surface along the axial direction. The protrusions 2 are spiral-shaped and form a certain angle with the axis of the anchor. The size range is 10-30mm, and the spacing is determined according to the tunnel scale and earthquake intensity. The grouting holes 3 between the protrusions 2 penetrate the rod wall 1, and the hole diameter is 5-10mm, which ensures that the slurry can evenly penetrate between the anchor and the surrounding rock to enhance the anchoring effect. The anchor head of the anchor is connected to one end of the anchor by threaded connection. The thread specification of the connecting part is M20, which ensures that the installation is convenient and firm. The shape of the anchor head can be selected as conical, umbrella or expansion type according to the geological conditions. Among them, the conical anchor head is suitable for harder rock formations, the umbrella anchor head is suitable for loose soil layers, and the expansion anchor head can increase the contact area with the surrounding rock by expansion after grouting, which is suitable for areas with frequent vibration.

[0023] A grouting plug is provided at one end of the anchor rod away from the anchor head. The grouting plug is made of rubber material and has an elastic sealing function. It can automatically fill the grouting hole 3 during the grouting process to prevent grout leakage. The grouting plug can be designed to be an expansion type as required, and automatically expands after grouting to ensure sealing. A damping inner layer is provided inside the anchor rod. The inner layer is made of a high damping material (such as polyurethane, rubber or viscoelastic composite material) with a thickness of 5-10mm. Its function is to absorb the vibration energy of seismic waves and reduce the impact generated when longitudinal and transverse waves propagate. The damping inner layer fits tightly with the inner wall of the anchor rod, which enhances the attenuation effect of the anchor rod on seismic waves. In order to further improve the seismic resistance, a damping outer layer is covered between the protrusions 2. The damping outer layer is made of polyurethane or rubber material with a thickness of 5-15mm, which absorbs the energy of seismic waves and prevents longitudinal and transverse waves from damaging the tunnel. The grouting hole 3 runs through the damping outer layer to ensure that the slurry can penetrate evenly during the injection process, while improving the bonding strength between the anchor rod and the surrounding rock.

[0024] The preparation of the present invention is relatively simple: first, a hollow anchor body is processed by high-strength alloy steel or composite material, the length of the anchor is usually 1.5-3m, the outer diameter is 25-50mm, and multiple protrusions 2 are spirally processed along the axial direction on the rod wall 1, the height of the protrusion 2 is 5-15mm, the spacing is 20-50mm, and a grouting hole 3 penetrating the rod wall 1 is drilled between adjacent protrusions 2, with a hole diameter of 5-10mm. Then, an anchor head is prepared at one end of the anchor rod by turning, welding or threading. The anchor head can be conical, umbrella-shaped or expansion-shaped, and is fixed to the anchor rod by threading or welding. A grouting plug is installed at the end of the anchor rod away from the anchor head. The grouting plug is made of high-elastic rubber or polyurethane material, and an expansion structure or mechanical locking device is prefabricated to ensure that the slurry will not leak out during grouting. Subsequently, a damping inner layer is coated or filled on the inner wall of the anchor rod, and a high damping material (such as polyurethane, rubber, composite polymer material) is used, with a thickness of 5-10mm to enhance the shock absorption capacity of the anchor rod. At the same time, a damping outer layer is coated or wrapped between adjacent protrusions 2. The thickness of the damping outer layer is 5-15 mm. The material is rubber, viscoelastic material or polymer coating. A channel is reserved at the grouting hole 3 to ensure that the slurry can penetrate smoothly during grouting.

[0025] Preferably, the protrusion 2 is designed to be multi-layer stepped, which can further optimize the seismic resistance and anchoring performance of the anchor rod, enhance the multiple reflection, refraction and scattering effects of seismic waves, and improve the bonding force between the anchor rod and the surrounding rock. Specifically, the protrusion 2 is a stepped increasing structure along the axial direction of the anchor rod, with each step having a height of 5-15mm, a width of 10-30mm, and a step spacing of 20-50mm, forming a multi-layer structure similar to a damping groove. When the longitudinal wave propagates to the anchor rod along the tunnel direction, the stepped structure will cause the wave to be reflected and refracted multiple times at different levels, greatly extending the propagation path of the wave and causing its energy to gradually attenuate. At the same time, for transverse waves, their shearing action will cause shear decomposition and scattering when contacting different step surfaces, so that the wave energy is distributed in multiple directions, thereby reducing the shear amplitude and reducing the impact on the tunnel structure. In addition, the stepped protrusion 2 can also increase the contact area between the anchor rod and the surrounding rock, improve the friction and embedding force, make the anchor rod more stable in a vibrating environment, prevent slipping or loosening, and optimize the grouting effect, so that the slurry can fill the surrounding rock cracks more evenly and improve the anchoring force.

[0026] Preferably, the cross section of the anchor rod is changed from cylindrical to polygonal or variable diameter structure to improve the seismic resistance, anchoring effect and force uniformity of the anchor rod. Specifically, the starting part of the anchor rod (close to the anchor head) remains cylindrical to facilitate drilling and installation, and gradually transitions to a polygonal cross section (such as a hexagon, octagon or dodecagon) along the axial direction of the anchor rod, and further reduces the diameter (variable diameter structure) at the distal end to form a conical or stepped contraction structure. Compared with traditional cylindrical anchor rods, polygonal cross sections can provide more angular contact points, increase the friction and mechanical embedding force between the anchor rod and the surrounding rock, make it more stable in a vibration environment, and reduce the risk of slippage. In addition, under the action of seismic waves, polygonal edges can guide the waves to refract, scatter and reflect, improve the energy dissipation efficiency, and reduce the transmission of seismic waves. Especially under the shear action of shear waves, the edges can form multiple shear interfaces, effectively reduce the shear amplitude, and reduce damage to the tunnel structure. On the other hand, the design of the variable diameter structure enables the anchor rod to provide gradient stress distribution when subjected to stress, reduce stress concentration problems, and improve overall tensile strength. At the same time, it optimizes the grouting effect, allowing the slurry to fill the surrounding rock voids more evenly and improve long-term anchoring performance.

[0027] Preferably, lower protrusions are arranged at intervals between adjacent protrusions 2 to form a multi-level seismic wave energy attenuation mechanism. Through structures of different heights, longitudinal waves are reflected, refracted and scattered multiple times during propagation, gradually weakening wave energy and reducing the impact on the tunnel structure. At the same time, a layered shear dissipation effect is provided for transverse waves, so that the shear stress is weakened at different levels, reducing the destructiveness to the surrounding rock. In addition, the lower protrusions increase the contact area between the anchor rod and the surrounding rock, increase friction and embedding force, enhance pull-out resistance, optimize the grouting filling effect, and improve long-term stability and seismic performance.

[0028] Example 2 The present invention provides a construction method for a tunnel seismic anchor rod, comprising the following specific steps: first, drilling an anchor rod installation hole in the tunnel surrounding rock according to design requirements, the hole diameter is 30-50 mm, the depth is determined according to geological conditions, usually 1.5-3 m, to ensure that the anchor rod can be fully embedded in the surrounding rock and have sufficient anchoring force. Then, the seismic anchor rod of the hollow structure is inserted into the drill hole in a manner consistent with the direction of the tunnel structure to ensure that the anchor rod can absorb and attenuate the longitudinal waves propagating along the tunnel direction and the transverse waves propagating in the vertical direction to the greatest extent when an earthquake occurs. The anchor head of the anchor rod (optionally conical, umbrella-shaped or expansion-shaped) is fixed to one end of the anchor rod by threaded connection to ensure stable installation, increase the contact area with the surrounding rock, and improve the pull-out resistance. Next, a grouting plug is installed at the end of the anchor rod away from the anchor head. The grouting plug adopts an elastic sealing or expansion design to ensure effective sealing during the grouting process to prevent slurry leakage and ensure that the slurry uniformly fills the surrounding rock gaps. Subsequently, cement slurry or modified slurry is injected into the anchor rod through high-pressure grouting equipment. The grouting pressure is generally controlled at 0.5-1.5MPa to ensure that the slurry can overflow through the grouting hole 3 that penetrates the rod wall 1, and evenly diffuse along the channel of the damping outer layer to fill the surrounding rock cracks around the anchor rod, thereby improving the anchoring force and structural stability. During the grouting process, the slurry will flow through the gap of the spiral protrusion 2, so that the anchor rod and the surrounding rock form multiple points of contact, increasing friction and adhesion. After the grouting is completed, wait for the slurry to solidify for 24-48 hours, and conduct seismic performance testing to ensure that the damping layer of the anchor rod can effectively absorb the energy of seismic waves, reduce the axial impact caused by longitudinal waves and the shear deformation caused by transverse waves, thereby improving the long-term seismic resistance and stability of the tunnel structure.

[0029] Preferably, the anchor rod is curved. Compared with the traditional straight anchor rod, the curved anchor rod can provide a more complex seismic wave propagation path, so that the longitudinal wave and the transverse wave produce more refraction, reflection and scattering during the propagation process, effectively reducing the energy of the seismic wave and reducing its impact on the tunnel structure. Since the curved structure changes the resonant frequency of the anchor rod, it avoids the resonance phenomenon of the seismic wave inside the anchor rod, thereby reducing the risk of anchor rod failure caused by resonance amplification. In addition, the curved anchor rod can better adapt to the deformation of the surrounding rock. When the tunnel surrounding rock is subjected to earthquake, stress release or long-term creep, it can buffer the shear force and compression force of the surrounding rock and reduce the possibility of anchor rod fracture or failure. Since the curved structure provides a longer embedding path, the anchor rod can disperse the load more evenly when subjected to force, reduce local stress concentration, and improve the overall support effect. The traditional straight anchor rod is prone to fracture along the shear surface under the action of shear force, while the curved anchor rod can convert the shear force into a more uniform bending stress due to its structural characteristics, so that it can still maintain stability in a high shear force environment and reduce the risk of fracture. During the construction process, the bending direction of the anchor rod should be consistent with the direction of the tunnel structure, that is, the bent anchor rod should be arranged along the axial direction of the tunnel. This can dissipate the longitudinal waves propagating along the tunnel direction to the greatest extent and reduce the impact of transverse waves in the shear direction.

[0030] In summary, the present invention provides a tunnel seismic anchor rod, which realizes effective attenuation of seismic longitudinal and transverse waves through the optimization design of the hollow structure, the spiral or multi-layer stepped protrusion 2, the grouting hole 3, the damping inner layer and the damping outer layer, and improves the seismic resistance of the tunnel structure. The protrusion 2 of the anchor rod not only enhances the anchoring force of the surrounding rock and prevents the anchor rod from sliding or loosening in a vibration environment, but also significantly reduces the destructive effects of seismic waves by multiple reflections, refractions and scattering of seismic waves. At the same time, the damping inner layer can absorb vibration energy and reduce longitudinal and shear shocks, while the damping outer layer combined with the grouting hole 3 structure allows the slurry to diffuse evenly, improves the bonding strength between the anchor rod and the surrounding rock, and enhances the shear resistance. In addition, the spiral protrusion 2 and the polygonal or variable diameter cross-section design further optimize the force mode of the anchor rod, reduce stress concentration, improve durability, and enable it to maintain stability under complex geological conditions. Compared with traditional smooth anchor rods, the present invention can not only effectively resist surrounding rock deformation and seismic shocks, but also optimize the grouting filling effect, improve construction efficiency and long-term reliability. Overall, the tunnel seismic anchor rods have significant advantages in structural stability, seismic resistance and construction adaptability, providing a safer, more efficient and durable seismic reinforcement solution for tunnel projects.

[0031] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A tunnel seismic anchor, characterized in that: The anchor rod is a hollow structure, a rod wall of the anchor rod is provided with a plurality of protrusions, grouting holes are provided between adjacent protrusions, and the grouting holes penetrate the rod wall.

2. The tunnel seismic anchor according to claim 1, characterized in that: It also includes an anchor head, which is connected to one end of the anchor rod.

3. The tunnel seismic anchor according to claim 2, characterized in that: The anchor head is threadedly connected to the anchor rod.

4. The tunnel seismic anchor according to claim 3, characterized in that: The anchor head is conical, umbrella-shaped or expansion-shaped.

5. The tunnel seismic anchor according to claim 1, characterized in that: It also includes a grouting stopper, which is arranged at one end of the anchor rod away from the anchor head.

6. The tunnel seismic anchor according to claim 1, characterized in that: It also includes a damping inner layer, which is arranged in the anchor rod and is attached to the rod wall.

7. The tunnel vibration absorbing anchor according to any one of claims 1 to 6, characterized in that: The protrusion is spirally arranged on the rod wall along the axial direction of the anchor rod.

8. The tunnel vibration absorbing anchor rod according to claim 7, characterized in that: The top of the protrusion is provided with a thread.

9. The tunnel vibration absorbing anchor rod according to claim 7, characterized in that: It also includes a damping outer layer, which is arranged between adjacent protrusions, and the grouting holes penetrate the damping outer layer.

10. A method for constructing a tunnel seismic anchor, characterized in that: The steps include: Step 1, fixing the anchor rod in the tunnel surrounding rock, wherein the direction of the anchor rod is consistent with the design direction of the tunnel structure; Step 2: injecting slurry into the anchor rod, and the slurry overflows from the grouting hole.

Images