Novel graded energy consumption type tunnel seismic mitigation and isolation structure

Abstract

The utility model discloses a novel graded energy dissipation type tunnel seismic mitigation and isolation structure, belongs to the field of tunnel seismic mitigation and disaster reduction, and solves the problems that an existing seismic mitigation and isolation structure is limited in energy dissipation capacity and poor in durability. The energy consumption type seismic mitigation and isolation layer is arranged between the primary support layer and the secondary lining of the tunnel, the energy consumption type seismic mitigation and isolation layer comprises the foam concrete layer and the concrete cushion layer, the foam concrete layer is close to the primary support layer, and the concrete cushion layer is close to the secondary lining. Connecting steel plates are arranged on the opposite faces of the foam concrete layer and the concrete cushion layer respectively, a plurality of containing shells are machined on the connecting steel plates on the sides of the foam concrete layer, metal rubber components are arranged in the containing shells and located between the two connecting steel plates, and a gap is formed between the two connecting steel plates. Under the earthquake action, the metal rubber component dissipates a large amount of earthquake energy. When a rare extra-large earthquake occurs, the connecting steel plate combined structure and the steel plate limiting mechanism utilize the yield of a metal plate for secondary energy consumption.

Description

Technical Field

[0001] The utility model belongs to the field of tunnel earthquake prevention and disaster reduction, and particularly relates to a novel hierarchical energy-dissipating tunnel isolation structure. Background Technique

[0002] The damage of a tunnel under the action of an earthquake is the result of the action of many factors such as the characteristics of seismic waves, the geological conditions of surrounding rocks, the tunnel burial depth, the lining type and shape, etc. Tunnel isolation design is different from ground structures. Its deformation is restricted by rock and soil masses. It is not only the vibration source of the structure itself, but also an additional load on the structure. Generally speaking, tunnel isolation design is composed of backfilling flexible materials between the primary support and the secondary lining, changing the original primary lining - surrounding rock system into a lining - shock-absorbing layer - surrounding rock system.

[0003] The disaster-causing modes of active fault zones on tunnels are divided into direct damage to the tunnel structure by fault dislocation, vibration damage to the tunnel caused by an earthquake, and earthquake-induced geological disaster chains. Fault dislocation directly generates shear displacement in the surrounding rock. The shear deformation is usually limited to a narrow range around the active fault, but the tunnel damage caused by this sudden displacement mode is catastrophic and the structure is difficult to resist, resulting in the main body damage of the tunnel.

[0004] Most of the current isolation structures use rubber layers as the additive materials for the isolation layer. During an earthquake, the seismic force is transmitted to the rubber, and the elastoplastic deformation of the rubber is used to dissipate energy to achieve the isolation function. However, its energy-dissipating ability is limited, and it will quickly lose the energy-dissipating ability under the action of large pulses in rare earthquakes, and the rubber has poor durability and is easily damaged under the action of long-term alternating loads.

[0005] In view of this, the utility model proposes a novel hierarchical energy-dissipating tunnel isolation structure, aiming to improve the energy-dissipating ability of the tunnel lining structure, ensure the durability of the isolation layer, and thus avoid seismic risks. Content of the Utility Model

[0006] The purpose of the utility model is to provide a novel hierarchical energy-dissipating tunnel isolation structure to solve the problems of limited energy-dissipating ability and poor durability of the existing isolation structure.

[0007] The technical solution of the utility model is: a novel hierarchical energy-dissipating tunnel isolation structure, in which an energy-dissipating isolation layer is provided between the primary support layer and the secondary lining of the tunnel. The energy-dissipating isolation layer includes a foamed concrete layer and a concrete cushion layer. The foamed concrete layer is close to the primary support layer, and the concrete cushion layer is close to the secondary lining. Connecting steel plates are respectively provided on the opposite surfaces of the foamed concrete layer and the concrete cushion layer. A plurality of accommodating shells are processed on the connecting steel plate on the side of the foamed concrete layer. A metal rubber member is provided in the accommodating shell. The metal rubber member is located between the two connecting steel plates, and there is a gap between the two connecting steel plates.

[0008] As a further improvement of the present utility model, steel plate limiting mechanisms are respectively provided at both ends of the metal rubber component. The steel plate limiting mechanism includes a base plate and two arc-shaped limiting steel plates. The two limiting steel plates are symmetrically arranged on both sides of the metal rubber component. The base plate is located at the end of the metal rubber component, and the limiting steel plates are welded to the base plate.

[0009] As a further improvement of the present utility model, the base plate is connected to the connecting steel plate through high-strength bolts and is respectively connected to the foam concrete layer and the concrete cushion layer.

[0010] As a further improvement of the present utility model, the steel plate limiting mechanism further includes stiffening ribs, and the stiffening ribs are welded between the limiting steel plates and the base plate.

[0011] As a further improvement of the present utility model, two stiffening ribs are provided on each limiting steel plate, and a reinforcing plate is provided between the two stiffening ribs to enhance the structural stability.

[0012] As a further improvement of the present utility model, a waterproof layer is provided between the secondary lining and the concrete cushion layer.

[0013] The beneficial effects of the present utility model are as follows:

[0014] 1. The seismic isolation and vibration reduction structure of the present utility model has excellent seismic energy dissipation performance. Under the action of an earthquake, the metal rubber component undergoes plastic deformation under force, and the friction between the stainless steel metal wires inside the metal rubber provides damping to dissipate a large amount of seismic energy. When suffering from a rare and extremely large earthquake, when the metal rubber component is compressed or sheared to the extreme displacement and loses its energy dissipation capacity, the connecting steel plate composite structure and the steel plate limiting mechanism use the yield of the metal plate for secondary energy dissipation and play a role in restricting the tangential displacement of the arch ring, thereby effectively preventing the occurrence of tunnel seismic disasters.

[0015] 2. The seismic isolation and vibration reduction structure of the present utility model has a simple and reasonable form, stable mechanical properties, good durability, simple process, light self-weight, high bearing capacity, good corrosion resistance, and excellent damping performance. It provides a reliable hierarchical energy dissipation type seismic isolation and vibration reduction structure for tunnel structures, especially has great significance for the seismic isolation and vibration reduction design of tunnel linings in high-intensity areas located in fault zones. Description of the Drawings

[0016] Figure 1 is the schematic cross-sectional layout diagram of the present utility model;

[0017] Figure 2 is Figure 1 the enlarged schematic diagram of part I in

[0018] Figure 3 is the distribution schematic diagram of the metal rubber component in the present utility model;

[0019] Figure 4 is the structural schematic diagram of the steel plate limiting mechanism in the present utility model.

[0020] In the figure: 1 - primary support layer; 2 - energy - dissipating seismic isolation layer; 20 - metal rubber component; 21 - foam concrete layer; 22 - connecting steel plate; 23 - stiffening rib; 24 - concrete cushion; 25 - high - strength bolt; 26 - reinforcement plate; 27 - accommodating shell; 28 - limiting steel plate; 29 - base plate; 3 - waterproof layer; 4 - secondary lining. Specific implementation mode

[0021] The following will describe the present utility model in detail with reference to the accompanying drawings.

[0022] As Figures 1-4 shown, a new - type hierarchical energy - dissipating tunnel seismic isolation structure is provided with an energy - dissipating seismic isolation layer 2 between the primary support layer 1 and the secondary lining 4 of the tunnel. The energy - dissipating seismic isolation layer 2 includes a foam concrete layer 21 and a concrete cushion 24. The foam concrete layer 21 is close to the primary support layer 1, and the concrete cushion 24 is close to the secondary lining 4. Connecting steel plates 22 are respectively arranged on the opposite surfaces of the foam concrete layer 21 and the concrete cushion 24. A plurality of accommodating shells 27 are processed on the connecting steel plate 22 on the side of the foam concrete layer 21. Each accommodating shell 27 is provided with a metal rubber component 20. The metal rubber components 20 are evenly distributed in the energy - dissipating seismic isolation layer 2. The metal rubber components 20 are located between the two connecting steel plates 22, and there is a gap between the two connecting steel plates 22.

[0023] Steel plate limiting mechanisms are respectively arranged at both ends of the metal rubber component 20. The steel plate limiting mechanism includes a base plate 29 and two arc - shaped limiting steel plates 28. The two limiting steel plates 28 are symmetrically arranged on both sides of the metal rubber component 20. The base plate 29 is located at the end of the metal rubber component 20, and the limiting steel plates 28 are welded to the base plate 29. The base plate 29 is connected to the connecting steel plate 22 through high - strength bolts 25 and is respectively connected to the foam concrete layer 21 and the concrete cushion 24.

[0024] The steel plate limiting mechanism further includes a stiffening rib 23. The stiffening rib 23 is welded between the limiting steel plate 28 and the base plate 29. Two stiffening ribs 23 are arranged on each limiting steel plate 28, and a reinforcement plate 26 is arranged between the two stiffening ribs 23.

[0025] A waterproof layer 3 is provided between the secondary lining 4 and the concrete cushion 24.

[0026] The metal rubber component 20 is a circular single - layer structure, which is made by processes such as winding austenitic stainless steel metal wires into spring coils and compression molding. The single - layer metal rubber structure can be formed at one time, has stable mechanical properties, good corrosion resistance and good damping performance. Its relative density is between 0.30 and 0.40, and the geometric size of the metal rubber component 20 can be determined by adjusting the die size.

[0027] Both the connecting steel plate 22 and the steel plate limiting mechanism are made of Q235 steel, and after galvanizing on their surfaces, antirust paint is applied to make them have good corrosion resistance.

[0028] The two connecting steel plates 22 respectively form a steel-concrete composite structure with the foam concrete layer 21 and the concrete cushion layer 24. There is a gap between the two steel-concrete composite structures to ensure that the metal rubber member 20 plays a role under the action of seismic loads. Under the action of an earthquake, the tunnel lining structure vibrates violently, generating cyclic alternating tensile and compressive strains applied to the metal rubber member 20. During the tensile and compressive process, the friction between the metal wires of the metal rubber member 20 and its plastic deformation provide damping to dissipate seismic energy. When encountering a particularly large earthquake, after the metal rubber member 20 reaches the bearing capacity limit and loses its energy dissipation capacity, the steel plate limiting mechanism starts to work and the two steel-concrete composite structures are in direct contact, using metal yield for secondary energy dissipation, so as to achieve the seismic resistance goals of multi-level fortification and hierarchical energy dissipation.

[0029] The utility model can exhibit good energy dissipation performance under strong earthquake actions and will not have an adverse impact on components such as the primary support layer 1 and the secondary lining 4, and is suitable for the seismic isolation design of tunnels in high-intensity areas and is worthy of popularization and application in practical projects.

Claims

1. A new type of graded energy-absorbing tunnel seismic isolation structure, in which an energy-absorbing seismic isolation layer is provided between the initial support layer and the secondary lining of the tunnel, characterized in that: The energy-absorbing seismic isolation layer (2) comprises a foam concrete layer (21) and a concrete cushion layer (24), wherein the foam concrete layer (21) is close to the initial support layer (1), and the concrete cushion layer (24) is close to the secondary lining (4), and connecting steel plates (22) are respectively provided on the opposite surfaces of the foam concrete layer (21) and the concrete cushion layer (24), and a plurality of containing shells (27) are processed on the connecting steel plate (22) on the side of the foam concrete layer (21), and a metal rubber component (20) is provided in the containing shell (27), and the metal rubber component (20) is located between the two connecting steel plates (22), and there is a gap between the two connecting steel plates (22).

2. According to claim 1, the novel graded energy dissipation tunnel seismic isolation structure is characterized by: The two ends of the metal rubber component (20) are respectively provided with a steel plate limiting mechanism, the steel plate limiting mechanism comprising a base plate (29) and two arc-shaped limiting steel plates (28), the two limiting steel plates (28) are symmetrically arranged on both sides of the metal rubber component (20), the base plate (29) is located at the end of the metal rubber component (20), and the limiting steel plates (28) are welded to the base plate (29).

3. According to claim 2, the novel graded energy dissipation tunnel seismic isolation structure is characterized by: The base plate (29) is connected to the connecting steel plate (22) via high-strength bolts (25) and is respectively connected to the foam concrete layer (21) and the concrete cushion layer (24).

4. According to claim 3, the novel graded energy dissipation tunnel seismic isolation structure is characterized by: The steel plate limiting mechanism further comprises a stiffening rib (23), wherein the stiffening rib (23) is welded between the limiting steel plate (28) and the base plate (29).

5. According to claim 4, the novel graded energy dissipation tunnel seismic isolation structure is characterized by: Two stiffening ribs (23) are provided on each limiting steel plate (28), and a reinforcement plate (26) is provided between the two stiffening ribs (23).

6. The novel graded energy dissipation tunnel seismic isolation structure according to claim 5 is characterized by: A waterproof layer (3) is provided between the secondary lining (4) and the concrete cushion layer (24).

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