Shock absorption and isolation structure for lining ring piece of shield tunnel undercrossing river channel section

Abstract

The utility model provides a shock absorption and isolation structure for a lining ring piece of a shield tunnel undercrossing river channel section, which is characterized in that an air bag is in a circular ring shape, a circle of air bag is attached to the inner wall of the tunnel, polyurethane is poured between the air bag and a shield segment to form a circle of bonding layer, and the air bag and the shield segment are consolidated through the bonding layer; the tensile reinforcing units are used for resisting shock of the area with the maximum tensile stress in the interval, and the multiple sets of tensile reinforcing units are arranged in the interval in the longitudinal depth direction of the tunnel at intervals; and the compression-resistant reinforcing unit is used for seismic resistance of the area with the maximum pressure stress in the interval, comprises a plurality of foam memory metal plates which are sequentially staggered and engaged in the circumferential direction of the tunnel, is located in the bonding layer, and is integrally attached to the inner surface of the shield segment in a matched mode and fixedly connected through the bonding layer. The anti-seismic structure provides an effective brand new scheme for the anti-seismic section of the shield tunnel passing through the river channel under the key disaster part, and the overall anti-seismic capacity and the structural stability of the tunnel can be remarkably improved.

Description

Technical Field

[0001] The utility model relates to a tunnel earthquake-resistant structure, in particular to a shock-absorbing and isolating structure for a lining ring piece of a shield tunnel under a river channel. Background Art

[0002] During the construction of tunnel projects, it is inevitable to encounter the situation of passing under a river. When the shield tunnel passing under the river is subjected to an earthquake, the underwater shield tunnel section is a weak link in earthquake resistance because the presence of groundwater has an enhanced effect on the earthquake.

[0003] At present, there are many designs for shield tunnel seismic resistance, but there is a lack of consideration for the seismic resistance of the shield tunnel under the river, especially the design for the seismic resistance of the key disaster-stricken areas. If the entire section of the shield tunnel under the river is reinforced, the cost of consumables will increase significantly. Since the active fault formed when the tunnel line encounters an earthquake cannot be completely avoided, the seismic resistance of the shield tunnel under the river has become a difficult problem that must be solved. Utility Model Content

[0004] In order to solve the above technical problems, the utility model proposes a seismic isolation structure for the lining ring of the shield tunnel under the river channel, which provides a new and effective solution for the seismic resistance of the shield tunnel under the river channel for key disaster-stricken areas, and can significantly improve the overall seismic resistance and structural stability of the tunnel.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] A seismic isolation structure for a lining ring of a shield tunnel under a river channel, which has the following structural features: it is used for seismic resistance of the section where the shield tunnel underpasses the river channel, and includes an air bag, a bonding layer, a tensile reinforcement unit, and a compressive reinforcement unit:

[0007] The airbag is in a ring shape and is arranged around the inner wall of the tunnel. A gap is left between the airbag and the shield segment in the radial direction, and polyurethane is poured to form a circle of the bonding layer, which is consolidated through the bonding layer.

[0008] The tensile reinforcement unit is used for earthquake resistance of the area with the largest tensile stress in the interval. Multiple groups are arranged in the interval along the longitudinal depth of the tunnel. Each group of tensile reinforcement units is composed of multiple tensile reinforcement devices spaced along the circumferential direction of the tunnel. Each tensile reinforcement device is used for reinforcement between two adjacent shield segments along the longitudinal depth of the tunnel. The overall structure is a symmetrical structure with the joint of the two shield segments as the symmetry center, including a precast concrete slab with a pair of embedded connection structures, a pair of connecting bolts, a pair of prestressed steel strands, and an energy dissipation unit. The precast concrete slab is fastened to the two shield segments at the pair of embedded connection structures through a pair of connecting bolts, and is close to the outer surfaces of the two shield segments. The pair of embedded connection structures are cantilevered toward the center of the tunnel, and the opposite end faces are respectively provided with prestressed steel strands. The pair of prestressed steel strands are connected by the energy dissipation unit.

[0009] The compression reinforcement unit is used for earthquake resistance in the area subject to the greatest compressive stress within the section, and includes a plurality of foam memory metal plates interlaced and interlocked in sequence along the circumferential direction of the tunnel, located within the bonding layer, and adaptively attached to the inner surface of the shield segment at the location as a whole and consolidated through the bonding layer, and the adjacent foam memory metal plates are tensioned by a spring arranged along the circumferential direction of the tunnel through the deformation direction.

[0010] The structural features of the utility model also lie in:

[0011] The length of the section along the longitudinal direction of the tunnel is 5m.

[0012] The tensile reinforcement units are arranged in groups of 3-4 at intervals along the longitudinal depth of the tunnel.

[0013] The compression reinforcement unit is continuous in its entirety along the longitudinal direction of the tunnel.

[0014] The energy dissipation unit is a columnar structure extending transversely between two prestressed steel strands and is made of steel. A spacing is reserved between the energy dissipation unit, a pair of prestressed steel strands and the precast concrete slab.

[0015] According to the position and the outer dimensions of the connecting bolts, the embedded connecting structure and the precast concrete slab are jointly formed with bolt holes for the connecting bolts to pass through.

[0016] Among the multiple foam memory metal plates of the compression reinforcement unit, the foam memory metal plates at both ends have an L-shaped cross-section, and the foam memory metal plates in between have a matching bending structure, consisting of two horizontal sections and a vertical section between the two horizontal sections. The two horizontal sections are engaged with the two adjacent foam memory metal plates, and two upper and lower gaps are left at the engagement of the two adjacent foam memory metal plates, and each gap is tensioned by a plurality of the springs.

[0017] Compared with the prior art, the beneficial effects of the utility model are embodied in:

[0018] 1. Reduce construction difficulty and save construction costs;

[0019] After determining the most vulnerable position of the shield tunnel under the river, the seismic isolation structure of the utility model is implemented for the key disaster-stricken areas. Compared with the reinforcement of the entire section, the utility model greatly reduces the construction difficulty and saves construction costs;

[0020] 2. Good earthquake resistance, especially suitable for earthquake resistance in shield tunnels under rivers;

[0021] The utility model is provided with airbags and bonding layers, a compression reinforcement unit is provided for earthquake resistance of the area in the interval subject to the largest compressive stress, and a tensile reinforcement unit is provided for earthquake resistance of the area in the interval subject to the largest tensile stress; the airbags are used to directly weaken the earthquake effect, the bonding layer is used to effectively block the gap between the shield pipe segment and the airbag to reduce the penetration of water flow, and the tensile reinforcement unit is used to fix and connect two adjacent shield pipe segments along the longitudinal direction of the tunnel into a whole, effectively preventing the shield from dislocation and deformation due to earthquake fault shearing, thereby improving the overall stability, and utilizing the supporting effect of multiple staggered foam memory metal plates in the compression reinforcement unit to limit the deformation of the shield pipe segment. The various functions work together to significantly improve the overall earthquake resistance and structural stability of the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is an example diagram of the typical maximum principal stress distribution of a shield tunnel under a river under earthquake conditions obtained from numerical simulation;

[0023] Figure 2 It is a cross-sectional structural schematic diagram of the utility model;

[0024] Figure 3 It is a structural schematic diagram of the tensile reinforcement device in the utility model;

[0025] Figure 4 It is a structural schematic diagram of the compression reinforcement unit in the utility model.

[0026] In the figure, 1 is the airbag; 2 is the bonding layer; 3 is the shield segment; 4 is the area subject to the greatest tensile stress; 5 is the tensile reinforcement device; 51 is the precast concrete slab; 52 is the connecting bolt; 53 is the prestressed steel strand; 54 is the energy dissipation unit; 55 is the embedded connection structure; 6 is the area subject to the greatest compressive stress; 7 is the compressive reinforcement unit; 71 is the foam memory metal plate; 72 is the spring. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model will be clearly and completely described below in combination with the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] Please refer to Figures 2 to 4 The seismic isolation structure for the lining ring of the shield tunnel under the river channel of this embodiment is used for the earthquake resistance of the shield tunnel under the river channel, and includes an air bag 1, an adhesive layer 2, a tensile reinforcement unit, and a compressive reinforcement unit 7:

[0029] The airbag 1 is in the shape of a ring and is arranged around the inner wall of the tunnel. A gap is left between the shield segment 3 in the radial direction and a circle of polyurethane is poured to form a bonding layer 2. The bonding layer 2 is solidified to effectively block the gap between the shield segment and the airbag, reducing water penetration.

[0030] The tensile reinforcement unit is used for earthquake resistance of the area 4 subject to the largest tensile stress in the interval. Multiple groups of tensile reinforcement units are arranged at intervals along the longitudinal depth of the tunnel in the interval. Each group of tensile reinforcement units is composed of multiple tensile reinforcement devices 5 distributed at intervals along the circumferential direction of the tunnel. Each tensile reinforcement device 5 is used for reinforcement between two adjacent shield segments 3 along the longitudinal depth of the tunnel. The overall structure is a symmetrical structure with the joint of the two shield segments 3 as the symmetry center, including a precast concrete slab 51 with a pair of embedded connection structures, a pair of connecting bolts 52, a pair of prestressed steel strands 53, and an energy dissipation unit 54. The precast concrete slab 51 is fastened to the two shield segments 3 at a pair of embedded connection structures 55 through a pair of connecting bolts 52, and is close to the outer surfaces of the two shield segments 3. The pair of embedded connection structures are cantilevered toward the center of the tunnel, and the opposite end faces are respectively provided with prestressed steel strands 53. The pair of prestressed steel strands 53 are connected by the energy dissipation unit 54.

[0031] The compression reinforcement unit 7 is used for earthquake resistance of the area 6 subject to the largest compressive stress in the section, and includes a plurality of foam memory metal plates 71 interlaced in sequence along the circumferential direction of the tunnel, located in the bonding layer 2, and the whole is adaptively attached to the inner surface of the shield segment 3 at the location and consolidated through the bonding layer. The adjacent foam memory metal plates 71 are tensioned by a spring 72 arranged along the circumferential direction of the tunnel in the deformation direction.

[0032] In a specific implementation, the corresponding structural arrangement of the above-mentioned seismic isolation structure also includes:

[0033] The airbag is made of highly elastic material, which has good bearing capacity, waterproof ability, resistance to plastic deformation and corrosion resistance, and can effectively reduce the impact of earthquake on the shield segment. The bonding layer is made of polyurethane material, which has good elasticity and impact resistance.

[0034] The length of the section along the longitudinal direction of the tunnel is 5m.

[0035] The tensile reinforcement units are arranged in groups of 3-4 at intervals along the longitudinal depth of the tunnel.

[0036] The compression reinforcement unit 7 is continuous along the length of the tunnel depth direction.

[0037] The energy dissipation unit 54 is a columnar structure extending transversely between the two prestressed steel strands 53 and is made of steel. A spacing is reserved between the energy dissipation unit 54 , the pair of prestressed steel strands 53 and the precast concrete slab 51 .

[0038] According to the position and the outer dimensions of the connection bolts 52 , the embedded connection structure and the precast concrete slab 51 are jointly formed with bolt holes for the connection bolts 52 to pass through.

[0039] Among the multiple foam memory metal plates 71 of the compression reinforcement unit 7, the cross-section of the foam memory metal plates 71 at both ends is L-shaped, and the cross-section of the foam memory metal plates 71 between them is an adaptive bending structure, which is composed of two horizontal sections and a vertical section between the two horizontal sections. The two horizontal sections are engaged with the two adjacent foam memory metal plates 71, and two upper and lower gaps are left at the engagement of the two adjacent foam memory metal plates 71, and each gap is tensioned by a number of springs 72. The number of foam memory metal plates is determined according to the size of the area with the greatest compressive stress. When the width of the area with the greatest compressive stress to be reinforced cannot be covered by a single foam memory metal plate, the overall structure formed by multiple staggered foam memory metal plates is reinforced, and the upper and lower gaps left at the engagement of the two adjacent foam memory metal plates are tensioned by springs. When subjected to earthquake impact, the foam memory metal plates and springs can simultaneously play a buffering role.

[0040] Therefore, it is necessary to determine the most vulnerable location by analyzing the response law of the lining ring of the shield tunnel under the river under the action of earthquake, and to design the seismic isolation structure of the shield tunnel under the river according to the damage form in this area.

[0041] Figure 1 Here is an example of determining the most vulnerable locations in a shield tunnel under a river:

[0042] Combined with the actual project overview, the numerical model was established through finite element software, and the numerical simulation method was adopted. The influence of common earthquake waveforms, Kobe waves and El-centro waves was comprehensively considered through the time history analysis method. From the analysis of the numerical simulation results, it can be seen that the major principal stress of the shield tunnel under the action of earthquake appears on the tunnel ring at the bottom of the river bank slope, the maximum tensile stress appears at the left spandrel and the right waist, and the maximum compressive stress is distributed at the right spandrel and the left waist.

[0043] like Figure 2 As shown, tensile reinforcement units are set corresponding to the areas subject to the greatest tensile stress, namely the left arch shoulder and the right arch waist; and compressive reinforcement units are set corresponding to the areas subject to the greatest compressive stress, namely the right arch shoulder and the left arch waist.

[0044] When the seismic isolation structure of this embodiment is used for earthquake resistance in the section where the shield tunnel passes under the river, the working principle is as follows:

[0045] First, the setting of airbags will directly weaken the effects of earthquakes;

[0046] As a further reinforcement device, the tensile reinforcement unit is located in the area with the greatest tensile stress. Multiple groups are arranged in the interval along the longitudinal depth of the tunnel. Each group of tensile reinforcement units is composed of multiple tensile reinforcement devices spaced along the circumference of the tunnel. Two adjacent shield segments along the longitudinal depth of the tunnel are fixedly connected into a whole, effectively preventing the shield from dislocation and deformation due to earthquake fault shearing, thereby improving the overall stability.

[0047] The compressive reinforcement unit is located in the area subject to the greatest compressive stress and in the bonding layer. The whole unit is adaptively attached to the inner surface of the shield segment at the location and is consolidated through the bonding layer. The deformation of the shield segment is limited by the support of multiple staggered foam memory metal plates.

[0048] Although the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A seismic isolation structure for a lining ring of a shield tunnel under a river channel, characterized in that: Used for earthquake resistance of shield tunnels under rivers, including airbags, bonding layers, tensile reinforcement units, and compressive reinforcement units: The airbag is in a ring shape and is arranged around the inner wall of the tunnel. A gap is left between the airbag and the shield segment in the radial direction, and polyurethane is poured to form a circle of the bonding layer, which is consolidated through the bonding layer. The tensile reinforcement unit is used for earthquake resistance of the area with the largest tensile stress in the interval. Multiple groups are arranged in the interval along the longitudinal depth of the tunnel. Each group of tensile reinforcement units is composed of multiple tensile reinforcement devices spaced along the circumferential direction of the tunnel. Each tensile reinforcement device is used for reinforcement between two adjacent shield segments along the longitudinal depth of the tunnel. The overall structure is a symmetrical structure with the joint of the two shield segments as the symmetry center, including a precast concrete slab with a pair of embedded connection structures, a pair of connecting bolts, a pair of prestressed steel strands, and an energy dissipation unit. The precast concrete slab is fastened to the two shield segments at the pair of embedded connection structures through a pair of connecting bolts, and is close to the outer surfaces of the two shield segments. The pair of embedded connection structures are cantilevered toward the center of the tunnel, and the opposite end faces are respectively provided with prestressed steel strands. The pair of prestressed steel strands are connected by the energy dissipation unit. The compression reinforcement unit is used for earthquake resistance in the area subject to the greatest compressive stress within the section, and includes a plurality of foam memory metal plates interlaced and interlocked in sequence along the circumferential direction of the tunnel, located within the bonding layer, and adaptively attached to the inner surface of the shield segment at the location as a whole and consolidated through the bonding layer, and the adjacent foam memory metal plates are tensioned by a spring arranged along the circumferential direction of the tunnel through the deformation direction.

2. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 is characterized in that: The length of the section along the longitudinal direction of the tunnel is 5m.

3. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 or 2 is characterized in that: The tensile reinforcement units are arranged in groups of 3-4 at intervals along the longitudinal depth of the tunnel.

4. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 or 2 is characterized in that: The compression reinforcement unit is continuous in its entirety along the longitudinal direction of the tunnel.

5. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 is characterized in that: The energy dissipation unit is a columnar structure extending transversely between two prestressed steel strands and is made of steel. A spacing is reserved between the energy dissipation unit, a pair of prestressed steel strands and the precast concrete slab.

6. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 is characterized by: According to the position and the outer dimensions of the connecting bolts, the embedded connecting structure and the precast concrete slab are jointly formed with bolt holes for the connecting bolts to pass through.

7. The seismic isolation structure for the lining ring of a shield tunnel under a river channel according to claim 1 is characterized by: Among the multiple foam memory metal plates of the compression reinforcement unit, the foam memory metal plates at both ends have an L-shaped cross-section, and the foam memory metal plates in between have a matching bending structure, consisting of two horizontal sections and a vertical section between the two horizontal sections. The two horizontal sections are engaged with the two adjacent foam memory metal plates, and two upper and lower gaps are left at the engagement of the two adjacent foam memory metal plates, and each gap is tensioned by a plurality of the springs.

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