Forked line tunnel structure for transforming and building existing tunnel

Abstract

The utility model discloses a bifurcation tunnel structure for reconstruction and construction of an existing tunnel, the bifurcation tunnel structure comprises supporting structures and an extension tunnel structure, the extension tunnel structure and the existing tunnel structure are connected to form a new double-layer extension subway tunnel, and the supporting structures are supported on the two sides and the bottom of the double-layer extension subway tunnel. According to the forked line tunnel structure for transforming and building the existing tunnel, deformation control over the existing structure can be achieved, feasibility of the construction technology is achieved, on the basis of the existing tunnel structure, under the condition that safety and structural stability are guaranteed, the structural style of the existing tunnel can be transformed, and the construction efficiency is improved. The technical problem that the branch line tunnel is safely connected into the existing tunnel structure in parallel is solved.

Description

Technical Field

[0001] This application relates to the field of subway engineering, specifically to a branch tunnel structure for the reconstruction and renovation of an existing tunnel. Background Technology

[0002] Subway construction, as a crucial means of alleviating traffic congestion in modern cities, is experiencing a continuous increase in scale and complexity with the acceleration of urbanization. Interoperability of rail transit networks is a mode of operation that enables compatibility between different lines' tracks, rolling stock, power supply, signaling, communication, platform screen doors, and operational organization. It also allows vehicles to operate across lines, thereby saving resources, reducing costs, and improving resource utilization efficiency and passenger service quality. However, due to the continuous construction of subway lines and the need to upgrade existing lines, the connection between new and existing lines often faces numerous challenges. To ensure smooth integration of subsequent lines, designers typically reserve transfer interfaces in the station design during the initial construction phase to facilitate the smooth implementation of subsequent projects.

[0003] However, with rapid urban development, the planning and construction of subway networks are constantly being adjusted. In some cases, even without pre-planned connection points, it is still necessary to construct branch tunnels. The implementation of such projects requires structural modifications or deformation control of existing tunnels; otherwise, it may seriously threaten the safety of existing tunnel stations and even lead to engineering accidents. Especially in later-built subway lines, if large-span lateral construction or complex environmental conditions are involved, temporary support measures may be insufficient to meet the deformation control requirements of the existing tunnel structure. In such cases, if the design and construction scheme of the branch tunnel structure is not scientifically sound, it may lead to irreversible damage to the existing tunnel structure, seriously threatening the safety of subway operations and the lives and property of passengers.

[0004] Therefore, how to provide a branch tunnel structure that can safely excavate the existing tunnel structure while controlling the deformation of the existing tunnel, and safely and feasiblely construct the tunnel expansion structure, has become a technical problem that needs to be solved in this field. Utility Model Content

[0005] In view of this, this application proposes a branch tunnel structure for the reconstruction of existing tunnels, which can solve the problem of deformation control of existing structures, has the feasibility of construction technology, and can modify the structural form of existing tunnels on the basis of existing tunnel structures while ensuring safety and structural stability, thus solving the technical problem of safely connecting branch tunnels to existing tunnel structures.

[0006] According to this application, a branch tunnel structure for the reconstruction of an existing tunnel is proposed. The branch tunnel structure includes a support structure and an expansion tunnel structure. The expansion tunnel structure is connected to the existing tunnel structure to form a new double-layer expanded subway tunnel. The support structure supports the sides and bottom of the double-layer expanded subway tunnel.

[0007] Preferably, the supporting structure includes an inner retaining structure and an outer retaining structure forming a diaphragm wall retaining structure.

[0008] Preferably, within the underground continuous wall retaining structure, multiple support pipes are sequentially installed from bottom to top according to the location of the existing tunnel structure during the initial construction phase.

[0009] Preferably, a pit bottom cushion layer is provided at the bottom of the underground continuous wall retaining structure, and a bottom slab waterproof layer and a waterproof protective layer are provided.

[0010] Preferably, the expanded tunnel structure includes an extended base plate disposed at the same horizontal plane as the base plate of the existing tunnel structure, and one side of the extended base plate is fixedly connected to one side of the base plate of the existing tunnel structure.

[0011] It also includes a new lower sidewall, which is vertically and fixedly connected to the outer expansion base plate on the side of the outer expansion base plate away from the existing tunnel structure;

[0012] It also includes an outwardly expanding central plate disposed at the same level as the top slab of the existing tunnel structure, one side of which is fixedly connected to one side of the top slab of the existing tunnel structure.

[0013] The system further includes an additional upper sidewall, which is vertically and fixedly connected to the outer expansion plate on the side of the outer expansion plate away from the existing tunnel structure.

[0014] The expanded tunnel structure also includes a new side roof slab, which is horizontally arranged and vertically fixedly connected to the upper end of the new upper side wall.

[0015] Preferably, the expanded tunnel structure further includes a new roof slab, which is arranged on the same horizontal plane as the new side roof slab and its two ends are fixedly connected to the side of the new side roof slab closest to the existing tunnel structure; it also includes a new partition wall, which is arranged on the same vertical plane as the partition wall in the existing tunnel structure, with its upper end vertically fixedly connected to the new roof slab and its lower end vertically fixedly connected to the roof slab of the existing tunnel structure.

[0016] Preferably, the expanded bottom plate, the newly added lower side wall, the expanded middle plate, the newly added upper side wall, and the newly added side top plate are arranged sequentially from bottom to top, and are all located within the spatial range of the underground continuous wall retaining structure;

[0017] When constructing the expanded tunnel structure within the underground continuous wall retaining structure, each support pipe is removed sequentially from bottom to top.

[0018] Preferably, a waterproof layer and a protective layer are provided between the newly added lower sidewall and the newly added upper sidewall and the outer enclosure structure;

[0019] A waterproof layer and a protective layer are provided on the newly added side top plate and the newly added top plate;

[0020] Preferably, the branch tunnel structure includes rebar anchoring, the rebar anchoring is located in the middle of the top slab of the existing tunnel structure, the protruding section of the rebar anchoring is buried at the lower end of the newly added partition wall, the interface of the top slab of the existing tunnel structure at the connection with the lower end of the newly added partition wall has a rough surface, and the interface connection between the lower end of the newly added partition wall and the top slab of the existing tunnel structure is coated with rebar anchoring adhesive and interface adhesive.

[0021] The anchoring adhesive uses Class A epoxy and modified vinyl ester adhesives, and the interface adhesive uses a high-adhesion cement-penetrating crystalline waterproof coating.

[0022] Preferably, the sidewalls of the existing tunnel structure and the inner retaining structure within the space of the expanded tunnel structure need to be removed.

[0023] According to the technical solution of this application, the stress and deformation problem of the connection between the existing open-cut tunnel project and the branch tunnel structure is solved, ensuring the safety of construction. It is also low in cost and highly feasible, realizing the interconnection between the old and new tunnel structures, and is conducive to the integration of passenger transport resources, improving transportation efficiency and reducing operating costs.

[0024] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application, and the illustrative embodiments and descriptions thereof are used to explain this application. In the drawings:

[0026] Figure 1 This is a schematic diagram of the branch tunnel structure of this application before the removal of excess structures;

[0027] Figure 2 This is a schematic diagram of the branch tunnel structure of this application;

[0028] Figure 3 This is a schematic diagram of the connection structure between the branch tunnel structure and the existing tunnel structure in this application;

[0029] Figure 4 This is a top-view schematic diagram showing the connection between the existing tunnel structure and the branch tunnel structure.

[0030] Attached drawings numbered: Supporting structure-10; Inner retaining structure-11; Outer retaining structure-12; Expanded tunnel structure-20; Expanded bottom slab-21; New lower sidewall-22; Expanded middle slab-23; New upper sidewall-24; New side roof slab-25; New roof slab-26; New partition wall-27; Rebar installation-30; Existing tunnel structure-40; Detailed Implementation

[0031] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the specific embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0032] It should be noted that the terms "upper," "lower," "left," and "right" used in this utility model are merely descriptive terms and should not be considered as limitations on this utility model application.

[0033] The technical solution of this application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0034] The branch tunnel structure for the reconstruction of an existing tunnel in the specific embodiments of this application includes a support structure 10 and an expansion tunnel structure 20. The expansion tunnel structure 20 is connected to the existing tunnel structure 40 to form a new double-layer expanded subway tunnel. The support structure 10 supports the sides and bottom of the double-layer expanded subway tunnel.

[0035] The structural design of the expanded tunnel structure 20 must meet the requirements of static and dynamic stability. Static stability refers to the ability of the support structure to withstand external loads such as groundwater and soil pressure under the influence of geological conditions inside and around the tunnel, maintaining the overall stability of the structure. In this specific embodiment, the expanded tunnel structure 20, together with the support structure 10, forms an external force protection and support structure for the existing tunnel structure 40. The support design of the expanded tunnel structure 20 and the support structure 10 ensures that the final double-layer expanded subway tunnel meets the requirements of static and dynamic stability. That is, by calculating and simulating the internal forces and deformations of the existing tunnel structure, the deformation of the tunnel structure can be minimized while ensuring the safety and reliability of the structure during construction. Even in the event of natural disasters such as earthquakes, the double-layer expanded subway tunnel can resist the action of seismic forces and maintain the stability of the structure and its superstructure or transportation facilities.

[0036] like Figure 1 , Figure 4As shown, the supporting structure 10 includes an inner retaining structure 11 and an outer retaining structure 12 that form the underground continuous wall retaining structure.

[0037] Within the underground continuous wall retaining structure, based on the location of the existing tunnel structure 40, multiple support pipes are sequentially installed from bottom to top during the initial construction phase.

[0038] The specific construction process is as follows;

[0039] a1. Level the site, construct guide walls and underground continuous wall retaining structures, construct dewatering wells in the pit, and construct temporary column piles and temporary columns.

[0040] a2. When the underground continuous wall retaining structure is excavated to the depth below the first support, the capping beam and reinforced concrete retaining wall are constructed, and the first steel pipe support is erected.

[0041] a3. Continue excavating downwards to the depth below the second support, and install the second steel pipe support.

[0042] a4. Continue excavating downwards to the depth below the third, fourth, and fifth supports, and install the third, fourth, and fifth steel pipe supports.

[0043] A pit bottom cushion layer is set at the bottom of the underground continuous wall retaining structure, and a bottom slab waterproof layer and a waterproof protective layer are also installed.

[0044] The specific construction steps are as follows: after the fifth steel pipe support is installed, continue excavation to the design base, inspect the trench, promptly install the bottom bedding layer, install integrated grounding, and lay the bottom waterproof layer and waterproof protective layer.

[0045] like Figure 1 , Figure 2 , Figure 3 As shown, the expanded tunnel structure 20 includes an extended base plate 21 disposed at the same horizontal plane as the base plate of the existing tunnel structure 40. One side of the extended base plate 21 is fixedly connected to one side of the base plate of the existing tunnel structure 40.

[0046] A new lower sidewall 22 is added, which is vertically and fixedly connected to the expanded base plate 21 on the side of the expanded base plate 21 away from the existing tunnel structure 40; and

[0047] An outwardly expanding central plate 23 is installed at the same horizontal level as the top plate of the existing tunnel structure 40. One side of the outwardly expanding central plate 23 is fixedly connected to one side of the top plate of the existing tunnel structure 40.

[0048] A new upper sidewall 24 is added, which is vertically and fixedly connected to the outer expansion plate 23 on the side of the outer expansion plate 23 away from the existing tunnel structure 40.

[0049] The expanded tunnel structure 20 also includes a new side roof slab 25, which is horizontally set and vertically fixedly connected to the upper end of the new upper side wall 24.

[0050] The expanded tunnel structure 20 also includes a new roof slab 26, which is set on the same horizontal plane as the new side roof slab 25 and its two ends are fixedly connected to the side of the new side roof slab 25 that is close to the existing tunnel structure 40. The expanded tunnel structure 20 also includes a new partition wall 27, which is set on the same vertical plane as the partition wall in the existing tunnel structure 40. The upper end of the new partition wall 27 is vertically fixedly connected to the new roof slab 26, and the lower end is vertically fixedly connected to the roof slab of the existing tunnel structure 40.

[0051] In a specific implementation, the thickness of the newly added partition wall 27 is preferably in the range of 350mm to 450mm, the concrete is C40 concrete, the horizontal reinforcement is set to φ18@200, and the vertical reinforcement is set to φ20@200 to meet the requirements of dynamic stability and seismic resistance.

[0052] During construction, the expanded bottom slab 21, the newly added lower sidewall 22, the expanded middle slab 23, the newly added upper sidewall 24, and the newly added side top slab 25 are installed sequentially from bottom to top, and are all located within the space of the underground continuous wall retaining structure; when constructing the expanded tunnel structure 20 within the underground continuous wall retaining structure, each support pipe is removed sequentially from bottom to top.

[0053] The specific implementation steps are as follows:

[0054] b1. Pour the concrete structure of the expanded base slab 21, construct the waterproof layer of the newly added lower sidewall 22, remove the fifth steel pipe support, and pour the portion of the newly added lower sidewall 22. After the concrete of the newly added lower sidewall 22 reaches its strength, erect the inverted supports.

[0055] b2. After the inverted support is erected, the fourth steel support is removed, and the remaining newly added lower side wall 22 and the underground expansion slab 23 structure are poured. After the construction is completed, the underground expansion slab 23 reaches the required strength.

[0056] b3. Remove the intermediate steel support and pour the new upper side wall 24, the new side top plate 25, and the new top plate 26 structure and waterproof layer.

[0057] b4. Apply the waterproof and protective layer to the top slab, remove the first steel support, remove the temporary columns, and apply the capping beam. After the newly added side slab 25, the newly added top slab 26, the newly added upper side wall 24, and the newly added partition wall 27 reach the design strength, backfill and compact them simultaneously. Remove the reinforced concrete retaining wall and backfill to the ground level.

[0058] As described above, a waterproof layer and a protective layer are provided between the newly added lower sidewall 22 and the newly added upper sidewall 24 and the outer enclosure structure 12;

[0059] A waterproof layer and a protective layer are installed on the newly added side roof slab 25 and the newly added roof slab 26;

[0060] In this specific embodiment, the roof slab waterproofing structure adopts a first-level waterproofing approach, with no fewer than three layers. The first layer is waterproof concrete, upon which two external waterproofing layers are applied, including at least one layer of waterproof membrane or waterproof coating. The concrete impermeability grade is no lower than P8; for locations where new and old tunnel structures meet, the concrete strength grade and impermeability grade should be increased by one level. At the junction of the new and old structures, the reinforcing layer material should be the same as the main waterproofing material.

[0061] like Figure 3 As shown, the connection construction steps for the new and old structures are as follows: roughen the interface between the new and old concrete, wash and dry it, spray epoxy mortar (1.0kg / ㎡), and insert shear steel bars φ16, arranged in a quincunx pattern with a spacing of 300x600.

[0062] The bending reinforcement of the connection structure between the newly added bottom slab 21 and the bottom slab of the existing tunnel structure 40 is arranged with φ28 bars spaced at 100mm diameter, and the bending reinforcement of the connection structure between the outer expansion middle slab and the top slab of the existing tunnel structure 40 is arranged with φ25 bars spaced at 200mm.

[0063] In this specific embodiment, the branch tunnel structure includes a rebar 30, which is set in the middle of the top plate of the existing tunnel structure 40. The protruding section of the rebar 30 is buried at the lower end of the newly added partition wall 27. The interface between the top plate of the existing tunnel structure 40 and the lower end of the newly added partition wall 27 is roughened. The interface between the lower end of the newly added partition wall 27 and the top plate of the existing tunnel structure 40 is coated with rebar adhesive and interface adhesive.

[0064] The anchoring adhesive uses Class A epoxy and modified vinyl ester adhesives, and the interface adhesive uses a high-adhesion cement-penetrating crystalline waterproof coating.

[0065] like Figure 2 As shown, the side walls of the existing tunnel structure 40 and the inner retaining structure 11 within the spatial range of the expanded tunnel structure 20 need to be removed.

[0066] The overall construction steps for the branch tunnel structure constructed by modifying an existing tunnel in this application are as follows:

[0067] S1. Construction enclosure and construction preparation;

[0068] S2. Construct the underground continuous wall retaining structure and excavate the underground continuous wall retaining structure to construct the foundation layer.

[0069] S3. Construct the outer expansion base slab, outer expansion middle slab, new underground second floor sidewalls and waterproof layer;

[0070] S4. Construction of the new underground floor sidewall and the new roof slab structure within the underground continuous wall retaining structure on both sides has been completed.

[0071] S5. Excavate the soil under the top slab in sections along the direction of the line, and excavate the soil over the existing tunnel to the position of the top slab to construct the new top slab within the width of the existing tunnel.

[0072] And construct a new partition wall in the middle of the basement floor;

[0073] S6. Remove the internal retaining structure of the first and second underground floors, connect the new bottom slab to the existing tunnel bottom slab, connect the new middle slab to the existing tunnel top slab, and remove the existing tunnel sidewalls.

[0074] The branch tunnel structure constructed by modifying existing tunnels in this application can withstand loads from earth pressure, groundwater pressure, and other factors, as well as dynamic loads mainly from earthquakes and traffic loads.

[0075] The branch tunnel structure proposed in this application for the reconstruction of existing tunnels exhibits high stability, ensuring the safe operation and service life of the tunnel project. It guarantees the normal operation of traffic facilities within the tunnel, reduces accidents, and improves traffic efficiency. It also reduces investment and maintenance costs for tunnel projects. The targeted design of the branch tunnel structure for the reconstruction of existing tunnels can reduce the stress and deformation of the existing tunnel structure, lower the difficulty and cost of tunnel structure maintenance, and improve the economic efficiency and sustainability of the project.

[0076] The preferred embodiments of this application have been described in detail above. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solution of this application, and these simple modifications all fall within the protection scope of this application.

[0077] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not describe the various possible combinations separately.

[0078] Furthermore, various different embodiments of this application can be combined in any way, as long as they do not violate the spirit of this application, they should also be regarded as the content disclosed by this utility model.

Claims

1. A branch tunnel structure for the reconstruction of an existing tunnel, characterized in that, The branch tunnel structure includes a support structure (10) and an expansion tunnel structure (20). The expansion tunnel structure (20) is connected to the existing tunnel structure (40) to form a new double-layer expanded subway tunnel. The support structure (10) supports the two sides and the bottom of the double-layer expanded subway tunnel.

2. The branch tunnel structure constructed by modifying an existing tunnel according to claim 1, characterized in that, The supporting structure (10) includes an inner retaining structure (11) and an outer retaining structure (12) that form the underground continuous wall retaining structure.

3. The branch tunnel structure constructed by modifying an existing tunnel according to claim 2, characterized in that, In the underground continuous wall retaining structure, according to the location of the existing tunnel structure (40), multiple support pipes are installed sequentially from bottom to top in the early stage of construction.

4. The branch tunnel structure constructed by modifying an existing tunnel according to claim 3, characterized in that, A pit bottom cushion layer is set at the bottom of the underground continuous wall retaining structure, and a bottom slab waterproof layer and a waterproof protective layer are also provided.

5. The branch tunnel structure constructed by modifying an existing tunnel according to claim 2, characterized in that, The expanded tunnel structure (20) includes an extended base plate (21) disposed at the same level as the base plate of the existing tunnel structure (40). One side of the extended base plate (21) is fixedly connected to one side of the base plate of the existing tunnel structure (40). A new lower sidewall (22) is added, which is vertically and fixedly connected to the expanded base plate (21) on the side of the expanded base plate (21) away from the existing tunnel structure (40); and An outwardly expanding central plate (23) is disposed at the same horizontal level as the top plate of the existing tunnel structure (40), one side of the outwardly expanding central plate (23) being fixedly connected to one side of the top plate of the existing tunnel structure (40), and A new upper sidewall (24) is added, which is vertically fixed to the outer expansion plate (23) on the side of the outer expansion plate (23) away from the existing tunnel structure (40); The expanded tunnel structure (20) also includes a new side top plate (25), which is horizontally set and vertically fixedly connected to the upper end of the new upper side wall (24).

6. The branch tunnel structure constructed by modifying an existing tunnel according to claim 5, characterized in that, The expanded tunnel structure (20) also includes a new top plate (26), which is set at the same level as the new side top plate (25) and its two ends are fixedly connected to the side of the new side top plate (25) that is close to the existing tunnel structure (40). and A new partition wall (27) is added, which is set on the same vertical plane as the partition wall in the existing tunnel structure (40). The upper end is vertically fixed to the new top plate (26), and the lower end is vertically fixed to the top plate of the existing tunnel structure (40).

7. The branch tunnel structure constructed by modifying an existing tunnel according to claim 6, characterized in that, The expanded bottom plate (21), the newly added lower side wall (22), the expanded middle plate (23), the newly added upper side wall (24), and the newly added side top plate (25) are arranged sequentially from bottom to top, and are all located within the spatial range of the underground continuous wall retaining structure. When constructing the expanded tunnel structure (20) within the underground continuous wall retaining structure, each support pipe is removed sequentially from bottom to top.

8. The branch tunnel structure constructed by modifying an existing tunnel according to claim 7, characterized in that, The newly added lower sidewall (22) and the newly added upper sidewall (24) are connected to the outer enclosure structure (12). A waterproof layer and a protective layer are installed between them; A waterproof layer and a protective layer are provided on the newly added side top plate (25) and the newly added top plate (26).

9. The branch tunnel structure constructed by modifying an existing tunnel according to claim 8, characterized in that, The branch tunnel structure includes a rebar (30), which is located in the middle of the top slab of the existing tunnel structure (40). The protruding section of the rebar (30) is embedded in the lower end of the newly added partition wall (27). The interface of the top plate of the existing tunnel structure (40) at the lower end of the newly added partition wall (27) is roughened, and the interface between the lower end of the newly added partition wall (27) and the top plate of the existing tunnel structure (40) is coated with anchoring adhesive and interface adhesive. The anchoring adhesive uses Class A epoxy and modified vinyl ester adhesives, and the interface adhesive uses a high-adhesion cement-penetrating crystalline waterproof coating.

10. The branch tunnel structure for the reconstruction of an existing tunnel according to any one of claims 2-9, characterized in that, The sidewalls of the existing tunnel structure (40) and the inner enclosure structure (11) within the space of the expanded tunnel structure (20) need to be removed.

Images