A water-permeable caisson structure for quickly forming a tunnel land approach section

Abstract

The application is a water-permeable caisson structure for quickly forming a tunnel shore connection section, comprising a caisson bin, a prefabricated tunnel structure, a bottom water passing structure and a water stop system; the caisson and the prefabricated tunnel structure comprise an upper layer bottom plate, the top of the upper layer bottom plate is provided with a caisson body on the front and back sides, the top of the upper layer bottom plate is provided with a tunnel joint on the left and right sides, and the top of the tunnel joint is provided with a water retaining wall; the bottom water passing structure comprises a lower layer bottom plate, a plurality of wall pieces are arranged between the lower layer bottom plate and the upper layer bottom plate, and a plurality of water passing channels are formed between the wall pieces. The application solves the problem of great influence of traditional island building technology on water power exchange by replacing the island building cofferdam with the water-permeable caisson; the problem of large amount of earthwork and long construction period of backfilling island formation in traditional shore connection island building is solved by quickly forming a shore section structure through installation of a single or multiple large-size caissons; the prefabricated caisson contains a tunnel joint, and the prefabrication degree is high, thereby reducing the steps of supporting and cast-in-place tunnel required by the traditional shore section structure.

Description

Technical Field

[0001] This invention relates to the technical field of immersed tunnel engineering, and in particular to a permeable caisson structure for rapidly forming the tunnel-to-shore section. Background Technology

[0002] Tunnel projects constructed using the immersed tube method typically consist of precast immersed tube sections in the water and cast-in-place sections for connection to the shore. To ensure proper connection with the immersed tube sections, the cast-in-place section for connection to the shore requires a certain water depth at the connection point (generally no less than 10m below the low water level). Therefore, it needs to extend a certain distance beyond the shoreline, forming the underwater section of the tunnel. Due to the limited water depth in this section, precast structures cannot be used. The conventional construction method involves building an island in the water to form a cofferdam, and then constructing the tunnel connection section within the island using cast-in-place casting. However, this method presents the following problems during construction:

[0003] The construction project involves many steps, including island filling, water stopping, support, and cast-in-place shoreline structure construction. The construction period is long.

[0004] The amount of earth and stone used is large, and the soil extraction has a significant impact on the ecological environment.

[0005] The tunnel section connecting to the shore usually requires the completion of the thrust section and secondary water-stopping structure before it can be installed with immersed tubes. Disruptions in the connection of the procedures often affect the overall project schedule.

[0006] Reclaiming islands in the water disrupts the hydrodynamic exchange in the surrounding area and has a significant impact on the ecological environment. Summary of the Invention

[0007] The present invention aims to overcome the shortcomings of the prior art and provide a permeable caisson structure for rapidly forming tunnel access sections.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A permeable caisson structure for rapidly forming a tunnel-to-bank section includes caisson compartments and a prefabricated tunnel structure, a bottom water passage structure, and a water-stopping system.

[0010] The caisson and precast tunnel structure includes an upper bottom slab, with caisson bodies on the front and rear sides of the top of the upper bottom slab, and tunnel joints on the left and right sides of the top of the upper bottom slab. The tunnel joints are located between the two caisson bodies, and a water-retaining wall is provided on the top of the tunnel joints. Several tongue and groove joints are provided on the left and right side walls of the caisson bodies.

[0011] The bottom water passage structure includes a lower bottom plate, which is located below the upper bottom plate. Several wall panels are provided between the lower bottom plate and the upper bottom plate, and several water passage channels are formed between the wall panels.

[0012] The water-stopping system consists of two parts: one part is a steel sealing door and a water-retaining wall installed on the tunnel joint; the other part is two tongue-and-groove inserts installed on the inner side of the tongue and groove at both ends of two adjacent sets of caisson bodies, with a concrete sealing section between the two tongue-and-groove inserts, and a rubber waterstop strip between the caisson body and the side wall of the concrete sealing section.

[0013] The caisson body includes an outer wall, and inside the outer wall are several transverse and longitudinal partitions, which divide the internal cavity of the caisson body into several compartments.

[0014] The outer wall has a water inlet, and the longitudinal partition wall has a water passage hole.

[0015] The retaining wall has an L-shaped structure.

[0016] Several reinforcing ribs are provided between the two side panels of the retaining wall from front to back.

[0017] After the caissons for the shore section are installed, the compartments of the caisson body are filled with backfill stones.

[0018] The beneficial effects of this invention are as follows: This invention replaces cofferdams with permeable caissons, solving the problem of significant impact on hydrodynamic exchange caused by traditional island-building techniques; by rapidly assembling shoreline structures from single or multiple large-sized caissons, it solves the problems of large earthwork volumes and long construction periods associated with traditional shoreline island construction; the prefabricated caissons include tunnel joints, exhibiting a high degree of prefabrication, reducing the need for traditional shoreline structure construction steps such as support installation and in-situ tunnel casting, thus solving the problem of construction time constraints; the caissons also serve as thrust sections, enabling the installation of immersed tunnels immediately after the shoreline caissons are installed, solving the problems of difficult process connections and numerous influencing factors. Attached Figure Description

[0019] Figure 1 This is a planar schematic diagram of the present invention;

[0020] Figure 2 This is a schematic longitudinal section view of the caisson body of the present invention.

[0021] Figure 3 This is a schematic longitudinal section view of the tunnel joint location of the present invention;

[0022] Figure 4 This is a cross-sectional view of the middle section of the present invention;

[0023] Figure 5 This is a schematic cross-sectional view of the tunnel joint of the present invention;

[0024] Figure 6 This is a schematic diagram of the water-stopping structure at the connection of the caisson body in this invention;

[0025] In the diagram: 1-Upper base plate; 2-Ceiling body; 3-Tunnel joint; 4-Water retaining wall; 5-Tie-and-groove joint; 6-Lower base plate; 7-Panel wall; 8-Water passage; 9-Tie-and-groove insert plate; 10-Concrete sealing section; 11-Rubber waterstop; 12-Reinforcing rib plate;

[0026] 21-Outer wall; 22-Transverse partition wall; 23-Longitudinal partition wall; 24-Storage compartment;

[0027] The following will describe in detail, with reference to the accompanying drawings, embodiments of the present invention. Detailed Implementation

[0028] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0029] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is described as "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is described as "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0032] A permeable caisson structure for rapidly forming a tunnel-to-shore section includes a caisson compartment and a prefabricated tunnel structure, a bottom water passage structure, and a water-stopping system.

[0033] like Figures 1 to 6 As shown,

[0034] The caisson and precast tunnel structure includes an upper base slab 1, with caisson bodies 2 located on the front and rear sides of the top of the upper base slab 1. The caisson body 2 includes an outer wall 21, with several transverse partitions 22 and longitudinal partitions 23 inside the outer wall 21. The transverse partitions 22 and longitudinal partitions 23 divide the inner cavity of the caisson body 2 into several compartments 24. The outer wall 21 has a water inlet, and the longitudinal partitions 23 have water passage holes. The upper base slab 1 has tunnel joints 3 located on the left and right sides of the top. The tunnel joints 3 are located between two caisson bodies 2. The top of the tunnel joints 3 has a water retaining wall 4, which is an L-shaped structure. Several reinforcing ribs 12 are provided between the two side plates of the water retaining wall 4 from front to back. Several tongue and groove joints 5 are provided on the left and right side walls of the caisson body 2.

[0035] Caisson body 2 is located on both sides. During the construction period, it serves as a floating body and protects the main tunnel during the operation period. After the caisson is installed in the shore section, the compartment 24 is backfilled with rubble for weight.

[0036] The tunnel joint 3 is prefabricated together with the caisson body 2. During the construction and floating project, the water-retaining wall 4 at the top of the tunnel joint 3 and the steel sealing door at the end of the tunnel joint 3 form water-stopping at both ends. The upper bottom plate 1 between the two tunnel joints 3 is the tunnel bottom plate section. After the installation is completed and the dry operation conditions are formed, the remaining part is recast. After the casting is completed, a full-section tunnel is formed.

[0037] The bottom water-passing structure includes a lower base slab 6, which is located below the upper base slab 1. Several partition walls 7 are provided between the lower base slab 6 and the upper base slab 1, forming several water-passing channels 8. The partition walls 7 correspond to the longitudinal partition walls 23. The elevation of the partition walls 7 can be adjusted according to the tunnel's longitudinal slope, and the spaces between the partition walls 7 form the water-passing channels 8. Below the partition walls 7 is the lower base slab 6, and below the lower base slab 6 is a leveled riprap foundation.

[0038] The water-stopping system consists of two parts: one part is a steel sealing door and a water-retaining wall 4 installed on the tunnel joint 3 for use during the floating period; the other part consists of two tongue-and-groove plates 9 installed on the inside of the tongue-and-groove joints 5 at both ends of the two adjacent sets of caisson bodies 2, with a concrete sealing section 10 between the two tongue-and-groove plates 9, and a rubber waterstop 11 between the caisson body 2 and the side wall of the concrete sealing section 10 for use during the docking period.

[0039] The permeable structure of the rapid island-building super-large caisson of this invention provides dry conditions for the construction of immersed tunnels. By rationally optimizing relevant structural dimensions, reducing structural weight, draft, and lateral dimensions, most docks can meet the construction requirements. During construction, the prefabricated super-large caisson is floated to the designated installation location. Seawater is injected into the ballast tank inside the caisson body 2 to sink and fix it to the foundation. Then, the compartments 24 of the prefabricated caisson body 2 are backfilled with rubble, and a breast wall is poured on top. Stone chips are backfilled inside the breast wall, and a temporary surface layer is poured to form a simple road, which serves as a temporary construction passage during the construction period. Gaps are left between the caisson bodies 2 to serve as the site for the in-situ casting of the immersed tunnel. The ends of the caisson bodies 2 are provided with tongue and groove joints 5, and reinforced concrete slabs are inserted behind the tongue and groove joints 5. Concrete is poured between the tongue and groove joints 5 to form a vertical waterstop. Curtain grouting is applied around the joints to stop water leakage, ultimately forming a sealed cavity. After the above construction is completed, water can be pumped out to create a dry site for construction operations. After the tunnel construction in the large caisson is completed, the tunnel will be backfilled with rubble and then a concrete surface layer will be poured. The protective compartments 24 on both sides will be cleaned and a permanent surface layer will be poured.

[0040] This invention enables the prefabrication of the submerged tunnel section connecting to the shore, optimizing the original process and eliminating steps such as building islands and installing supports in the water. After the prefabricated caisson for the shore connection section is installed, the tunnel section can be cast in place, saving construction time. In the later stage, only the caisson body 2 is backfilled with rubble, with less earthwork and reducing the environmental impact of the original island filling and earthwork. After installation, the immersed tube connection can be carried out, solving the problem of the pre-process of the push section and secondary water stop in the original process. The process is fast and the prefabricated shore connection caisson has a water passage 8 at the bottom, which solves the problem of the original process having a great impact on the hydrodynamic exchange of the engineering water area.

[0041] This invention utilizes a caisson structure to construct the tunnel section connecting to the shore. Large caissons with tunnel joints 3 are prefabricated in a prefabrication yard or dock. During floating, the compartments 24 of the caisson bodies 2 on both sides serve as floating bodies for the tunnel section, solving the floating problem. During operation, the compartments 24 on both sides are backfilled with boulders to ensure the stability of the tunnel structure connecting to the shore and prevent impacts. A double-layer bottom plate structure is adopted. The lower bottom plate 6 is the structural grounding bottom plate, resting on the foundation bed. The upper bottom plate 1 is the caisson body 1 and the tunnel bottom plate. The upper bottom plate 1 and the lower bottom plate 6 are connected by a partition wall 7, which forms a water passage 8. A buttress water-retaining wall 4 is installed at the top of the prefabricated tunnel joint 3, and a steel sealing door is installed at the tunnel joint 3 opening to ensure water stoppage during floating. A tongue and groove joint 5 is provided at the end of the caisson body 2. A reinforced concrete slab, i.e., a tongue and groove plate 9, is inserted after the tongue and groove joint 5. Concrete is poured between the tongue and groove plates 9 to form a vertical water-stopping body. Curtain grouting is applied around the joint to stop water leakage, ultimately forming a sealed cavity at the joint.

[0042] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or direct application to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A permeable caisson structure for rapidly forming a tunnel-to-bank section, characterized in that, It includes caisson compartments and prefabricated tunnel structures, bottom water passage structures and water-stopping systems, wherein the caisson compartments and prefabricated tunnel structures and bottom water passage structures are connected as a whole; The caisson compartment and prefabricated tunnel structure includes an upper bottom plate (1), a caisson body (2) on the front and rear sides of the top of the upper bottom plate (1), a tunnel joint (3) on the left and right sides of the top of the upper bottom plate (1), the tunnel joint (3) is located between the two caisson bodies (2), a water retaining wall (4) is provided on the top of the tunnel joint (3), and several tongue and groove joints (5) are provided on the left and right side walls of the caisson body (2). The bottom water passage structure includes a lower bottom plate (6), which is located below the upper bottom plate (1). Several wall panels (7) are provided between the lower bottom plate (6) and the upper bottom plate (1), and several water passage channels (8) are formed between the wall panels (7). The water-stopping system consists of two parts: a steel sealing door and a water-retaining wall (4) installed on the tunnel joint (3), and two tongue-and-groove inserts (9) installed on the inside of the tongue-and-groove joints (5) at both ends of the two adjacent sets of caisson bodies (2). A concrete sealing section (10) is provided between the two tongue-and-groove inserts (9), and a rubber waterstop (11) is provided between the caisson body (2) and the side wall of the concrete sealing section (10). The caisson body (2) includes an outer wall (21), and the outer wall (21) is provided with several transverse partitions (22) and longitudinal partitions (23). The transverse partitions (22) and longitudinal partitions (23) divide the inner cavity of the caisson body (2) into several compartments (24). The outer wall (21) is provided with a water inlet, and the longitudinal partitions (23) are provided with water passage holes.

2. The permeable caisson structure for rapidly forming a tunnel-to-bank section according to claim 1, characterized in that, The retaining wall (4) is an L-shaped structure.

3. The permeable caisson structure for rapidly forming a tunnel-to-bank section according to claim 2, characterized in that, Several reinforcing ribs (12) are provided between the two side plates of the water retaining wall (4) from front to back.

4. The permeable caisson structure for rapidly forming a tunnel-to-bank section according to claim 3, characterized in that, After the caissons for the connecting section are installed, backfill stones are placed in the compartments (24) of the caisson body (2).

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