Segmented anti-retraction device for final joint of immersed tube tunnel and dry-wet alternating construction method thereof

Abstract

The present invention belongs to the technical field of immersed tube tunnel engineering, and relates to a segmented stop device for the final joint of an immersed tube tunnel and a dry-wet alternating construction method thereof, wherein the device comprises: a corbel, which is prefabricated on the side of the final joint; a stop assembly, whose top is flush with the top of the final joint and whose bottom is flush with the bottom of the final joint; the stop assembly comprises a first stop member pre-buried in an underground continuous wall and a second stop member arranged opposite to the corbel, the second stop member being composed of N, N≥2 sections of independent stop parts; N first connecting members are preset on the first stop member, and the same number of second connecting members as the first connecting members are preset on the second stop member, each first connecting member corresponds to a second connecting member one by one, and the first connecting member cooperates with the second connecting member to form a connector to connect the first stop member and the second stop member. The present invention reduces underwater construction time, simplifies construction technology, reduces construction difficulty, and realizes fast and convenient construction of the final joint.

Description

Technical Field

[0001] The invention belongs to the technical field of immersed tube tunnel engineering, and relates to an immersed tube underwater installation technology, and specifically, to a segmented anti-retraction device for a final joint of an immersed tube tunnel and a dry-wet alternating construction method thereof. Background Art

[0002] Immersed tube tunnel is a commonly used method in modern underwater tunnel construction. Its final joint is an important connection structure to achieve the final penetration of the tunnel. The form and construction process of the final joint are one of the key and difficult points in the construction of immersed tube tunnel, which is directly related to the overall stability and safety of the tunnel.

[0003] The traditional construction of the final joint of immersed tube tunnel usually involves installing water-stop steel sealing plates underwater around the joint, and then casting the joint reinforced concrete structure (i.e., the stop device) inside the sealing plate. This construction method requires ensuring that the final joint can be installed after undocking. Therefore, the reinforced concrete structure needs to carry out underwater operations such as steel bar connection and binding and template installation after the final joint is installed in place.

[0004] This traditional construction method has the following main problems:

[0005] Complex construction process: installing water-stop steel sealing plates underwater and casting joint reinforced concrete structures involves multiple complex construction links, including underwater steel bar binding, formwork installation and concrete pouring, etc. These links require superb technology and precise operation, which increases the difficulty of construction.

[0006] Long construction period: Due to the particularity of the underwater working environment, the construction speed is limited, resulting in a long construction process. Underwater steel bar connection and binding, formwork installation and other processes are not only time-consuming, but also require strict quality control in each link to ensure the safety and effectiveness of the construction.

[0007] Long time for artificial underwater operation: During the construction process, divers need to operate underwater for a long time, which increases the labor intensity and safety risks of construction workers. Underwater operation not only has high technical requirements for divers, but also is affected by factors such as water flow, pressure, visibility, etc. The construction conditions are poor and there are great safety hazards.

[0008] Difficulty in controlling construction quality: Construction in an underwater environment is limited by external factors such as water flow, temperature and pressure. It is difficult to control construction quality, and construction quality problems are prone to occur, affecting the overall performance and life of the tunnel.

[0009] In view of the above problems, how to achieve the rapid and convenient construction of the final joint stop device of the immersed tube tunnel has become an important research direction of the immersed tube tunnel construction method. By improving the construction technology, reducing the underwater operation time, and simplifying the construction process, the construction efficiency can be effectively improved, the construction cost can be reduced, and the construction safety can be improved. This will have a positive impact on the construction and maintenance of immersed tube tunnels and promote the development of underwater tunnel engineering technology. Summary of the invention

[0010] In view of the above-mentioned problems existing in the existing final joint construction process, such as complex construction process, great construction difficulty and long construction period of the anti-retreat device, the present invention provides a segmented anti-retreat device for the final joint of an immersed tube tunnel and a dry-wet alternating construction method thereof, which reduces the underwater operation time, simplifies the construction process, reduces the construction difficulty of the final joint anti-retreat device, realizes the fast and convenient construction of the final joint anti-retreat device, and shortens the construction period.

[0011] In order to achieve the above-mentioned object, the present invention provides, in a first aspect, a segmented anti-retraction device for the final joint of an immersed tube tunnel, comprising:

[0012] Corbel, prefabricated on the side of the final joint;

[0013] A backstop assembly, the top of which is flush with the top of the final joint, and the bottom of which is flush with the bottom of the final joint; the backstop assembly includes a first backstop member pre-buried in the underground continuous wall and a second backstop member arranged opposite to the corbel, the second backstop member is composed of N, N≥2 sections of independent backstop parts, the first section of the backstop part is the first backstop part, the second section of the backstop part is the second backstop part, and so on, the Nth section of the backstop part is the Nth backstop part, and the first backstop part to the Nth backstop part are connected in sequence from bottom to top; N first connecting members are preset on the first backstop member, and the second connecting members with the same number as the first connecting members are preset on the second backstop member, each first connecting member corresponds to a second connecting member one by one, and the first connecting member and the second connecting member cooperate to form a connecting body to connect the first backstop member and the second backstop member.

[0014] In some embodiments, a water stop assembly is further included, and the water stop assembly includes:

[0015] A first water stop, prefabricated at the top of the final joint;

[0016] A second water stop is cast on the top of the stop assembly;

[0017] The steel cofferdam is installed on the first water stop sill and the second water stop sill.

[0018] In some embodiments, the side of the second stop member near the corbel near the underground continuous wall end extends out to form an extension portion on the side of the second stop member near the underground continuous wall. When the stop member assembly is constructed, the extension portion contacts and connects with the first stop member and the underground continuous wall to enable the first stop member and the second stop member to dock into place.

[0019] In some embodiments, each stop portion includes a first side portion close to the underground continuous wall and a second side portion close to the final joint, the first side portion is provided with a first cavity running through the first side portion from top to bottom, the second side portion is provided with a second cavity running through the second side portion from top to bottom, the second cavity is connected to the first cavity, a longitudinal reinforcement rib connecting the two lateral walls of the second side portion is provided in the second cavity, and a side of the second side portion away from the corbel is set as an inclined surface.

[0020] In order to achieve the above object, the second aspect of the present invention provides a dry-wet alternating construction method of the segmented stop device for the final joint of the immersed tube tunnel according to the first aspect of the present invention, comprising the following steps:

[0021] Dry operation steps: before filling the dry dock with water, prefabricate the first stop piece and the second stop piece, prefabricate the first connecting piece on the first stop piece, and prefabricate the second connecting piece on the second stop piece; pre-embed the first stop piece on the underground continuous wall; prefabricate the corbel and the first water stop on the final joint;

[0022] Final joint installation steps: fill the dry dock with water until the water levels inside and outside the dock door are level, remove the dry dock door, undocking the final joint and sinking it into place to dock with the installed immersed tube;

[0023] The second stopper is installed in sections as follows: hoist the first stopper to the installation position and sink it, and connect the first stopper to the first stopper by cooperating with the first connecting member and the second connecting member; hoist the second stopper to the installation position and sink it above the first stopper, and connect the second stopper to the first stopper by cooperating with the first connecting member and the second connecting member, and so on, until all the stopper parts are connected to the first stopper; reserve water-stopping gaps between the second stopper and the final joint and the corbel respectively;

[0024] Casting step: a concave steel plate is arranged at a set position between the second stop member and the corbel and the final joint, the groove of the concave steel plate is filled and sealed to serve as an end sealing structure of the water stop gap, and concrete is cast in the water stop gap to perform water stop treatment;

[0025] Second water stop installation steps: install the water stop template above the stop assembly, pour concrete into the water stop template to form the second water stop, and remove the water stop template;

[0026] Steel cofferdam installation steps: insert the steel cofferdam on the first water stop sill and the second water stop sill;

[0027] Inspection steps: drain the water inside the pipe and check whether there is water seepage on the surface of the anti-retraction device. If there is water seepage, fill and seal the water seepage position.

[0028] In some embodiments, in the final joint installation step, the dry dock is filled with water using a siphon pumping system, which connects the water areas inside and outside the dry dock. The siphon pumping system causes the water in the water areas to flow into the dry dock through the siphon phenomenon, thereby filling the dry dock with water to adjust the water levels inside and outside the dock gate to be level.

[0029] In some embodiments, the siphon pumping system includes a pumping pipe, one end of which is arranged inside the dry dock, and the other end of the pumping pipe is respectively connected to a first branch pipe and a second branch pipe, the first branch pipe is used to connect to the water area outside the dry dock, and the second branch pipe is connected to a submersible pump arranged in the water area. A first valve is provided on the first branch pipe, and a second valve is provided on the second branch pipe; by controlling the opening and closing of the first valve and the second valve and the start and stop of the submersible pump, the water flow forms a siphon phenomenon and flows into the dry dock through the pumping pipe.

[0030] In some embodiments, in the pouring step, lightweight concrete is filled into the cavity of the second retaining member.

[0031] In some embodiments, during the steel cofferdam installation step, lightweight concrete is filled into the steel cofferdam.

[0032] Compared with the prior art, the advantages and positive effects of the present invention are:

[0033] (1) The segmented stop device for the final joint of the immersed tube tunnel provided by the present invention adopts a segmented structural design. The device includes a corbel, a first stop member pre-buried in the underground continuous wall, a second stop member arranged opposite to the corbel, a first connecting member arranged on the first stop member, and a second connecting member arranged on the second stop member. The first connecting member cooperates with the second connecting member to form a connecting member connecting the first stop member and the second stop member. When constructing the segmented stop device for the final joint, the corbel, the first stop member, the second stop member, the first connecting member and the second connecting member are prefabricated in dry operation before the final joint is installed underwater. After the final joint is installed underwater, the second stop member is installed in sections between the first stop member and the final joint corbel, and is connected to the first stop member through the first connecting member and the second connecting member. Finally, concrete is poured into the water-stopping gap underwater to stop water. The entire construction process is simple. Corbels, stoppers and connectors are prefabricated through dry operations. There is no need for underwater operations to carry out processes such as steel bar connection and binding and formwork support. Only underwater pouring of concrete is required to stop water. The underwater operation time is reduced during the entire construction process, the construction difficulty is reduced, the construction process is simplified, the underwater operation time is short, the waiting time for concrete strength is short, the construction period is shortened, and the construction safety is improved.

[0034] (2) The dry-wet alternating construction method provided by the present invention adopts dry-wet alternating construction, prefabricates the corbels, stopper components, connectors, and water-stop components (except the second water-stop sill) through dry operations, and pre-buries the first stopper. The second stopper is installed in sections through wet operations (i.e., underwater operations), casts the second water-stop sill, installs the steel cofferdam, and casts concrete. The entire construction process is simple, the stopper components are prefabricated through dry operations, and there is no need for underwater operations to perform processes such as steel bar connection and binding and supporting formwork. The first stopper is pre-buried in the underground continuous wall, the second stopper is installed in sections, and the first connector and the second connector cooperate to form a connector to connect the first stopper and the second stopper. The operation is convenient, the underwater operation time is reduced, the construction process is simplified, the construction difficulty of the final joint is reduced, the underwater operation time is short, the waiting time for concrete strength is short, the construction period is shortened, and the construction safety is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the top view effect after the installation of the segmented anti-retraction device for the final joint of the immersed tube tunnel according to the embodiment of the present invention;

[0036] Figure 2 It is a schematic diagram of the side effect of the segmented withdrawal prevention device for the final joint of the immersed tube tunnel according to the embodiment of the present invention after installation;

[0037] Figure 3 This is a schematic structural diagram of the first retaining member according to an embodiment of the present invention;

[0038] Figure 4 It is a structural schematic diagram of the anti-retraction part according to an embodiment of the present invention;

[0039] Figure 5 This is a flow chart of the dry-wet alternating construction method according to an embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the front effect of the pre-embedding of the first stop member in the dry-wet alternating construction method according to an embodiment of the present invention;

[0041] Figure 7 It is a schematic diagram of a top view of the effect of pre-embedding the first stop member in the dry-wet alternating construction method according to an embodiment of the present invention;

[0042] Figure 8 This is a schematic diagram of the front effect of the final joint being installed in place in the dry-wet alternating construction method according to an embodiment of the present invention;

[0043] Fig. 9 It is a top view of the final joint installed in the dry-wet alternating construction method according to an embodiment of the present invention;

[0044] Fig.10 It is a schematic diagram of the front effect of the second stop member being installed in place in the dry-wet alternating construction method according to the embodiment of the present invention;

[0045] Fig.11 It is a top view of the effect of the second stop member being installed in place in the dry-wet alternating construction method according to an embodiment of the present invention;

[0046] Fig.12 It is a schematic diagram of the front effect of the completion of pouring concrete in the water-stop gap in the dry-wet alternating construction method according to the embodiment of the present invention;

[0047] Fig.13 It is a schematic diagram of the top view of the completed pouring of concrete in the water-stop gap in the dry-wet alternating construction method according to an embodiment of the present invention;

[0048] Fig.14 This is a schematic diagram of the front effect of the second water stop installed in the dry-wet alternating construction method according to an embodiment of the present invention;

[0049] Fig.15 It is a schematic diagram of a top view of the effect of the second water stop installed in the dry-wet alternating construction method according to an embodiment of the present invention;

[0050] Fig.16 This is a schematic diagram of the front effect of the final joint segmented backstop device being installed after the dry-wet alternating construction method according to an embodiment of the present invention is completed;

[0051] Fig.17 This is a top view of the effect of the final joint segmented backstop device being installed in the dry-wet alternating construction method according to an embodiment of the present invention;

[0052] Fig.18 This is a schematic diagram of a top view of the siphon pumping system after installation according to an embodiment of the present invention;

[0053] Fig.19 for Fig.18 A magnified view of part A;

[0054] Fig. 20 This is a schematic diagram of the side effect of the siphon pumping system after installation according to an embodiment of the present invention.

[0055] In the figure, 1, corbel, 2, first stop piece, 3, second stop piece, 301, extension part, 302, first side part, 303, second side part, 304, first cavity, 305, second cavity, 306, reinforcement rib, 4, underground continuous wall, 5, final joint, 6, connector, 601, first connector, 602, second connector, 701, concave steel plate, 702, poured concrete, 801, first water stop, 802, second water stop, 803, steel cofferdam, 9, inside of dry dock, 10, pumping pipe, 11, first branch pipe, 12, second branch pipe, 13, submersible pump, 14, water area, 15, first valve, 16, second valve. DETAILED DESCRIPTION

[0056] The present invention is described in detail below by way of exemplary embodiments. However, it should be understood that elements, structures, and features in one embodiment may also be beneficially combined in other embodiments without further description.

[0057] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "top", "bottom", "inside", "outside", "left", "right", "front", "back", "vertical", "horizontal", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. The terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0058] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] The first embodiment of the present invention provides a segmented anti-retraction device for the final joint of an immersed tube tunnel, which is used for anti-retraction of the final joint. Figures 1 to 4 The segmented anti-retraction device of the final joint of the immersed tube tunnel includes a corbel 1 and an anti-retraction assembly, the top of the anti-retraction assembly is flush with the top of the final joint 5, and the bottom of the anti-retraction assembly is flush with the bottom of the final joint 5.

[0060] The bracket 1 is prefabricated on the side of the final joint 5. When installing the final joint, it is installed in place together with the final joint. By prefabricating the bracket 1 on the side of the final joint 5, the underwater construction steps can be reduced and the processing accuracy of the final joint can be improved. This design is based on the concept of modular prefabrication. The connection between the bracket 1 and the final joint 5 is completed in a dry dock, ensuring high precision while simplifying the underwater construction process.

[0061] The backstop assembly includes a first backstop component 2 embedded in the underground continuous wall 4 and a second backstop component 3 arranged opposite to the corbel 1, the second backstop component 3 is composed of N, N≥2 independent backstop parts, the first backstop part is the first backstop part, the second backstop part is the second backstop part, and so on, the Nth backstop part is the Nth backstop part, and the first backstop part to the Nth backstop part are connected in sequence from bottom to top; N first connecting parts 601 are preset on the first backstop component 2, and the second backstop component 602 with the same number as the first connecting parts 601 is preset on the second backstop component 3, each first connecting part 601 corresponds to a second connecting part 602 one by one, and the first connecting part 601 and the second connecting part 602 cooperate to form a connecting body 6 to connect the first backstop component 2 and the second backstop component 3.

[0062] Specifically, in some embodiments, the first connecting member is a clamping hole that passes through the first retaining member, and the second connecting member is a clamping claw that is clamped with the clamping hole. The first connecting member and the second connecting member are clamped together to form a clamp (i.e., a connector), which is connected by clamping to facilitate underwater operation to connect the first retaining member and the second retaining member.

[0063] In some embodiments, the side of the second stopper near the corbel near the underground continuous wall end extends out of the second stopper near the underground continuous wall to form an extension portion 301. When constructing the stopper assembly, the extension portion is in contact and connected with the first stopper and the underground continuous wall, so that the first stopper and the second stopper are docked in place. The design of the extension portion, on the one hand, ensures the accurate docking of the second stopper with the first stopper, and effectively avoids the problem of docking error. On the other hand, it makes the force transmission effect of the entire stopper assembly more stable, ensuring the stability and safety of the second stopper during the construction process. Accurate docking and positioning reduce the risk of movement and tilting of the second stopper during underwater construction, and reduce the probability of underwater construction accidents. On the other hand, the first stopper and the second stopper are closely fitted to achieve a water-stopping effect.

[0064] In some embodiments, each stopper includes a first side portion 302 close to the underground continuous wall and a second side portion 303 close to the final joint. The first side portion 302 is provided with a first cavity 304 running through the first side portion from top to bottom, and the second side portion 303 is provided with a second cavity 305 running through the second side portion from top to bottom. The second cavity 305 is connected to the first cavity 304. A longitudinal reinforcing rib 306 connecting the two lateral walls of the second side portion 303 is provided in the second cavity 305. The side of the second side portion 303 away from the corbel 1 is set as an inclined surface. The design of the cavity of each stopper can reduce the weight of each stopper, which is convenient for belt hoisting. Reinforcing ribs are designed in the second cavity, and the force-bearing capacity of each stopper is improved by the reinforcing ribs, so that the force transmission effect of the second stopper is more stable. Setting the side of the second side away from the corbel as an inclined surface can reduce the pressure of water flow on the final joint 5, ensuring the safety and stable operation of the final joint.

[0065] Through the segmented design and extension design of the stopper, on the one hand, the docking accuracy of the second stopper with the first stopper and the bracket structure during the construction process is significantly improved; on the other hand, the number of repeated adjustments and rework during the docking process of the second stopper is reduced, thereby reducing the construction cost. On the other hand, the design of the extension reduces construction time and labor costs, and improves construction efficiency.

[0066] During the construction of the existing final joint stop device, it is necessary to perform steel bar binding work underwater. Due to the particularity of the underwater working environment, divers need to operate underwater for a long time during the underwater construction process. On the one hand, the construction is difficult and the operation time is long. On the other hand, it increases the labor intensity and safety risks of the construction personnel. When constructing the final joint segmented stop device of the present invention, the corbel, the first stop piece, the second stop piece, the first connecting piece and the second connecting piece are prefabricated in dry operation before the final joint is installed underwater. After the final joint is installed underwater, the second stop piece is installed in sections between the first stop piece and the final joint corbel, and is connected to the first stop piece through the first connecting piece and the second connecting piece. Finally, concrete is poured into the water-stopping gap underwater to stop water. The entire construction process is simple. Corbels, stoppers and connectors are prefabricated through dry operations. There is no need for underwater operations to carry out processes such as steel bar connection and binding and formwork support. Only underwater pouring of concrete is required to stop water. The underwater operation time is reduced during the entire construction process, the construction difficulty is reduced, the construction process is simplified, the underwater operation time is short, the waiting time for concrete strength is short, the construction period is shortened, and the construction safety is improved.

[0067] In some embodiments, see Figures 6 to 17 The segmented stop device for the final joint of the immersed tube tunnel also includes a water stop assembly, which includes:

[0068] The first water stop 801 is prefabricated at the top of the final joint 5;

[0069] A second water stop 802 is cast on the top of the stop assembly;

[0070] The steel cofferdam 803 is installed on the first water stop 801 and the second water stop 802 .

[0071] The final joint is water-stopped by a water-stop assembly.

[0072] The above-mentioned segmented anti-retraction device for the final joint of the immersed tube tunnel in the embodiment of the present invention adopts a segmented structural design, and the device includes a corbel, a first anti-retraction member, a second anti-retraction member, and a first connecting member and a second connecting member that cooperate to form a connecting member to connect the first anti-retraction member and the second anti-retraction member. When constructing the segmented anti-retraction device for the final joint, the first anti-retraction member and the second anti-retraction member are prefabricated by dry operation before the final joint is installed underwater, and the first anti-retraction member is pre-buried in the underground continuous wall. After the final joint is installed underwater, the second anti-retraction member is installed in sections between the first anti-retraction member and the final joint by underwater operation, and connected to the first anti-retraction member through the connecting member. A concave steel plate is set at a set position between the second anti-retraction member and the corbel and the final joint, and the groove of the concave steel plate is filled and sealed to serve as an end sealing structure of the water-stopping gap. Concrete is poured into the water-stopping gap, and the water-stopping assembly is installed to achieve anti-retraction and water-stopping.

[0073] The entire construction process of the segmented stop device for the final joint of the immersed tube tunnel in the embodiment of the present invention is simple. The stop parts are cast in a dry working environment, and there is no need to perform underwater operations for the construction of processes such as steel bar connection and binding and supporting formwork. It is only necessary to cast concrete underwater for water stopping, which simplifies the construction process, reduces underwater operation time, shortens the waiting time for concrete strength, shortens the construction period, and improves construction safety. The final joint constructed by the segmented stop device for the final joint of the immersed tube tunnel is stable and reliable.

[0074] See also Figures 5 to 17 The second embodiment of the present invention provides a dry-wet alternating construction method of the segmented stop device for the final joint of the immersed tube tunnel according to the first embodiment of the present invention, comprising the following steps:

[0075] S1. Dry operation steps: before filling the dry dock with water, prefabricate the first stop member and the second stop member, prefabricate the first connecting member on the first stop member, and prefabricate the second connecting member on the second stop member; pre-embed the first stop member on the underground continuous wall; prefabricate the corbel and the first water stop on the final joint.

[0076] S2. Final joint installation steps: Fill the dry dock with water until the water levels inside and outside the dock door are level, remove the dry dock door, undocking the final joint and sinking it into place to dock with the installed immersed tube.

[0077] Specifically, in some embodiments, the dry dock is filled with water using a siphon pumping system, which connects the water area inside the dry dock and the water area outside the dry dock. The siphon pumping system causes the water in the water area to flow into the dry dock through the siphon phenomenon, and fills the dry dock with water to adjust the water level inside and outside the dock door to be level. The present invention uses a siphon pumping system to fill the dry dock with water, and by utilizing the siphon principle, it is possible to fill the dry dock with water without the need for additional power. On the one hand, the operation process is simplified, the construction is simple, and the installation is convenient. On the other hand, it is energy-saving and environmentally friendly, reduces operating costs, and has high water filling efficiency.

[0078] Specifically, in some embodiments, see Figures 18 to 20 The siphon pumping system includes a pumping pipe 10, one end of which is arranged inside the dry dock 9, and the other end of the pumping pipe 10 is connected to a first branch pipe 11 and a second branch pipe 12 respectively. The first branch pipe 11 is used to connect to the water area 14 outside the dry dock, and the second branch pipe 12 is connected to a submersible pump 13 arranged in the water area. The first branch pipe 11 is provided with a first valve 15, and the second branch pipe 12 is provided with a second valve 16. By controlling the opening and closing of the first valve 15 and the second valve 16 and the start and stop of the submersible pump 13, the water flow forms a siphon phenomenon and flows into the dry dock 9 through the pumping pipe 10. Among them, the pumping pipe 10 plays the role of connecting and conveying water in the whole system. The first branch pipe 11 and the second branch pipe 12 are connected to the external water area 14 and the submersible pump 13 respectively, and are used to control the water flow into the pumping pipe 10. The first valve 15 and the second valve 16 control the water flow path by opening and closing to ensure that the system works according to the designed process. The submersible pump 13 provides water flow power in the initial stage, so that the pumping pipe is filled with water to form a siphon condition.

[0079] Specifically, when the siphon pumping system fills the dry dock with water, the first valve is closed, the second valve is opened, and the submersible pump is turned on to extract water in the water area into the second branch pipe. The water in the water area flows through the pumping pipe into the dry dock. When the pumping pipe inside the dry dock is filled, the submersible pump is turned off and the first valve is opened. At this time, the water flow forms a siphon phenomenon, so that the ground water flow can flow into the dry dock without the help of external force, and no longer needs to rely on the power of the submersible pump. The siphon pumping system of the present invention utilizes the siphon principle and realizes the automatic filling process of water flowing from the water area into the dry dock through the control of the submersible pump and the valve.

[0080] Specifically, in some embodiments, the siphon pumping system can be set to multiple groups, specifically according to the target water level setting. For example: the target water level is 0.5m, the total water volume is 232,000 cubic meters, 6 groups of siphon pumping systems are set, the submersible pump flow is 200m / h, the water height is 25m, and the pumping pipe adopts DN200.

[0081] Specifically, in some embodiments, the dry dock door is removed by using an existing dry dock door removal method.

[0082] S3, the steps of installing the second stop part in sections: lift the first stop part to the installation position and sink it, and connect the first stop part to the first stop part by cooperating with the first connecting member and the second connecting member; lift the second stop part to the installation position and sink it above the first stop part, and connect the second stop part to the first stop part by cooperating with the first connecting member and the second connecting member, and so on, until all the stop parts are connected to the first stop part; reserve water-stop gaps between the second stop part and the final joint and the corbel respectively.

[0083] The second stop is installed in sections, and the size of each stop can be set according to actual needs. The second stop is divided into multiple sections, which is convenient for underwater installation and can be completed without large-scale lifting equipment.

[0084] S4, casting step: a concave steel plate is arranged at a set position between the second retaining piece and the corbel and the final joint, the groove of the concave steel plate is filled and sealed to serve as an end sealing structure of the water-stop gap, and concrete is cast in the water-stop gap to perform water-stop treatment.

[0085] Specifically, in some embodiments, the poured concrete is C35 concrete, which has high mechanical strength after hardening, so that the force transmission member is firmly bonded to the stop member, the bracket, and the final joint, thereby ensuring the safety of the final joint.

[0086] Specifically, in some embodiments, lightweight concrete (for example, concrete labeled C15) is poured into the cavity of the second stopper, and the grouting process refers to the existing underwater concrete pouring of cast-in-place piles. By pouring lightweight concrete, the bearing capacity of the second stopper is increased.

[0087] S5. Second waterstop installation steps: install the waterstop template above the stop assembly, pour concrete into the waterstop template to form the second waterstop, and remove the waterstop template.

[0088] Specifically, in some embodiments, when the water stop template is disassembled and assembled, it can be disassembled and assembled by divers working underwater, or it can be installed by an underwater robot.

[0089] S6, steel cofferdam installation steps: insert the steel cofferdam on the first water stop sill and the second water stop sill. The installation of the steel cofferdam is fixed by the preset water stop sill position, so that it can effectively block external water flow and sediment.

[0090] Specifically, in some embodiments, after the steel cofferdam is inserted into the water stop, lightweight concrete is filled into the steel cofferdam. The filling of lightweight concrete not only enhances the overall stability of the cofferdam, but also improves its waterproof performance. Lightweight concrete is easy to construct and has low cost, which helps to save construction costs and improve efficiency.

[0091] Specifically, in some embodiments, the lightweight concrete is made of environmentally friendly materials, reducing the negative impact on the environment.

[0092] Specifically, in some embodiments, concrete with a label of C15 is used but is not limited thereto. According to different construction requirements, the proportion, density and filling height of the lightweight concrete can be adjusted to optimize the performance of the steel cofferdam.

[0093] Specifically, in some embodiments, in the connection between the steel cofferdam and the water stop, N methods such as welding, bolt connection or snap connection can be used to ensure the firmness and sealing of the connection.

[0094] It should be noted that the steel cofferdam can be installed in sections or as a whole, and the specific choice depends on the space and conditions of the construction site.

[0095] S7. Inspection steps: drain the water inside the tank and check whether there is water leakage in the anti-retraction device. If there is water leakage, fill and seal the leakage position.

[0096] Specifically, the water seepage phenomenon includes small water flows, wet marks, etc.

[0097] After the installation of the anti-recession device is completed, check whether the anti-recession device is leaking. If water leakage occurs, fill it with wind to improve the water-stopping effect of the anti-recession device.

[0098] The dry-wet alternating construction method of the segmented stop device of the final joint of the immersed tube tunnel in the embodiment of the present invention adopts dry-wet alternating construction, prefabricates the corbel, stop assembly, connector, water-stop assembly (except the second water-stop sill) through dry operation, and pre-buries the first stop member. The wet operation (i.e., underwater operation) installs the second stop member in sections, casts the second water-stop sill, installs the steel cofferdam, and casts concrete. The entire construction process is simple, the stop assembly is prefabricated through dry operation, and there is no need for underwater operation to perform processes such as steel bar connection and binding and supporting formwork. The first stop member is pre-buried on the underground continuous wall, the second stop member is installed in sections, and the first connector and the second connector cooperate to form a connector to connect the first stop member and the second stop member. The operation is convenient, the underwater operation time is reduced, the construction process is simplified, the construction difficulty of the final joint is reduced, the underwater operation time is short, the waiting time for concrete strength is short, the construction period is shortened, and the construction safety is improved.

[0099] The following is a detailed description of the dry-wet alternating construction method of the above-mentioned immersed tube tunnel final joint segmented anti-retraction device in conjunction with the specific final joint.

[0100] Example: The height of the final joint is 10.65m.

[0101] The specific construction method of the above-mentioned final joint segmented anti-retraction device is as follows:

[0102] S1. Dry operation steps: before filling the dry dock with water, prefabricate the first stop member and the second stop member, prefabricate the first connecting member on the first stop member, and prefabricate the second connecting member on the second stop member; pre-embed the first stop member on the underground continuous wall; prefabricate the corbel and the first water stop on the final joint.

[0103] S2. Final joint installation steps: Fill the dry dock with water until the water levels inside and outside the dock door are level, remove the dry dock door, undocking the final joint and sinking it into place to dock with the installed immersed tube.

[0104] S3, the steps of installing the second stop part in sections: lift the first stop part to the installation position and sink it, and form a connecting body by cooperating with the first connecting member and the second connecting member to connect the first stop part to the first stop part; lift the second stop part to the installation position and sink it above the first stop part, and form a connecting body by cooperating with the first connecting member and the second connecting member to connect the second stop part to the first stop part, and so on, until all the stop parts are connected to the first stop part; reserve water-stop gaps between the second stop part and the final joint and the corbel respectively.

[0105] S4, casting step: a concave steel plate is arranged at a set position between the second retaining piece and the corbel and the final joint, the groove of the concave steel plate is filled and sealed to serve as an end sealing structure of the water-stop gap, and concrete is cast in the water-stop gap to perform water-stop treatment.

[0106] S5, second water stop installation step: the diver works underwater to install the water stop template above the backstop assembly, and pours concrete into the water stop template to form the second water stop. After the second water stop is formed, the water stop template is removed.

[0107] S6. Steel cofferdam installation steps: Install the steel cofferdam in sections on the first water stop sill and the second water stop sill, and connect them with snap fasteners.

[0108] S7. Inspection steps: drain the water inside the tank and check whether there is water leakage in the anti-retraction device. If there is water leakage, fill and seal the leakage position.

[0109] The above embodiments are used to explain the present invention rather than to limit the present invention. Any modification and change made to the present invention within the spirit of the present invention and the protection scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A segmented anti-retraction device for the final joint of an immersed tube tunnel, characterized in that: include: Corbel, prefabricated on the side of the final joint; A backstop assembly, the top of which is flush with the top of the final joint, and the bottom of which is flush with the bottom of the final joint; The stop assembly includes a first stop member pre-buried in the underground continuous wall and a second stop member arranged opposite to the corbel, the second stop member is composed of N sections of independent stop parts, N ≥ 2; the first section of the stop part is the first stop part, the second section of the stop part is the second stop part, and so on, the Nth section of the stop part is the Nth stop part, and the first stop part to the Nth stop part are connected in sequence from bottom to top; N first connecting members are preset on the first stop member, and the second stop member is preset on the second stop member with the same number of second connecting members as the first connecting members, each first connecting member corresponds to a second connecting member one by one, and the first connecting member cooperates with the second connecting member to form a connecting body to connect the first stop member and the second stop member; The side of the second stopper close to the corbel extends out from the side of the second stopper close to the underground continuous wall to form an extension portion. When the stopper assembly is constructed, the extension portion is in contact and connected with the first stopper and the underground continuous wall, so that the first stopper and the second stopper are docked in place. Each stop portion includes a first side portion close to the underground continuous wall and a second side portion close to the final joint. The first side portion is provided with a first cavity running through the upper and lower parts of the first side portion, and the second side portion is provided with a second cavity running through the upper and lower parts of the second side portion. The second cavity is connected to the first cavity, and a longitudinal reinforcement rib connecting the two lateral walls of the second side portion is provided in the second cavity. The side of the second side portion away from the corbel is set as an inclined surface.

2. The segmented anti-retraction device for the final joint of the immersed tube tunnel according to claim 1, characterized in that: It also includes a water stop assembly, the water stop assembly comprising: A first water stop, prefabricated at the top of the final joint; A second water stop is cast on the top of the stop assembly; The steel cofferdam is installed on the first water stop sill and the second water stop sill.

3. A dry-wet alternating construction method for the segmented stop device for the final joint of an immersed tube tunnel as claimed in claim 2, characterized in that: The following steps are involved: Dry operation steps: before filling the dry dock with water, prefabricate the first stop piece and the second stop piece, prefabricate the first connecting piece on the first stop piece, and prefabricate the second connecting piece on the second stop piece; pre-embed the first stop piece on the underground continuous wall; prefabricate the corbel and the first water stop on the final joint; Final joint installation steps: fill the dry dock with water until the water levels inside and outside the dock door are level, remove the dry dock door, undocking the final joint and sinking it into place to dock with the installed immersed tube; The second stopper is installed in sections as follows: hoist the first stopper to the installation position and sink it, and connect the first stopper to the first stopper by cooperating with the first connecting member and the second connecting member; hoist the second stopper to the installation position and sink it above the first stopper, and connect the second stopper to the first stopper by cooperating with the first connecting member and the second connecting member, and so on, until all the stopper parts are connected to the first stopper; reserve water-stopping gaps between the second stopper and the final joint and the corbel respectively; Casting step: a concave steel plate is arranged at a set position between the second stop member and the corbel and the final joint, the groove of the concave steel plate is filled and sealed to serve as an end sealing structure of the water stop gap, and concrete is cast in the water stop gap to perform water stop treatment; Second water stop installation steps: install the water stop template above the stop assembly, pour concrete into the water stop template to form the second water stop, and remove the water stop template; Steel cofferdam installation steps: insert the steel cofferdam on the first water stop sill and the second water stop sill; Inspection steps: drain the water in the dock and check whether there is water seepage on the surface of the anti-retraction device. If water seepage exists, fill and seal the water seepage position.

4. The dry-wet alternating construction method according to claim 3, characterized in that: In the final joint installation step, the dry dock is filled with water using a siphon pumping system, which connects the water areas inside and outside the dry dock. The siphon pumping system causes the water in the water areas to flow into the dry dock through the siphon phenomenon, thereby filling the dry dock with water to adjust the water levels inside and outside the dock gate to be level.

5. The dry-wet alternating construction method according to claim 4, characterized in that: The siphon pumping system includes a pumping pipe, one end of which is arranged inside the dry dock, and the other end of the pumping pipe is respectively connected to a first branch pipe and a second branch pipe. The first branch pipe is used to connect to the water area outside the dry dock, and the second branch pipe is connected to a submersible pump arranged in the water area. A first valve is arranged on the first branch pipe, and a second valve is arranged on the second branch pipe. By controlling the opening and closing of the first valve and the second valve and the start and stop of the submersible pump, the water flow forms a siphon phenomenon and flows into the dry dock through the pumping pipe.

6. The dry-wet alternating construction method according to claim 3, characterized in that: In the pouring step, the cavity of the second retaining member is filled with lightweight concrete.

7. The dry-wet alternating construction method according to claim 3, characterized in that: In the steel cofferdam installation step, lightweight concrete is filled into the steel cofferdam.

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