Combined 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 combined anti-retraction device for the final joint of an immersed tube tunnel and a dry-wet alternating construction method thereof. The device comprises an anti-retraction member, a force transmission member and a support member. The anti-retraction member is cast at the underground continuous wall and arranged opposite to the corbel prefabricated at the final joint. The distance from the top of the anti-retraction member to the horizontal plane is L Satisfy the conditions L ≥ H ‑ h + l , so that the final joint can be undocking and installed when constructing the final joint; the force transmission member is arranged between the stop member and the corbel; the force transmission member includes a first force transmission part, a second force transmission part and a third force transmission part connected in sequence, the first force transmission part is used for contacting and connecting with the underground continuous wall, and the third force transmission part is used for matching and connecting with the steel cofferdam installed above the final joint; the support member is used for connecting the upper part of the force transmission member with the underground continuous wall. The present invention simplifies the construction process of the stop device, reduces the construction difficulty, realizes the fast and convenient construction of the final joint, and shortens the construction period.

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 an immersed tube tunnel final joint combined back-off device and a dry-wet alternating construction method thereof. Background Art

[0002] The final joint of an immersed tube tunnel is an important connection structure for achieving the final penetration of the tunnel. The form of the final joint and the construction process are one of the key difficulties in the construction of an immersed tube tunnel. In the past, the construction of the final joint of an immersed tube tunnel mostly adopted the method of installing a water-stop steel sealing plate underwater around the joint, and then casting the joint reinforced concrete structure (i.e., the anti-retreat device) inside the sealing plate to achieve the anti-retreat of the final joint. In order to ensure that the final joint can be installed out of the dock, the reinforced concrete structure needs to be constructed by underwater operations for the steel bar connection binding, formwork installation and other processes after the final joint is installed in place. The construction process is complex, the cycle is long, and it involves long-term manual underwater operations. How to achieve the rapid and convenient construction of the final joint of the immersed tube tunnel is an important research direction of the immersed tube tunnel construction method.

[0003] The Chinese patent with the announcement number CN103741725B discloses a construction method for the final joint of a shore-side immersed tube tunnel, including: the last section of the immersed tube tunnel is sunk into place, and after the grouting tape and rubber water stop strip are processed, a temporary steel cofferdam is installed, and underwater concrete is poured at the intersection of the last section of the immersed tube section and the retaining structure of the underground continuous wall and the shore wall on both sides, and waterproof concrete is poured between two adjacent temporary cofferdams and grouting is closed; after the underwater concrete on both sides of the temporary steel cofferdam reaches the strength, the stagnant water between the temporary steel cofferdam and the shore wall is extracted, and the temporary diagonal brace is installed according to the height of the water level drop. The temporary diagonal brace is welded on the temporary steel cofferdam, and the top plate and bottom plate steel supports are erected to connect the gap between the last section of the immersed tube section and the shore buried section to dry the final joint, and concrete is poured to integrate the last section of the immersed tube section with the shore buried section. In this patent, onshore construction is adopted, and the construction risks can be reduced through effective construction measures and detection means during the construction process. However, there are still problems such as complex construction process, high difficulty and long construction period. Summary of the invention

[0004] 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 combined anti-retreat device for the final joint of an immersed tube tunnel and a dry-wet alternating construction method thereof, which simplifies the construction process of the final joint anti-retreat device, reduces the construction difficulty of the final joint anti-retreat device, realizes rapid and convenient construction of the final joint anti-retreat device, and shortens the construction period.

[0005] In order to achieve the above-mentioned object, the present invention provides, in a first aspect, a combined anti-retraction device for the final joint of an immersed tube tunnel, comprising:

[0006] Corbel, prefabricated on the side of the final joint;

[0007] The stopper is cast in the underground continuous wall and is set opposite to the corbel. The distance from the top of the stopper to the horizontal plane is L Satisfy the conditions L ≥ H - h + l , so that the final joint can be undocking and installed when constructing the final joint, where: H is the final joint height, h is the freeboard height, l The installation distance is the clearance;

[0008] A force transmission member is arranged between the stop member and the corbel; the force transmission member comprises a first force transmission part, a second force transmission part and a third force transmission part which are connected in sequence, the first force transmission part is used for contacting and connecting with the underground continuous wall, and the third force transmission part is used for matching and connecting with the steel cofferdam installed above the final joint; the tops of the first force transmission part, the second force transmission part and the third force transmission part are flush with the top of the steel cofferdam, the bottoms of the first force transmission part and the second force transmission part are flush with the bottom of the final joint, and the bottom of the third force transmission part is flush with the bottom of the steel cofferdam;

[0009] The support member is used to connect the upper part of the force transmission member with the underground continuous wall to tighten the force transmission member.

[0010] In some embodiments, a water stop assembly is further included, and the water stop assembly includes:

[0011] A water stop, prefabricated at the top of the final joint;

[0012] A steel cofferdam is installed on the water stop sill;

[0013] A first water stop member is pre-buried on a side of the second force transmission portion close to the water stop sill, the first water stop member being in contact and connected with the water stop sill;

[0014] A first grouting pipe is pre-buried on one side of the second force transmission part close to the water stop sill, so as to inject grout through the first grouting pipe to seal the gap between the first water stop and the water stop sill when constructing the final joint;

[0015] A second water stop, pre-buried in the underground continuous wall, in contact with and connected to the first force transmission part;

[0016] The second grouting pipe is pre-buried in the underground continuous wall so that grouting can be performed through the second grouting pipe to seal the gap between the second water stop and the first force transmission part when constructing the final joint.

[0017] In some embodiments, a cavity is provided inside the force transmission member, and a grouting port connecting the outside with the cavity is provided on the top of the force transmission member, so that the cavity can be filled through the grouting port when constructing the final joint.

[0018] In some embodiments, the third force transmission portion is buckled with the steel cofferdam.

[0019] In some embodiments, the thickness of the first force transmission part and the third force transmission part is the same as the thickness of the steel cofferdam, and the thickness of the second force transmission part is greater than the thickness of the first force transmission part and the third force transmission part to increase the load-bearing capacity of the force transmission member.

[0020] In order to achieve the above-mentioned object, the second aspect of the present invention provides a dry-wet alternating construction method of the combined anti-retraction device of the final joint of the immersed tube tunnel according to the first aspect of the present invention, which is used for construction and comprises the following steps:

[0021] S1. Before filling the dry dock with water, dry-cast the stoppers at the underground continuous wall, embed the water-stoppers and grouting pipes in the force-transmitting parts and underground continuous wall, and prefabricate the corbels and water-stop sills at the final joints;

[0022] S2. Fill the dry dock with water, the distance from the horizontal surface to the top of the stop L Satisfy the conditions L ≥ H - h + l Stop watering when H is the final joint height, h is the freeboard height, l The clearance installation distance is removed; the dry dock door is removed, the final joint is undocking from above the stopper and sunk into place to dock with the installed immersed tube;

[0023] S3. Install the force transmission member between the corbel and the stop member, and reserve water-stopping gaps between the force transmission member and the stop member, the final joint, and the corbel; and insert the steel cofferdam into the water-stop sill;

[0024] S4. Install the support member between the upper part of the force transmission member and the underground continuous wall;

[0025] S5. A concave steel plate is arranged at a set position between the force transmission member and the underground continuous wall, the stop member, 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 stop gap;

[0026] S6. Pour concrete into the water-stop gaps between the force transmission parts and the stoppers, the brackets, and the final joints to perform water-stop treatment;

[0027] S7. Drain the water inside the tank 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 step S2, 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 water in the water areas to flow into the dry dock through the siphon phenomenon, thereby filling the dry dock with water.

[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 step S4, after the support member is installed, lightweight concrete is filled into the force transmission member and the steel cofferdam.

[0031] In some embodiments, in step S5, the groove of the concave steel plate is filled and sealed by film bag grouting.

[0032] In some embodiments, in step S6, the water-stop gap between the force transmission member and the stop member is concreted to the top of the stop member, and the water-stop gap between the force transmission member and the final joint is concreted to the bottom of the steel cofferdam.

[0033] In some embodiments, in step S6, after pouring concrete in the water stop gap, grouting is performed through a grouting pipe to seal the tiny gaps between the water stop and the force transmission member, the water stop sill and the contact surface of the poured concrete.

[0034] Compared with the prior art, the advantages and positive effects of the present invention are:

[0035] (1) The combined anti-retraction device for the final joint of the immersed tube tunnel provided by the present invention adopts a combined structural design. The anti-retraction device includes a corbel, an anti-retraction member, a force transmission member and a support member. When constructing the anti-retraction device, the corbel, the force transmission member, the support member and the anti-retraction member are prefabricated by dry operation first. After the final joint is installed underwater, the force transmission member is installed between the anti-retraction member and the corbel. Then, the upper part of the force transmission member and the underground continuous wall are connected through the support member to tighten the force transmission member. A concave steel plate is set at a set position in the gap around the force transmission member, and the end sealing structure of the water stop gap is filled and sealed. Finally, the water stop gap is cast underwater. The entire construction process is simple. It only requires the installation of prefabricated corbels, cast stoppers, prefabricated force transmission parts, and prefabricated support parts, and then pouring concrete to connect them together to complete the installation. There is no need to use underwater operations to carry out processes such as steel bar connection and binding and formwork installation, which simplifies the construction process. It only requires underwater pouring of concrete for water stopping. Underwater operations are time-saving, and the waiting time for concrete strength is short, which shortens the construction period and improves construction safety.

[0036] (2) The dry-wet alternating construction method provided by the present invention adopts dry-wet alternating construction when constructing the combined anti-recoil device of the final joint of the immersed tube tunnel, that is, dry operation is used to prefabricate the brackets, force transmission parts, support parts and water-stop components, cast the anti-recoil parts, embed the water-stop parts and grouting pipes, and underwater operation is used to install the force transmission parts, support parts, brackets, water-stop sills and steel cofferdams. The whole construction process is simple, and there is no need to use underwater operation to carry out the processes such as steel bar connection and binding and formwork installation. The underwater operation is short in time and the waiting time for concrete strength is short, which shortens the construction period and improves construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the side effect of the combined anti-retraction device for the final joint of the immersed tube tunnel according to the embodiment of the present invention after installation;

[0038] Figure 2 It is a schematic diagram of the top view of the combined anti-retraction device for the final joint of the immersed tube tunnel according to the embodiment of the present invention after installation;

[0039] Figure 3 It is a structural schematic diagram of the force transmission member according to an embodiment of the present invention;

[0040] Figure 4 It is a schematic diagram of the structure of the support member according to an embodiment of the present invention;

[0041] Figure 5 A top view of the support member according to an embodiment of the present invention;

[0042] Figure 6 This is a flow chart of the dry-wet alternating construction method according to an embodiment of the present invention;

[0043] Figure 7This is a schematic diagram of the front effect of the completion of casting of the stop-and-retract parts in the dry-wet alternating construction method according to an embodiment of the present invention;

[0044] Figure 8 It is a schematic diagram of a top view of the completed casting of the stop-and-retract parts in the dry-wet alternating construction method according to an embodiment of the present invention;

[0045] Fig. 9 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;

[0046] Fig.10 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;

[0047] Fig.11 It is a schematic diagram of the front effect of the force transmission member and the steel cofferdam being installed in place in the dry-wet alternating construction method according to an embodiment of the present invention;

[0048] Fig.12 It is a schematic diagram of the top view of the installed force transmission member and the steel cofferdam in the dry-wet alternating construction method according to the embodiment of the present invention;

[0049] Fig.13 This is a schematic diagram of the front effect of the support member being installed in place in the dry-wet alternating construction method according to an embodiment of the present invention;

[0050] Fig.14 This is a schematic diagram of the front effect of the final joint installation completed by the dry-wet alternating construction method according to an embodiment of the present invention;

[0051] Fig.15 This is a top view of the final joint installation completed by the dry-wet alternating construction method according to an embodiment of the present invention;

[0052] Fig.16 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.17 for Fig.16 Enlarged view of part A.

[0054] Fig.18 It 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. stop member, 2. force transmission member, 201. first force transmission part, 202. second force transmission part, 203. third force transmission part, 3. support member, 301. reinforcing rib plate, 4. underground continuous wall, 5. final joint, 6. corbel, 701. water stop, 702. steel cofferdam, 703. first water stop member, 704. second water stop member, 8. pouring concrete, 9. concave steel plate, 10. inside of dry dock, 11. pumping pipe, 12. first branch pipe, 13. second branch pipe, 14. submersible pump, 15. water area, 16. first valve, 17. 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 combined 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 5 The combined anti-retraction device of the final joint of the immersed tube tunnel includes an anti-retraction member 1, a force transmission member 2, a support member 3 and a corbel 6.

[0060] The corbel 6 is prefabricated on the side of the final joint 5 .

[0061] The stopper 1 is cast at the underground continuous wall 4 and is arranged opposite to the corbel 6; the bottom of the stopper 1 is flush with the bottom of the final joint 5, and the distance from the top of the stopper to the horizontal plane is L Satisfy the conditions L ≥ H - h + l , so that the final joint can be undocking and installed when constructing the final joint, where: H is the final joint height, h is the freeboard height, l For example, if the height of the final joint is 10.65m, the freeboard height of the final joint is 0.15m, and the clearance installation distance is 0.5m, then the distance from the top of the stop to the horizontal plane is L It can be 11m, or greater than 11m, such as 11.5m, 12m. It can be set according to the actual situation, as long as the final joint is ensured to be installed out of the dock during construction. The existing cast concrete stop structure (for example: the top elevation is about -5.5m) requires underwater operations to complete the casting after the final joint is installed, and underwater formwork installation is required. The concrete pouring time is long. Compared with the existing cast concrete stop structure, the stop can be cast by dry operations before the final joint is installed. There is no need for underwater operations, the construction is simple and convenient, and the underwater construction process is reduced. It should be noted that the clearance installation distance can be set according to the actual situation, as long as the final joint can be ensured to be installed out of the dock.

[0062] Specifically, in some embodiments, a surface of the stop member 1 away from the force transmission member 2 is set as an inclined surface to reduce the pressure of the water flow on the final joint and ensure the safe and stable operation of the final joint.

[0063] The force transmission member 2 is arranged between the stop member 1 and the corbel 6. The force transmission member 2 comprises a first force transmission part 201, a second force transmission part 202 and a third force transmission part 203 which are connected in sequence. The first force transmission part 201 is used for contacting and connecting with the underground continuous wall 4, and the third force transmission part 203 is used for matching and connecting with the steel cofferdam 702 installed above the final joint 5; the tops of the first force transmission part 201, the second force transmission part 202 and the third force transmission part 203 are flush with the top of the steel cofferdam 702, the bottoms of the first force transmission part 201 and the second force transmission part 202 are flush with the bottom of the final joint 5, and the bottom of the third force transmission part 203 is flush with the bottom of the steel cofferdam 702. Before the force transmission member is installed underwater, it is prefabricated by dry operation, and there is no need for underwater operation steel bar connection and binding, template installation and other processes for construction. It only needs to be installed underwater between the corbel and the stop member. The construction is simple and convenient, which reduces the underwater operation construction process.

[0064] Specifically, a cavity is provided inside the force transmission member, and a grouting port (not shown in the figure) is provided on the top of the force transmission member to connect the outside with the cavity, so that the cavity can be filled through the grouting port when the final joint stop device is constructed. When the final joint stop device is constructed, after the force transmission member is installed in place, a grouting conduit is used to pour lightweight concrete (for example, concrete with a label of C15) into the cavity of the force transmission member through the grouting port, and the grouting process refers to the existing underwater concrete pouring of bored piles.

[0065] In some embodiments, the thickness of the first force transmission part 201 and the third force transmission part 203 is the same as the thickness of the steel cofferdam 702, and the thickness of the second force transmission part 202 is greater than the thickness of the first force transmission part 201 and the third force transmission part 203 to increase the bearing capacity of the force transmission member 2.

[0066] In some embodiments, the third force transmission part is buckled with the steel cofferdam, and the buckling method is used to facilitate the connection between the force transmission part and the steel cofferdam to reduce the difficulty of construction.

[0067] In some embodiments, the force transmission member adopts a steel box beam structure to facilitate construction operations and reduce construction difficulty.

[0068] The support member 3 is used to connect the upper part of the force transmission member 2 with the underground continuous wall 4 to tighten the force transmission member. On the one hand, the force transmission member is supported by the support member and the stop member; on the other hand, the force transmission member is pushed by the support member and the stop member, and the push force is transmitted to the corbel of the final joint through the force transmission member, so as to stop the final joint.

[0069] Specifically, in some embodiments, when constructing the combined anti-retraction device of the final joint, after the force transmission member is installed, the support member is installed at an elevation of +3m. It should be noted that the installation position of the support member is set according to actual needs, and can be set specifically according to the height of the force transmission member and the anti-retraction member, so as to meet the purpose of supporting the force transmission member and preventing the final joint from retreating.

[0070] In some embodiments, the support member 3 is a cantilevered steel corbel, which is provided with a plurality of reinforcing rib plates 301 and can be stably supported between the underground continuous wall 4 and the force transmission member 2 .

[0071] In some embodiments, see Figures 7 to 15 The combined anti-retraction device for the final joint of the immersed tube tunnel also includes a water-stop assembly, and the water-stop assembly includes:

[0072] A water stop 701 is prefabricated at the top of the final joint 5;

[0073] A steel cofferdam 702 is installed on the water stop sill 701;

[0074] A first water stop 703 is pre-buried on one side of the second force transmission portion close to the water stop sill 701, and the first water stop 703 is in contact with and connected to the water stop sill 701;

[0075] A first grouting pipe (not shown in the figure) is pre-buried on one side of the second force transmission part close to the water stop 701, so as to inject grout through the first grouting pipe to seal the gap between the first water stop 703 and the water stop 701 when constructing the final joint 5;

[0076] A second water stop 704 is pre-buried in the underground continuous wall 4 and is in contact with and connected to the first force transmission part;

[0077] The second grouting pipe (not shown in the figure) is pre-buried in the underground continuous wall 4 so as to inject grout through the second grouting pipe to seal the gap between the second water stop 704 and the first force transmission part when constructing the final joint 5.

[0078] The final joint is watertightened by the waterstop assembly. Grouting is performed through the pre-buried grouting pipe to seal the tiny gaps between the waterstop and the force transmission member, the waterstop sill and the contact surface of the poured concrete, thus improving the grouting waterstop performance.

[0079] The combined anti-retraction device for the final joint of the immersed tube tunnel in the embodiment of the present invention adopts a combined design. Through the design of the anti-retraction parts and the force transmission parts, when constructing the combined anti-retraction device for the final joint, the anti-retraction parts, prefabricated corbels, prefabricated force transmission parts, prefabricated support parts, prefabricated water-stopping components, embedded water-stopping parts and grouting pipes are first cast in dry operation before the final joint is installed underwater. After the final joint is installed underwater, the force transmission parts are installed between the anti-retraction parts and the final joint corbels, and then the upper part of the force transmission parts and the underground continuous wall are connected through the support parts to tighten the force transmission parts. Concave steel plates are set at set positions in the gaps around the force transmission parts, and filled and sealed as end sealing structures of the gaps, and finally the gaps are cast underwater. The entire construction process is simple. It only requires the installation of prefabricated corbels, cast stoppers, prefabricated force transmission parts, and prefabricated support parts, and then pouring concrete to connect them together to complete the installation. There is no need to use underwater operations to carry out processes such as steel bar connection and binding and formwork installation, which simplifies the construction process. It only requires underwater pouring of concrete for water stopping. Underwater operations are time-saving, and the waiting time for concrete strength is short, which shortens the construction period and improves construction safety.

[0080] See also Figures 6 to 15 The second embodiment of the present invention provides a dry-wet alternating construction method of the combined anti-retraction device for the final joint of the immersed tube tunnel according to the first embodiment of the present invention, comprising the following steps:

[0081] S1. Before filling the dry dock with water, cast the stopper 1 at 4 locations of the underground continuous wall by dry operation, embed the water stopper and grouting pipe in the force transmission parts and the underground continuous wall, and prefabricate the corbel and water stop sill on the final joint.

[0082] Specifically, at the position where the force transmission member is connected to the water stop sill, a first water stop member 703 and a first grouting pipe (not shown in the figure) are pre-buried from the bottom of the water stop sill to the top of the water stop sill.

[0083] Specifically, at the position on the underground continuous wall 4 connected to the force transmission member 2 , a second water stop member 704 and a second grouting pipe (not shown in the figure) are pre-buried from the bottom of the force transmission member 2 to the top of the force transmission member 2 .

[0084] S2. Fill the dry dock with water, the distance from the horizontal surface to the top of the stop L Satisfy the conditions L ≥ H - h + l Stop watering when H is the final joint height, h is the freeboard height, l The clearance installation distance is set; the dry dock door is removed, the final joint is undocking from above the stop member and lowered into place to dock with the installed immersed tube.

[0085] 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 to fill the dry dock. Using the siphon pumping system to fill the dry dock with water is simple in construction and installation, and energy-saving and environmentally friendly, and has high filling efficiency.

[0086] Specifically, in some embodiments, see Figures 16 to 18 The siphon pumping system includes a pumping pipe 11, one end of which is arranged inside the dry dock 10, and the other end of the pumping pipe 11 is connected to a first branch pipe 12 and a second branch pipe 13 respectively. The first branch pipe 12 is used to connect to the water area 15 outside the dry dock, and the second branch pipe 13 is connected to a submersible pump 14 arranged in the water area. A first valve 16 is arranged on the first branch pipe 12, and a second valve 17 is arranged on the second branch pipe 13. By controlling the opening and closing of the first valve 16 and the second valve 17 and the start and stop of the submersible pump 14, the water flow forms a siphon phenomenon and flows into the dry dock 10 through the pumping pipe 11. Among them, the pumping pipe 11 plays the role of connecting and conveying water flow in the whole system. The first branch pipe 12 and the second branch pipe 13 are respectively connected to the external water area 15 and the submersible pump 14, and are used to control the water flow to enter the pumping pipe 11. The first valve 16 and the second valve 17 control the water flow path by opening and closing to ensure that the system works according to the designed process. The submersible pump 14 provides water flow power in the initial stage, so that the pumping pipe 11 is filled with water, forming a siphon condition.

[0087] 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.

[0088] 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.

[0089] Specifically, in some embodiments, the dry dock door is removed by using an existing dry dock door removal method.

[0090] S3. Install the force transmission member 2 between the corbel 6 and the stop member 1, and reserve water-stopping gaps between the force transmission member 2 and the stop member 1, the final joint 5, and the corbel 6 respectively; and insert the steel cofferdam 702 into the water-stop sill 701.

[0091] Specifically, the width of the water stop gap is greater than the diameter of the underwater concrete conduit, so that concrete can be poured into the water stop gap through the underwater concrete conduit. For example, the diameter of the underwater concrete conduit is 25 cm, and the width of the water stop gap is 50 mm.

[0092] S4. Install the support member 3 between the upper part of the force transmission member 2 and the underground continuous wall 4.

[0093] Specifically, after the support member 3 is installed, lightweight concrete (for example, concrete labeled C15) is filled into the force transmission member 2 and the steel cofferdam 702 through a grouting conduit, and the grouting process refers to the existing underwater concrete pouring of bored piles.

[0094] In some embodiments, the support member is installed at an elevation of +3m. It should be noted that the installation position of the support member is set according to actual needs, and can be set according to the height of the force transmission member and the stop member, so as to meet the purpose of supporting the force transmission member and stopping the final joint.

[0095] S5. Concave steel plates are arranged at set positions between the force transmission member and the underground continuous wall, the stop member, the corbel, and the final joint, and the grooves of the concave steel plates are filled and sealed to serve as end sealing structures of the gaps.

[0096] Specifically, there are five concave steel plates, and the first concave steel plate and the second concave steel plate are respectively arranged at the two ends of the side where the force transmission member is connected to the underground continuous wall, so as to block the gap between the force transmission member and the underground continuous wall, and ensure the water-stopping effect. The third concave steel plate is arranged at the end of the side of the corbel close to the force transmission member and far away from the final joint, so as to serve as an end sealing structure for blocking the gap between the corbel and the force transmission member, thereby facilitating the pouring of concrete into the gap between the force transmission member and the corbel, and ensuring the water-stopping effect. The fourth concave steel plate is arranged at the water stop sill of the final joint, so as to serve as a gap sealing structure for blocking the gap between the force transmission member and the final joint, thereby facilitating the pouring of concrete into the gap between the force transmission member and the final joint, and ensuring the water-stopping effect. The fifth concave steel plate is arranged at the side of the stop member close to the force transmission member and far away from the end of the underground continuous wall, so as to serve as an end sealing structure for blocking the gap between the stop member and the force transmission member, thereby facilitating the pouring of concrete into the gap between the force transmission member and the stop member, and ensuring the water-stopping effect.

[0097] Specifically, in some embodiments, the groove of the concave steel plate is filled and sealed by film bag grouting, which can improve the construction accuracy and efficiency on the one hand, and reduce the waste and damage of concrete on the other hand.

[0098] S6. Pour concrete into the water-stopping gaps between the force transmission parts and the stop parts, the corbels, and the final joints to perform water-stopping treatment.

[0099] Specifically, the water-stop gap between the force transmission member and the stop member is concreted to the top of the stop member, and the water-stop gap between the force transmission member and the final joint is concreted to the bottom of the steel cofferdam. On the one hand, it can effectively stop water, and on the other hand, it can reduce the use of concrete and save costs.

[0100] Specifically, after pouring concrete in the water-stop gap, grouting is performed through the pre-buried grouting pipe to seal the tiny gaps between the water-stop and the force-transmitting parts, the water-stop sill and the contact surface of the poured concrete, thereby improving the grouting water-stopping performance.

[0101] Specifically, in some embodiments, the concrete poured in the water stop gap is C35 concrete. After hardening, C35 concrete has high mechanical strength, so that the force transmission member is firmly bonded with the stop member, the bracket, and the final joint, ensuring the safety of the final joint.

[0102] S7. Drain the water inside the tank 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.

[0103] Specifically, the water seepage phenomenon includes small water flows, wet marks, etc.

[0104] After the installation of the anti-retraction device is completed, check whether the anti-retraction device is leaking. If water seepage occurs, fill and seal it to improve the water-stopping effect of the anti-retraction device.

[0105] The dry-wet alternating construction method of the assembled stop device for the final joint of the immersed tube tunnel in the embodiment of the present invention adopts dry-wet alternating construction, that is, prefabricating the bracket, force transmission parts, support parts and water-stop components through dry operation, casting the stop parts, pre-embedding the water-stop parts and grouting pipes, and installing the force transmission parts, support parts, brackets, water-stop sills and steel cofferdams through underwater operation. The whole construction process is simple, and there is no need to use underwater operation to construct the processes such as steel bar connection and binding and template installation. The underwater operation is short in time, and the waiting time for concrete strength is short, which shortens the construction period and improves construction safety.

[0106] The following is a detailed description of the dry-wet alternating construction method of the assembled anti-retraction device for the final joint of the immersed tube tunnel in combination with the specific final joint.

[0107] Example: The height of the final joint is 10.65m, the freeboard height of the final joint is 0.15m, and the clearance installation distance is 0.5m.

[0108] The specific construction method of the above-mentioned final joint combined anti-retraction device is as follows:

[0109] S1. Before filling the dry dock with water, dry cast the stopper at the underground continuous wall. At the position where the force transmission piece is connected to the water stop sill, pre-embed the first water stop piece and the first grouting pipe from the bottom of the water stop sill to the top of the water stop sill. At the position where the force transmission piece is connected to the underground continuous wall, pre-embed the second water stop piece and the second grouting pipe from the bottom of the force transmission piece to the top of the force transmission piece. Prefabricate the corbel on the side of the final joint, and prefabricate the first water stop sill at the top of the final joint.

[0110] S2. Fill the dry dock with water, the distance from the horizontal surface to the top of the stop L 11.5m (satisfying the following conditions: L ≥ H - h + l =10.65m-0.15m+0.5=11m); stop filling with water; remove the dry dock door, undocking the final joint from above the stopper and sinking it into place to dock with the installed immersed tube.

[0111] S3. Install the force transmission piece between the corbel and the stopper, and reserve a 50mm wide water-stop gap between the force transmission piece and the stopper, the final joint, and the corbel. Insert the steel cofferdam into the water-stop sill and connect it with a buckle.

[0112] S4. Install the support member between the upper part of the force transmission member and the underground continuous wall. After installing the support member, fill the force transmission member and the steel cofferdam with concrete of grade C15 through the grouting conduit.

[0113] S5. Concave steel plates are respectively arranged at the two ends of the side where the force transmission member is connected to the underground continuous wall, at the end of the side of the corbel close to the force transmission member and away from the final joint, at the water stop of the final joint, and at the end of the side of the stop member close to the force transmission member and away from the underground continuous wall, and the grooves of the concave steel plates are filled and sealed to serve as end sealing structures for the gap.

[0114] S6. Pour concrete into the water-stop gaps between the force transmission parts and the stoppers, corbels, and final joints to perform water-stop treatment. After pouring concrete into the water-stop gaps, grouting is performed through the pre-buried grouting pipes to seal the tiny gaps between the water-stop parts and the force transmission parts, the water-stop sill, and the contact surface of the poured concrete.

[0115] S7. Drain the water inside the tank 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.

[0116] 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 dry-wet alternating construction method for a combined anti-retraction device for the final joint of an immersed tube tunnel, characterized in that: The anti-retraction device includes: a corbel, which is prefabricated on the side of the final joint; a anti-retraction piece, which is cast at the underground continuous wall and arranged opposite to the corbel; the distance from the top of the anti-retraction piece to the horizontal plane is L Satisfy the conditions L ≥ H - h + l , so that the final joint can be undocking and installed when constructing the final joint, where: H is the final joint height, h is the freeboard height, l is the clearance installation distance; a force transmission member is arranged between the stop member and the corbel; the force transmission member comprises a first force transmission part, a second force transmission part and a third force transmission part connected in sequence, the first force transmission part is used for contacting and connecting with the underground continuous wall, and the third force transmission part is used for matching and connecting with the steel cofferdam installed above the final joint; the tops of the first force transmission part, the second force transmission part and the third force transmission part are flush with the top of the steel cofferdam, the bottoms of the first force transmission part and the second force transmission part are flush with the bottom of the final joint, and the bottom of the third force transmission part is flush with the bottom of the steel cofferdam; a support member is used for connecting the upper part of the force transmission member with the underground continuous wall to tighten the force transmission member; the method comprises the following steps: S1. Before filling the dry dock with water, dry-cast the stoppers at the underground continuous wall, embed the water-stoppers and grouting pipes in the force-transmitting parts and underground continuous wall, and prefabricate the corbels and water-stop sills at the final joints; S2. Fill the dry dock with water, the distance from the horizontal surface to the top of the stop L Satisfy the conditions L ≥ H - h + l Stop watering when H is the final joint height, h is the freeboard height, l The clearance installation distance is removed; the dry dock door is removed, the final joint is undocking from above the stopper and sunk into place to dock with the installed immersed tube; S3. Install the force transmission member between the corbel and the stop member, and reserve water-stopping gaps between the force transmission member and the stop member, the final joint, and the corbel; and insert the steel cofferdam into the water-stop sill; S4. Install the support member between the upper part of the force transmission member and the underground continuous wall; S5. Concave steel plates are arranged at set positions between the force transmission member and the underground continuous wall, the stop member, the corbel, and the final joint, and the grooves of the concave steel plates are filled and sealed to serve as end sealing structures of the gaps; S6. Pour concrete into the water-stop gaps between the force transmission parts and the stoppers, the brackets, and the final joints to perform water-stop treatment; S7. 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.

2. The dry-wet alternating construction method according to claim 1, characterized in that: It also includes a water stop assembly, the water stop assembly comprising: A water stop, prefabricated at the top of the final joint; A steel cofferdam is installed on the water stop sill; A first water stop member is pre-buried on a side of the second force transmission portion close to the water stop sill, the first water stop member being in contact and connected with the water stop sill; A first grouting pipe is pre-buried on one side of the second force transmission part close to the water stop sill, so as to inject grout through the first grouting pipe to seal the gap between the first water stop and the water stop sill when constructing the final joint; A second water stop, pre-buried in the underground continuous wall, in contact with and connected to the first force transmission part; The second grouting pipe is pre-buried in the underground continuous wall so that grouting can be performed through the second grouting pipe to seal the gap between the second water stop and the first force transmission part when constructing the final joint.

3. The dry-wet alternating construction method according to claim 2, characterized in that: A cavity is arranged inside the force transmission member, and a grouting port connecting the outside with the cavity is arranged on the top of the force transmission member, so that the cavity can be filled through the grouting port when constructing the final joint.

4. The dry-wet alternating construction method according to claim 2, characterized in that: The third force transmission part is buckled with the steel cofferdam.

5. The dry-wet alternating construction method according to claim 2, characterized in that: The thickness of the first force transmission part and the third force transmission part is the same as the thickness of the steel cofferdam, and the thickness of the second force transmission part is greater than the thickness of the first force transmission part and the third force transmission part, so as to increase the bearing capacity of the force transmission member.

6. The dry-wet alternating construction method according to claim 1, characterized in that: In step S2, 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, thereby filling the dry dock with water.

7. The dry-wet alternating construction method according to claim 6, 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.

8. The dry-wet alternating construction method according to claim 1, characterized in that: In step S4, after the support members are installed, lightweight concrete is filled into the force transmission members and the steel cofferdam.

9. The dry-wet alternating construction method according to claim 1, characterized in that: In step S6, concrete is poured into the water-stop gap between the force transmission member and the stop member to the top of the stop member, and concrete is poured into the water-stop gap between the force transmission member and the final joint to the bottom of the steel cofferdam; after concrete is poured into the water-stop gap, grouting is performed through a grouting pipe to seal the tiny gaps between the water-stop member and the force transmission member, the water-stop sill and the contact surface of the poured concrete.

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