A jacking type final joint device for immersed tunnel and construction method thereof

Abstract

The present invention discloses a jacking type final joint device for immersed tunnels and a construction method. The device includes: a foundation cushion layer, an enlarged section, a connecting section and a pushing section arranged on the foundation cushion layer; an enlarged end is provided at the front end of the enlarged section, the pushing section is arranged inside the enlarged end, and a jacking jack is provided between the two; an enlarged section end sealing door is provided at the rear end of the enlarged section, and a pushing section end sealing door is provided in the pushing section, so as to form a cavity between the enlarged section and the pushing section, and a water injection system is connected to the cavity; the water injection system includes a water injection pipe, a water injection water tank, a pressure regulating pipe and a water outlet pipe. The water injection pipe connects the water injection water tank and the cavity, one end of the pressure regulating pipe is connected to the cavity, the other end penetrates above the water surface, the water outlet pipe connects the cavity and the external water, and the water injection water tank is arranged at the rear end of the enlarged section; the jacking jacks are divided into two groups with the same number and arranged staggeredly, water is injected into the cavity through the water injection system to balance the water pressure on both sides of the pushing section end sealing door, and the pushing section is pushed out to be connected with the connecting section in combination with the jacking jacks.

Description

Technical Field

[0001] The invention belongs to the technical field of immersed tunnel construction, and more specifically, relates to a pushing type final joint device and construction method for an immersed tunnel. Background Art

[0002] With the advent of modernization, people's demand for transportation is increasing. Land transportation can no longer meet daily travel needs. When crossing rivers or seas, ferry crossings were mostly used in the past. However, this public transportation cannot meet the demand for rapid passage, and a large number of passengers have the need to drive by themselves. Therefore, building a bridge across the river or sea has become the simplest solution. As the planned span connecting the two banks becomes larger and larger, the construction difficulty of the bridge also increases accordingly. Building a tunnel under the water has become the best construction plan for large-span rivers and seas. To shorten the project cycle, when building an underwater tunnel, the commonly adopted plan is to synchronously sink the pipe sections of the immersed tunnel from both longitudinal sides and use a final joint at the middle position to connect and form a complete underwater tunnel.

[0003] Currently, the final joints of immersed tunnels include water stop plates, V-block methods, Key pipe section methods, integral hoisting methods, and final sinking methods. In the final sinking method, generally, small pipe sections with the same cross-section as the standard pipe sections are prefabricated, with a GINA water stop belt installed at one end and a temporary seal door at the back. An enlarged section is set at the front end of the last pipe section to be sunk, and the final joint is placed in the enlarged section. After the last pipe section is sunk, the pushing section is pushed out from the enlarged section using a pushing system so that it contacts the end face of the adjacent pipe section, completing the initial crimping of the GINA water stop belt. Then, the water in the docking cavity is pumped out, and the GINA water stop belt is fully compressed using hydraulic crimping. Finally, the construction of water stop and longitudinal locking is carried out inside the immersed tunnel.

[0004] However, in this pushing scheme, since the pushing side is in contact with the water at the bottom of the water, there is a large pressure, which generates a great resistance to the pushing process. At the bottom of the water with particularly deep water depth, a pushing device with a greater power is required for pushing. Moreover, due to the action of water pressure, the stability of the high-power pushing device will be affected. Therefore, a pushing type final joint device and construction method for an immersed tunnel are needed to overcome the influence of huge water pressure on construction in deep water. Summary of the Invention

[0005] In view of the above defects or improvement requirements of the prior art, the present invention provides a jacking type final joint device and construction method for a immersed tube tunnel. Water is injected into the cavity through a water injection system to adjust the water pressure on both sides of the end seal door of the pushing section, so that the water pressure on both sides of the end seal door of the pushing section is always kept in dynamic balance. Then, the pushing section is pushed out by a jacking jack to be connected with the connecting section, so as to realize the connection of the final joint of the immersed tube tunnel, reduce the load of the jacking jack, and enable a smaller power jack to be selected for the jacking operation during its selection, saving the usage cost. At the same time, under the condition of pressure balance, the jacking operation can be better controlled and adjusted in real time, improving the quality and efficiency of the operation.

[0006] According to the first aspect of the embodiment of the present invention, a jacking type final joint device for an immersed tube tunnel is provided, including: a foundation cushion layer, an enlarged section, a connecting section and a pushing section arranged on the foundation cushion layer;

[0007] An enlarged end is provided at the front end of the enlarged section, the pushing section is arranged in the enlarged end, and a jacking jack is arranged between the two;

[0008] An enlarged section end seal door is provided at the rear end of the enlarged section, and a pushing section end seal door is arranged in the pushing section. A cavity is formed between the enlarged section and the pushing section through the two end seal doors, and a water injection system is connected to the cavity;

[0009] The water injection system includes a water injection pipe, a water injection water tank, a pressure regulating pipe and a water outlet pipe. The water injection pipe connects the water injection water tank and the cavity. One end of the pressure regulating pipe is connected to the cavity, and the other end passes through the enlarged section to above the water surface. The water outlet pipe connects the cavity and the outside water. The water injection water tank is arranged at the rear end of the enlarged section;

[0010] The jacking jacks are divided into two groups, one group is for normal use and the other group is set as a spare. The two groups have the same number and are arranged staggeredly. Water is injected into the cavity through the water injection system to balance the water pressure on both sides of the pushing section end seal door, and the pushing section is pushed out to be connected with the connecting section by combining with the jacking jack.

[0011] Furthermore, stiffening rib plates and a first slideway are also arranged in the enlarged section;

[0012] The stiffening rib plates are trapezoidal plates and are arranged between the enlarged end and the rear end of the enlarged section;

[0013] The first slideway is embedded in the bottom plate inside the enlarged end, and a second slideway is arranged at the corresponding position of the pushing section. The first slideway and the second slideway cooperate with each other.

[0014] Furthermore, no less than two alignment jacks are respectively arranged on the side plates on both sides of the enlarged end. The alignment jacks apply a lateral force to the pushing section to adjust its pushing direction in real time.

[0015] Furthermore, a water stop structure is provided between the pushing-out section, the expanding section and the connecting section;

[0016] The water stop structure includes an M water stop belt provided at the end of the expanding end and the pushing-out section, an inflatable water stop belt provided in the connection gap between the expanding end and the pushing-out section, and a GINA water stop belt provided at the end of the connecting section and the pushing-out section.

[0017] Furthermore, a temporary slide rail is provided on the foundation cushion layer between the expanding section and the connecting section. The bottom of the temporary slide rail is supported by piers, and a leveling base is provided between the temporary slide rail and the piers;

[0018] An auxiliary jack is further provided on the temporary slide rail. The auxiliary jack is connected between the temporary slide rails through a sliding connection base, and the sliding connection base slides on the temporary slide rail.

[0019] Furthermore, a combined cavity is formed between the pushing-out section and the connecting section, and a temporary water tank is provided in the combined cavity;

[0020] A cross beam and steel supports are provided on the temporary water tank, and the temporary water tank is connected to the inner wall of the pushing-out section as a whole through the cross beam and the steel supports.

[0021] According to another aspect of the embodiment of the present invention, a construction method of a pushing-type final joint device for a immersed tube tunnel is provided, including the following steps:

[0022] S100. Select a window period to integrally float the expanding section and the pushing-out section to the installation position of the immersed tube tunnel, and make the expanding end face the connecting section;

[0023] S200. Slowly inject water into the cavity through the water injection system to sink the expanding section and the pushing-out section to the installation position, and release the locking device between the expanding section and the pushing-out section;

[0024] S300. Continuously inject water into the cavity to balance the water pressure in the cavity and the water pressure outside the end seal door of the pushing-out section;

[0025] S400. Start the pushing jack to provide thrust to the pushing-out section, and at the same time continuously inject water into the cavity to keep the water pressure on both sides of the end seal door of the pushing-out section in dynamic balance, so that the pushing-out section is slowly pushed out to be preliminarily pressed against the connecting section;

[0026] S500. Drain the water in the combined cavity to realize the crimping between the connecting section and the pushing-out section, and use temporary tie rods to connect the connecting section and the pushing-out section;

[0027] S600. Drain the water in the cavity, weld the post-weld section steel plate, perform grouting operations on the joints between the pushing-out section, the connecting section and the expanding section, and remove the temporary tie rods;

[0028] S700. Complete the grouting at the bottom of the pushing-out section and the backfilling of the pipe joints, remove the temporary components including the end seal doors of the enlarged section, the end seal doors of the pushing-out section, and the temporary water tank, and construct the road surface and ancillary facilities.

[0029] Further, during the water injection process, water in the water injection tank is injected into the cavity via the water injection pipe by a water pump. After the cavity is filled with water, it enters the pressure regulating pipe upward. By adjusting the height of the water in the pressure regulating pipe, the water pressure in the cavity is adjusted.

[0030] In steps S200 and S300, during the continuous water injection into the cavity, the pressure regulating pipe is connected to the external water environment, and the water level in the pressure regulating pipe is made flush with the external water surface by means of gravity water injection, so that the water pressure in the cavity is the same as the external water pressure.

[0031] In step S200, water is injected into the cavity to overcome the upward buoyancy force generated by the water, so that the enlarged section and the pushing-out section continuously sink to the preset position of the foundation cushion at a slow speed, and the water level in the pressure regulating pipe remains below the external liquid level.

[0032] In step S300, water is injected until the water level in the pressure regulating pipe is flush with the external liquid level. At this time, the water pressures on both sides of the end seal door of the pushing-out section reach equilibrium.

[0033] Further, in step S400, the jack is controlled to overcome the initial resistance to realize the initial pushing of the pushing-out section. The initial resistance includes the water resistance at the front end of the end seal door of the pushing-out section during the uniform pushing of the pushing-out section, the viscous resistance at the rear end of the end seal door of the pushing-out section during the uniform pushing of the pushing-out section, and the friction between the pushing-out section and the slide rail.

[0034] The water resistance at the front end of the end seal door of the pushing-out section during the uniform pushing of the pushing-out section is:

[0035]

[0036] where F w is the water resistance at the front end of the end seal door of the pushing-out section,

[0037] C w is the water flow resistance coefficient,

[0038] ρ is the density of water,

[0039] V is the water flow velocity,

[0040] A is the projected area of the pushing-out section in the pushing direction.

[0041] The viscous resistance at the rear end of the end seal door of the pushing-out section during the uniform pushing of the pushing-out section is:

[0042]

[0043] Among them, D is the viscous resistance at the rear end of the closing door of the pushing section,

[0044] C d is the resistance coefficient.

[0045] The frictional force between the pushing section and the slide rail is:

[0046]

[0047] Among them, D f is the frictional force between the pushing section and the slide rail,

[0048] C f is the frictional resistance coefficient,

[0049] L is the length of the pushing section.

[0050] Among them, the frictional resistance coefficient C f is:

[0051]

[0052] Among them, Re is the Reynolds number, and

[0053] μ is the dynamic viscosity of water.

[0054] The initial resistance F c is:

[0055] F c = F w + D + D f ;

[0056] During this process, water in the water injection tank is continuously injected into the cavity through the water injection pipe, so that the water level in the pressure regulating pipe is always kept at the same height as the external liquid level, so as to achieve the dynamic balance of the water pressure on both sides of the end closing door of the pushing section.

[0057] Furthermore, during the pushing process of the pushing section, it also includes:

[0058] S410. During the pushing process, the attitude of the pushing section is monitored by the monitoring system to determine whether the pushing direction deviates;

[0059] S420. A lateral force is provided to the pushing section by the deviation correction jack, and the pushing direction of the pushing section is adjusted by this lateral force to ensure that the pushing path of the pushing section always remains within the design range;

[0060] S430. The auxiliary jack slides on the temporary slide rail according to the speed of the pushing section, and at the same time provides a pulling force to the pushing section, and the auxiliary pushing jack pushes the pushing section out of the enlarged end;

[0061] When the pushing section is pushed to a position where the tip of the GINA water stop is 3 - 5 cm away from the end face of the connecting section, both groups of pushing jacks are activated, and the two groups of pushing jacks are used to synchronously push, compressing the GINA water stop to achieve the preliminary pressing between the connecting section and the pushing section;

[0062] In step S410, the monitoring system is arranged on the end face of the pushing section, and is used to monitor information of the pushing section including the pushing speed, direction, and angle, so as to adjust the pushing action. When it is monitored that the angle deviation of the pushing section is too large and it cannot continue to be pushed, a retraction operation is required. Specifically:

[0063] S411. Stop the output of the pushing jacks and the auxiliary jacks, adjust the force output by the pushing jacks to a pulling force, so that the pushing section becomes loose at the original stuck position, facilitating subsequent retraction;

[0064] S412. After the stuck part of the pushing section becomes loose, activate the deviation - correcting jacks to adjust the angle of the pushing section so that it returns to the set pushing angle;

[0065] S413. Adjust the force output by the auxiliary jacks to a pushing force, and the auxiliary jacks move on the temporary slide rail as the pushing section retracts to assist the retraction of the pushing section;

[0066] S414. Drain the water in the cavity to the water injection water tank through the water outlet pipe, control the rise of the water level in the pressure - regulating pipe when the pushing section retracts, and keep the water level in the pressure - regulating pipe flush with the external water surface.

[0067] Generally speaking, compared with the prior art through the above - mentioned technical solutions conceived by the present invention, the following beneficial effects can be obtained:

[0068] 1. In the construction method of a pushing - type final joint device for a immersed - tube tunnel of the present invention, water is injected into the cavity through the water injection system to adjust the water pressure on both sides of the end - sealing door of the pushing section, so that the water pressure on both sides of the end - sealing door of the pushing section always maintains a dynamic balance. Then, the pushing section is pushed out by the pushing jacks to be connected with the connecting section to realize the connection of the final joint of the immersed - tube tunnel, reducing the load of the pushing jacks, so that a smaller - power jack can be selected for the pushing operation during the selection, saving the usage cost. At the same time, under the condition of pressure balance, the pushing operation can be better controlled and adjusted in real time, improving the quality and efficiency of the operation.

[0069] 2. In the construction method of a pushing - type final joint device for an immersed - tube tunnel of the present invention, when balancing the pressure on both sides of the end - sealing door of the pushing section, water is directly introduced by connecting the pressure - regulating pipe to the external water without controlling the water flow rate. During the subsequent process of adjusting the water pressure, the water stored in the water injection water tank is used to adjust the height of the water level in the pressure - regulating pipe, realizing the precise adjustment of the pressure on both sides of the end - sealing door of the pushing section.

[0070] 3. Construction method of a pushing-type final joint device for immersed tube tunnel of the present invention. When floating and expanding the extended section and the pushing section, the steel plate of the post-welding section is placed at the rear end of the large section and floated simultaneously. By using one-time floating and sinking, the transportation of multiple precast parts can be completed, saving construction procedures and construction time, and providing counterweight for the extended section and the pushing section, facilitating subsequent sinking.

[0071] 4. Construction method of a pushing-type final joint device for immersed tube tunnel of the present invention. A temporary water tank is arranged in the joint cavity formed by the pushing section and the connecting section to balance the buoyancy it receives, avoiding the inability to normally connect the pushing section and the connecting section due to the decline of anti-corrosion performance after draining water in the joint cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 It is a schematic structural diagram of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0073] Figure 2 It is a schematic structural diagram of the extended section and the pushing section of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0074] Figure 3 It is a schematic diagram of the sinking of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0075] Figure 4 It is a schematic structural diagram of the installed pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0076] Figure 5 It is a schematic structural diagram of the extended section of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0077] Figure 6 It is a schematic structural diagram of the water stop structure of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0078] Figure 7 It is a schematic diagram of the position of the deviation correction jack of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0079] Figure 8 It is a schematic structural diagram of the temporary slide rail of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0080] Figure 9 It is a top view of the temporary slide rail structure of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention;

[0081] Figure 10 It is a schematic flow chart of the construction method of a pushing-type final joint device for immersed tube tunnel according to an embodiment of the present invention.

[0082] In all the attached drawings, the same reference numerals denote the same technical features, specifically: 1 - foundation cushion layer, 2 - enlarged section, 21 - enlarged end, 22 - end seal door of the enlarged section, 23 - stiffening rib plate, 24 - first slideway, 3 - connecting section, 4 - pushing-out section, 41 - end seal door of the pushing-out section, 42 - second slideway, 5 - pushing jack, 6 - deviation-correcting jack, 7 - water injection system, 71 - water injection pipe, 72 - water injection water tank, 73 - pressure-regulating pipe, 74 - water outlet pipe, 8 - water stop structure, 81 - M water stop belt, 82 - inflatable water stop belt, 83 - GINA water stop belt, 9 - temporary slide rail, 91 - pier, 92 - leveling base, 93 - auxiliary jack, 94 - sliding connection base, 10 - temporary water tank, 101 - cross beam, 102 - steel support, 11 - temporary tie rod, 12 - manhole shaft, 13 - steel plate of the post-welding section. Detailed implementation manners

[0083] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the attached drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various implementation manners of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0084] Embodiment 1

[0085] As Figure 1-4As shown in the figure, an embodiment of the present invention provides a jacking type final joint device for a immersed tube tunnel, which includes an enlarged section 2, a connecting section 3 and a pushing section 4. The enlarged section 2, the connecting section 3 and the pushing section 4 are all arranged on a foundation cushion 1. The rear end of the enlarged section 2 has the same size as other pipe sections of the immersed tube tunnel, and the front end is set as an enlarged end 21 with a larger size. The pushing section 4 is arranged in the enlarged end 21, and the two are connected by a locking device. A jacking jack 5 is also arranged between the two. The rear end of the enlarged section 2 is provided with an end seal door 22 of the enlarged section, and the pushing section 4 is provided with an end seal door 41 of the pushing section. A cavity is formed between the enlarged section 2 and the pushing section 4 through the two end seal doors. A water injection system 7 is connected to the cavity. Water is injected into the cavity through the water injection system 7 to adjust the water pressure on both sides of the end seal door 41 of the pushing section, so that the water pressure on both sides of the end seal door 41 of the pushing section always remains dynamically balanced. Then, the pushing section 4 is pushed out by the jacking jack 5 to be connected with the connecting section 3, so as to realize the connection of the final joint of the immersed tube tunnel. The water pressure is used to balance the pressure on both sides of the end seal door 41 of the pushing section, and then the pushing section 4 is pushed out by the jacking jack 5 to complete the connection of the final joint, so as to reduce the load of the jacking jack 5, so that a smaller power jack can be selected during its selection to complete the jacking operation, saving the use cost. At the same time, under the condition of pressure balance, the jacking operation can be better controlled and adjusted in real time, improving the quality and efficiency of the operation.

[0086] As Figure 5 shown, the enlarged section 2 is also provided with stiffening rib plates 23 and a first slideway 24. The stiffening rib plates 23 are trapezoidal plates, which are arranged between the enlarged end 21 and the rear end of the enlarged section 2 and are used to reinforce the top plate and side plates of the enlarged end 21. The first slideway 24 is embedded in the bottom plate inside the enlarged end 21, and a second slideway 42 is arranged at the corresponding position of the pushing section 4. Through the cooperation of the first slideway 24 and the second slideway 42, the stability of the pushing section 4 during pushing is improved.

[0087] The bottom plates at the rear end of the enlarged section 2 and the front end of the connecting section 3 are both locally thickened to adapt to the height of the bottom plate of the pushing section 4 from the foundation cushion 1, ensuring the smooth pushing and connection of the pushing section 4. The bottom plate of the enlarged section 2 adopts a steel shell concrete composite structure, and the top plate and side plates are both pure steel structures. One end of the connecting section 3 close to the pushing section 4 adopts a steel shell concrete composite structure, and the rest adopts a steel structure. The pushing section 4 is cast from self-compacting concrete.

[0088] The fixed end of the jacking jack 5 is fixed on the top plate and bottom plate at the rear end of the enlarged section 2, and the output end is connected to the top plate and bottom plate of the pushing section 4. The jacking jack 5 is divided into two groups. One group is for normal use and the other group is set as a spare. The two groups have the same quantity and are arranged staggeredly.

[0089] The water injection system 7 includes a water injection pipe 71, a water injection water tank 72, a pressure regulating pipe 73 and a water outlet pipe 74. One end of the water injection pipe 71 is connected to the water injection water tank 72, and the other end passes through the end seal door 22 of the enlarged section and is connected to the cavity. The water in the water injection water tank 72 is injected into the cavity by the water injection pipe 71. One end of the pressure regulating pipe 73 is connected to the cavity, and the other end passes out of the enlarged section 2 above the water surface. The water outlet pipe 74 connects the cavity and the external environment. The water injection water tank 72 is arranged at the rear end of the enlarged section 2, and the water injection water tank 72 is connected to a water storage tank arranged above the water surface by a water pipe. The same water as the external environment of the immersed tube tunnel is stored in the water storage tank, and the water storage tank replenishes water to the water injection water tank 72, and then the water injection water tank 72 injects water into the cavity to achieve dynamic balance of the water level.

[0090] As Figure 6 shown, a water stop structure 8 is provided between the pushing section 4, the enlarged section 2 and the connecting section 3. The water stop structure 8 includes an M water stop belt 81 arranged at the enlarged end 21 and the end of the pushing section 4, an inflatable water stop belt 82 arranged in the connecting gap between the enlarged end 21 and the pushing section 4, and a GINA water stop belt 83 arranged at the end of the connecting section 3 and the pushing section 4.

[0091] As Figure 7 shown, during the pushing process, affected by the lateral water flow thrust, the pushing section 4 will deviate from the original advancing direction, resulting in an uncontrollable pushing direction and even jamming, which affects the efficiency and quality of the construction operation. Therefore, no less than two deviation correction jacks 6 are respectively provided on the side plates on both sides of the enlarged end 21. The deviation correction jacks 6 apply a lateral force to the pushing section 4 to adjust its pushing direction in real time to ensure the normal progress of the pushing operation.

[0092] As Figure 8 、 9 shown, a temporary slide rail 9 is further provided on the foundation cushion 1 between the enlarged section 2 and the connecting section 3. The bottom of the temporary slide rail 9 is supported by piers, and a leveling base is provided between the temporary slide rail 9 and the piers to adjust the levelness of the temporary slide rail 9 through the leveling base. An auxiliary jack 93 is further provided on the temporary slide rail 9. The auxiliary jack 93 is connected to the temporary slide rail 9 through a sliding connection base 94, and the sliding connection base 94 slides on the temporary slide rail 9. The output end of the auxiliary jack 93 is fixedly connected to the front end of the pushing section 4. When the pushing section 4 is pushed out, the auxiliary jack 93 provides auxiliary pulling force for it, and at the same time, the sliding connection base 94 moves synchronously and actively with the movement of the pushing section 4. When the pushing section 4 is blocked during underwater pushing and needs to be pulled back, it is pulled back by the jacking jack 5 at this time, and the auxiliary jack 93 provides auxiliary thrust.

[0093] After the pushing section 4 and the connecting section 3 are connected, a combined cavity is formed between them. A large amount of water is stored in this combined cavity, and the water in the combined cavity needs to be drained completely. When draining the water, the anti-floating ability of the combined cavity is reduced. Therefore, a temporary water tank 10 is arranged in the combined cavity, and the temporary water tank 10 is used to store a large amount of water to increase the overall gravity and balance the buoyancy received by the pushing section 4. The temporary water tank 10 is provided with a cross beam 101 and a steel support 102, and the temporary water tank 10 is connected to the inner wall of the pushing section 4 as a whole through the cross beam 101 and the steel support 102.

[0094] After the pushing section 4 is pushed until it contacts the connecting section 3, the water used to balance the water pressure in the cavity needs to be emptied. At this time, the pushing section 4 may rebound, resulting in the failure of the press connection between the pushing section 4 and the connecting section 3. Therefore, a temporary pull rod 11 is used to lock the pushing section 4 and the connecting section 3 to prevent the pushing section 4 from rebounding, and it is removed after the two are connected.

[0095] A hole is opened at the top of the rear end of the enlarged section 2, and a manhole is provided. Operators enter the immersed tube tunnel through this manhole and perform operations inside the tube.

[0096] Preferably, the end sealing door 22 of the enlarged section and the end sealing door 41 of the pushing section are of double-layer steel plate structure, with a drain opening at the bottom. The drain opening is connected to a drain pipe, and a glass lens and a door mirror are provided.

[0097] To ensure the stability of the connection of the pushing section 4, after it is connected to the connecting section 3, the pushing section 4 and the enlarged section 2 also need to be welded and fixed by the post-welding section steel plate 13. The post-welding section steel plate 13 is stored at the rear end of the enlarged section 2.

[0098] A locking device is also provided between the pushing section 4 and the enlarged section 2 to connect the two into one body before floating transportation.

[0099] Embodiment 2

[0100] As Figure 10 shown, the embodiment of the present invention provides a construction method for a jacking type final joint device of an immersed tube tunnel, including the following steps:

[0101] S100. Select a window period to float the enlarged section 2 and the pushing section 4 as a whole to the installation position of the immersed tube tunnel, and make the enlarged end 21 face the connecting section 3;

[0102] S200. Slowly inject water into the cavity through the water injection system 7 to sink the enlarged section 2 and the pushing section 4 to the installation position, and release the locking device between the enlarged section 2 and the pushing section 4;

[0103] S300. Continuously inject water into the cavity to balance the water pressure in the cavity and the water pressure outside the end sealing door 41 of the pushing section;

[0104] S400. Start the pushing jack 5 to provide thrust to the pushing section 4. Meanwhile, continuously inject water into the cavity to keep the water pressure on both sides of the end seal door 41 of the pushing section dynamically balanced, so that the pushing section 4 is slowly pushed out until it is initially pressed against the connecting section 3.

[0105] S500. Drain the water in the joint cavity to achieve the crimping between the connecting section 3 and the pushing section 4, and use the temporary tie rod 11 to connect the connecting section 3 and the pushing section 4.

[0106] S600. Drain the water in the cavity, weld the post-weld section steel plate 13, carry out grouting operations at the joints between the pushing section 4, the connecting section 3 and the enlarged section 2, and remove the temporary tie rod 11.

[0107] S700. Complete the grouting of the bottom foundation of the pushing section 4 and the backfilling operation of the pipe section, remove the temporary components including the end seal door 22 of the enlarged section, the end seal door 41 of the pushing section and the temporary water tank 10, and construct the road surface and ancillary facilities.

[0108] Among them, in step S100, to save processes and construction time, when floating the enlarged section 2 and the pushing section 4, place the post-weld section steel plate 13 at the rear end of the enlarged section 2 and float them simultaneously.

[0109] During the water injection process, replenish water to the water injection water tank 72 through the water storage tank on the water surface, and then inject the water in the water injection water tank 72 into the cavity through the water injection pipe 71 by a water pump. After the cavity is filled with water, it enters the pressure regulating pipe 73 upward. By adjusting the height of the water in the pressure regulating pipe 73, the water pressure in the cavity is adjusted.

[0110] In steps S200 and S300, during the continuous water injection into the cavity, connect the pressure regulating pipe 73 to the external water environment, and make the water level in the pressure regulating pipe 73 flush with the external water surface by means of gravity water injection, so that the water pressure in the cavity is the same as the external water pressure.

[0111] In step S200, inject water into the cavity to overcome the upward buoyancy generated by the water, so that the enlarged section 2 and the pushing section 4 continuously sink to the preset position of the foundation cushion 1 at a slow speed. Therefore, during this process, the amount of water injection can make it sink, that is, the water level in the pressure regulating pipe 73 remains below the external liquid level.

[0112] In step S300, inject water until the water level in the pressure regulating pipe 73 is flush with the external liquid level. At this time, the water pressures on both sides of the end seal door 41 of the pushing section reach balance.

[0113] In step S400, controlling the pushing jack 5 to overcome the initial resistance can achieve the initial pushing of the pushing section 4. The initial resistance includes the water resistance at the front end of the pushing-section sealing door during the uniform pushing of the pushing section, the viscous resistance at the rear end of the pushing-section sealing door during the uniform pushing of the pushing section, and the frictional force between the pushing section and the slide rail.

[0114] The water resistance at the front end of the pushing-section sealing door during the uniform pushing of the pushing section is:

[0115]

[0116] where F w is the water resistance at the front end of the pushing-section sealing door,

[0117] C w is the water flow resistance coefficient,

[0118] ρ is the density of water,

[0119] V is the water flow velocity,

[0120] A is the projected area of the pushing section in the pushing direction.

[0121] The viscous resistance at the rear end of the pushing-section sealing door during the uniform pushing of the pushing section is:

[0122]

[0123] where D is the viscous resistance at the rear end of the pushing-section sealing door,

[0124] C d is the resistance coefficient.

[0125] The frictional force between the pushing section and the slide rail is:

[0126]

[0127] where D f is the frictional force between the pushing section and the slide rail,

[0128] C f is the frictional resistance coefficient,

[0129] L is the length of the pushing section.

[0130] where the frictional resistance coefficient C f is:

[0131]

[0132] where Re is the Reynolds number, and

[0133] μ is the dynamic viscosity of water.

[0134] The initial resistance Fc is:

[0135] F c = F w + D + D f .

[0136] During the process of the pushing section 4 being pushed out, the space in the cavity gradually increases, which will cause the water level in the pressure regulating pipe 73 to decrease, resulting in an imbalance in water pressure on both sides of the end sealing door 41 of the pushing section, increasing the load on the jacking jack 5, and even causing the pushing section 4 to retract. Therefore, during this process, water in the water injection tank 72 is continuously injected into the cavity through the water injection pipe 71 to keep the water level in the pressure regulating pipe 73 always at the same height as the external liquid level, so as to maintain the dynamic balance of water pressure on both sides of the end sealing door 41 of the pushing section.

[0137] In step S400, during the process of the pushing section 4 being pushed out, it further includes:

[0138] S410. During the jacking process, the attitude of the pushing section 4 is monitored by the monitoring system to determine whether the pushing direction deviates;

[0139] S420. A lateral force is provided to the pushing section 4 by the deviation correction jack 6, and the pushing direction of the pushing section 4 is adjusted through this lateral force to ensure that the pushing path of the pushing section 4 always remains within the design range;

[0140] S430. The auxiliary jack 93 slides on the temporary slide rail 9 according to the speed of the pushing section 4, and at the same time provides a pulling force for the pushing section 4, and the auxiliary jacking jack 5 pushes the pushing section 4 out of the enlarged end 21;

[0141] S440. When the pushing section 4 is pushed to a position where the tip of the GINA waterstop 83 is 3 - 5 cm away from the end face 3 of the connecting section 3, both groups of jacking jacks 5 are activated, and the two groups of jacking jacks 5 are used to synchronously jack and compress the GINA waterstop 83 to achieve the preliminary pressing between the connecting section 3 and the pushing section 4.

[0142] In step S410, the monitoring system is arranged on the end face of the pushing section 4 and is used to monitor information of the pushing section 4 including the pushing speed, direction, and angle, so as to adjust the pushing action. When it is monitored that the angle deviation of the pushing section 4 is too large to continue pushing, a retraction operation is required. Specifically:

[0143] S411. Stop the output of the jacking jack 5 and the auxiliary jack 93, and adjust the force output by the jacking jack 5 to a pulling force to loosen the pushing section 4 at the original stuck position for subsequent retraction;

[0144] After the pushing section 4 jams and loosens, activate the alignment jack 6 to adjust the angle of the pushing section 4 so that it returns to the set pushing angle;

[0145] S413. Adjust the force output by the auxiliary jack 93 to a thrust force, and this auxiliary jack 93 moves on the temporary slide rail 9 as the pushing section 4 retracts to assist the retraction of the pushing section 4;

[0146] S414. Drain the water in the cavity to the water injection tank 72 through the water outlet pipe 74, control the rise of the water level in the pressure regulating pipe 73 when the pushing section 4 retracts, and keep the water level in the pressure regulating pipe 73 flush with the external water surface.

[0147] Before both groups of pushing jacks 5 are activated in step S440, it further includes:

[0148] S441. The operator dives to check the end face data, clean the end face, ensure that the docking angle is correct and there is no foreign object between the docking end faces, meeting the conditions required for crimping.

[0149] Step S500 is specifically as follows:

[0150] S510. During the process of compressing the GINA water stop 83, the excess water in the joint cavity is simultaneously pressed out, and the connection between the water in the joint cavity and the external water is disconnected, that is, the water pressure in the joint cavity decreases, creating a pressure difference on both sides of the end seal door 41 of the pushing section. Through this pressure difference, the GINA water stop 83 is hydraulically crimped for the first time;

[0151] S520. Use the drain pipe to drain the water between the connecting section 3 and the pushing section 4, further increasing the pressure difference on both sides of the end seal door 41 of the pushing section. Through this increased pressure difference, the GINA water stop 83 is hydraulically crimped for the second time;

[0152] S530. Check the connection condition of the joint cavity, and conduct a through measurement on the connection between the connecting section 3 and the pushing section 4. After checking and measuring and finding no problems, use the temporary tie rod 11 to temporarily connect the two.

[0153] Step S600 is specifically as follows:

[0154] S610. Use the water pump to drain the water in the cavity to the external water environment through the water outlet pipe 74, move the post-welding section steel plate 13 to the enlarged end 21, and weld it between the pushing section 4 and the enlarged end 21 to complete the overall connection of the pushing section 4 and the enlarged section 2;

[0155] S620. Conduct grouting treatment on the connection between the enlarged section 2 and the pushing section 4, and conduct grouting treatment on the connection between the connecting section 3 and the pushing section 4 to connect the enlarged section 2, the connecting section 3, and the pushing section 4 into a whole.

[0156] In step S700, the specific operation of removing the temporary components is as follows:

[0157] S710. Remove the end sealing doors in each section and perform watertight treatment in the bonding cavity;

[0158] S720. Drain the water in the water injection tank 72 and the temporary water tank 10, and then remove them.

[0159] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not used to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. A top-pushing final joint device for an immersed tube tunnel, characterized in that: include: A base cushion layer (1), an expansion section (2) arranged on the base cushion layer (1), a connection section (3) and a push-out section (4); The front end of the enlarged section (2) is provided with an enlarged end (21), the push-out section (4) is arranged inside the enlarged end (21), and a push jack (5) is arranged between the two; The rear end of the enlarged section (2) is provided with an enlarged section end sealing door (22), and the push-out section (4) is provided with a push-out section end sealing door (41). A cavity is formed between the enlarged section (2) and the push-out section (4) through the two end sealing doors, and a water injection system (7) is connected to the cavity; The water injection system (7) comprises a water injection pipe (71), a water injection tank (72), a pressure regulating pipe (73) and a water outlet pipe (74); the water injection pipe (71) connects the water injection tank (72) and the cavity; one end of the pressure regulating pipe (73) is connected to the cavity and the other end passes through the expansion section (2) to above the water surface; the water outlet pipe (74) connects the cavity and external water; the water injection tank (72) is arranged at the rear end of the expansion section (2); The push jacks (5) are divided into two groups, one for normal use and the other for standby use. The two groups are equal in number and are arranged in a staggered manner. Water is injected into the cavity through a water injection system (7) to balance the water pressure on both sides of the sealing door (41) at the end of the push section. The push jacks (5) are used to push the push section (4) out until it is connected to the connecting section (3). A temporary slide rail (9) is also provided on the foundation cushion layer (1) between the enlarged section (2) and the connecting section (3); the bottom of the temporary slide rail (9) is supported by a buttress, and a leveling base is provided between the temporary slide rail (9) and the buttress; The temporary slide rail (9) is also provided with an auxiliary jack (93), and the auxiliary jack (93) is connected to the temporary slide rail (9) via a sliding connection base (94), and the sliding connection base (94) slides on the temporary slide rail (9).

2. The immersed tube tunnel top-pushing final joint device according to claim 1 is characterized in that: The enlarged section (2) is also provided with a stiffening rib plate (23) and a first slideway (24); The stiffening rib plate (23) is a trapezoidal plate, and is arranged between the enlarged end (21) and the rear end of the enlarged section (2); The first slideway (24) is embedded in the bottom plate inside the enlarged end (21), and a second slideway (42) is provided at a corresponding position of the pushing section (4), and the first slideway (24) and the second slideway (42) cooperate with each other.

3. The immersed tube tunnel top-pushing final joint device according to claim 1 is characterized in that: At least two deviation-correcting jacks (6) are provided on the side plates on both sides of the enlarged end (21), and the deviation-correcting jacks (6) are used to apply a lateral force to the ejection section (4) to adjust its ejection direction in real time.

4. The immersed tube tunnel top-pushing final joint device according to claim 1, characterized in that: A water-stop structure (8) is provided between the pushing section (4), the enlarged section (2) and the connecting section (3); The water-stop structure (8) comprises an M water-stop strip (81) provided at the end of the enlarged end (21) and the push-out section (4), an inflatable water-stop strip (82) provided in the connection gap between the enlarged end (21) and the push-out section (4), and a GINA water-stop strip (83) provided at the end of the connection section (3) and the push-out section (4).

5. The immersed tube tunnel top-pushing final joint device according to any one of claims 1 to 4, characterized in that: A combination cavity is formed between the pushing section (4) and the connecting section (3), and a temporary water tank (10) is provided in the combination cavity; The temporary water tank (10) is provided with a crossbeam (101) and a steel support (102), and the temporary water tank (10) is connected to the inner wall of the push-out section (4) into a whole through the crossbeam (101) and the steel support (102).

6. A construction method for a top-pushing final joint device for an immersed tube tunnel as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S100, selecting a window period to float the enlarged section (2) and the pushed-out section (4) as a whole to the installation position of the immersed tube tunnel, and making the enlarged end (21) face the connecting section (3); S200, slowly injecting water into the cavity through the water injection system (7), so that the expansion section (2) and the push-out section (4) are sunk to the installation position, and the locking device between the expansion section (2) and the push-out section (4) is released; S300, continuously injecting water into the cavity to balance the water pressure in the cavity with the water pressure outside the sealing door (41) at the end of the push-out section; S400, starting the push jack (5) to provide thrust to the push-out section (4), and at the same time continuously injecting water into the cavity, so that the water pressure on both sides of the push-out section end sealing door (41) maintains a dynamic balance, so that the push-out section (4) is slowly pushed out until it is initially pressed together with the connecting section (3); S500, draining the water in the connection cavity, achieving compression connection between the connection section (3) and the push-out section (4), and connecting the connection section (3) and the push-out section (4) using a temporary tie rod (11); S600, drain the water in the cavity, weld the rear weld section steel plate (13), perform grouting operation on the connection between the push-out section (4) and the connection section (3) and the expansion section (2), and remove the temporary tie rod (11); S700, complete the grouting of the bottom foundation of the push-out section (4) and the backfilling of the pipe section, remove the temporary components including the expansion section end sealing door (22), the push-out section end sealing door (41) and the temporary water tank (10), and construct the road surface and ancillary facilities.

7. The construction method according to claim 6, characterized in that: During the water injection process, water in the water injection tank (72) is injected into the cavity through the water injection pipe (71) by a water pump. After the cavity is filled with water, the water flows upward into the pressure regulating pipe (73). By adjusting the height of the water in the pressure regulating pipe (73), the water pressure in the cavity is adjusted. In steps S200 and S300, during the process of continuously injecting water into the cavity, the pressure regulating pipe (73) is connected to the external water environment, and the water level in the pressure regulating pipe (73) is flush with the external water surface by gravity injection, so that the water pressure in the cavity is the same as the water pressure outside; In step S200, water is injected into the cavity to overcome the upward buoyancy exerted by the water, so that the expansion section (2) and the push-out section (4) continue to sink to a preset position of the base cushion layer (1) at a slow speed, and the water level in the pressure regulating pipe (73) is maintained below the external liquid surface; In step S300, water is injected until the water level in the pressure regulating pipe (73) is flush with the external liquid surface, and at this time, the water pressure on both sides of the push-out section end sealing door (41) reaches equilibrium.

8. The construction method according to claim 6, characterized in that: In step S400, the push jack (5) is controlled to overcome the initial resistance to realize the initial pushing of the pushing section (4), wherein the initial resistance includes the water resistance at the front end of the pushing section sealing door when the pushing section is pushed out at a uniform speed, the viscous resistance at the rear end of the pushing section sealing door when the pushing section is pushed out at a uniform speed, and the friction between the pushing section and the slide rail; When the push-out section is pushed out at a uniform speed, the water resistance at the front end of the push-out section sealing door is: Among them, F w The water resistance at the front end of the push-out section sealing door. C w is the water flow resistance coefficient, ρ is the density of water, V is the flow rate of water, A is the projection area of ​​the push-out section in the push-out direction; When the push-out section is pushed out at a uniform speed, the viscous resistance at the rear end of the push-out section sealing door is: Among them, D is the viscous resistance at the rear end of the sealing door in the push-out section, C d is the drag coefficient; The friction force between the push-out section and the slide rail is: Among them, D f is the friction between the push-out section and the slide rail, C f is the friction coefficient, L is the length of the push-out section; Wherein, the friction resistance coefficient C f for: where Re is the Reynolds number, and μ is the dynamic viscosity of water; The initial resistance F c for: F c =F w +D+D f ; During this process, water in the water injection tank (72) is continuously injected into the cavity through the water injection pipe (71), so that the water level in the pressure regulating pipe (73) is always kept at the same height as the external liquid level, so as to achieve a dynamic balance of water pressure on both sides of the push-out section end sealing door (41).

9. The construction method according to claim 8, characterized in that: The pushing process of the pushing section (4) also includes: S410, during the pushing process, the posture of the pushing section (4) is monitored by a monitoring system to determine whether the pushing direction thereof is offset; S420, providing a lateral force to the push-out section (4) by means of the deviation-correcting jack (6), and adjusting the push-out direction of the push-out section (4) by means of the lateral force, so as to ensure that the push-out path of the push-out section (4) always remains within the design range; S430, the auxiliary jack (93) slides on the temporary slide rail (9) according to the speed of the push-out section (4), and at the same time provides a pulling force for the push-out section (4), and the auxiliary push jack (5) pushes the push-out section (4) out of the enlarged end (21); S440, when the push-out section (4) is pushed to the point where the nose of the GINA water stop (83) is 3-5 cm away from the end face of the connecting section (3), both sets of push-out jacks (5) are started, and the two sets of push-out jacks (5) are used to push synchronously to compress the GINA water stop (83) to achieve preliminary pressing between the connecting section (3) and the push-out section (4); In step S410, the monitoring system is arranged at the end face of the pushing section (4) to monitor information of the pushing section (4) including the pushing speed, direction and angle, so as to adjust the pushing action. When it is detected that the angle deviation of the pushing section (4) is too large and it cannot continue to push, a retraction operation needs to be performed, specifically: S411, stopping the output of the push jack (5) and the auxiliary jack (93), adjusting the force output by the push jack (5) to a pulling force, so that the push section (4) is loosened at the original stuck position, so as to facilitate subsequent retreat; S412, after the ejection section (4) is stuck and loosened, the deviation correction jack (6) is started to adjust the angle of the ejection section (4) so ​​that it returns to the set ejection angle; S413, adjusting the force output by the auxiliary jack (93) to thrust, and the auxiliary jack (93) moves on the temporary slide rail (9) as the push-out section (4) retreats, thereby assisting the push-out section (4) in retreating; S414, draining the water in the cavity into the water injection tank (72) through the water outlet pipe (74), controlling the increase of the water level in the pressure regulating pipe (73) when the push-out section (4) retreats, and keeping the water level in the pressure regulating pipe (73) flush with the external water surface.

Images