The pulling and closing technology of the final joint pre-pulling and closing system of the inland river immersed tube tunnel

Abstract

The present invention discloses a final joint pre-tensioning system and process for an inland river immersed tube tunnel, and belongs to the technical field of immersed tube tunnel construction. The process includes preparation before pre-tensioning of the pipe segment, a pipe segment pulling and moving stage, and a pipe segment pulling and moving stage. The pipe segment pulling and moving stage includes: adjusting the initial tension of the steel strand, pre-setting the tensioning force on the jack; applying tensioning force step by step by the second group of jacks until the E1 pipe segment slightly slips; each jack is de-oiled, the anchor follows up and anchors, the first group of jacks applies the set tensioning force, the second group of jacks applies tensioning force step by step until the E1 pipe segment starts to slip, and the tensioning force applied by the first group of jacks is kept within 20kN; the sliding distance of the E1 pipe segment is close to the effective stroke of the jack, each jack is de-oiled, the anchor follows up and anchors, and the E1 pipe segment stops sliding. The final joint pre-tensioning system and process for an inland river immersed tube tunnel provided by the present invention can realize the pre-tensioning of the E1 pipe segment and the E2 pipe segment in a dry dock, ensure accurate docking of the pipe segments, and have high construction efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of immersed tube tunnel construction, and in particular relates to a drawing and closing process of a final joint pre-drawing and closing system of an inland river immersed tube tunnel. Background Art

[0002] The immersed tube tunnel is composed of multiple immersed tubes. After the immersed tubes are prefabricated in the prefabrication yard, they are floated to the site for docking and installation. After the immersed tubes are initially positioned and sunk, the horizontal distance between the two immersed tubes is accurately adjusted through the pulling and closing device, so that the adjacent end faces of the pipe section to be installed and the installed pipe section are in contact, completing the initial docking of the immersed tubes. However, the above docking method is only applicable to pipe sections with longer lengths. When one of the pipe sections is shorter, it is difficult to control the orientation of the pipe section during the docking process, resulting in the inability to accurately dock the pipe sections.

[0003] In this regard, Chinese patent CN220686131U discloses a final joint structure for an immersed tube tunnel on land, where the short tube section and the adjacent long tube section are pre-tensioned in advance in the dry dock and floated and sunk together. However, it does not mention how to specifically implement the pre-tensioning of the short tube section and the adjacent long tube section. Summary of the invention

[0004] In view of the deficiencies existing in the related art, the purpose of the present invention is to provide a pulling and closing process of a final joint pre-pulling and closing system of an inland river immersed tube tunnel, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A final joint pre-tensioning system for an inland river immersed tube tunnel is used for pre-tensioning an E1 pipe segment and an E2 pipe segment in a dry dock, wherein the E1 pipe segment is a final joint end pipe segment, and the E2 pipe segment is a long pipe segment adjacent to the E1 pipe segment. The E1 pipe segment and the E2 pipe segment respectively have a first end and a second end, and the second end of the E1 pipe segment and the first end of the E2 pipe segment are tensioned butt ends, comprising:

[0007] A second draw-in crossbeam, the second draw-in crossbeam being installed in a draw-in process hole reserved on the middle partition wall at the first end of the E2 pipe segment;

[0008] a first pull-to-close crossbeam, wherein the first pull-to-close crossbeam is installed at the first end of the E1 pipe section, the first pull-to-close crossbeam is in close contact with the end surface of the first end of the E1 pipe section, and the first pull-to-close crossbeam is opposite to the second pull-to-close crossbeam;

[0009] A fixed anchor, the fixed anchor is installed on the second pulling and closing cross beam;

[0010] A pull-and-close assembly, the pull-and-close assembly comprising a working anchor, a tool anchor, a jack and a steel strand, the working anchor, the tool anchor and the jack being installed on the first pull-and-close crossbeam, one end of the steel strand being connected to the fixed anchor, and the other end being passed through the working anchor, the tool anchor and the jack;

[0011] Among them, there are at least two second pull-to-close beams, one is located at the upper part of the middle partition wall at the first end of the E2 pipe section, and the other is located at the lower part of the middle partition wall at the first end of the E2 pipe section. There are at least two first pull-to-close beams, which are arranged at the upper and lower parts of the first end of the E1 pipe section opposite to the at least two second pull-to-close beams.

[0012] In some of the embodiments, the final joint pre-tensioning system of the inland river immersed tube tunnel also includes a plurality of cable embedded parts, and the plurality of cable embedded parts are arranged one by one at the second end of the E1 pipe segment and the first end of the E2 pipe segment.

[0013] In some of the embodiments, the final joint pre-tensioning system of the inland river immersed tube tunnel also includes a bottom steel plate, which is installed on the bottom plate surface of the E1 pipe section, and a plastic film isolation layer is laid on the lower surface of the bottom steel plate.

[0014] In some of the embodiments, the final joint pre-tensioning system of the inland river immersed tube tunnel also includes a steel guide beam, which is installed on both sides of the E1 pipe section and the E2 pipe section, and a polytetrafluoroethylene plate is installed on the side of the steel guide beam that contacts the side of the pipe section.

[0015] A drawing and closing process of a final joint pre-drawing and closing system of an inland river immersed tube tunnel, using the above-mentioned final joint pre-drawing and closing system of an inland river immersed tube tunnel, comprises the following steps:

[0016] S1. Preparation before pre-tensioning of pipe joints

[0017] When prefabricating the E1 pipe segment and the E2 pipe segment, a pull-in process hole is reserved on the middle partition wall at the first end of the E2 pipe segment. After the pipe segment is prefabricated, the end steel shell, the cable embedded parts, the GINA water stop, the concrete shear key, the first pull-in crossbeam, the second pull-in crossbeam, the fixing anchor and the pull-in assembly are installed at the preset positions on the E1 pipe segment and the E2 pipe segment;

[0018] S2, tube segment traction stage

[0019] S21. Adjust the initial tension of the steel strands so that each strand can be evenly stressed. Each jack has a pre-tensioning force of 20kN.

[0020] S22, the jacks close to the top plate of the pipe section are the first group of jacks, and the jacks close to the bottom plate of the pipe section are the second group of jacks. The first group of jacks maintains the pre-tensioning force unchanged, and the second group of jacks applies tensioning force step by step with 10kN as one level until the E1 pipe section slightly slips;

[0021] After the S23 and E1 pipe sections slip slightly, all the jacks are de-oiled, and the working anchor and tool anchor cooperate to automatically follow up the anchoring. The first group of jacks applies a tension force of 20kN, and the second group of jacks applies tension force step by step with 10kN as the initial value until the E1 pipe section starts to slip. During the slipping process, the tension force applied by the first group of jacks is adjusted at any time to keep it within 20kN;

[0022] When the sliding distance of the S24 and E1 pipe segments approaches the effective stroke of the jacks, the tension of each jack is lowered until all the jacks are de-oiled, the working anchor and the tool anchor are automatically followed up and anchored, and the sliding of the E1 pipe segment is suspended to prepare for the next round of traction operation;

[0023] S3, pipe joint pulling and closing stage

[0024] Pull the E1 pipe section closer to the E2 pipe section. When the E1 pipe section is partially in contact with the GINA waterstop but has not been compressed, adjust the tensioning force of each jack to make the joint surfaces of the E1 pipe section and the E2 pipe section basically parallel. At the same time, each jack applies tensioning force step by step with 10kN as a level to compress the GINA waterstop. When the entire GINA waterstop is evenly and stably compressed to the set requirements, lock each jack.

[0025] In some embodiments, the closing process of the final joint pre-closing system of the inland river immersed tube tunnel further includes step S4, post-processing of the pipe segment pre-closing:

[0026] Confirm that the joints of E1 pipe section and E2 pipe section are not loose or open, install OMEGA waterstop and check for leaks, connect the cables between the second end of E1 pipe section and the first end of E2 pipe section, and then release the tension of each jack. The jacking force of each jack is borne by the cables. After measuring and confirming that the joints of E1 pipe section and E2 pipe section are not loose or open, remove each jack and seal the tensioning and closing process holes reserved on the middle partition wall at the first end of E2 pipe section according to construction requirements.

[0027] In some embodiments, step S4 also includes: after confirming that the deformation of the joints of the E1 pipe section and the E2 pipe section is stable, installing steel shear keys and temporary steel pads between the concrete shear keys of the E1 pipe section and the E2 pipe section, and sticking a layer of hard rubber on the upper surface of the temporary steel pads.

[0028] In some of the embodiments, after the E1 pipe segment and the E2 pipe segment are placed, the hard rubber layer is melted away by overheating, the temporary steel pad is taken out, and the rubber bearing is installed.

[0029] In some of the embodiments, in step S1, a buried end steel shell is installed at the second end of the E1 pipe segment, the first end of the E2 pipe segment and the second end of the E2 pipe segment, and a GINA waterstop is installed at the second end of the E1 pipe segment; a concrete shear key is installed in the middle part of the middle partition wall at the first end of the E2 pipe segment, and concrete shear keys are installed at the upper and lower parts of the middle partition wall at the second end of the E1 pipe segment.

[0030] In some of the embodiments, in step S23 and step S24, the pulling speed of the E1 pipe segment during the pulling process and the accumulated stroke difference of the jacks are monitored to keep the pulling speed within a preset speed range. When the accumulated stroke difference of the jacks exceeds the set value, the order in which the forces are applied by the jacks is adjusted to ensure smooth pulling of the E1 pipe segment.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The drawing and closing process of the final joint pre-drawing and closing system of the inland river immersed tube tunnel provided by the present invention includes the preparation before the pre-drawing and closing of the S1 pipe segment, the pulling and moving stage of the S2 pipe segment and the drawing and closing stage of the S3 pipe segment. The first group of jacks and the second group of jacks cooperate to apply different tensioning forces to realize the pulling and moving of the pipe segment. When the E1 pipe segment is pulled and moved to a part of the contact with the GINA waterstop but not yet compressed, the tensioning force of each jack is adjusted to make the joint surfaces of the E1 pipe segment and the E2 pipe segment basically parallel, and then the GINA waterstop compression operation is performed to complete the pre-drawing and closing of the E1 pipe segment and the E2 pipe segment in the dry dock, which can ensure the accurate docking of the pipe segments and improve the construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0034] Figure 1 It is a schematic diagram of preparation before pre-pull-and-pull of a pipe segment in one embodiment of a pull-and-pull process of a final joint pre-pull-and-pull system for an inland river immersed tube tunnel of the present invention;

[0035] Figure 2 for Figure 1 A top view of

[0036] Figure 3 It is a schematic diagram of the pipe segment pulling and pulling-in stages of one embodiment of the pulling-in process of the final joint pre-pulling-in system of the inland river immersed tube tunnel of the present invention;

[0037] Figure 4 for Figure 3 A top view of

[0038] Figure 5It is a schematic diagram of the post-processing of the pre-tensioning of the pipe segment in one embodiment of the tensioning process of the final joint pre-tensioning system of the inland river immersed tube tunnel of the present invention;

[0039] Figure 6 for Figure 5 A top view of

[0040] Figure 7 It is a schematic diagram of the arrangement of the pre-embedded parts of the cable at the end face of the pipe segment of an embodiment of the drawing and closing process of the final joint pre-drawing and closing system of the inland river immersed tube tunnel of the present invention;

[0041] Figure 8 It is a schematic diagram of the arrangement of the first end horizontal limit beam and the steel shear key of the E2 pipe segment of one embodiment of the drawing and closing process of the final joint pre-drawing and closing system of the inland river immersed tube tunnel of the present invention;

[0042] Fig. 9 It is a schematic diagram of the arrangement of the second end horizontal limit beam and the steel shear key of the E1 pipe segment of one embodiment of the drawing and closing process of the final joint pre-drawing and closing system of the inland river immersed tube tunnel of the present invention;

[0043] Fig.10 for Figure 8 AA section view;

[0044] Fig.11 for Fig.10 An enlarged schematic diagram of the C portion;

[0045] Fig.12 for Fig. 9 BB cross-section diagram.

[0046] In the figure:

[0047] 1. E1 pipe section; 2. E2 pipe section; 3. Top plate; 4. Bottom plate; 5. Middle partition wall; 6. Side wall; 7. Cable embedded parts; 71. Cable; 8. Concrete shear key; 9. Closing process hole; 10. First closing beam; 11. Second closing beam; 12. Fixed anchor; 13. Working anchor; 14. Tool anchor; 15. Jack; 16. Steel strand; 17. OMEGA waterstop; 18. Horizontal limit beam; 19. Steel end sealing door; 20. Steel shear key; 21. Temporary steel pad; 22. Steel guide beam; 23. PTFE plate. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0049] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying 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 should not be understood as a limitation on the present invention.

[0050] 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.

[0051] Embodiment 1:

[0052] See attached Figures 1 to 12 , a schematic embodiment of the final joint pre-tensioning system of the inland river immersed tube tunnel proposed in the present invention is given, the final joint pre-tensioning system of the inland river immersed tube tunnel comprises a second tensioning beam 11, a first tensioning beam 10, a fixed anchor 12 and a tensioning assembly, wherein the tensioning assembly comprises a working anchor 13, a tool anchor 14, a jack 15 and a steel strand 16.

[0053] The final joint pre-tensioning system for the inland river immersed tube tunnel provided in this embodiment is used for pre-tensioning the E1 pipe section 1 and the E2 pipe section 2 in the dry dock. The E1 pipe section is the final joint end pipe section, and the E2 pipe section is a long pipe section adjacent to the E1 pipe section. The E1 pipe section 1 and the E2 pipe section 2 have a first end and a second end respectively, and the second end of the E1 pipe section 1 and the first end of the E2 pipe section 2 are the tensioning butt ends. The second tensioning crossbeam 11 is installed in the tensioning process hole 9 reserved on the middle partition wall at the first end of the E2 pipe section 2, and the first tensioning crossbeam 10 is installed at the first end of the E1 pipe section 1. The first tensioning crossbeam 10 is in close contact with the end face of the first end of the E1 pipe section 1. The first tensioning crossbeam 10 and the second tensioning crossbeam 11 are opposite in position, so that the components used for tensioning can be located at corresponding horizontal positions to ensure the stability of the tensioning process.

[0054] The fixed anchor 12 is installed on the second pull-close beam 11, the working anchor 13, the tool anchor 14 and the jack 15 in the pull-close assembly are installed on the first pull-close beam 10, one end of the steel strand 16 is connected to the fixed anchor 12, and the other end is passed through the working anchor 13, the tool anchor 14 and the jack 15. The fixed anchor 12 and the pull-close assembly cooperate to realize the pulling and moving of the pipe section.

[0055] In order to better control the pulling and closing process of the E1 pipe section 1 and the E2 pipe section 2, at least two second pulling and closing beams 11 are provided, one is located at the upper part of the middle partition wall at the first end of the E2 pipe section 2, and the other is located at the lower part of the middle partition wall at the first end of the E2 pipe section 2. At least two first pulling and closing beams 10 are provided, which are arranged at the upper and lower parts of the first end of the E1 pipe section opposite to the at least two second pulling and closing beams 11. In this embodiment, two of the second pulling and closing beams 11 and two of the first pulling and closing beams 10 are provided, and each of the first pulling and closing beams 10 is provided with four jacks 15, for a total of eight jacks 15. The eight jacks 15 are grouped, wherein the jacks 15 close to the pipe joint top plate 3 are the first group of jacks 15, and the jacks 15 close to the pipe joint bottom plate 4 are the second group of jacks 15. Thus, during the pulling and closing process, the order and magnitude of the force applied by the first group of jacks 15 and the second group of jacks 15 can be adjusted according to the actual pulling and closing conditions, to ensure that the pre-pulling work can be completed smoothly and accurately.

[0056] After the pre-tensioning work is completed, the fixed anchor 12 and the tensioning assembly will be removed for subsequent construction work. During this process, it is still necessary to ensure that the docking ends of the E1 pipe segment 1 and the E2 pipe segment 2 are stable and not separated. Therefore, the final joint pre-tensioning system of the inland river immersed tube tunnel also includes multiple cable embedded parts 7, and the multiple cable embedded parts 7 are arranged one by one at the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2.

[0057] See attached Figure 7 , is a schematic diagram of the arrangement of the cable embedded parts 7 on the end face of the pipe segment in this embodiment. In this embodiment, thirty-six cable embedded parts 7 are respectively provided corresponding to the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2, of which eighteen cable embedded parts 7 are provided on the top plate of the pipe segment, and the other eighteen cable embedded parts 7 are provided on the bottom plate of the pipe segment. Before removing the fixing anchor 12 and the pulling assembly, the cable 71 is connected between the corresponding cable embedded parts 7 so that the top force of each jack 15 is transferred to the cable 71 to ensure that the butt ends of the E1 pipe segment 1 and the E2 pipe segment 2 are stable and not separated.

[0058] In order to reduce friction and improve the working efficiency of pulling together the E1 pipe segment 1 and the E2 pipe segment 2, in this embodiment, the final joint pre-pulling system of the inland river immersed tube tunnel also includes a bottom steel plate, which is installed on the bottom plate surface of the E1 pipe segment 1. The lower surface of the bottom steel plate is coated with butter and a plastic film isolation layer is laid. Considering the practical application, the laid plastic film isolation layer is 2 mm thick.

[0059] The final joint pre-tensioning system of the inland river immersed tube tunnel also includes a steel guide beam 22, which is installed on both sides of the E1 pipe section 1 and the E2 pipe section 2. The steel guide beam 22 plays a guiding and limiting role in the process of pulling the E1 pipe section 1 and the E2 pipe section 2 together to improve the accuracy of the pulling and docking. Therefore, effective measures must be taken during the construction process to ensure that the steel guide beam 22 is firm and stable in the horizontal direction. In order to reduce the friction resistance of the steel guide beam 22 and the side surface of the pipe section, in this embodiment, a polytetrafluoroethylene plate 23 is installed on the side of the steel guide beam 22 that contacts the side surface of the pipe section. Considering the actual application, the thickness of the installed polytetrafluoroethylene plate 23 is 20 mm.

[0060] In order to monitor the pre-tensioning process of the E1 pipe segment 1 and the E2 pipe segment 2, and timely discover and adjust when the pulling deviation occurs during the pre-tensioning process, the final joint pre-tensioning system of the inland river immersed tube tunnel also includes monitoring points, which are symmetrically arranged at the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2. In this embodiment, four monitoring points are arranged on the pipe segment top plate 3, two monitoring points are arranged on the side walls 6 on both sides of the pipe segment, and four monitoring points are arranged on the pipe segment bottom plate 4. The specific location of each monitoring point should be determined according to the actual construction situation to ensure that it is obvious, easy to measure, and representative.

[0061] In the above-mentioned schematic embodiment, the final joint pre-tensioning system of the inland river immersed tube tunnel includes a second tensioning beam, a first tensioning beam, a fixed anchor and a tensioning assembly. The fixed anchor and the tensioning assembly cooperate to complete the pre-tensioning of the E1 pipe section and the E2 pipe section in the dry dock. The multiple jacks provided in the tensioning assembly are grouped, and the order and size of the force applied by each group of jacks can be adjusted during the tensioning process according to the actual tensioning situation, thereby ensuring accurate docking of the pipe sections and high construction efficiency.

[0062] Embodiment 2:

[0063] The present embodiment provides a pulling and closing process of a final joint pre-pulling system for an inland river immersed tube tunnel, adopting the final joint pre-pulling system for an inland river immersed tube tunnel described in Example 1. The pulling and closing process of the final joint pre-pulling system for an inland river immersed tube tunnel includes S1 pipe segment pre-pulling preparation, S2 pipe segment pulling and moving stage, and S3 pipe segment pulling and closing stage.

[0064] S1. Preparation before pre-tensioning of pipe joints

[0065] When prefabricating the E1 pipe segment 1 and the E2 pipe segment 2, a pull-in process hole 9 is reserved on the middle partition wall at the first end of the E2 pipe segment 2. After the pipe segment is prefabricated, the end steel shell, the cable embedded part 7, the GINA water stop, the concrete shear key 8, the first pull-in cross beam 10, the second pull-in cross beam 11, the fixing anchor 12 and the pull-in assembly are installed at the preset positions on the E1 pipe segment 1 and the E2 pipe segment 2;

[0066] S2, tube segment traction stage

[0067] S21, adjust the initial tension of the steel strand 16, so that each bundle of steel strand 16 can be uniformly stressed together, each jack 15 pre-tensioning force 20kN;

[0068] S22, assuming that the jacks 15 close to the pipe joint top plate 3 are the first group of jacks 15, and the jacks 15 close to the pipe joint bottom plate 4 are the second group of jacks 15. The first group of jacks 15 maintain the pre-tensioning force unchanged, and the second group of jacks 15 apply the tensioning force step by step with 10 kN as one level until the E1 pipe joint 1 slips slightly; step S22 can complete overcoming static friction.

[0069] After the S23 and E1 pipe segments 1 have slightly slipped, all the jacks 15 are de-oiled, and the working anchor 13 and the tool anchor 14 cooperate to automatically follow up the anchoring. The first group of jacks 15 applies a tensioning force of 20 kN, and the second group of jacks 15 applies a tensioning force in steps of 10 kN with 20 kN as the initial value until the E1 pipe segment 1 starts to slip. During the slipping process, the tensioning force applied by the first group of jacks 15 is adjusted at any time to be kept within 20 kN.

[0070] S24, when the sliding distance of the E1 pipe segment 1 approaches the effective stroke of the jack 15, the tension of each jack 15 is lowered until all the jacks 15 are fully de-oiled, the working anchor 13 and the tool anchor 14 cooperate to automatically follow up the anchoring, and the E1 pipe segment 1 stops sliding to prepare for the next round of pulling and moving operation. By repeating steps S22 and S23, the cyclic pulling and moving of the E1 pipe segment 1 is realized, and the pulling and moving work is performed in multiple times to ensure accuracy, and timely adjustment is made when the E1 pipe segment 1 has a sliding deviation.

[0071] S3, pipe joint pulling and closing stage

[0072] Pull and move the E1 pipe section 1 close to the E2 pipe section 2. When the E1 pipe section 1 is partially in contact with the GINA waterstop but has not been compressed, adjust the tension of each jack 15 to make the joint surface of the E1 pipe section 1 and the E2 pipe section 2 basically parallel. At the same time, each jack 15 applies tension step by step with 10kN as a level to compress the GINA waterstop steadily, graded and evenly. When the GINA waterstop is uniformly and stably compressed to the set requirements, lock each jack 15. In this embodiment, after the GINA waterstop is uniformly and stably compressed by 80mm, immediately lock each jack 15 to ensure that the joint does not loosen and rebound.

[0073] In this embodiment, there are four pulling and closing process holes 9, and each of the four pairs of pulling and closing beams on the E1 pipe section 1 and the E2 pipe section 2 is provided with a group of jacks 15, totaling two groups, each group of 4 jacks 15. The effective tension of each jack 15 is not less than 3000kN, and the effective stroke should be not less than 500mm. Corresponding to each jack 15, a bundle of high-strength and low-relaxation steel strands 16 is provided, and the specification of the steel strands 16 is selected as 12-Φj15.24, and the anchor is selected as the GVM series prestressed anchor in the bridge engineering. The working anchor 13 and the tool anchor 14 installed on the first pulling and closing beam 10 on the E1 pipe section 1 are 8-hole working anchors 13 and tool anchors 14, and the fixed anchor 12 installed on the second pulling and closing beam 11 on the E2 pipe section 2 is an 8-hole fixed anchor 12, which can be selected as a P anchor.

[0074] In order to ensure smooth subsequent construction, the tensioning process of the final joint pre-tensioning system of the inland river immersed tube tunnel also includes step S4 pipe segment pre-tensioning post-processing: confirm that the joints of the E1 pipe segment 1 and the E2 pipe segment 2 are not loose or open, install the OMEGA waterstop 17 and perform leak detection, connect the cable 71 between the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2, and then release the tensioning force of each jack 15, and the jacking force of each jack 15 is borne by the cable 71. After measuring and confirming that the joints of the E1 pipe segment 1 and the E2 pipe segment 2 are not loose or open, remove each jack 15, and seal the tensioning process hole 9 reserved on the middle partition wall 5 at the first end of the E2 pipe segment 2 according to construction requirements.

[0075] Step S4 also includes: constructing a horizontal limit beam 18 at the middle corridor between the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2, installing a steel end sealing door 19 at the first end of the E1 pipe segment 1, and measuring and recording the actual final compression of the GINA waterstop.

[0076] Step S4 also includes: after confirming that the deformation of the joint of E1 pipe section 1 and E2 pipe section 2 is stable, install the steel shear key 20 and the temporary steel pad 21 between the concrete shear key 8 of E1 pipe section 1 and E2 pipe section 2, and stick a layer of 1 cm thick hard rubber on the upper surface of the temporary steel pad 21. The height of the temporary steel pad 21 should be determined according to the actual distance between the steel shear keys 20 after the E1 pipe section 1 and E2 pipe section 2 are pulled together stably. After the E1 pipe section 1 and E2 pipe section 2 are placed, melt the 1 cm thick hard rubber layer by overheating, take out the temporary steel pad 21, and install the rubber bearing. Here, the 1 cm thick hard rubber stuck on the upper surface of the temporary steel pad 21 is of the same material as the rubber bearing installed after the temporary steel pad 21 is taken out.

[0077] In step S1, various embedded parts of the connecting end faces of the E1 pipe segment 1 and the E2 pipe segment 2 are accurately installed, an embedded end steel shell is installed at the second end of the E1 pipe segment 1, the first end of the E2 pipe segment 2 and the second end of the E2 pipe segment 2, an embedded cable embedded part 7 is installed at the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2, and a GINA waterstop is installed at the second end of the E1 pipe segment 1; a concrete shear key 8 is installed in the middle of the middle partition wall 5 at the first end of the E2 pipe segment 2, and concrete shear keys 8 are installed at the upper and lower parts of the middle partition wall 5 at the second end of the E1 pipe segment 1. A second pulling and closing beam 11 is installed in the pulling and closing process hole 9 reserved on the middle partition wall 5 at the first end of the E2 pipe segment 2, and a first pulling and closing beam 10 is installed at a position corresponding to the second pulling and closing beam 11 on the first end of the E1 pipe segment 1. The first pulling and closing beam 10 is in close contact with the end surface of the first end of the E1 pipe segment 1. A working anchor 13, a tool anchor 14 and a jack 15 are installed on the first pulling and closing beam 10, and a fixed anchor 12 is installed on the second pulling and closing beam 11. One end of the steel strand 16 is connected to the fixed anchor 12, and the other end is penetrated by the working anchor 13, the tool anchor 14 and the jack 15.

[0078] In step S1, steel guide beams 22 are installed on both sides of the E1 pipe segment 1 and the E2 pipe segment 2, and a 20 mm thick polytetrafluoroethylene plate 23 is installed on the side of the steel guide beam 22 that contacts the side of the pipe segment to reduce friction and facilitate the pulling and moving of the E1 pipe segment 1. During the construction process, effective measures should be taken to ensure that the steel guide beams 22 are firm and stable in the horizontal direction, so that the steel guide beams 22 can guide the E1 pipe segment 1 during the pulling and moving process of the E1 pipe segment 1.

[0079] In step S1, monitoring points are symmetrically arranged at the second end of the E1 pipe segment 1 and the first end of the E2 pipe segment 2, wherein four monitoring points are arranged on the top plate 3, two monitoring points are arranged on the side walls 6 on both sides, and four monitoring points are arranged on the bottom plate 4. The specific location of each monitoring point should be determined according to the actual construction situation to ensure that it is obvious, easy to measure, and representative. The pre-tensioning process of the E1 pipe segment 1 and the E2 pipe segment 2 is monitored, and timely adjustments are made when deviations occur.

[0080] In step S23 and step S24, the pulling speed of the E1 pipe segment 1 and the accumulated stroke difference of the jack 15 during the pulling process are monitored to keep the pulling speed within a preset speed range. When the accumulated stroke difference of the jack 15 exceeds the set value, the order of applying the force of each jack is adjusted to ensure smooth pulling of the E1 pipe segment. In this embodiment, the pulling speed is maintained within 300 mm / min. When the accumulated stroke difference of the jack 15 exceeds 10 mm, the order of applying the force is adjusted to ensure smooth pulling of the E1 pipe segment 1.

[0081] In order to reduce friction, make E1 pipe segment 1 easier to be pulled, and improve the working efficiency of pulling together E1 pipe segment 1 and E2 pipe segment 2, in step S1, a bottom steel plate is installed on the bottom plate surface of E1 pipe segment 1, butter is applied on the lower surface of the bottom steel plate, and a 2mm thick plastic film isolation layer is laid.

[0082] After the E1 pipe segment 1 and the E2 pipe segment 2 are pre-tensioned in the dry dock, they are floated and sunk together, and the thrust wall at the dock entrance and the secondary water-stop steel cofferdam on the upper part of the E1 pipe segment 1 are constructed. The dock is drained and the stress of the cable 71 and the compression of the GINA waterstop are monitored. After the construction of the buried section is completed and the top of the immersed pipe section is backfilled and covered, the cable 71 between the E1 pipe segment 1 and the E2 pipe segment 2 is cut. It should be noted that the cable 71 should be cut symmetrically in sections, and anti-corrosion protection should be carried out. The stress condition is monitored at all times, and finally the horizontal limit beam 18 is chiseled out.

[0083] In the above-mentioned schematic embodiment, the drawing and closing process of the final joint pre-drawing and closing system of the inland river immersed tube tunnel includes the S1 pipe segment pre-drawing and closing preparation, the S2 pipe segment pulling and closing stage and the S3 pipe segment pulling and closing stage. The first group of jacks and the second group of jacks cooperate to apply different tensioning forces to realize the pulling and closing of the pipe segment. When the E1 pipe segment is pulled and closed to partially contact with the GINA waterstop but not yet compressed, the tensioning force of each jack is adjusted to make the joint surfaces of the E1 pipe segment and the E2 pipe segment basically parallel, and then the GINA waterstop compression operation is performed to complete the pre-drawing and closing of the E1 pipe segment and the E2 pipe segment in the dry dock, which can ensure the accurate docking of the pipe segments and improve construction efficiency.

[0084] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0085] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A closing process of a final joint pre-closing system for an inland river immersed tube tunnel, used for pre-closing an E1 pipe segment and an E2 pipe segment in a dry dock, wherein the E1 pipe segment is a final joint end pipe segment, and the E2 pipe segment is a long pipe segment adjacent to the E1 pipe segment. The E1 pipe segment and the E2 pipe segment respectively have a first end and a second end, and the second end of the E1 pipe segment and the first end of the E2 pipe segment are closing butt ends, characterized in that: The final joint pre-tensioning system of the inland river immersed tube tunnel comprises: A second draw-in crossbeam, the second draw-in crossbeam being installed in a draw-in process hole reserved on the middle partition wall at the first end of the E2 pipe segment; a first pull-to-close crossbeam, wherein the first pull-to-close crossbeam is installed at the first end of the E1 pipe section, the first pull-to-close crossbeam is in close contact with the end surface of the first end of the E1 pipe section, and the first pull-to-close crossbeam is opposite to the second pull-to-close crossbeam; A fixed anchor, the fixed anchor is installed on the second pulling and closing cross beam; A pull-and-close assembly, the pull-and-close assembly comprising a working anchor, a tool anchor, a jack and a steel strand, the working anchor, the tool anchor and the jack being installed on the first pull-and-close crossbeam, one end of the steel strand being connected to the fixed anchor, and the other end being passed through the working anchor, the tool anchor and the jack; A plurality of cable embedded parts, wherein the plurality of cable embedded parts are arranged at the second end of the E1 pipe section and the first end of the E2 pipe section in a one-to-one correspondence; There are at least two second pull-together cross beams, one located at the upper part of the middle partition wall at the first end of the E2 pipe section, and the other located at the lower part of the middle partition wall at the first end of the E2 pipe section. There are at least two first pull-together cross beams, which are located at the upper part and the lower part of the first end of the E1 pipe section opposite to the at least two second pull-together cross beams. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel comprises the following steps: S1. Preparation before pre-tensioning of pipe joints When prefabricating the E1 pipe segment and the E2 pipe segment, a pull-in process hole is reserved on the middle partition wall at the first end of the E2 pipe segment. After the pipe segment is prefabricated, the end steel shell, the cable embedded parts, the GINA water stop, the concrete shear key, the first pull-in crossbeam, the second pull-in crossbeam, the fixing anchor and the pull-in assembly are installed at the preset positions on the E1 pipe segment and the E2 pipe segment; S2, tube segment traction stage S21. Adjust the initial tension of the steel strands so that each strand can be evenly stressed. Each jack has a pre-tensioning force of 20kN. S22, the jacks close to the top plate of the pipe section are the first group of jacks, and the jacks close to the bottom plate of the pipe section are the second group of jacks. The first group of jacks maintains the pre-tensioning force unchanged, and the second group of jacks applies tensioning force step by step with 10kN as one level until the E1 pipe section slightly slips; After the S23 and E1 pipe sections slip slightly, all the jacks are de-oiled, and the working anchor and tool anchor cooperate to automatically follow up the anchoring. The first group of jacks applies a tension force of 20kN, and the second group of jacks applies tension force step by step with 10kN as the initial value until the E1 pipe section starts to slip. During the slipping process, the tension force applied by the first group of jacks is adjusted at any time to keep it within 20kN; When the sliding distance of the S24 and E1 pipe segments approaches the effective stroke of the jacks, the tension of each jack is lowered until all the jacks are de-oiled, the working anchor and the tool anchor are automatically followed up and anchored, and the sliding of the E1 pipe segment is suspended to prepare for the next round of traction operation; S3, pipe joint pulling and closing stage Pull the E1 pipe section closer to the E2 pipe section. When the E1 pipe section is partially in contact with the GINA waterstop but has not been compressed, adjust the tensioning force of each jack to make the joint surfaces of the E1 pipe section and the E2 pipe section basically parallel. At the same time, each jack applies tensioning force step by step with 10kN as a level to compress the GINA waterstop. When the entire GINA waterstop is evenly and stably compressed to the set requirements, lock each jack.

2. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 1 is characterized in that: The final joint pre-tensioning system of the inland river immersed tube tunnel also includes a bottom steel plate, which is installed on the bottom plate surface of the E1 pipe section, and a plastic film isolation layer is laid on the lower surface of the bottom steel plate.

3. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 1 is characterized in that: The final joint pre-tensioning system of the inland river immersed tube tunnel also includes a steel guide beam, which is installed on both sides of the E1 pipe section and the E2 pipe section, and a polytetrafluoroethylene plate is installed on the side of the steel guide beam that contacts the side of the pipe section.

4. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 1 is characterized in that: The step S4 is also included, and the pipe segment is pre-stretched and then processed: Confirm that the joints of E1 pipe section and E2 pipe section are not loose or open, install OMEGA waterstop and check for leaks, connect the cables between the second end of E1 pipe section and the first end of E2 pipe section, and then release the tension of each jack. The jacking force of each jack is borne by the cables. After measuring and confirming that the joints of E1 pipe section and E2 pipe section are not loose or open, remove each jack and seal the tensioning and closing process holes reserved on the middle partition wall at the first end of E2 pipe section according to construction requirements.

5. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 4 is characterized in that: Step S4 also includes: after confirming that the deformation of the joints of the E1 pipe section and the E2 pipe section is stable, installing steel shear keys and temporary steel pads between the concrete shear keys of the E1 pipe section and the E2 pipe section, and sticking a layer of hard rubber on the upper surface of the temporary steel pad.

6. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 5, characterized in that: After the E1 and E2 pipe segments are sunk, the hard rubber layer is melted away by overheating, the temporary steel pads are removed, and the rubber bearings are installed.

7. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 1, characterized in that: In step S1, a buried end steel shell is installed at the second end of the E1 pipe segment, the first end of the E2 pipe segment and the second end of the E2 pipe segment, and a GINA waterstop is installed at the second end of the E1 pipe segment; a concrete shear key is installed in the middle of the middle partition wall at the first end of the E2 pipe segment, and concrete shear keys are installed at the upper and lower parts of the middle partition wall at the second end of the E1 pipe segment.

8. The closing process of the final joint pre-closing system of the inland river immersed tube tunnel according to claim 1, characterized in that: In step S23 and step S24, the pulling speed of the E1 pipe segment and the accumulated stroke difference of the jacks during the pulling process are monitored to keep the pulling speed within a preset speed range. When the accumulated stroke difference of the jacks exceeds the set value, the order in which the forces are applied by the jacks is adjusted to ensure smooth pulling of the E1 pipe segment.

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