Marine cable bent tower component construction method

Abstract

The invention relates to the technical field of bridge construction, in particular to an offshore cable bent tower component construction method which comprises the steps that S1, a cross beam profile steel framework, a tower column profile steel framework, cross beam steel bars, tower column steel bars, an inner die system and a bottom die system are preprocessed; s2, mounting the tower column profile steel framework on the tower column; s3, an assembling bracket is installed on the inner side of the tower column profile steel framework, and a jack is arranged at the top of the assembling bracket; s4, the cross beam profile steel framework is installed on the assembling bracket; s5, the cross beam profile steel framework and the tower column profile steel framework are closed; s6, disassembling and assembling the bracket, and completing system conversion; s7, pouring for the first time; s8, part of the prestressed steel beams are tensioned, and secondary pouring is conducted; and S9, the residual prestressed steel beams are tensioned, the side formworks, the inner formwork system and the bottom formwork system are dismantled, and construction is completed. According to the construction method, temporary structure consumables and construction machinery cost are saved, the high-altitude operation difficulty and risk are reduced, the construction period is effectively shortened, and the construction progress is accelerated.

Description

Technical Field

[0001] The invention relates to the technical field of bridge construction, and in particular to a componentized construction method for an offshore cable tower. Background Art

[0002] Cable towers are important load-bearing structures for cable-stayed bridges and suspension bridges. The main function of cable towers is to support and transfer the loads from the bridge deck and cable net, and to transfer the vertical loads generated by the bridge deck and the tension from the cables to the foundation to ensure the stability and safety of the bridge. The height of the cable tower is usually related to the main span of the bridge. The ratio of the maximum span of the main beam to the height of the cable tower is generally 3.1-6.3, with an average of about 5.0.

[0003] There are many types of cable tower structures, one of which is a portal cable tower. The upper and lower beams are set between the tower columns of this type of cable tower to form a portal frame structure. The crossbeam construction can adopt the cast-in-place method of brackets. The cast-in-place method of brackets is a method of setting up brackets on the bridge position and completing the processes of supporting formwork, tying steel bars, pouring concrete, and prestressing on the brackets to build continuous beams. In the process of using the cast-in-place method of brackets for crossbeam construction, the support system of the brackets often includes ground-mounted steel pipe brackets and suspended pre-buried brackets. On the one hand, as the span of the bridge increases, the cable towers are getting higher and higher, which makes the ground-mounted steel pipe brackets have problems such as poor stability, large construction consumables, long construction period, and difficult removal and turnover. On the other hand, although the suspended pre-buried bracket can make full use of the completed structure as a load-bearing structure and save the amount of temporary structural materials, the force of this suspended pre-buried bracket is generally large, and the force conditions at the connection nodes of each pole position of the bracket are more complicated, which is easy to cause instability due to excessive local stress.

[0004] In summary, both traditional construction methods in the prior art consume a large amount of support materials, have many nodes, and the welding quality is difficult to guarantee. They need to be dismantled after the construction is completed. In addition, the risk of high-altitude operations is high, the construction period is long, and the construction cost is high. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present application provides a componentized construction method for an offshore cable tower.

[0006] The component construction method of an offshore cable tower provided by the present invention adopts the following technical solution:

[0007] A componentized construction method for an offshore cable tower comprises the following steps:

[0008] S1: Component processing of crossbeam steel frame, tower column steel frame, crossbeam steel bars, tower column steel bars, inner mold system and bottom mold system;

[0009] S2: Install the tower column steel frame on the tower column of the cable tower;

[0010] S3: Install an assembly bracket on the inner side of the tower column steel frame, and sequentially set a three-way jack and a shoulder pole beam on the top of the assembly bracket;

[0011] S4: Install the crossbeam steel frame on the shoulder beam of the assembled bracket;

[0012] S5: Join the crossbeam steel frame and the tower column steel frame, and remove the three-way jack;

[0013] S6: Remove the assembly bracket and complete the system conversion;

[0014] S7: first pouring;

[0015] S8: tensioning some prestressed steel tendons and then pouring for the second time;

[0016] S9: Tension the remaining prestressed steel strands, remove the formwork, and complete the construction of the tower beams.

[0017] Preferably, in S1, the crossbeam steel frame, tower column steel frame, crossbeam steel bars, tower column steel bars, inner mold system and bottom mold system are pre-processed in the factory to form components; wherein, the crossbeam steel frame and the tower column steel frame both include a horizontal connection system, a vertical connection system and a chord rod which are connected to each other, the chord rod includes an upper chord rod and a lower chord rod, the horizontal connection system is welded to the chord rod, and the vertical connection system is bolted to the chord rod; the bottom mold system is respectively composed of a steel panel, a plurality of ribs, a plurality of pads and a plurality of bottom beams from top to bottom, the ribs and the bottom beams are tightened by pads, the plurality of bottom beams are perpendicular to the ribs, and the plurality of bottom beams are spaced apart along the length direction of the ribs, the lower chord rod of the crossbeam steel frame is provided with a lifting bracket, a suspension rod is connected between the lifting bracket of the crossbeam steel frame and the bottom beam of the bottom mold system, the upper end of the suspension rod is anchored to the lifting bracket, and the lower end of the suspension rod is anchored to the bottom beam, so that the bottom mold system is connected to the bottom of the crossbeam steel frame.

[0018] Preferably, in S2, the crossbeam steel frame and the tower column steel frame are shipped to the construction site by sea, the tower column steel frame is hoisted onto the installed tower column segment on the cable tower by means of a floating crane, and is welded after being fine-tuned to the designed position; the reserved section steel frame is measured and cut on site, the reserved section steel frame is welded to the installed tower column steel frame, and the stiffening plate is welded at the connection position between the reserved section steel frame and the tower column steel frame.

[0019] Preferably, in S3, an assembly bracket is welded on site, the assembly bracket including interconnected cross bars and short diagonal bars, and then the assembly bracket is hoisted to the inner side of the tower column steel frame and welded at the designed position, and then a three-way jack is placed on the cross bar of the assembly bracket, and then a shoulder pole beam is installed on the three-way jack.

[0020] Preferably, in S4, the beam steel frame is hoisted onto the shoulder beam of the assembly bracket by means of a floating crane, the beam steel frame is fine-tuned to the designed position by a three-way jack, and then the bottom formwork system is fixed to the tower column by a climbing cone.

[0021] Preferably, in S5, the three-way jack is lifted to a certain height, cushion blocks and unloading blocks are placed on the cross bars of the assembly bracket in sequence, and then the three-way jack is returned to the top, and then the three-way jack is removed; the distance between the crossbeam steel frame and the reserved section steel frame is measured on site, and after the joint section is processed on site, the joint section is hoisted between the crossbeam steel frame and the reserved section steel frame, and the crossbeam steel frame and the reserved section steel frame are welded into a whole using the joint section to complete the joint.

[0022] Preferably, in S6, the unloading blocks are removed to disengage the crossbeam steel frame, and then the assembly brackets are removed, and after the removal is completed, the long diagonal rods are installed to complete the system conversion.

[0023] Preferably, in S7, the remaining steel bars and prestressed steel strands are tied, the side formwork is installed for the first time, and after the installation is completed, the first layer of concrete is poured.

[0024] Preferably, in S8, after the first layer of concrete reaches the design strength after curing, some prestressed steel strands are tensioned, and after the tensioning is completed, the side formwork is installed for a second time, and after the installation is completed, the second layer of concrete is poured.

[0025] Preferably, in S9, after the second layer of concrete reaches the design strength after curing, the remaining prestressed steel strands are tensioned, the side formwork, the inner formwork system and the bottom formwork system are removed, and the construction of the cable tower beam is completed.

[0026] The beneficial effects of the present invention are:

[0027] 1. The beam steel frame, tower steel frame and bottom formwork system are processed into a whole in the factory, shipped to the construction site by ship, and hoisted to the designed position by floating crane. Only one set of assembly brackets is set, which greatly reduces the use of temporary structural materials, makes the force more reasonable, and reduces the difficulty and risk of high-altitude operations;

[0028] 2. Measure and cut on site to form reserved steel skeletons and joint sections to joint the crossbeam steel skeleton and tower column steel skeleton, which greatly improves the installation accuracy;

[0029] 3. The crossbeam steel frame and tower column steel frame serve as the load-bearing structure of steel bars, formwork and concrete. It only needs to set a set of assembly brackets on the inner side of the tower column steel frame during the installation stage. There is no need to set up additional floor brackets or suspended embedded brackets, which greatly reduces the workload of installing and removing the brackets, speeds up the construction progress and reduces the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a hoisting arrangement diagram of the crossbeam steel frame in the embodiment of the present application;

[0031] Figure 2 It is one of the installation layout diagrams of the crossbeam steel frame in the embodiment of the present application;

[0032] Figure 3 This is the second installation layout diagram of the crossbeam steel frame in the embodiment of the present application;

[0033] Figure 4 This is a vertical view of the concrete pouring of the beam in the embodiment of the present application.

[0034] Explanation of the reference numerals: 1. Beam steel frame; 11. Bottom formwork system; 111. Bottom beam; 112. Ribs; 113. Steel panels; 114. Hanging rods; 115. Pads; 12. Upper chords; 13. Lower chords; 14. Lifting corbels; 2. Tower steel frame; 3. Assembly bracket; 31. Cross bar; 32. Short diagonal rod; 33. Three-way jack; 34. Shoulder pole beam; 35. Pads; 36. Unloading blocks; 4. Reserved section steel frame; 5. Joint section; 6. Long diagonal rod; 7. First layer of concrete; 8. Second layer of concrete. DETAILED DESCRIPTION

[0035] The following will be combined with the attached Figure 1 -Attached Figure 4 The present invention is further illustrated by the following embodiments.

[0036] This embodiment discloses a componentized construction method for an offshore cable tower.

[0037] Reference Figures 1 to 4 The component construction method of offshore cable tower includes the following steps:

[0038] S1: 11 parts processing including crossbeam steel frame 1, tower column steel frame 2, crossbeam reinforcement, tower column reinforcement, inner mold system and bottom mold system.

[0039] S2: Install the tower column steel frame 2 on the tower column of the cable tower.

[0040] S3: Install the assembling bracket 3 on the inner side of the tower column steel frame 2, and sequentially arrange a three-way jack 33 and a shoulder beam 34 on the top of the assembling bracket 3.

[0041] S4: Install the crossbeam steel frame 1 on the shoulder beam 34 of the assembling bracket 3.

[0042] S5: The crossbeam steel frame 1 and the tower column steel frame 2 are joined together, and the three-way jack 33 is removed.

[0043] S6: Remove the assembly bracket 3 to complete the system conversion.

[0044] S7: First pouring.

[0045] S8: Tension some prestressed steel tendons and then carry out the second pouring.

[0046] S9: Tension the remaining prestressed steel strands, remove the formwork, and complete the construction of the tower beams.

[0047] In the above method, the beam steel frame 1, the tower column steel frame 2 and the bottom mold system 11 are processed into a whole in the factory, shipped to the construction site by ship, and hoisted to the designed position as a whole by floating crane. Only one set of assembly brackets 3 is set, which greatly reduces the use of temporary structural materials, makes the force more reasonable, and reduces the difficulty and risk of high-altitude operations.

[0048] Each step in the component construction method of offshore cable towers is as follows:

[0049] S1: The crossbeam steel frame 1, the tower column steel frame 2, the crossbeam steel bars, the tower column steel bars, the inner mold system and the bottom mold system 11 are pre-processed in the factory to form components; wherein the crossbeam steel frame 1 and the tower column steel frame 2 both include a horizontal connection system, a vertical connection system and a chord rod connected to each other, the chord rod includes an upper chord rod 12 and a lower chord rod 13, the horizontal connection system is welded to the chord rod, and the vertical connection system is bolted to the chord rod; the bottom mold system 11 is composed of a steel panel 113, a plurality of ribs 112, a plurality of pads 115 and a plurality of bottom beams 111 from top to bottom. The ribs 112 and the bottom beams 111 are tightened by pads 115, and a plurality of bottom beams 111 are perpendicular to the ribs 112. A plurality of bottom beams 111 are spaced apart along the length direction of the ribs 112. A lower chord 13 of the cross-beam steel frame 1 is provided with a lifting bracket 14. A suspension rod 114 is connected between the lifting bracket 14 of the cross-beam steel frame 1 and the bottom beam 111 of the bottom formwork system 11. The upper end of the suspension rod 114 is anchored to the lifting bracket 14, and the lower end of the suspension rod 114 is anchored to the bottom beam 111, so that the bottom formwork system 11 is connected to the bottom of the cross-beam steel frame 1.

[0050] S2: The crossbeam steel frame 1 and the tower column steel frame 2 are shipped to the construction site by sea, and the tower column steel frame 2 is hoisted onto the installed tower column segment on the cable tower by means of a floating crane, and is welded after being fine-tuned to the designed position; the reserved section steel frame 4 is measured and cut on site, and the reserved section steel frame 4 is welded to the installed tower column steel frame 2, and a stiffening plate is welded at the connection position between the reserved section steel frame 4 and the tower column steel frame 2.

[0051] S3: An assembly bracket 3 is welded on site. The assembly bracket 3 includes a cross bar 31 and a short diagonal bar 32 that are connected to each other. The assembly bracket 3 is then hoisted to the inner side of the tower column steel frame 2 and welded at the designed position. Then, a three-way jack 33 is placed on the cross bar 31 of the assembly bracket 3, and a shoulder beam 34 is installed on the three-way jack 33.

[0052] S4: The beam steel frame 1 is hoisted onto the shoulder beam 34 of the assembly bracket 3 by means of floating crane, and the beam steel frame 1 is fine-tuned to the designed position by means of the three-way jack 33, and then the bottom formwork system 11 is fixed to the tower column by means of a climbing cone.

[0053] S5: The three-way jack 33 is lifted to a certain height, and the cushion block 35 and the unloading block 36 are placed on the crossbar 31 of the assembly bracket 3 in sequence, and then the three-way jack 33 is returned to the top, and then the three-way jack 33 is removed; the distance between the crossbeam steel frame 1 and the reserved section steel frame 4 is measured on site, and the joint section 5 is processed on site, and then the joint section 5 is hoisted between the crossbeam steel frame 1 and the reserved section steel frame 4, and the crossbeam steel frame 1 and the reserved section steel frame 4 are welded into a whole by using the joint section 5 to complete the joint. In the above process, the crossbeam steel frame 1 and the tower column steel frame 2 are jointed by measuring and cutting on site to form the reserved section steel frame 4 and the joint section 5, which greatly improves the installation accuracy.

[0054] S6: Remove the unloading block 36 to disengage the cross beam steel frame 1, then remove the assembly bracket 3, and install the long diagonal rod 6 after the removal is completed to complete the system conversion. In the above process, since the cross beam steel frame 1 and the tower column steel frame 2 serve as the load-bearing structure of the steel bar, formwork and concrete, it is only necessary to further set a set of assembly brackets 3 on the inner side of the tower column steel frame 2 during the installation stage, and there is no need to set up additional floor brackets or suspended pre-buried brackets, thereby greatly reducing the workload of installing and removing brackets, accelerating the construction progress and reducing construction costs.

[0055] S7: Tie the remaining steel bars and prestressed steel strands, install the side formwork for the first time, and pour the first layer of concrete after installation is completed 7.

[0056] S8: After the first layer of concrete 7 reaches the design strength after curing, some prestressed steel strands are tensioned. After the tensioning is completed, the side formwork is installed for the second time. After the installation is completed, the second layer of concrete 8 is poured.

[0057] S9: After the second layer of concrete 8 reaches the design strength, the remaining prestressed steel strands are tensioned, the side formwork, inner formwork system and bottom formwork system are removed, and the construction of the cable tower beam is completed.

[0058] In the remaining embodiments, before S7 (first pouring), it also includes S6.5: structural inspection and reinforcement, that is, after completing the installation of the tower steel skeleton 2, the assembly bracket 3, and the beam steel skeleton 1 and completing the system conversion, all structural components are comprehensively inspected, especially the structural connection parts, the tensioning of the prestressed steel bundles, the fixing stability of the assembly bracket 3, etc. Use professional testing equipment for inspection, including but not limited to ultrasonic flaw detection, infrared imaging detection, etc., to ensure that there are no structural defects and hidden dangers, so as to avoid construction interruption or safety hazards due to structural instability after pouring. Specifically, if any connection part is found to be loose or unstable during the inspection, it can be reinforced by a temporary reinforcement device to ensure that no slip or displacement occurs during construction. Perform preliminary tensioning adjustments on the installed prestressed steel bundles to ensure that they are evenly stressed and that no unnecessary deformation or stress concentration occurs during the pouring process. During the inspection, the stability of the inner mold and bottom mold system 11 is confirmed at the same time, especially in an offshore construction environment, affected by marine climate changes, the stability of the mold is crucial.

[0059] In other embodiments, before S8 (second pouring), S7.5: environmental adaptability adjustment is also included, that is, between the first pouring and the second pouring, construction is suspended and environmental adaptability adjustment is performed. For example, under low temperature conditions, according to the change in the setting time of the concrete poured for the first time, the concrete ratio is appropriately adjusted to ensure that the second pouring can achieve better quality.

[0060] The above are all preferred embodiments of the present invention, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A componentized construction method for an offshore cable tower, characterized in that: The following steps are involved: S1: Component processing of the crossbeam steel frame (1), tower column steel frame (2), crossbeam steel bars, tower column steel bars, inner mold system and bottom mold system (11); S2: installing the tower column steel frame (2) on the tower column of the cable tower; S3: installing an assembly bracket (3) on the inner side of the tower column steel frame (2), and sequentially arranging a three-way jack (33) and a shoulder pole beam (34) on the top of the assembly bracket (3); S4: installing the crossbeam steel frame (1) on the shoulder beam (34) of the assembly bracket (3); S5: Joining the crossbeam steel frame (1) and the tower column steel frame (2), and removing the three-way jack (33); S6: dismantle the assembly bracket (3) to complete the system conversion; S7: first pouring; S8: tensioning some prestressed steel tendons and then pouring for the second time; S9: Tension the remaining prestressed steel strands, remove the formwork, and complete the construction of the tower beams.

2. The component construction method of an offshore cable tower according to claim 1, characterized in that: In S1, the cross beam steel frame (1), the tower column steel frame (2), the cross beam steel bars, the tower column steel bars, the inner mold system and the bottom mold system (11) are pre-processed in a factory to form components; wherein the cross beam steel frame (1) and the tower column steel frame (2) both include a horizontal connection system, a vertical connection system and a chord rod connected to each other, the chord rod includes an upper chord rod (12) and a lower chord rod (13), the horizontal connection system is welded to the chord rod, and the vertical connection system is bolted to the chord rod; the bottom mold system (11) includes a steel panel (113), a plurality of rib plates (112), a plurality of pads (115) and a plurality of bottom beams (111) from top to bottom, the rib plates (112) The bottom beam (111) is tightly connected to the bottom beam (111) by a pad (115), the bottom beams (111) are perpendicular to the ribs (112), and the bottom beams (111) are arranged at intervals along the length direction of the ribs (112). The lower chord (13) of the cross beam steel frame (1) is provided with a hanging bracket (14), and a hanging rod (114) is connected between the hanging bracket (14) of the cross beam steel frame (1) and the bottom beam (111) of the bottom formwork system (11). The upper end of the hanging rod (114) is anchored to the hanging bracket (14), and the lower end of the hanging rod (114) is anchored to the bottom beam (111), so that the bottom formwork system (11) is connected to the bottom of the cross beam steel frame (1).

3. The component construction method of an offshore cable tower according to claim 2, characterized in that: In S2, the crossbeam steel frame (1) and the tower column steel frame (2) are shipped to the construction site by sea, the tower column steel frame (2) is hoisted onto the tower column segment installed on the cable tower by means of a floating crane, and is welded after being fine-tuned to the designed position; the reserved section steel frame (4) is measured and cut on site, the reserved section steel frame (4) is welded to the installed tower column steel frame (2), and a stiffening plate is welded at the connection position between the reserved section steel frame and the tower column steel frame (2).

4. The component construction method of an offshore cable tower according to claim 3, characterized in that: In S3, an assembly bracket (3) is welded on site, and the assembly bracket (3) includes a cross bar (31) and a short diagonal bar (32) connected to each other. The assembly bracket (3) is then hoisted to the inner side of the tower column steel frame (2) and welded at the designed position. Then, a three-way jack (33) is placed on the cross bar (31) of the assembly bracket (3), and then a shoulder pole beam (34) is installed on the three-way jack (33).

5. The component construction method of an offshore cable tower according to claim 4, characterized in that: In S4, the cross beam steel frame (1) is hoisted onto the shoulder beam (34) of the assembly bracket (3) by means of a floating crane, and the cross beam steel frame (1) is fine-tuned to the designed position by means of a three-way jack (33), and then the bottom formwork system (11) is fixed to the tower column by means of a climbing cone.

6. The component construction method of an offshore cable tower according to claim 5, characterized in that: In S5, the three-way jack (33) is lifted to a certain height, and a cushion block (35) and a removal block (36) are placed on the crossbar (31) of the assembly bracket (3) in sequence, and then the three-way jack (33) is returned to the top, and then the three-way jack (33) is removed; the distance between the crossbeam steel frame (1) and the reserved section steel frame (4) is measured on site, and after the joint section (5) is processed on site, the joint section (5) is hoisted between the crossbeam steel frame (1) and the reserved section steel frame (4), and the crossbeam steel frame (1) and the reserved section steel frame (4) are welded into a whole by using the joint section (5), thereby completing the joint.

7. The componentized construction method of an offshore cable tower according to claim 6, characterized in that: In S6, the unloading block (36) is removed to disengage the crossbeam steel frame (1), and then the assembly bracket (3) is removed. After the removal is completed, the long diagonal rod (6) is installed to complete the system conversion.

8. The component construction method of an offshore cable tower according to claim 7, characterized in that: In S7, the remaining steel bars and prestressed steel strands are tied, the side formwork is installed for the first time, and after the installation is completed, the first layer of concrete is poured (7).

9. The component construction method of an offshore cable tower according to claim 8, characterized in that: In S8, after the first layer of concrete (7) has been cured to reach the designed strength, some prestressed steel strands are tensioned. After the tensioning is completed, the side formwork is installed for the second time. After the installation is completed, the second layer of concrete (8) is poured.

10. The component construction method of an offshore cable tower according to claim 9, characterized in that: In S9, after the second layer of concrete (8) has been cured to reach the design strength, the remaining prestressed steel strands are tensioned, the side formwork, the inner formwork system and the bottom formwork system are removed, and the construction of the cable tower beam is completed.

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