Single-slope open-web type steel box girder and manufacturing method thereof

Abstract

The invention discloses a single-slope open-web steel box girder and a manufacturing method thereof, and relates to the technical field of steel box girders. The bottom plate unit is located below the top plate unit, and an assembly space is reserved between the bottom plate unit and the top plate unit; the web unit is arranged between the top plate unit and the bottom plate unit; the partition plate units are arranged between the web plate units; and the tuyere block body is arranged at one end of the assembly space. The invention further discloses a manufacturing method of the single-slope open-web type steel box girder. The technical problems that in the prior art, an open-web type steel box girder is complex in structure, large in dead weight and high in cost are solved.

Description

Technical Field

[0001] This invention relates to the field of steel box girder technology, and in particular to a single-slope hollow steel box girder and its manufacturing method. Background Technology

[0002] Steel structure bridges are increasingly widely used in highway construction, especially in large-scale continuous bridge projects such as newly built or expanded expressways and cross-sea channels. Steel structure beams, with their advantages of large span capacity, light weight, high degree of prefabrication, and fast construction speed, have become a key structural form for achieving complex alignments and improving project quality. With the development of engineering technology, continuous steel box girders are evolving towards larger spans, larger cross-sectional dimensions, and more complex spatial alignments (horizontal curves, vertical curves, and super-high cross slopes).

[0003] Driven by the pursuit of lightweight and economical structures, hollow steel box girders have emerged as a highly efficient structural design. Their core feature lies in the hollow (open-ended or truss-type) design of the internal diaphragms, which significantly reduces steel usage and lowers the structure's self-weight while ensuring necessary structural stiffness. This type of structure is commonly found in bridges with compact cross-sections and relatively small widths (usually no more than 20 meters), such as highway ramp bridges. In these applications, due to the limited width of the girder itself and its relatively high overall stiffness, the hollow diaphragms provide effective lateral support, achieving excellent weight reduction while meeting strength requirements.

[0004] However, when applying open-web structures to wider main beams, such as large single-slope steel box girders with widths of 27 to 32 meters, traditional design and manufacturing methods face severe challenges. To meet railway requirements, these wide beams are often designed as uniformly widened structures with a unidirectional cross slope on the top surface, a horizontal bottom plate, and mostly open-web internal diaphragms without other auxiliary support members. To address the stiffness issues of large-span open-web structures, a common solution in existing technology is to add structural steel (such as angle steel and channel steel) to the open-web diaphragms for internal stiffening, forming more complex truss-type diaphragms. (While this method effectively improves local stiffness, it also introduces new problems: First, it increases the complexity and number of components, leading to increased workload in factory prefabrication and on-site assembly, partially offsetting the advantage of rapid construction of open-web structures; second, the additional steel increases material usage and structural weight, raising construction costs; finally, the complex internal structure may cause inconvenience for subsequent inspection, maintenance, and pipeline layout within the box girder.) Summary of the Invention

[0005] The purpose of this invention is to provide a single-slope hollow steel box girder and its manufacturing method, which solves the technical problems of complex structure, heavy weight and high cost of hollow steel box girders in the prior art.

[0006] This application discloses a single-slope hollow steel box girder, characterized in that it includes: Top plate unit; A base plate unit is located below the top plate unit, and an assembly space is provided between the base plate unit and the top plate unit; A web plate unit is disposed between the top plate unit and the bottom plate unit; A partition unit is disposed between the web units; The nozzle block is located at one end of the assembly space. The base plate unit includes: Flat bottom plate unit; At least two inclined bottom plate units are disposed at both ends of the flat bottom plate unit; The web plate unit includes a first web plate unit, a second web plate unit, a third web plate unit, and a fourth web plate unit. The first web plate unit is located at the other end of the assembly space, and the second to fourth web plate units are distributed at intervals along the width direction of the assembly space. The partition unit includes a first partition unit, a second partition unit, a third partition unit, and a fourth partition unit, which are spaced apart along the width direction of the assembly space.

[0007] This application employs multiple diaphragm units and web units working together to ensure the stability of the steel box girder.

[0008] Based on the above technical solution, the present application can be further improved as follows: Furthermore, each of the first to fourth partition units includes one solid partition and three hollow partitions. The solid partition is located between any two adjacent hollow partitions. The beneficial effect of this step is that the hollow partitions can minimize the structural weight and reduce material costs.

[0009] Furthermore, the hollow partition includes bottom plate transverse ribs, which are disposed on the top of the bottom plate unit. The beneficial effect of this step is to enhance the stability of the connection between the partition itself and the bottom plate unit and improve the strength of the box girder bottom plate.

[0010] Furthermore, the two inclined base plate units have different inclination angles.

[0011] This application also discloses a method for manufacturing a single-slope hollow steel box girder, including the following steps: S1: Set up a special frame according to the shape and structural stiffness of the single-slope hollow steel box girder, and arrange the frame support plate. The height of the frame support plate is determined according to the outline dimension of the single-slope hollow steel box girder after reverse deformation. S2: Position the middle base plate unit, and use the middle base plate unit as a reference to position and assemble the flat base plate units and inclined base plate units on both sides. After the base plate unit is attached to the jig, use the elastic board to fix it to the jig to fix the transverse outline of the box after rotation. S3: Weld the first bulkhead unit and the bottom plate transverse ribs of the compartment it belongs to, based on the longitudinal baseline of the bottom plate unit and the position lines of the bulkhead and transverse rib units. S4: Assemble the second web unit based on the longitudinal and transverse baselines and web position lines on the base plate unit; S5: Sequentially assemble the solid-web partition and bottom plate transverse rib in the second partition unit, the third web unit, the solid-web partition and bottom plate transverse rib in the third partition unit, the fourth web unit, and the solid-web partition and bottom plate transverse rib in the fourth partition unit. S6: Assemble the first web plate unit and the nozzle block based on the horizontal baseline of the side measuring tower and the bottom plate; S7: Using the intermediate measuring tower position line and the bottom plate horizontal baseline as a reference, position and assemble one of the top plate units; S8: Using the longitudinal and transverse baselines of the positioned top plate unit as a reference, position and assemble the remaining top plate units, and set up anti-deformation rigid supports. S9: After welding the butt joint of the top panel, remove the rigid support and weld the remaining joints; S10: After all the welds of the box girder are completed, the temporary consolidation between the girder and the formwork is released to allow it to spring back and meet the cross slope value required by the girder design.

[0012] Based on the above technical solution, the present application can be further improved as follows: Furthermore, the anti-deformation step of the single-slope hollow steel box girder in step S1 is as follows: taking the bottom of the second web unit and the fourth web unit as the process rotation point, the entire range of the two side compartments is rotated downward by 0.12% of the cross slope value, while the range of the middle compartment remains unchanged at 2.5% of the cross slope, in order to counteract the upward warping of the beam caused by welding shrinkage.

[0013] Furthermore, step S7 also includes the following: using temporary rigid supports to support the transverse ribs of the top plate unit to form a stable structure; and using rigid supports to make fine adjustments to counteract the shrinkage deformation of the top plate butt joint welding, increasing the anti-deformation amount by 3mm to counteract the welding deformation caused by single-sided welding.

[0014] Furthermore, the arrangement of the support plates in step S1 is as follows: the support plates are arranged on the crossbeams and diagonal braces of the support plate based on the outline of the bottom plate of the rotated single-slope hollow steel box girder. The arrangement principle is that the support plates are arranged 200mm on both sides of the joint of the bottom plate unit and the position of the web unit. The remaining support plates are arranged in a denser manner with a spacing of no more than 1.5 meters. At the same time, a special support plate that fits the arc is set at the arc position of the inclined bottom plate unit to ensure that the arc surface remains smooth and consistent.

[0015] Furthermore, in step S2, after the base plate unit is assembled, it is symmetrically welded in the same direction.

[0016] Furthermore, the partition unit is provided with process allowance according to the amount of reverse deformation; the bottom plate transverse rib of the partition unit is cut by laser cutting at the splicing break point. After cutting, the break point is broken after the temperature drops to room temperature, and the cutting position is polished evenly.

[0017] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: This application improves the single-slope hollow steel box girder by adopting hollow diaphragms and using a reasonable assembly and welding sequence to control the accuracy, consistency and dispersion of the transverse alignment of each beam segment, improve the pass rate of misalignment of the entire box girder section, reduce the total assembly time, speed up the construction progress, and help improve the construction quality and precision control. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a structural schematic diagram of a single-slope hollow steel box girder according to specific embodiment 1 of the present invention; Figure 2 for Figure 1 A schematic diagram of the exploded structure; Figure 3 This is a flowchart of a method for manufacturing a single-slope hollow steel box girder according to a specific embodiment 2 of the present invention; Figure 4 This is a schematic diagram of a method for manufacturing a single-slope hollow steel box girder according to a specific embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the shrinkage of the steel box girder in a method for manufacturing a single-slope hollow steel box girder according to a specific embodiment 2 of the present invention; Figure 6This is a welding sequence diagram of a method for manufacturing a single-slope hollow steel box girder according to a specific embodiment 2 of the present invention. The attached figures are labeled as follows: 1-Top plate unit; 2-Bottom plate unit; 3-Assembly space; 4-Body plate unit; 5-Partition plate unit; 6-Air nozzle block; 201 - Flat bottom plate unit; 202 - Sloping bottom plate unit; 401-First web plate unit; 402-Second web plate unit; 403-Third web plate unit; 404-Fourth web plate unit; 405-Solid web diaphragm; 406-Hollow web diaphragm; 407-Bottom plate transverse rib; 501 - First partition unit; 502 - Second partition unit; 503 - Third partition unit; 504 - Fourth partition unit. Detailed Implementation

[0020] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention. It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0021] In the description of this application, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0022] In this application, unless otherwise expressly specified and limited, the terms "connection," "setup," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0024] Example 1: like Figure 1-2As shown in the embodiment of this application, a single-slope hollow steel box girder and its manufacturing method are disclosed. The single-slope hollow steel box girder is a single-slope asymmetrical structure, which adopts the superposition of horizontal and vertical curves. The beam body is a structure with equal height and variable width. The top surface is a unidirectional transverse slope, and the bottom plate is horizontal. The flat bottom plate unit and the inclined bottom plate unit are connected by bending the bottom plate. The top plate is bolted and welded together, the panel is welded, and the longitudinal ribs are bolted together. Most of the internal partitions are hollow structures and there are no other supporting members. Every three hollow partitions are provided with one solid partition. This structure has a short overall assembly time and can speed up the construction progress.

[0025] The specific structure of this application includes: Top plate unit 1, which is composed of multiple top plates spliced ​​together; The bottom plate unit 2 is located below the top plate unit 1, and an assembly space 3 is left between the bottom plate unit 2 and the top plate unit 1; Web plate unit 4 is disposed between the top plate unit 1 and the bottom plate unit 2, that is, the web plate unit 4 is used to connect the top plate unit 1 and the bottom plate unit 2 to ensure the stability of the entire structure; Partition unit 5 is disposed between the web plate units 4; The nozzle block 6 is disposed at one end of the assembly space 3; Specifically, the base plate unit 2 in this application includes: Flat bottom plate unit 201; At least two inclined bottom plate units 202 are disposed at both ends of the flat bottom plate unit 201; The web plate unit 4 includes a first web plate unit 401, a second web plate unit 402, a third web plate unit 403 and a fourth web plate unit 404. The first web plate unit 401 is located at the other end of the assembly space 3, and the second to fourth web plate units are distributed at intervals along the width direction of the assembly space 3. The partition unit 5 includes a first partition unit 501, a second partition unit 502, a third partition unit 503, and a fourth partition unit 504, which are distributed at intervals along the width direction of the assembly space 3.

[0026] Compared to existing steel box girders, this application is a single-slope open-web type, which omits the members and supporting steel. This significantly reduces the amount of steel used in the box while ensuring lateral stiffness and local stability, thus reducing the overall self-weight of the structure. In addition, reducing the number of structural components can improve construction efficiency.

[0027] The first to fourth partition units each include one solid partition 405 and three hollow partitions 406. The solid partition 405 is located between any two adjacent hollow partitions 406. That is, the use of hollow partitions 406 in this application can reduce the overall mass of the steel box girder.

[0028] The hollow partition 406 includes a bottom plate transverse rib 407, which is disposed on the top of the bottom plate unit 2. Specifically, the hollow partition 406 also includes a top plate transverse rib and a web T-rib. The top plate transverse rib is installed at the bottom of the top plate unit, while the web T-rib is installed on the side of the web unit 4. All the above components cooperate with each other to form a stable hollow partition 406, thereby ensuring the stability of the overall structure of the steel box girder.

[0029] The two inclined base plate units 202 have different inclination angles, which facilitates the formation of an asymmetrical structure to meet the user's design requirements.

[0030] Example 2: like Figure 3-6 As shown in the figure, this application discloses a method for manufacturing a single-slope hollow steel box girder. The single-slope hollow steel box girder is the single-slope hollow steel box girder structure in Example 1. The steps are as follows: S1: Set up a special jig according to the shape and structural stiffness of the single-slope hollow steel box girder, and arrange jig support plates. The height of the jig support plates is determined according to the outline dimensions of the single-slope hollow steel box girder after reverse deformation. Specifically, the reverse deformation step of the single-slope hollow steel box girder in step S1 is as follows: Using the bottom of the second web plate unit and the fourth web plate unit as the process rotation point, rotate the entire range of the two side compartments downward by 0.12% of the cross slope value, while keeping the cross slope of the middle compartment range unchanged at 2.5%, in order to offset the upward warping of the beam caused by welding shrinkage. The specific arrangement of the support plates in step S1 is as follows: the support plates are arranged on the crossbeams and diagonal braces of the support plate based on the outline of the bottom plate of the rotated single-slope hollow steel box girder. The arrangement principle is that the support plates are arranged 200mm on both sides of the joint of the bottom plate unit and the position of the web plate unit. The remaining support plates are arranged in a denser manner with a spacing of no more than 1.5 meters. At the same time, a special support plate that fits the arc is set at the arc position of the inclined bottom plate unit to ensure that the arc surface remains smooth and consistent. S2: Position the middle base plate unit, and use the middle base plate unit as a reference to position and assemble the flat base plate unit and the inclined base plate unit on both sides. After the base plate unit is attached to the jig, use the elastic horse plate to fix it to the jig to fix the transverse outline of the box after rotation. During assembly, weld the butt weld between the base plate and the inclined base plate symmetrically in the same direction. S3: Weld the first bulkhead unit and the bottom plate transverse ribs of the compartment it belongs to, based on the longitudinal baseline of the bottom plate unit and the position lines of the bulkhead and transverse rib units. S4: Assemble the second web unit based on the longitudinal and transverse baselines and web position lines on the base plate unit; S5: Sequentially assemble the solid-web partition and bottom plate transverse rib in the second partition unit, the third web unit, the solid-web partition and bottom plate transverse rib in the third partition unit, the fourth web unit, and the solid-web partition and bottom plate transverse rib in the fourth partition unit. S6: Assemble the first web plate unit and the nozzle block based on the horizontal baseline of the side measuring tower and the bottom plate; S7: Using the intermediate measuring tower position line and the bottom plate horizontal baseline as a reference, position and assemble one of the top plate units. During assembly, temporary rigid supports are used to support the horizontal ribs of the top plate unit to form a stable structure. In order to offset the shrinkage deformation of the top plate butt joint welding, the rigid supports are used for fine adjustment to increase the anti-deformation amount by 3mm to offset the welding deformation caused by single-sided welding. S8: Using the longitudinal and transverse baselines of the positioned top plate unit as a reference, position and assemble the remaining top plate units, and set up anti-deformation rigid supports. S9: After welding the butt joint of the top panel, remove the rigid support and weld the remaining joints; S10: After all the welds of the box girder are completed, the temporary consolidation between the girder and the formwork is released to allow it to spring back and meet the cross slope value required by the girder design.

[0031] In this application, the partition unit is provided with a process allowance based on the amount of reverse deformation; the bottom plate transverse rib of the partition unit is cut by laser cutting at the splicing break point. After cutting, the break point is broken after the temperature drops to room temperature, and the cutting position is polished evenly.

[0032] This application is welded in the following welding sequence; Symmetrical welding of butt welds ①, ②, ③, and ④ between the base plate and the inclined base plate in the same direction; Welding joints ⑤ and ⑥ between the intermediate partition plate and the side partition plate and the bottom plate; ⑦ Welded joint between the diaphragm and the web; Partially penetrated fillet weld between the web plate and the base plate during welding ⑧; ⑨ Partially penetrated fillet weld between the side web plate and the bottom plate; Hoist the air nozzle block and weld the butt weld between the air nozzle partition and the box girder partition ⑩; Butt weld between the bottom plate of the welding nozzle and the bottom plate of the box girder ; Assemble the top plate unit near the bridge, first weld the partial penetration fillet weld between the web and the top plate. ; Symmetrical welding of butt welds between top plates in the same direction ; Butt welds between welded partition plates ; Welded joint between the partition plate and the horizontal rib of the partition plate ; Welded joint between the diaphragm plate and the web ; Hoist the side span roof slab units and weld the butt welds between the roof slab units. ; Butt welds between welded partition plates ; Butt weld between the welding nozzle baffle and the baffle joint plate ; Welded joint between the partition plate and the horizontal rib of the partition plate ; The butt weld between the top plate of the welding nozzle and the top plate of the box girder.

[0033] The following is a further explanation of the preparation method of this application: According to the steel box girder structure in Example 1, this application Example 2 adopts the process of parts → plate unit → segment. During the manufacturing process, the cross slope of the beam is mainly affected by the lateral upward tilt caused by the welding shrinkage during the overall assembly, as well as the local deviation caused by insufficient constraint of the top plate during the assembly of the unsupported open diaphragm.

[0034] To reduce the impact of unsupported open diaphragm structures on the transverse alignment accuracy of steel box girders, improve the transverse alignment accuracy and ring alignment accuracy of steel box girders, and ensure the box opening dimensions, this application proposes a beam anti-deformation control process and an internal anti-deformation support control process in the fabrication process of single-slope open diaphragm steel box girder structures.

[0035] Firstly, regarding the beam deformation control process, it mainly utilizes the principle of welding shrinkage. After welding, the two sides of the beam will warp upwards, causing changes in the transverse alignment of the box girder. Therefore, based on this phenomenon, the assembly dimensions of the steel box girder are controlled to a certain extent in the direction of reverse shrinkage during assembly, thereby achieving the goal of controlling the accuracy of its transverse alignment. Specifically, the bottom of the second and fourth web plate units is used as the process rotation point. The entire range of the two side compartments is rotated downwards by a cross slope of 0.12%, while the cross slope of the middle compartment remains unchanged at 2.5%, to counteract the upward warping of the beam caused by welding shrinkage.

[0036] Secondly, the beam anti-deformation control process: a special jig is set up according to the box girder shape and structural stiffness position; jig support plates are arranged, and the height of the support plates should be determined according to the outline dimensions of the beam after anti-deformation; the corresponding diaphragms and transverse ribs are made with process allowances according to the corresponding anti-deformation amount; at the same time, in order to ensure the straightness of the transverse rib unit and reduce thermal input deformation during cutting, laser cutting of the splicing breakpoint is adopted. After cutting, the breakpoint is disconnected after the temperature drops to room temperature, and the cutting position is ground evenly; a special jig is used for assembly welding, with multiple points of limitation to control welding deformation.

[0037] Numerous specific details are set forth in this specification. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A single-slope hollow steel box girder, characterized in that, include: Top plate unit; A base plate unit is located below the top plate unit, and an assembly space is provided between the base plate unit and the top plate unit; A web plate unit is disposed between the top plate unit and the bottom plate unit; A partition unit is disposed between the web units; The nozzle block is located at one end of the assembly space. The base plate unit includes: Flat bottom plate unit; At least two inclined bottom plate units are disposed at both ends of the flat bottom plate unit; The web plate unit includes a first web plate unit, a second web plate unit, a third web plate unit, and a fourth web plate unit. The first web plate unit is located at the other end of the assembly space, and the second to fourth web plate units are distributed at intervals along the width direction of the assembly space. The partition unit includes a first partition unit, a second partition unit, a third partition unit, and a fourth partition unit, which are spaced apart along the width direction of the assembly space.

2. The single-slope hollow steel box girder according to claim 1, characterized in that, Each of the first to fourth partition units includes one solid partition and three hollow partitions, with the solid partition located between any two adjacent hollow partitions.

3. The single-slope hollow steel box girder according to claim 2, characterized in that, The hollow partition includes bottom plate transverse ribs, which are disposed on the top of the bottom plate unit.

4. The single-slope hollow steel box girder according to claim 3, characterized in that, The two inclined base plate units have different inclination angles.

5. A method for manufacturing a single-slope hollow steel box girder according to any one of claims 1-4, characterized in that, Includes the following steps: S1: Set up a special frame according to the shape and structural stiffness of the single-slope hollow steel box girder, and arrange the frame support plate. The height of the frame support plate is determined according to the outline dimension of the single-slope hollow steel box girder after reverse deformation. S2: Position the middle base plate unit, and use the middle base plate unit as a reference to position and assemble the flat base plate units and inclined base plate units on both sides. After the base plate unit is attached to the jig, use the elastic board to fix it to the jig to fix the transverse outline of the box after rotation. S3: Weld the first bulkhead unit and the bottom plate transverse ribs of the compartment it belongs to, based on the longitudinal baseline of the bottom plate unit and the position lines of the bulkhead and transverse rib units. S4: Assemble the second web unit based on the longitudinal and transverse baselines and web position lines on the base plate unit; S5: Sequentially assemble the solid-web partition and bottom plate transverse rib in the second partition unit, the third web unit, the solid-web partition and bottom plate transverse rib in the third partition unit, the fourth web unit, and the solid-web partition and bottom plate transverse rib in the fourth partition unit. S6: Assemble the first web plate unit and the nozzle block based on the horizontal baseline of the side measuring tower and the bottom plate; S7: Using the intermediate measuring tower position line and the bottom plate horizontal baseline as a reference, position and assemble one of the top plate units; S8: Using the longitudinal and transverse baselines of the positioned top plate unit as a reference, position and assemble the remaining top plate units, and set up anti-deformation rigid supports. S9: After welding the butt joint of the top panel, remove the rigid support and weld the remaining joints; S10: After all the welds of the box girder are completed, the temporary consolidation between the girder and the formwork is released to allow it to spring back and meet the cross slope value required by the girder design.

6. The manufacturing method according to claim 5, characterized in that, The anti-deformation step of the single-slope hollow steel box girder in step S1 is as follows: taking the bottom of the second web plate unit and the fourth web plate unit as the process rotation point, the entire range of the two side compartments is rotated downward by 0.12% of the cross slope value, while the range of the middle compartment remains unchanged at 2.5% cross slope, in order to counteract the upward warping of the beam caused by welding shrinkage.

7. The manufacturing method according to claim 5, characterized in that, Step S7 also includes the following: Temporary rigid supports are used to support the transverse ribs of the top plate unit to form a stable structure. In order to offset the shrinkage deformation of the welded joint of the top plate, the rigid supports are used for fine adjustment to increase the anti-deformation amount by 3mm to offset the welding deformation caused by single-sided welding.

8. The manufacturing method according to claim 5, characterized in that, The specific arrangement of the support plates in step S1 is as follows: the support plates are arranged on the crossbeams and diagonal braces of the support plate based on the outline of the bottom plate of the rotated single-slope hollow steel box girder. The arrangement principle is that the support plates are arranged 200mm on both sides of the joint of the bottom plate unit and the position of the web unit. The remaining support plates are arranged in a denser manner with a spacing of no more than 1.5 meters. At the same time, a special support plate that fits the arc is set at the arc position of the inclined bottom plate unit to ensure that the arc surface remains smooth and consistent.

9. The manufacturing method according to claim 5, characterized in that, In step S2, after the base plate unit is assembled, it is symmetrically welded in the same direction.

10. The manufacturing method according to claim 5, characterized in that, The partition unit has a process allowance based on the amount of reverse deformation; the bottom plate transverse ribs of the partition unit are cut by laser cutting at the splicing break point. After cutting, the break point is broken after the temperature drops to room temperature, and the cutting position is polished evenly.

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