A welding method for a curved variable-beam-width continuous steel box girder structure

Abstract

This invention provides a welding method for a curved variable-width continuous steel box girder structure, comprising the following steps: S1, prefabricating and assembling the top plate unit, bottom plate unit, diaphragm unit, and web unit separately; S2, measuring and setting out, and erecting a ground support; S3, sequentially installing the bottom plate unit, diaphragm unit, web unit, and top plate unit on the ground support to form the steel box girder body; S4, disassembling the ground support and inspecting and correcting the alignment of the steel box girder body. This welding method for a curved variable-width continuous steel box girder structure ensures the positioning accuracy and straightness of the longitudinal ribs, minimizes welding deformation, significantly improves the overall assembly efficiency and product quality of the unit components, provides precise interface positioning for subsequent on-site installation of the steel box girder, reduces the amount of welding work during on-site installation, simplifies operation, and saves on-site installation time. It ensures the overall structural stability and reliability of the bridge while guaranteeing its load-bearing capacity.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bridges, and particularly relates to a welding method for a curved variable-width continuous steel box girder structure. BACKGROUND

[0002] With the continuous application and development of continuous box girder bridges, steel box girder bridge technology is widely used in current highway construction in China, and the box girder is effectively connected mainly by using a welding method. However, in the actual manufacturing process, especially the welding method for a curved variable-width continuous steel box girder, there is no mature welding process, and reasonable welding sequence and weld arrangement are factors that need to be considered, so the welding method for the curved variable-width continuous steel box girder structure needs to be optimized to meet the durability and appearance line type of the bridge structure. In the prior art, the curved variable-width continuous steel box girder is a single-span single-box multi-cell continuous girder structure, the steel box girder width is between 24.8-39.92 meters, the cross section changes from a single 2% cross slope to a double 2% cross slope; the steel box girder height at the bridge structure center line is 2 meters, the top and bottom plates are parallel, and the webs and diaphragms are plumb to the ground; the side bottom plate, cantilever bottom plate and cantilever decorative plate are all parts with spatial arc lines, and the control of the planeness, dimensional accuracy, horizontal curve and vertical curve type of each box girder segment during the welding process is a construction difficulty. SUMMARY

[0003] Therefore, the present application aims to provide a welding method for a curved variable-width continuous steel box girder structure to solve the problem that the planeness, dimensional accuracy, horizontal curve and vertical curve type of each box girder segment are difficult to control during the welding process.

[0004] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0005] A welding method for a curved variable-width continuous steel box girder structure, comprising the following steps:

[0006] S1, respectively pre-assemble and weld the top plate unit, the bottom plate unit, the diaphragm unit and the web unit;

[0007] S2, measure and lay out the line, and set up the ground bed;

[0008] S3, sequentially install the bottom plate unit, the diaphragm unit, the web unit and the top plate unit on the ground bed to form a steel girder box body;

[0009] S4, disassemble and remove the ground bed, and check and correct the line shape of the steel girder box body.

[0010] Further, the bottom plate unit element comprises a plurality of linear segment bottom plates and arc segment bottom plates connected head to tail, the linear segment bottom plate is a horizontal iron plate, and the arc segment bottom plate is obtained by rolling the linear segment bottom plate to a preset arc through a plate rolling machine; the method for prefabricating, assembling and welding the bottom plate unit element is that the linear segment bottom plate or the arc segment bottom plate is spliced in the sequence of longitudinal segments first spliced in the horizontal seam and then spliced in the longitudinal seam, transverse segments first spliced in the longitudinal seam and then spliced in the horizontal seam, small units first spliced and large units spliced later.

[0011] Further, the method for erecting the ground tire is that a ground tire support point is arranged at the intersection of the steel box girder structure center line and the partition plate center line, the intersection of the web plate center line and the partition plate center line, the intersection of the bottom plate broken line and the partition plate center line, and the intersection of the web plate outer edge line and the partition plate center line, an H-shaped support is erected below the ground tire support point, the support has a base at the bottom end, the relative position of the support and the base does not move upward or sink, and two adjacent supports are connected through a rigid tie.

[0012] Further, the method for forming the steel beam box body in the step S3 comprises the following steps.

[0013] A1, welding of the weld seam between the web plate and the bottom plate;

[0014] A2, welding of the weld seam between the partition plate and the web plate;

[0015] A3, welding of the weld seam between the partition plate and the bottom plate;

[0016] A4, bottoming of the weld seam between the web plate and the top plate;

[0017] A5, bottoming welding of the weld seam between the top plate and the partition plate on both sides;

[0018] A6, checking of the interface misalignment and flatness;

[0019] A7, adjustment of the bolted U-rib embedded patch segment of the top plate to ensure that all holes can be connected with the positioning pin and the connecting plate, and checking of the connection precision of the bolted U-rib;

[0020] A8, welding and installation of the lifting lug, and turning over of the lifting lug.

[0021] Further, the method for checking and correcting the line shape of the steel beam box body comprises the following steps.

[0022] B1, checking of the line shape, the overall size of the bridge, the interface misalignment and the flatness of the bridge before the bridge is finally delivered from the factory to ensure that the on-site installation precision requirement is met;

[0023] B2, installation of the positioning plate, and group positioning and welding of the positioning plate;

[0024] B3, actual measurement of the tire measurement positioning point, and taking the data as the final installation positioning data.

[0025] Compared with the prior art, the welding method of the continuous steel box girder structure with variable curve and variable width has the following beneficial effects: the positioning accuracy and flatness of the longitudinal rib of the continuous steel box girder with variable curve and variable width are ensured, the welding deformation is small, the overall assembly efficiency and product quality of the unit are greatly improved, the installation sequence and installation nodes of the stiffening on the top and bottom plates, the partition plates and the web plates are determined, the deformation is strictly controlled and reduced, the smooth installation of the top and bottom plate units, the web plate units and the partition plate units during the overall assembly is ensured, the welding quality of the welds between the partition plates, the web plates and the top and bottom plates is improved, and the bending and shearing resistance of the whole steel box girder is improved. Precise interface positioning is provided for the later on-site installation of the steel box girder, the welding workload during the on-site installation is reduced, the operation is simple, and the on-site installation time is saved. The overall structure of the bridge is stable and reliable, and the stress of the bridge can be ensured. The operation method has strong operability and is suitable for popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the present application, and serve as an explanation of the illustrative embodiments of the present application, and are not intended to limit the present application. In the drawings:

[0027] Figure 1 The cross-sectional view of the continuous steel box girder with variable curve and variable width is described in the embodiments of the present application.

[0028] Explanation of reference signs:

[0029] 1-top plate; 2-U rib; 3-partition plate; 4-web plate; 5-web plate longitudinal rib; 6-cantilever partition plate; 7-bottom plate. DETAILED DESCRIPTION

[0030] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0031] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0032] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0034] As Figure 1 shown, a welding method of a curved variable beam width continuous steel box girder structure comprises the following steps:

[0035] S1, the top plate 1 unit, the bottom plate 7 unit, the partition plate 3 unit and the web plate 4 unit are respectively pre-assembled and welded;

[0036] S2, measure the line and set up the ground tire;

[0037] S3, sequentially install the bottom plate 7 unit, the partition plate 3 unit, the web plate 4 unit and the top plate 1 unit on the ground tire to form the steel girder box body;

[0038] S4, disassemble the tire, check and correct the line shape of the steel girder box body.

[0039] The bottom plate 7 unit comprises a plurality of linear segment bottom plates 7 and arc segment bottom plates 7 connected end to end, the linear segment bottom plate 7 is a horizontal iron plate, and the arc segment bottom plate 7 is obtained by rolling the linear segment bottom plate 7 to a preset arc through a plate rolling machine,

[0040] The method of pre-assembling and welding the top plate 1 unit, the bottom plate 7 unit, the partition plate 3 unit and the web plate 4 unit respectively is:

[0041] ① The plate splicing sequence is longitudinal segment first horizontal joint and then longitudinal joint, transverse segment first longitudinal joint and then horizontal joint, small unit splicing first and then large unit splicing.

[0042] This welding sequence is in line with the characteristics that the longitudinal segment of the steel box girder mainly bears longitudinal force and the transverse segment mainly bears transverse force, so that the vehicle load is uniformly transmitted from the bridge deck plate to the longitudinal rib, longitudinal beam, transverse beam and support, and stress concentration is reduced during welding.

[0043] ② A field piece is reserved at the field butt joint position, the length of the field piece is 400mm, and the factory is not welded 200mm away from the two ends of the longitudinal rib except for the reserved field joint.

[0044] The positioning accuracy and flatness of the longitudinal ribs are ensured, the welding workload during on-site installation is reduced, the welding deformation is small, and the installation efficiency and product quality of the top, bottom and web plate 3 units are greatly improved.

[0045] ③The uppermost and lowermost longitudinal ribs on one side of the web plate 4 are left for assembly and welding during final assembly, and the middle two layers of longitudinal ribs are reserved for final assembly and patching at the position of the web plate 3.

[0046] The deformation is strictly controlled and reduced, the smooth installation of the web plate 4 unit and the web plate 3 unit during final assembly is ensured, the welding quality of the weld between the web plate 4 and the top and bottom plates 7 is improved, and the bending and shearing resistance of the web plate 4 is improved.

[0047] ④During the production of the top and bottom plate 7 unit, the welding of the longitudinal ribs and the top and bottom plates 7 is performed on the jig, the jig is arched according to the reverse deformation of 5%, the welding sequence is to weld the weld between the middle longitudinal ribs and the top and bottom plates 7 first, and then weld the weld between the edge longitudinal ribs and the top and bottom plates 7, and each two welds or four welds are welded in the same direction and flat position.

[0048] Since the longitudinal ribs of the top and bottom plates 7 are arranged on one side, the top and bottom plates 7 will be angularly deformed after welding, so the top and bottom plate 7 unit must be welded on the reverse deformation welding jig, the jig is arched according to the reverse deformation of 5%, and the welding shrinkage deformation of the top and bottom plates 7 is effectively controlled.

[0049] ⑤The welding sequence of the transverse stiffening of the web plate 3 unit is: a, first symmetrically welding the outer sides of the upper and lower two transverse stiffenings on one side, b, then symmetrically welding the outer sides of the upper and lower two transverse stiffenings on the other side, c, then symmetrically welding the inner sides of the upper and lower two transverse stiffenings on the same side, and d, finally symmetrically welding the inner sides of the upper and lower two transverse stiffenings on the other side, and the transverse stiffening is welded by using the solid mixed gas shielded welding semi-automatic trolley.

[0050] During the assembly process of the web plate 3 unit, the welding sequence of the transverse stiffening is reasonably arranged, symmetrically welding is used as much as possible, the workpiece is uniformly heated and shrunk on both sides, thereby reducing the deformation of the web plate 3 and effectively controlling the flatness of the web plate 3 unit.

[0051] ⑥During the production of the top and bottom plate 7 unit, part of the U ribs 2 does not pass through the web plate 3, is disconnected at the position of the web plate 3, and is welded with the web plate 3, and the U ribs 2 at this position of the top and bottom plate 7 unit need to reserve a patching section of 300mm-500mm long.

[0052] The web plate 3 is a main force component, the web plate 3 connects the top and bottom plates 7 to form an integral cross section to resist distortion under eccentric load and transverse bending deformation under vehicle load, maintain stable cross section shape, and provide elastic support for the longitudinal ribs of the top plate 1. In order to ensure the weld between the web plate 3 and the top and bottom plates 7 during final assembly, the web plate 3 and the top and bottom plates 7 are welded and inspected after completion, and then installed.

[0053] The method of erecting the ground tire is: setting the ground tire support point at the intersection of the center line of the steel box girder structure and the center line of the partition plate 3, the intersection of the center line of the web plate 4 and the center line of the partition plate 3, the intersection of the bottom plate 7 fold line and the center line of the partition plate 3, and the intersection of the outer edge line of the web plate 4 and the center line of the partition plate 3, erecting the H steel support under the ground tire support point, the support has a base at the bottom end, the relative position of the support and the base does not move up or sink, and two adjacent supports are connected through rigid bracing.

[0054] The method of step S3 for constituting the steel beam box body includes the following steps:

[0055] A1, welding the weld between the web plate 4 and the bottom plate 7;

[0056] A2, welding the weld between the partition plate 3 and the web plate 4;

[0057] A3, welding the weld between the partition plate 3 and the bottom plate 7;

[0058] A4, bottoming the weld between the web plate 4 and the top plate 1;

[0059] A5, bottoming the weld between the top plate 1 and the partition plate 3 on both sides;

[0060] A6, checking the interface misalignment and flatness;

[0061] A7, adjusting the bolted U rib 2 embedded section of the top plate 1 to ensure that all holes can be connected with the connecting plate using positioning pins, and checking the connection accuracy of the bolted U rib 2;

[0062] A8, welding and installing the lifting lug, and turning over the lifting lug.

[0063] ①Sequential installation of the bottom plate 7 unit, the partition plate 3, the web plate 4 unit, and the top plate 1 unit: welding the weld between the web plate 4 and the bottom plate 7 → welding the weld between the partition plate 3 and the web plate 4 → welding the weld between the partition plate 3 and the bottom plate 7 → bottoming the weld between the web plate 4 and the top plate 1 → bottoming the weld between the top plate 1 and the partition plate 3 on both sides

[0064] First, the weld between the web plate 4 and the bottom plate 7 is welded, and then the weld between the partition plate 3 and the web plate 4 is welded, through welding process control, the steel box girder is fully matched with the ground tire, and the vertical linear type of the steel bridge is ensured; after bottoming the weld between the web plate 4 and the top plate 1, the weld between the top plate 1 and the partition plate 3 on both sides is bottomed, the welding sequence reasonably controls the linear type of the planar direction circular arc line and the gentle curve of the steel box girder, thereby realizing the linear control of the overall structure of the bridge.

[0065] ②Before the roof 1 unit is made, the U rib 2 standard section is placed in the corresponding partition plate 3 U type rib slot hole. When the roof 1 unit is made, the U type rib standard section is not assembled. When the assembly is completed, the U rib 2 standard section is connected together by the connecting plate, the diagonal hole position of each surface is fixed by the pin, and the remaining hole position is randomly arranged two bolts, and the U rib 2 standard section is fixed firmly by the connecting plate. The welding seam between the positioning and reinforcing U rib 2 standard section and the roof 1 is welded after the bottom filling, and then the connecting plate is disassembled.

[0066] Due to the above method, the positioning accuracy and flatness of the U rib 2 are ensured, the welding deformation is small, the bending and torsional stiffness is large, the stability is good, the elastic performance is good, the fatigue resistance is good, and the method is suitable for structures bearing dynamic load. The positioning difficulty of the assembly and assembly is greatly reduced, the welding workload during the on-site installation is reduced, the operation is simple, and the assembly and installation time is saved.

[0067] The method for checking and correcting the line shape of the steel beam box body comprises the following steps:

[0068] B1, check the line type, the overall size of the bridge, the site opening error and the flatness before the bridge is finally delivered from the factory, and ensure that the on-site installation precision requirements are met;

[0069] B2, install the positioning plate, and the positioning plate is positioned and welded in groups;

[0070] B3, measure the positioning points of the real measurement and the data is used as the final installation positioning data.

[0071] The above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A welding method of a curved variable-width continuous steel box girder structure, characterized by: The method comprises the following steps: S1, the top plate (1) unit, the bottom plate (7) unit, the partition plate (3) unit and the web plate (4) unit are respectively pre-assembled and welded; S2, measure the line and set up the ground tire; S3, sequentially install the bottom plate (7) unit, the partition plate (3) unit, the web plate (4) unit and the top plate (1) unit on the ground tire to form the steel beam box body; S4, disassemble the tire, and check and correct the line shape of the steel beam box body; The bottom plate (7) unit comprises a plurality of linear segment bottom plates (7) and arc segment bottom plates (7) connected end to end, the linear segment bottom plate (7) is a horizontal iron plate, and the arc segment bottom plate (7) is obtained by rolling the linear segment bottom plate (7) to a preset arc through a plate rolling machine, and the pre-assembled and welded method of the bottom plate (7) unit is that the splicing sequence of the linear segment bottom plate (7) or the arc segment bottom plate (7) is that the longitudinal segment is spliced first in the transverse seam and then in the longitudinal seam, the transverse segment is spliced first in the longitudinal seam and then in the transverse seam, and small units are spliced first and then large units are spliced; The welding sequence conforms to the characteristics that the longitudinal segment of the steel box girder mainly bears longitudinal force and the transverse segment mainly bears transverse force, so that the vehicle load is uniformly transmitted from the bridge deck to the longitudinal rib, the longitudinal beam, the transverse beam and the support, and stress concentration is reduced in the welding process; The method for setting up the ground tire in step S2 is that a ground tire support point is arranged at the intersection of the steel box girder structure center line and the partition plate (3) center line, the intersection of the web plate (4) center line and the partition plate (3) center line, the intersection of the bottom plate (7) broken line and the partition plate (3) center line and the intersection of the web plate (4) outer edge line and the partition plate (3) center line, an H-shaped support is erected below the ground tire support point, the support has a base at the bottom end, the relative position of the support and the base does not move up or sink, and two adjacent supports are connected through a rigid stay.

2. The method of claim 1, wherein the method further comprises: welding the first and second curved steel plates to the first and second straight steel plates, respectively, to form the first and second curved beam portions, respectively. The method for forming the steel beam box body in step S3 comprises the following steps: A1, welding the weld joint between the web plate (4) and the bottom plate (7); A2, welding the weld joint between the partition plate (3) and the web plate (4); A3, welding the weld joint between the partition plate (3) and the bottom plate (7); A4, bottoming the weld joint between the web plate (4) and the top plate (1); A5, bottoming the weld joint on both sides of the top plate (1) and the partition plate (3); A6, checking the interface gap and flatness; A7, adjusting the bolted U rib (2) embedded section of the top plate (1) to ensure that all holes can be connected with the connecting plate through the positioning pin, and checking the connection accuracy of the bolted U rib (2); A8, welding and installing the lifting lug, and turning over the lifting lug.

3. The method of claim 1, wherein the method further comprises: welding the first and second curved steel plates to the first and second straight steel plates, respectively, to form the curved variable-width continuous steel box girder structure. The method for checking and correcting the line shape of the steel beam box body in step S4 comprises the following steps: B1, checking the line type, the overall size of the bridge, the interface gap and the flatness of the bridge before the bridge is finally delivered from the factory to ensure that the installation precision requirements are met; B2, installing the positioning plate, and the positioning plate is welded in groups; B3, actually measuring the positioning points of the tire and taking the data as the final installation positioning data.

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