Hoisting and welding process of steel box girder

Abstract

The present application relates to a kind of hoisting and welding process of steel box girder, steel box girder is composed of multiple box girder segments, box girder segment includes beam bottom plate, web plate arranged at the both ends of beam bottom plate and intermediate transverse partition plate arranged on beam bottom plate and between two web plates, the upper end of beam bottom plate, web plate and intermediate transverse partition plate is connected with beam top plate, the center position between beam top plate and beam bottom plate has longitudinal partition plate, the interval between two web plates gradually increases from bottom to top;Specific steps include: hoisting and positioning beam bottom plate of steel box girder to pier and preliminary fixed by spot welding, hoist web plate, intermediate transverse partition plate, longitudinal partition plate and beam top plate in sequence, temporarily positioned and connected between two beam segments connected adjacent by flexible member, then welded to form box girder segment in sequence, adjacent box girder segment is welded to form steel box girder.The present application has the following advantages: reduce the generation of welding deformation and structural secondary force, protect steel box girder from stress damage.

Description

Technical Field

[0001] This invention belongs to the field of steel box girders, and specifically relates to a hoisting and welding process for steel box girders. Background Technology

[0002] Currently, steel box girder structures are mainly used for urban elevated curved bridges, long-span cable-stayed bridges, and suspension bridges. When calculating the overall structure of a box girder, the dead load, vehicle load, wind load, and seismic load are mainly considered, but explosive loads are not yet considered. When designing the cross-section of a steel box girder structure, the overall stability and local stability of the structure during construction and fatigue issues during operation are mainly considered.

[0003] The hoisting and welding process of steel box girders is a key part of the entire bridge design and construction. The quality of the hoisting and welding process plays a decisive role in the safety and stability of the bridge. In the traditional steel box girder hoisting and welding process, the bottom plate, web, diaphragm, and top plate are hoisted and welded one segment at a time. After the welding of one segment is completed, the next segment is hoisted and welded until the box girder segment is completed. Before welding, the linear lifting range of the beam segment is relatively large. If the ends or bottoms of adjacent beam segments are welded closed at this time, it will cause excessive tensile stress in the axial direction of the beam segment. If the tensile stress exceeds the allowable strength value, it will cause structural damage to the bottom plate, web, diaphragm, and top plate of the beam. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a hoisting and welding process for steel box girders, which reduces welding deformation and the generation of secondary internal forces in the structure, and protects the steel box girders from stress damage.

[0005] The objective of this invention is achieved through the following technical solution: a hoisting and welding process for a steel box girder, wherein the steel box girder is composed of multiple box girder segments, each box girder segment including a bottom plate, webs at both ends of the bottom plate, and intermediate transverse partitions on the bottom plate and between the two webs. The top plate, webs, and intermediate transverse partitions are connected together at their upper ends to a top plate. A longitudinal partition is located at the center between the top plate and the bottom plate, and side plates are located on both sides of the longitudinal partition between the top plate and the bottom plate. The two webs are arranged axially symmetrically, and the distance between the two webs gradually increases from bottom to top.

[0006] The specific steps of the hoisting and welding process for steel box girders include: hoisting the bottom plate of the steel box girder onto the pier for positioning and initially fixing it by spot welding; hoisting the web plate, intermediate transverse diaphragm, longitudinal diaphragm, and top plate in sequence; temporarily positioning and connecting two adjacent beam segments through flexible components; and then welding them in sequence to form box girder segments. Adjacent box girder segments are then welded together to form a steel box girder.

[0007] A further improvement of the present invention is that, when welding the box girder segments, the weld between the intermediate transverse diaphragm and the web is welded first, then the weld between the web and the bottom plate of the beam is welded, then the weld between the intermediate transverse diaphragm and the longitudinal diaphragm is welded, and finally the weld between the top plate of the beam and the web, the intermediate transverse diaphragm, and the longitudinal diaphragm is welded.

[0008] A further improvement of the present invention is that, when welding two adjacent box girder segments, the two adjacent web plates are first butted and welded, then the two adjacent bottom plates are butted and welded, and finally the two adjacent top plates are butted and welded.

[0009] A further improvement of the present invention is that: two adjacent beam segments in the hoisting web, intermediate transverse partition, longitudinal partition and beam top plate are temporarily connected by hinges.

[0010] A further improvement of the present invention is that the intermediate transverse partition has multiple ventilation holes.

[0011] A further improvement of the present invention is that: the lower end face of the beam top plate and the upper end face of the beam bottom plate both have a plurality of U-shaped reinforcing ribs distributed along the radial direction of the beam bottom plate, and the openings of the U-shaped reinforcing ribs are set facing the corresponding beam bottom plate or beam top plate.

[0012] A further improvement of the present invention is that the inner wall of the web has an L-shaped reinforcing rib with an opening facing the bottom plate of the beam.

[0013] A further improvement of the present invention is that the U-shaped reinforcing ribs and L-shaped reinforcing ribs are welded and fixed after the bottom plate, web, intermediate transverse diaphragm, top plate and longitudinal diaphragm of the box girder segment are all welded.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] In this invention, when hoisting and welding steel box girder segments, welding is carried out only after all segments have been hoisted. During the hoisting process, adjacent segments are initially positioned and connected using a hinged connection method to ensure that the distance between the lower edges of all segments is minimized during welding. This prevents excessive secondary internal forces from being generated after forced welding. The elevations of the segments before and after welding are basically consistent, minimizing welding deformation and the generation of secondary internal forces, and protecting the steel box girder from stress damage. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the steel box girder segment in this invention.

[0017] Numbering on the map:

[0018] 1-Box girder segment, 2-Bottom plate of girder, 3-Web plate, 4-Intermediate transverse diaphragm, 5-Top plate of girder, 6-Longitudinal diaphragm, 7-Flexible component, 8-Ventilation hole, 9-U-shaped reinforcing rib, 10-L-shaped reinforcing rib, 11-Side plate. Detailed Implementation

[0019] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0020] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship, such as those based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the structure or unit referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0021] In this invention, unless otherwise explicitly specified and limited, terms such as “connection,” “provided with,” and “have” should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. They can be described as a mechanical connection, a direct connection, or a connection through an intermediate medium. Those skilled in the art can understand the basic meaning of the above terms in this invention according to the specific circumstances.

[0022] A steel box girder hoisting and welding process, such as Figure 1 As shown, the steel box girder is composed of multiple box girder segments 1. Each box girder segment 1 includes a bottom plate 2, webs 3 set at both ends of the bottom plate 2, and intermediate transverse partitions 4 set on the bottom plate 2 and between the two webs 3. The bottom plate 2, webs 3, and intermediate transverse partitions 4 are connected to a top plate 5 at their upper ends. A longitudinal partition 6 is located at the center between the top plate 5 and the bottom plate 2. Side plates 11 are located on both sides of the longitudinal partition 6 between the top plate 5 and the bottom plate 2. The two webs 3 are arranged axially symmetrically, and the distance between the two webs 3 gradually increases from bottom to top.

[0023] The specific steps of the hoisting and welding process of the steel box girder include: hoisting the bottom plate 2 of the steel box girder to the pier for positioning and fixing it initially by spot welding; hoisting the web plate 3, the intermediate transverse diaphragm 4, the longitudinal diaphragm 6 and the top plate 5 in sequence; temporarily positioning and connecting two adjacent beam segments through flexible parts 7; and then welding them in sequence to form box girder segments 1. Adjacent box girder segments 1 are then welded together to form a steel box girder.

[0024] In this invention, when hoisting and welding steel box girder segments, welding is carried out only after all segments have been hoisted. During the hoisting process, adjacent segments are initially positioned and connected using a hinged connection method to ensure that the distance between the lower edges of all segments is minimized during welding. This prevents excessive secondary internal forces from being generated after forced welding. The elevations of the segments before and after welding are basically consistent, minimizing welding deformation and the generation of secondary internal forces, and protecting the steel box girder from stress damage.

[0025] Based on this embodiment, when welding box girder segment 1, the weld between the intermediate transverse diaphragm 4 and the web 3 is welded first, then the weld between the web 3 and the bottom plate 2 is welded, then the weld between the intermediate transverse diaphragm 4 and the longitudinal diaphragm 6 is welded, and finally the weld between the top plate 5 and the web 3, the intermediate transverse diaphragm 4, and the longitudinal diaphragm 6 is welded.

[0026] Based on this embodiment, when welding two adjacent box girder segments 1, the two adjacent web plates 3 are first butted and welded, then the two adjacent bottom plates 2 are butted and welded, and finally the two adjacent top plates 5 are butted and welded.

[0027] Based on this embodiment, the two adjacent beam segments in the hoisting web 3, intermediate transverse partition 4, longitudinal partition 6, and beam top plate 5 are temporarily connected by hinges.

[0028] Based on this embodiment, the intermediate transverse partition 4 has multiple ventilation holes 8. The ventilation holes 8 on the intermediate transverse partition 4 play a role in stress relief. The ventilation holes 8 reduce the flow velocity in the water, reduce the impact of the water flow on the bridge pier, drain the water accumulated under the bridge, prevent the water level from rising, ensure the stability of the bridge structure, and play a good role in ventilation.

[0029] Based on this embodiment, the lower end face of the beam top plate 5 and the upper end face of the beam bottom plate 2 both have multiple U-shaped reinforcing ribs 9 distributed along the radial direction of the beam bottom plate 2, and the openings of the U-shaped reinforcing ribs 9 are set facing the corresponding beam bottom plate 2 or beam top plate 5.

[0030] Based on this embodiment, the inner wall of the web 3 has an L-shaped reinforcing rib 10 with an opening facing the bottom plate 2 of the beam.

[0031] Based on this embodiment, the U-shaped reinforcing rib 9 and the L-shaped reinforcing rib 10 are welded and fixed after the bottom plate 2, web 3, intermediate transverse diaphragm 4, top plate 5 and longitudinal diaphragm 6 of the box girder segment 1 are all welded.

[0032] In this application, the U-shaped reinforcing rib 9 provides good reinforcement to the bottom plate 2 and the top plate 5 of the beam, and the L-shaped reinforcing rib 10 provides good reinforcement to the web plate 3.

[0033] Those skilled in the art should understand that this invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to this invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A hoisting and welding process for steel box girders, characterized in that: The steel box girder is composed of multiple box girder segments (1). Each box girder segment (1) includes a bottom plate (2), webs (3) set at both ends of the bottom plate (2), and an intermediate transverse partition (4) set on the bottom plate (2) and between the two webs (3). The bottom plate (2), webs (3), and intermediate transverse partition (4) are connected together to a top plate (5). A longitudinal partition (6) is located at the center between the top plate (5) and the bottom plate (2). Side plates (11) are located on both sides of the longitudinal partition (6) between the top plate (5) and the bottom plate (2). The two webs (3) are arranged axially symmetrically, and the distance between the two webs (3) gradually increases from bottom to top. The specific steps of the hoisting and welding process of the steel box girder include: hoisting the bottom plate (2) of the steel box girder to the pier for positioning and fixing it initially by spot welding; hoisting the web plate (3), the intermediate transverse diaphragm (4), the longitudinal diaphragm (6) and the top plate (5) in sequence; temporarily positioning and connecting the two adjacent beam segments through the flexible parts (7); and then welding them in sequence to form the box girder segment (1); and welding adjacent box girder segments (1) to form the steel box girder.

2. The hoisting and welding process for a steel box girder according to claim 1, characterized in that: When welding the box girder segment (1), first weld the weld between the intermediate transverse diaphragm (4) and the web (3), then weld the weld between the web (3) and the bottom plate (2), then weld the weld between the intermediate transverse diaphragm (4) and the longitudinal diaphragm (6), and finally weld the weld between the top plate (5) and the web (3), the intermediate transverse diaphragm (4), and the longitudinal diaphragm (6).

3. The hoisting and welding process for a steel box girder according to claim 2, characterized in that: When welding two adjacent box girder segments (1), first connect and weld the two adjacent web plates (3), then connect and weld the two adjacent bottom plates (2), and finally connect and weld the two adjacent top plates (5).

4. The hoisting and welding process for a steel box girder according to claim 3, characterized in that: The two adjacent beam segments in the hoisting web (3), intermediate transverse partition (4), longitudinal partition (6) and beam top plate (5) are temporarily connected by hinges.

5. The hoisting and welding process for a steel box girder according to claim 4, characterized in that: The intermediate transverse partition (4) has multiple ventilation holes (8).

6. The hoisting and welding process for a steel box girder according to claim 5, characterized in that: The lower end face of the top plate (5) and the upper end face of the bottom plate (2) both have multiple U-shaped reinforcing ribs (9) distributed along the radial direction of the bottom plate (2), and the openings of the U-shaped reinforcing ribs (9) are set facing the corresponding bottom plate (2) or top plate (5).

7. The hoisting and welding process for a steel box girder according to claim 6, characterized in that: The inner wall of the web (3) has an L-shaped reinforcing rib (10) with an opening facing the bottom plate (2) of the beam.

8. The hoisting and welding process for a steel box girder according to claim 7, characterized in that: The U-shaped reinforcing ribs (9) and L-shaped reinforcing ribs (10) are welded and fixed after the bottom plate (2), web (3), intermediate transverse diaphragm (4), top plate (5) and longitudinal diaphragm (6) of the box girder segment (1) are all welded.

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