Steel bridge cantilever and welding method thereof

Abstract

The present application relates to the field of steel components, in particular to a steel bridge cantilever and its welding method; the steel bridge cantilever comprises a top plate, a group of rib plates arranged at the bottom of the top plate, a group of cantilever partitions and inner partitions arranged at the bottom of the top plate, and webs separating the inner partitions and the cantilever partitions; the bottom edge of each inner partition is in an arc shape protruding away from the top plate, and the bottom edge of each cantilever partition is in an arc shape protruding towards the top plate; the structure further comprises a bottom plate and a side sealing plate; the large-scale structure cantilever is more material-saving and lighter in weight; when the cantilever is welded and assembled, the modules are first welded to form the cantilever as a whole by assembling and welding the modules; the welding deformation can be better controlled by modular welding and assembly.

Description

Technical Field

[0001] This invention relates to the field of steel components, and more particularly to cantilevered steel bridges and their welding methods. Background Technology

[0002] With the rapid expansion of urban populations and the widespread adoption of automobiles, existing municipal roads can no longer meet the ever-increasing traffic demands. Constrained by limited urban space, large-span, ultra-wide municipal bridges are increasingly favored by design institutes. However, the increased bridge width also leads to problems such as lateral displacement, internal stress in steel box girder welding, and large cantilever deformation of steel box girders. Therefore, research on the construction technology of wide-span steel box girders is of great significance. In recent years, with rapid economic development, my country's traffic volume has increased significantly. Traditional concrete box girder bridges often experience problems such as diagonal cracking of the web and excessive deflection at mid-span during operation. With the updating of continuous bridge design concepts and continuous optimization of structural sections, box girder bridges are gradually developing towards high span ratios and large cantilever designs. As people's requirements for the appearance and function of bridges become increasingly demanding, steel box girder bridges are beginning to adopt design concepts from concrete bridges, and wide, streamlined, large cantilever steel box girders are gradually being widely used in urban bridges.

[0003] Traditional steel bridge cantilever steel components are typically open-type channel structures consisting of three parts: top plate unit, side sealing plate unit, and T-rib. They do not have web plate units, making the structure relatively simple. The components themselves have small geometric dimensions and no closed bottom plate unit, resulting in a large operating space, which facilitates assembly and welding operations. Furthermore, the internal welds are mostly fillet welds with minimal welding deformation. They are usually assembled using the "integral assembly method," making overall manufacturing relatively easy. For example, the bicycle high-speed steel box girder structure and its manufacturing method disclosed in Chinese invention patent application CN107142831A involve a fish-belly cantilever structure and its manufacturing method. The cantilever part uses a partition with a uniform curvature, and the decorative panel is connected to the partition by welding. This structure is simple and convenient for manufacturing small-sized cantilevers. However, when the cantilever is wider, the unreasonable design of the partition curvature leads to a larger area of ​​the cantilever partition and an increase in mass. At the same time, the assembly and welding in this patent application adopts a sequential welding method, which makes it difficult to control the welding deformation of large-sized steel structures. This can easily result in low dimensional accuracy of the finished product, causing difficulties in subsequent assembly. In addition, the method of fixing the decorative panel by welding makes subsequent maintenance and replacement difficult. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a novel cantilever structure that saves sheet metal, reduces the weight of large-format fish-belly cantilever arms, and facilitates convenient and quick assembly and welding, effectively controlling welding thermal deformation. The technical solution adopted in this invention is as follows:

[0005] A steel-framed bridge cantilever includes a top plate that serves as the bridge deck of the cantilever portion.

[0006] A set of ribs is arranged along the width direction of the top plate at the bottom of the top plate;

[0007] A set of cantilevered partitions and inner partitions are arranged along the length of the top plate at the bottom of the top plate;

[0008] A web plate separating the inner partition plate and the cantilever partition plate is provided at the bottom of the top plate along the length of the top plate;

[0009] The bottom edge of each inner partition is an arc shape that protrudes away from the top plate, and the bottom edge of each cantilever partition is an arc shape that protrudes closer to the top plate.

[0010] A bottom plate is provided at the bottom of the inner partition, covering the bottom edge of the inner partition and matching the arc shape of the bottom edge of the inner partition;

[0011] A side sealing plate covering the end of the cantilever partition is provided at the end of the top plate away from the inner partition.

[0012] Furthermore, reinforcing ribs are provided on the side of the web and bottom plate that connects with the inner partition.

[0013] Furthermore, the ribs include U-shaped ribs and flat ribs, with one set of each flat rib disposed on the side of the side sealing plate.

[0014] Furthermore, mounting plates are provided at the arc-shaped edges of each of the aforementioned cantilever partitions, arranged in a T-shape with respect to the cross-section of the cantilever partition.

[0015] Furthermore, a decorative panel is bolted to the mounting plate.

[0016] A method for assembling the steel bridge cantilever of claim 1 includes the following steps:

[0017] a. Prepare materials and cut the plates to obtain the top plate plate, inner partition plate plate, cantilever partition plate plate, web plate plate, bottom plate plate, reinforcing rib plate plate, rib plate plate, and side sealing plate plate. Bend some of the rib plate plates into U-shaped rib plates and bend the bottom plate plate plate into an arc-shaped bottom plate.

[0018] b. Module welding: Weld the rib plate and U-shaped rib to the bottom of the top plate to obtain the top plate module; weld the reinforcing rib plate and inner partition plate to the web plate to obtain the inner partition module; weld the reinforcing rib plate to the bottom plate to obtain the bottom plate module.

[0019] c. Assemble the cantilever: Weld the inner partition module to the side of the top plate module with the rib, weld the cantilever partition plate to the side of the top plate module with the rib, weld the side sealing plate to the edge of the top plate module and weld it to one end of each cantilever partition plate, and weld the bottom plate module to the web plate and the bottom edge of each inner partition plate.

[0020] Furthermore, during material preparation, the top plate material has several sections. When welding the top plate module, the rib plate material and U-shaped rib are first welded to the corresponding sections of the top plate material. Then, the sections of the top plate material with the rib plate material and U-shaped rib are spliced ​​and welded together to form the top plate module.

[0021] Furthermore, during the assembly of the cantilever, the top surface of the top plate module is inverted onto a horizontal plane for welding of each module.

[0022] Furthermore, during material preparation in step a, the mounting plate and decorative plate are cut and obtained; during module welding in step b, the mounting plate is welded to the arc-shaped edge of the cantilever partition plate so that the cross-section of the mounting plate and the cantilever partition plate forms a T-shape in the cantilever partition module; after the cantilever is assembled in step c, the decorative plate is bolted to the mounting plate; the bolt mounting holes on the decorative plate are drilled before installation, and the bolt connection holes on the mounting plate are positioned and drilled through the bolt mounting holes on the decorative plate during installation.

[0023] By adopting the above technical solution, the partition is divided into an inner partition and a cantilever partition. The cantilever partition's arc-shaped edge protrudes towards the top plate, reducing material consumption and thus lightening the overall weight of the cantilever. The web between the inner partition and the cantilever partition facilitates their installation and fixation, and provides effective support for the cantilever partition, resulting in better stress distribution. During welding, a prefabricated modular structure is used, followed by assembly and welding of the modules, which effectively controls thermal deformation during welding and provides better precision. The decorative panel is bolted to the cantilever partition for easy disassembly and maintenance. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the top plate module structure;

[0026] Figure 3 This is a schematic diagram of the inner partition module structure;

[0027] Figure 4 This is a schematic diagram of the base plate module structure;

[0028] Figure 5 This is a schematic diagram of the cantilever partition module;

[0029] Figure 6 A schematic diagram of the assembly structure of the top plate module and the inner partition module;

[0030] Figure 7 This is a schematic diagram of the assembly structure of the cantilever partition module and the top plate module;

[0031] Figure 8This is a schematic diagram of the assembly structure of the base plate module and the inner partition module;

[0032] Figure 9 A schematic diagram of the cantilever structure after the decorative panel is installed.

[0033] The components are: 1. Top plate; 2. Rib plate; 2a. U-shaped rib plate; 2b. Flat rib plate; 3. Cantilever partition plate; 4. Inner partition plate; 5. Web plate; 6. Bottom plate; 7. Side sealing plate; 8. Reinforcing rib; 9. Mounting plate; 10. Decorative plate. Detailed Implementation

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings. The length and width referred to below are with reference to the extension direction of the bridge, that is, the extension direction of the bridge is the length direction.

[0035] like Figure 1 The steel bridge cantilever shown includes a top plate 1, a rib plate 2, a cantilever diaphragm 3, an inner diaphragm 4, a web plate 5, a bottom plate 6, and a side sealing plate 7.

[0036] The top surface of the top plate 1 serves as the bridge deck, which is spliced ​​with the bridge steel structure to increase the width of the bridge deck.

[0037] A set of ribs 2 are arranged on the bottom surface of the top plate 1 along the width of the top plate 1. Each rib 2 extends along the length of the top plate 1. The ribs 2 are divided into two types according to their cross-sectional structure: U-shaped ribs 2a and flat ribs 2b. U-shaped ribs 2a have a larger cross-sectional area and better strength. A set of them is arranged on a section of the top plate 1 near the inner side of the main body of the bridge. Since the edge of the cantilever is mainly a sidewalk, and there is not enough space to install U-shaped ribs 2a when the height of the cantilever partition 3 is reduced near the edge, a set of flat ribs 2b is arranged on a section near the outer edge of the top plate 1.

[0038] Both the inner partition 4 and the cantilever partition 3 are arranged along the length of the top plate 1 on the bottom surface of the top plate 1. The bottom edge of the inner partition 4 is set as an arc and the arc protrusion faces away from the top plate. The bottom edge of the cantilever partition (3) is also set as an arc but the arc protrusion faces the top plate. As a result, the cantilever partition 3 uses less material for the same specifications compared to the structure with the arc protrusion at the bottom edge away from the top plate 1 or the bottom inclined straight line, thus making the cantilever lighter.

[0039] A web plate 5 is also provided on the bottom surface of the top plate 1, which separates the inner partition plate 4 and the cantilever partition plate 3 along the length of the top plate 1. Due to the special arc shape of the bottom edge of the cantilever partition plate 3, the web plate 5 can provide better stress support for the cantilever partition plate 3, ensuring the structural strength requirements of the cantilever.

[0040] To increase the fit between the web 5 and the inner diaphragm 4, a set of reinforcing ribs 8 are provided on the side of the web 5 closest to the inner diaphragm 4.

[0041] A base plate 6 is provided at the bottom edge of the inner partition 4. The base plate 6 has a certain curvature that matches the curvature of the bottom edge of the inner partition 4. The base plate 6 completely covers the web 5 and one bottom end of the inner partition 4. Similarly, in order to increase the strength of the base plate 6, a reinforcing rib 8 is provided on the side of the base plate 6 near the inner partition 4.

[0042] The side sealing plate 7 is installed on the outer edge of the top plate 1 as a protective and decorative element, covering one end of the outer side of the cantilever partition 3.

[0043] For both protection and decoration, mounting plates 9 are provided at the curved edges of the bottom of each cantilever partition 3. The mounting plates 9 and the cantilever partition 3 have a T-shaped cross-section. Decorative panels 10 can also be installed on the mounting plates 9 by bolts. Figure 8 (The corresponding display is shown in the middle), which facilitates the installation and disassembly of the decorative panel 10, and makes maintenance and replacement easier.

[0044] The above describes the cantilever structure of this bridge. Due to its complex structure and difficult assembly and welding, the assembly and welding method of the cantilever is further explained in detail below with reference to the attached drawings to ensure effective control of welding deformation:

[0045] a. Material preparation:

[0046] The top plate, inner partition plate, cantilever partition plate, web plate, bottom plate, reinforcing rib plate, rib plate, and side sealing plate are obtained by cutting the plates. These plates are then assembled and welded to form a cantilever, corresponding to the top plate, inner partition, cantilever partition, web, bottom plate, and the reinforcing ribs, ribs, and side sealing plates on the web and bottom plates, respectively. Because the ribs have different cross-sections, some rib plates need to be bent in advance to obtain U-shaped ribs 2a. Furthermore, because the bottom plate 6 has a certain curvature, it also needs to be pre-bent to conform to the curvature of the bottom edge of the inner partition. The remaining plates are cut according to their specifications and shapes.

[0047] The mounting plate 9 and decorative plate 10 mentioned in the above cantilever structure are not essential components of the cantilever. Therefore, when it is necessary to add decorative plate 10, the corresponding mounting plate material and decorative plate material also need to be cut during material preparation.

[0048] b. Module welding:

[0049] During module welding, different sheet materials are welded separately into smaller, assembled modules. This includes welding ribbed sheet materials and U-shaped ribs to the top sheet material to obtain the top plate module. (When the top sheet material is composed of multiple sets of spliced ​​materials, the ribbed sheet materials or U-shaped ribs are first welded to each fixed top sheet material, such as...) Figure 2As shown, the top plate panels are then spliced ​​and welded together along the width direction to form a single top plate module; the web plates and reinforcing rib plates are welded together, and then the inner partition plates are welded to the web plates to obtain the desired result. Figure 3 The inner partition module shown; the reinforcing rib plate is welded to the pre-bent base plate to obtain the following: Figure 4 The base plate module shown;

[0050] When decorative panels need to be installed on cantilever partitions, the mounting plate is welded to the end of the cantilever partition plate with the curved edge during module welding to form a shape like... Figure 5 The cantilever partition module shown.

[0051] c. Assemble the cantilever:

[0052] To facilitate welding, the top plate material in the top plate module is placed horizontally with the top surface facing down.

[0053] like Figure 6 The inner partition module is welded to the corresponding position on one side of the top plate module where the rib is set;

[0054] Then as Figure 7 The cantilever partition module is welded to the top plate module on one side of the rib plate (in this embodiment, since the cantilever partition plate is welded with an installation plate, when the decorative plate is not required, it is only necessary to weld the cantilever partition plate to the top plate module on one side of the rib plate).

[0055] Then as Figure 7 The diagram shows the side sealing plate being welded to the edge of the top plate and to the end edges of each cantilever partition plate.

[0056] like Figure 8 The bottom plate module is welded to the bottom edge of the inner partition plate and the web plate, as shown.

[0057] like Figure 9The decorative panel is bolted to the mounting plate. Since drilling holes in both the decorative and mounting plates is necessary for bolt installation, the decorative panels are cut to size according to the design drawings. Because the mounting plate needs to be welded to the cantilever partition, deformation and assembly errors can occur. Therefore, to avoid misalignment, the mounting plate is positioned using the gaps in the decorative panel, and holes are then drilled before the decorative panel is installed. Since the cantilever partition is shorter closer to the side panel, and considering that there are no pipes or other devices in this area for future maintenance, this part of the decorative panel can be welded to the mounting plate. The decorative panel closer to the inner partition usually contains pipes, and this part can be bolted. When bolting, the edge where the decorative panel meets the base plate also needs to be bolted. Of course, the optimal solution is to bolt all the decorative panels together.

[0058] Using the above method, a modular welding forming method with a relatively simple structure and small specifications is adopted. Finally, the cantilever is formed by welding and combining the modules, which can better control welding deformation and ensure the dimensional specifications of the finished cantilever beam. The decorative panels are connected by bolts, which facilitates installation and disassembly and makes it easier for later maintenance.

Claims

1. A steel-structured bridge cantilever, comprising a top plate (1) serving as the bridge deck of the cantilever portion, characterized in that: A set of ribs (2) are arranged at the bottom of the top plate (1) along the width direction of the top plate (1); the ribs (2) include U-shaped ribs (2a) and flat ribs (2b), and each set of flat ribs (2b) is provided on the side of the side sealing plate (7); A set of cantilever partitions (3) and inner partitions (4) are arranged along the length of the top plate (1) at the bottom of the top plate (1); A web plate (5) is provided at the bottom of the top plate (1) along the length direction of the top plate (1) to separate the inner partition plate (4) and the cantilever partition plate (3); The bottom edge of each inner partition (4) is an arc shape that protrudes away from the top plate (1), and the bottom edge of each cantilever partition (3) is an arc shape that protrudes closer to the top plate (1). A bottom plate (6) is provided at the bottom of the inner partition (4) to cover the bottom edge of the inner partition (4) and to match the arc shape of the bottom edge of the inner partition (4); a reinforcing rib (8) is provided on the side of the web plate (5) and the bottom plate (6) that is connected to the inner partition (4); A side sealing plate (7) covering the end of the cantilever partition (3) is provided at the end of the top plate (1) away from the inner partition (4).

2. A steel bridge cantilever according to claim 1, characterized in that: Mounting plates (9) are provided at the arc-shaped edges of each of the cantilever partitions (3) in a T-shape arrangement with the cross-section of the cantilever partition (3).

3. A steel bridge cantilever according to claim 2, characterized in that: A decorative panel (10) is bolted to the mounting plate (9).

4. A method for welding the cantilever of a steel bridge as described in claim 1, comprising the following steps: a. Prepare materials and cut the plates to obtain the top plate plate, inner partition plate plate, cantilever partition plate plate, web plate plate, bottom plate plate, reinforcing rib plate plate, rib plate plate, and side sealing plate plate. Bend some of the rib plate plates into U-shaped rib plates and bend the bottom plate plate plate into an arc-shaped bottom plate. b. Module welding: Weld the rib plate and U-shaped rib to the bottom of the top plate to obtain the top plate module; weld the reinforcing rib plate and inner partition plate to the web plate to obtain the inner partition module; weld the reinforcing rib plate to the bottom plate to obtain the bottom plate module. c. Assemble the cantilever: Weld the inner partition module to the side of the top plate module with the rib, weld the cantilever partition plate to the side of the top plate module with the rib, weld the side sealing plate to the edge of the top plate module and weld it to one end of each cantilever partition plate, and weld the bottom plate module to the web plate and the bottom edge of each inner partition plate.

5. A method for welding a cantilevered steel structure bridge according to claim 4, characterized in that: When preparing the materials, the top plate has several sections. When welding the top plate module, first weld each rib plate and U-shaped rib to the corresponding top plate section. Then, splice and weld the top plate sections with rib plates and U-shaped ribs to form the top plate module.

6. A method for welding a cantilevered steel bridge according to claim 4 or 5, characterized in that: When assembling the cantilever, the top surface of the top plate module is inverted on a horizontal plane for welding of each module.

7. A method for welding a cantilevered steel structure bridge according to claim 5, characterized in that: In step a, during material preparation, the mounting plate and decorative plate are cut and obtained; in step b, during module welding, the mounting plate is welded to the arc edge of the cantilever partition plate so that the cross-section of the mounting plate and the cantilever partition plate forms a T-shape in the cantilever partition module; in step c, after the cantilever is assembled, the decorative plate is bolted to the mounting plate; the bolt mounting holes on the decorative plate are drilled before installation, and the bolt connection holes on the mounting plate are drilled for positioning through the bolt mounting holes on the decorative plate during installation.

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