A structure and manufacturing method suitable for a steel truss arch bridge arch foot joint section

Abstract

The application relates to a structure and manufacturing method suitable for a steel truss arch bridge arch foot joint segment, which comprises a first main chord plate, a second main chord plate, a third main chord plate and a fourth main chord plate which are connected to form a rectangular section, and a plurality of flat boxes, the first main chord plate is located at the outer side of the main chord, the second main chord plate is located at the inner side of the main chord, the end of the first main chord plate and the end of the second main chord plate are respectively cantilevered relative to the third main chord plate and the fourth main chord plate, the cantilevered position of the first main chord plate is provided with a first cantilevered stiffener, the cantilevered position of the second main chord plate is provided with a second cantilevered stiffener, a plurality of flat boxes are symmetrically arranged on the outer wall of the first main chord plate, a plurality of flat boxes are symmetrically arranged on the outer wall of the second main chord plate, the number of the flat boxes arranged on the first main chord plate is greater than that of the flat boxes arranged on the second main chord plate, a plurality of flat boxes are respectively arranged on the outer walls of the third main chord plate and the fourth main chord plate, and the flat boxes are arranged close to the side of the second main chord plate. The structure is simple, convenient to use and good in effect.

Description

Technical Field

[0001] This invention relates to the field of bridge technology, and in particular to a construction and manufacturing method applicable to the arch foot joint section of a steel truss arch bridge. Background Technology

[0002] Large-span steel truss arch bridges require the transfer of dead loads from the arch ribs and bridge deck system, as well as live loads and wind loads during operation, to the arch abutment foundation via the arch foot connection section. The arch foot bears significant axial forces and bending moments. The axial compressive stiffness and bending stiffness of the steel truss arch foot members are much lower than those of the concrete arch abutment foundation, resulting in a significant abrupt change in stiffness at the connection interface and stress concentration in the structure. The steel structure of the arch ribs and the concrete structure of the arch abutment in steel truss arches and steel box arches complete the steel-concrete transition connection through the arch foot connection structure. There are two main types of arch foot connection structures: one is a bearing-shear-transfer steel-concrete hybrid structure, and the other is a fully bearing steel-concrete composite connection structure.

[0003] The first type of shear-loaded steel-concrete hybrid structure involves embedding a certain length of main truss members into the arch abutment. Shear studs are installed on the sidewalls of the members to connect them to the arch abutment concrete. The axial force of the truss members is transferred to the concrete arch abutment through friction between the members and the arch abutment concrete, and the shear force of the shear studs. The bending moment of the truss members is transferred to the concrete arch abutment through the pull-out and shear resistance of the shear studs. This connection method has good reliability. However, its disadvantages include abrupt stiffness changes at the interface between the truss members and the arch abutment. The portion of the main truss members embedded in the arch abutment forms a steel-concrete hybrid structure, resulting in unclear stress patterns and force transmission paths. The stress field in the arch abutment concrete within the embedded section is complex, making the concrete prone to cracking during operation. The larger dimensions of the embedded section also increase the difficulty of pouring the arch abutment concrete.

[0004] The second type of fully bearing steel-concrete composite connection structure solves many problems associated with the first type. Its working principle involves the axial force of the chord members being transferred to the concrete arch abutment through a bearing plate lattice, while the bending moment of the chord members is balanced by external prestressing. This effectively solves the problem of internal force transmission within the chord members, resulting in a clear force pattern and a well-defined force transmission path. It allows for manual calculation during the design phase, avoiding the need for repeated analysis and verification using finite element methods. It also avoids the inherent drawbacks of embedded structures, such as abrupt stiffness changes and complex stress distribution at the chord-abutment interface, making accurate analysis difficult. The steel-concrete composite connection structure is integrated with the arch foot chord, and the prestressing is applied outside the chord members.

[0005] This eliminates the need to pour concrete into the confined space inside the chord, simplifying construction and ensuring reliable quality. The steel-concrete composite connection fully leverages the advantages of both steel and concrete materials, simplifying construction and manufacturing, clearly transmitting internal forces, and exhibiting novel structure and distinctive features. This new connection method, with its clear force distribution, well-defined force transmission path, simple construction process, and high structural reliability, is therefore highly necessary.

[0006] However, when the structure is subjected to lateral wind control, resulting in significant tensile forces and unbalanced lateral bending moments at the arch foot under ultimate wind loads, the size of the main chord dictates that numerous flat boxes must be arranged on the outer side to anchor the steel tie rods, and larger flat boxes cannot be arranged internally. Figure 1 and Figure 2 As shown, the second proposed fully pressure-bearing steel-concrete composite connection structure has certain drawbacks:

[0007] (1) The existing scheme cannot effectively connect a large number of steel tie rods that meet the stress requirements to the main chord plate. In the figure, some steel tie rods are anchored to the bearing plate.

[0008] (2) The existing scheme's symmetrically arranged steel tie rods cannot balance the load, especially the large lateral bending moment generated by the ultimate wind load.

[0009] (3) When a large number of flat boxes are arranged on the outside according to the stress requirements, there is a large difference in stiffness between the inner and outer sides of the chord, resulting in inconsistent out-of-plane deformation of the chord.

[0010] (4) When many flat boxes are welded onto the web plate, the spacing between the flat boxes is small, and construction personnel cannot enter the space to perform full penetration welding.

[0011] Therefore, a new type of fully pressure-bearing steel-concrete composite connection structure and construction method is needed to solve the above problems. Summary of the Invention

[0012] The purpose of this invention is to address the problems in existing fully pressure-bearing steel-concrete composite connection structures, such as the weak ability of the main chord to resist the axial tensile force generated by extreme wind, and the inability of symmetrically arranged steel tie rods to balance the large lateral bending moment generated by the load, especially the extreme wind load. This invention provides a structure and manufacturing method suitable for the arch foot joint section of a steel truss arch bridge.

[0013] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0014] In a first aspect, the present invention provides a structure suitable for the arch foot joint section of a steel truss arch bridge, comprising a first main chord plate, a second main chord plate, a third main chord plate, and a fourth main chord plate connected to each other to form a rectangular cross-section, and further comprising a plurality of flat boxes. The first main chord plate is located outside the main chord, and the second main chord plate is located inside the main chord. The ends of the first main chord plate and the ends of the second main chord plate are cantilevered relative to the third main chord plate and the fourth main chord plate, respectively. The cantilevered portion of the first main chord plate is provided with a first cantilever stiffening plate, and the cantilevered portion of the second main chord plate is provided with a second cantilever stiffening plate. A plurality of flat boxes are symmetrically arranged on the outer wall of the first main chord plate, and a plurality of flat boxes are symmetrically arranged on the outer wall of the second main chord plate. The number of flat boxes arranged on the first main chord plate is greater than the number of flat boxes arranged on the second main chord plate. A plurality of flat boxes are arranged on the outer walls of the third main chord plate and the fourth main chord plate, and the flat boxes are arranged closer to the second main chord plate.

[0015] The flat box is used to anchor the steel tie rod.

[0016] The present invention employs a structure suitable for the arch foot joint section of a steel truss arch bridge. By cantilevering the first and second main chord plates, all the flat boxes can be connected to the main chord, more effectively transferring the force of the steel tie rods to the main chord, and then to the bearing plate and the foundation. This allows the prestress of the steel tie rods to be more effectively transferred to the main chord to resist the axial tension generated by extreme winds. The first and second cantilever stiffening plates reinforce the cantilevered sections, preventing deformation under the prestress of the steel tie rods. The asymmetrical arrangement of the flat boxes on the outer side of the main chord, which is greater than the number on the inner side, more effectively balances the huge unbalanced bending moment generated by the parallel arch bridge, resulting in a more reasonable stress distribution.

[0017] As a preferred technical solution of the present invention, the inner walls of the first main string plate, the second main string plate, the third main string plate and the fourth main string plate are provided with at least one main string stiffening plate.

[0018] By adopting this structure, the stiffening plate of the main chord is set on the inner wall of the main chord plate to balance the external stiffness of the inner and outer sides of the main chord plate, so that the deformation of the main chord of the arch foot is more coordinated, and the stress concentration phenomenon at the corner of the main chord caused by the difference in stiffness is alleviated, making the entire arch foot structure more uniform and reasonable in terms of force.

[0019] As a further preferred technical solution of the present invention, the first main chord plate, the second main chord plate, the third main chord plate, the fourth main chord plate, the flat box, the main chord stiffening plate, the first cantilever stiffening plate and the second cantilever stiffening plate are all connected to the bearing plate.

[0020] As a preferred technical solution of the present invention, the pressure plate is provided with a first pressure-bearing stiffening plate and a second pressure-bearing stiffening plate. The cross-section formed by the first pressure-bearing stiffening plate and the second pressure-bearing stiffening plate is arranged in a grid pattern. The first pressure-bearing stiffening plate is connected to the first main chord plate and the second main chord plate, and the second pressure-bearing stiffening plate is connected to the third main chord plate and the fourth main chord plate.

[0021] As a further preferred technical solution of the present invention, the longitudinal section of the first pressure-bearing stiffening plate is U-shaped.

[0022] As a preferred technical solution of the present invention, the tension of the steel tie rod in the flat box on the first main chord plate is greater than the tension of the steel tie rod in the flat box on the second main chord plate.

[0023] This structure can more effectively balance the huge unbalanced bending moment generated by parallel arch bridges, making the stress distribution more reasonable.

[0024] As a preferred technical solution of the present invention, each of the flat boxes includes two vertical plates arranged opposite each other, one end of the two vertical plates is connected to a horizontal plate, and the other end is connected to the first main chord plate, the second main chord plate, the third main chord plate or the fourth main chord plate, and the top of the vertical plates and the horizontal plates is connected to a top plate.

[0025] Secondly, the present invention also provides a steel truss arch bridge, including an arch base foundation, wherein the arch base foundation is provided with a structure as described in any of the above claims suitable for the arch foot joint section of a steel truss arch bridge.

[0026] The steel truss arch bridge of this invention employs a cantilevered arrangement of the first and second main chord plates, allowing all the flat boxes to be connected to the main chord. This more effectively transfers the force of the steel tie rods to the main chord, then to the bearing plate, and finally to the foundation. This allows the prestress of the steel tie rods to be more effectively transferred to the main chord to resist the axial tension generated by extreme winds. The cantilevered sections are stiffened by the first and second cantilever stiffening plates to prevent deformation under the prestress of the steel tie rods. The asymmetrical arrangement of the flat boxes on the outer side of the main chord, exceeding the number on the inner side, more effectively balances the enormous unbalanced bending moment generated by the parallel arch bridge, resulting in a more rational stress distribution.

[0027] Thirdly, the present invention also provides a manufacturing method for a structure applicable to the arch foot joint section of a steel truss arch bridge as described above, wherein the flat box on the third main chord plate is asymmetrically arranged about the central axis of the third main chord plate, and the flat box on the fourth main chord plate is asymmetrically arranged about the central axis of the fourth main chord plate, with the flat boxes on the third and fourth main chord plates closer to the second main chord plate. The method includes the following steps:

[0028] The flat boxes on the third and fourth main chord plates are constructed and connected to the vertical plates sequentially from the second main chord plate side to the first main chord plate side. Each vertical plate is connected to the third or fourth main chord plate and then immediately connected to the top plate. The vertical plate closest to the first main chord plate has a reserved space between it and the first main chord plate. Then, the horizontal plate is connected to the vertical plate and the top plate.

[0029] The present invention employs a manufacturing method for a structure suitable for the arch foot joint section of a steel truss arch bridge. By using an asymmetrical arrangement of the flat boxes on the non-cantilevered main chord plate close to the cantilevered main chord plate on the same side, the flat boxes are sequentially connected from the cantilevered main chord plate on the closer side to the cantilevered main chord plate on the farther side. The reserved space ensures that there is no obstruction within the connection position range of the vertical plate of the farthest flat box, thus guaranteeing the quality of the connection. This allows the connection work of the entire structure to be completed in a confined space.

[0030] As a preferred technical solution of the present invention, each of the vertical plates is welded to the third main chord plate or the fourth main chord plate by a single-sided bevel weld, and the range of the single-sided bevel of the vertical plate closest to the first main chord plate that is less than or equal to 50° is the reserved space.

[0031] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0032] 1. The present invention describes a structure applicable to the arch foot joint section of a steel truss arch bridge and a steel truss arch bridge. By cantilevering the first main chord plate and the second main chord plate, all the flat boxes can be connected to the main chord, which more effectively transmits the force of the steel tie rod to the main chord, and then to the bearing plate and the foundation. This allows the prestress of the steel tie rod to be more effectively transmitted to the main chord to resist the axial tensile force generated by extreme wind. The first and second cantilever stiffening plates are used to stiffen the cantilevered parts to prevent them from deforming under the prestress of the steel tie rod. The asymmetrical arrangement of the number of flat boxes on the outside of the main chord being greater than the number of flat boxes on the inside of the main chord more effectively balances the huge unbalanced bending moment generated by the parallel arch bridge, making the stress distribution more reasonable.

[0033] 2. A preferred embodiment of the present invention is a structure suitable for the arch foot joint section of a steel truss arch bridge. By setting the main chord stiffening plate on the inner wall of the main chord plate, the external stiffness of the inner and outer sides of the main chord plate is balanced, so that the deformation of the main chord of the arch foot is more coordinated, and the stress concentration phenomenon at the corner of the main chord caused by the difference in stiffness is alleviated, so that the entire arch foot structure is more uniformly and rationally stressed.

[0034] 3. In a preferred embodiment of the present invention, the tension of the steel tie rod in the flat box on the first main chord plate is greater than that of the steel tie rod in the flat box on the second main chord plate. This can more effectively balance the huge unbalanced bending moment generated by the parallel arch bridge, making the stress distribution more reasonable.

[0035] 4. The manufacturing method of the structure applicable to the arch foot joint section of a steel truss arch bridge according to the present invention involves an asymmetrical arrangement of the flat boxes on the non-cantilevered main chord plate close to the cantilevered main chord plate on the same side. The flat boxes are connected sequentially from the cantilevered main chord plate on the closer side to the cantilevered main chord plate on the farther side. The reserved space ensures that there is no obstruction within the connection position range of the vertical plate of the farthest flat box, thus ensuring the quality of the connection and completing the connection work of the entire structure in a narrow space. Attached Figure Description

[0036] Figure 1 This is a schematic elevation view of the existing fully pressure-bearing steel-concrete composite connection structure.

[0037] Figure 2 This is a plan view of the existing proposed fully pressure-bearing steel-concrete composite connection structure;

[0038] Figure 3 This is an elevation view of the structure of the arch foot joint section of a steel truss arch bridge to which this application applies;

[0039] Figure 4 for Figure 2 Schematic diagram of the sectional view along the central AA direction;

[0040] Figure 5 for Figure 3 Schematic diagram of the BB-direction section.

[0041] The markings in the diagram are: 1-First main chord plate, 2-Second main chord plate, 3-Third main chord plate, 4-Fourth main chord plate, 5-Flat box, 6-Main chord stiffening plate, 7-First cantilever stiffening plate, 8-Second cantilever stiffening plate, 9-First bearing stiffening plate, 10-Second bearing stiffening plate, 11-Bearing plate, 12-Vertical plate, 13-Horizontal plate, 14-Top plate, 15-Horizontal bracing, 16-Steel tie rod. Detailed Implementation

[0042] The present invention will now be described in detail with reference to the accompanying drawings.

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0044] Example 1

[0045] When the arch foot of a steel truss arch bridge is subjected to lateral loads, especially extreme winds, it experiences significant axial tensile force and lateral bending moment. In this situation, to ensure the bearing plate 11 remains in a continuous state, numerous flat boxes 5 need to be welded around the main chord plate to anchor the steel tie rods 16. Existing fully bearing steel-concrete composite connection structures only weld the flat boxes 5 to the main chord plate. However, due to the limited dimensions of the main chord, the number of flat boxes 5 and steel tie rods 16 arranged on the main chord plate is extremely limited. Some steel tie rods 16 are only anchored to the bearing plate 11, such as... Figure 1 and Figure 2 As shown, firstly, although this method can effectively anchor the bearing plate 11, the main chord has a weak ability to resist the axial tensile force generated by the extreme wind due to the small number of flat boxes 5 and steel tie rods 16 connecting the main chord. Secondly, under the action of extreme wind load, the outer side of the main chord of a steel truss arch bridge, especially a parallel arch bridge, is generally in an unfavorable tensile state under the action of a huge lateral unbalanced bending moment. The symmetrically arranged steel tie rods 16 cannot balance the load, especially the large lateral bending moment generated by the extreme wind load. Thirdly, according to the force requirements, a large number of large-diameter steel tie rods 16 need to be arranged in the steel-concrete composite section at the arch foot. In order to meet the size requirements of the nuts of the steel tie rods 16, the flat boxes 5 need to be made larger. At this time, the flat boxes 5 are only arranged on the outer side of the main chord plate, and it is difficult to arrange them in the inner space of the main chord plate. This makes the out-of-plane stiffness of the main chord plate significantly greater than the inner stiffness, which will produce a large out-of-plane stiffness inconsistency of the main chord plate. Under the action of huge pressure at the arch foot, a large displacement difference will occur between the inner and outer sides of the main chord plate.

[0046] like Figures 3 to 5 As shown, the present invention provides a structure suitable for the arch foot joint section of a steel truss arch bridge, comprising a first main chord plate 1, a second main chord plate 2, a third main chord plate 3, and a fourth main chord plate 4 connected to each other to form a rectangular cross section, and further comprising several flat boxes 5 and several main chord stiffening plates 6, wherein the flat boxes 5 are used to anchor steel tie rods 16.

[0047] like Figure 4 As shown, the first main string plate 1 is located outside the main string, and the second main string plate 2 is located inside the main string. The ends of the first main string plate 1 and the second main string plate 2 are respectively cantilevered relative to the third main string plate 3 and the fourth main string plate 4. The cantilevered part of the first main string plate 1 is provided with a first cantilever stiffening plate 7, and the cantilevered part of the second main string plate 2 is provided with a second cantilever stiffening plate 8.

[0048] like Figure 4As shown, a plurality of flat boxes 5 are symmetrically arranged on the outer wall of the first main chord plate 1, and a plurality of flat boxes 5 are symmetrically arranged on the outer wall of the second main chord plate 2. The number of flat boxes 5 on the first main chord plate 1 is greater than the number of flat boxes 5 on the second main chord plate 2. In this embodiment, eight flat boxes 5 are symmetrically arranged on the first main chord plate 1, and seven flat boxes 5 are symmetrically arranged on the second main chord plate 2. When a horizontal bracing 15 is welded to the main chord of the steel truss arch bridge, the flat boxes 5 need to be moved to avoid the horizontal bracing 15, which may reduce the number of flat boxes 5. Figure 4 The diagram illustrates that the second main string plate 2 is connected to the flat coupling 15. In this embodiment, cantilevering the first main string plate 1 and the second main string plate 2 can also effectively solve the problem of excessive displacement of the flat box 5 or reduce the number of the flat box 5.

[0049] like Figure 4 As shown, a plurality of flat boxes 5 are respectively provided on the outer walls of the third main chord plate 3 and the fourth main chord plate 4. The flat boxes 5 on the third main chord plate 3 are asymmetrically arranged about the central axis of the third main chord plate 3, and the flat boxes 5 on the fourth main chord plate 4 are asymmetrically arranged about the central axis of the fourth main chord plate 4. The flat boxes 5 are located closer to the second main chord plate 2. In this embodiment, five flat boxes 5 are respectively provided on the third main chord plate 3 and the fourth main chord plate 4.

[0050] like Figure 4 and Figure 5 As shown, at least one main chord stiffening plate 6 is provided on the inner wall of the first main chord plate 1, the second main chord plate 2, the third main chord plate 3, and the fourth main chord plate 4. With this structure, the external stiffness of the inner and outer sides of the main chord plate is balanced by setting the main chord stiffening plate 6 on the inner wall of the main chord plate, so that the deformation of the main chord of the arch foot is more coordinated, and the stress concentration phenomenon at the corner of the main chord caused by the difference in stiffness is alleviated, so that the entire arch foot structure is more uniformly and reasonably stressed. In this embodiment, three main chord stiffening plates 6 are respectively provided on the first main chord plate 1 and the second main chord plate 2 at intervals, and one main chord stiffening plate 6 is provided on the third main chord plate 3 and the fourth main chord plate 4.

[0051] like Figures 3 to 5As shown, the first main chord plate 1, the second main chord plate 2, the third main chord plate 3, the fourth main chord plate 4, the flat box 5, the main chord stiffening plate 6, the first cantilever stiffening plate 7, and the second cantilever stiffening plate 8 are all connected to the pressure plate 11. The pressure plate 11 is provided with a first pressure stiffening plate 9 and a second pressure stiffening plate 10. The cross-section formed by the first pressure stiffening plate 9 and the second pressure stiffening plate 10 is arranged in a grid pattern. The first pressure stiffening plate 9 is connected to the first main chord plate 1 and the second main chord plate 2, and the second pressure stiffening plate 10 is connected to the third main chord plate 3 and the fourth main chord plate 4. The longitudinal section of the first pressure stiffening plate 9 is U-shaped.

[0052] In one specific embodiment, the tension of the steel tie rod 16 installed in the flat box 5 on the first main chord plate 1 is greater than the tension of the steel tie rod 16 installed in the flat box 5 on the second main chord plate 2. With this structure, the huge unbalanced bending moment generated by the parallel arch bridge can be more effectively balanced, making the stress more reasonable.

[0053] In one specific embodiment, each of the flat boxes 5 includes two vertical plates 12 arranged opposite to each other. One end of each of the two vertical plates 12 is connected to a horizontal plate 13, and the other end is connected to the first main chord plate 1, the second main chord plate 2, the third main chord plate 3, or the fourth main chord plate 4. A top plate 14 is connected to the top of the vertical plates 12 and the horizontal plates 13.

[0054] Among them, the first main chord plate 1, the second main chord plate 2, the third main chord plate 3, the fourth main chord plate 4, the flat box 5, the main chord stiffening plate 6, the first cantilever stiffening plate 7, the second cantilever stiffening plate 8, the first pressure-bearing stiffening plate 9, the second pressure-bearing stiffening plate 10 and the pressure plate 11 are all steel structures and are connected by welding.

[0055] This embodiment describes a structure suitable for the arch foot joint section of a steel truss arch bridge. By cantilevering the first main chord plate 1 and the second main chord plate 2, all the flat boxes 5 can be connected to the main chord, more effectively transferring the force of the steel tie rod 16 to the main chord, and then to the bearing plate 11 and the foundation. This allows the prestress of the steel tie rod 16 to be more effectively transferred to the main chord to resist the axial tension generated by extreme winds. The first cantilever stiffening plate 7 and the second cantilever stiffening plate 8 are used to stiffen the cantilevered parts to prevent them from deforming under the prestress of the steel tie rod 16. The asymmetrical arrangement of the number of flat boxes 5 on the outside of the main chord being greater than the number of flat boxes 5 on the inside of the main chord more effectively balances the huge unbalanced bending moment generated by the parallel arch bridge, making the stress distribution more reasonable.

[0056] Example 2

[0057] like Figures 3 to 5 As shown, the present invention provides a steel truss arch bridge, including an arch base foundation, on which a structure suitable for the arch foot joint section of a steel truss arch bridge as described in Example 1 is provided.

[0058] The steel truss arch bridge described in this embodiment cantilevered the first main chord plate 1 and the second main chord plate 2, allowing all the flat boxes 5 to be connected to the main chord. This more effectively transfers the force of the steel tie rod 16 to the main chord, and then to the bearing plate 11 and the foundation. This allows the prestress of the steel tie rod 16 to be more effectively transferred to the main chord to resist the axial tension generated by extreme winds. The first cantilever stiffening plate 7 and the second cantilever stiffening plate 8 stiffen the cantilevered parts to prevent deformation under the prestress of the steel tie rod 16. The asymmetrical arrangement of the flat boxes 5 on the outer side of the main chord, which is greater than the number of flat boxes 5 on the inner side, more effectively balances the huge unbalanced bending moment generated by the parallel arch bridge, resulting in a more reasonable stress distribution.

[0059] Example 3

[0060] The existing fully pressure-bearing steel-concrete composite connection structure has a problem: when the main chord plate is connected to a large number of steel flat boxes 5, resulting in a small spacing between the flat boxes 5, construction personnel cannot enter the space to perform full penetration welding to connect the flat boxes 5 and the main chord plate.

[0061] like Figures 3 to 5 As shown, the present invention discloses a manufacturing method for a structure applicable to the arch foot joint section of a steel truss arch bridge as described in Embodiment 1. The flat box 5 on the third main chord plate 3 is asymmetrically arranged about the central axis of the third main chord plate 3, and the flat box 5 on the fourth main chord plate 4 is asymmetrically arranged about the central axis of the fourth main chord plate 4. The flat boxes 5 on the third and fourth main chord plates 3 and 4 are closer to the second main chord plate 2. The method includes the following steps:

[0062] The flat boxes 5 on the third main chord plate 3 and the fourth main chord plate 4 are connected to the vertical plates 12 sequentially from the side of the second main chord plate 2 to the side of the first main chord plate 1. Each vertical plate 12 is connected to the third main chord plate 3 or the fourth main chord plate 4 and then immediately connected to the top plate 14. The vertical plate 12 closest to the first main chord plate 1 has a reserved space with the first main chord plate 1. Then the horizontal plate 13 is connected to the vertical plate 12 and the top plate 14.

[0063] Specifically, construction first Figure 4The rightmost vertical plate 12 on the third main chord plate 3 and the fourth main chord plate 4 is welded to the third main chord plate 3 or the fourth main chord plate 4 with a single-sided bevel weld at its end, and then welded to the top plate 14 with a single-sided bevel weld. After completion, the vertical plates 12 are welded sequentially from right to left. The reserved space is defined as the area where the single-sided bevel of the vertical plate 12 closest to the first main chord plate 1 is less than or equal to 50°. Figure 4 The diagram illustrates a 50° angle, where there are no obstructions within the reserved space. Then, the horizontal plate 13 is welded to the vertical plate 12 and the top plate 14 using a single-sided bevel welding technique. Finally, the first cantilever stiffening plate 7 and the first main chord plate 1 are welded together.

[0064] This embodiment describes a manufacturing method for a structure applicable to the arch foot joint section of a steel truss arch bridge. By arranging the flat boxes 5 on the non-cantilevered main chord plate in an asymmetrical manner close to the cantilevered main chord plate on the same side, the flat boxes 5 are connected sequentially from the cantilevered main chord plate on the closer side to the cantilevered main chord plate on the farther side. The reserved space ensures that there is no obstruction within the connection position range of the vertical plate 12 of the farthest flat box 5, thus ensuring the quality of the connection. This allows the connection work of the entire structure to be completed in a confined space, providing a good solution for single-sided welding of the vertical plate 12 to the main chord plate, the top plate 14, and the horizontal plate 13 in a confined space.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A structure suitable for the arch foot joint section of a steel truss arch bridge, comprising a first main chord plate (1), a second main chord plate (2), a third main chord plate (3), and a fourth main chord plate (4) connected to each other to form a rectangular cross section, and further comprising a plurality of flat boxes (5), characterized in that, The first main chord plate (1) is located outside the main chord, and the second main chord plate (2) is located inside the main chord. The ends of the first main chord plate (1) and the second main chord plate (2) are respectively cantilevered relative to the third main chord plate (3) and the fourth main chord plate (4). The cantilevered part of the first main chord plate (1) is provided with a first cantilever stiffening plate (7), and the cantilevered part of the second main chord plate (2) is provided with a second cantilever stiffening plate (8). A plurality of flat boxes (5) are symmetrically arranged on the outer wall of the first main chord plate (1), and a plurality of flat boxes (5) are symmetrically arranged on the outer wall of the second main chord plate (2). The number of flat boxes (5) arranged on the first main chord plate (1) is greater than the number of flat boxes (5) arranged on the second main chord plate (2). A plurality of flat boxes (5) are respectively arranged on the outer walls of the third main chord plate (3) and the fourth main chord plate (4), and the flat boxes (5) are arranged closer to the second main chord plate (2).

2. The structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 1, characterized in that, The inner walls of the first main chord plate (1), the second main chord plate (2), the third main chord plate (3) and the fourth main chord plate (4) are provided with at least one main chord stiffening plate (6).

3. The structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 2, characterized in that, The first main chord plate (1), the second main chord plate (2), the third main chord plate (3), the fourth main chord plate (4), the flat box (5), the main chord stiffening plate (6), the first cantilever stiffening plate (7) and the second cantilever stiffening plate (8) are all connected to the pressure plate (11).

4. The structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 1, characterized in that, The pressure plate (11) is provided with a first pressure-bearing stiffening plate (9) and a second pressure-bearing stiffening plate (10). The cross-section formed by the first pressure-bearing stiffening plate (9) and the second pressure-bearing stiffening plate (10) is arranged in a grid pattern. The first pressure-bearing stiffening plate (9) is connected to the first main chord plate (1) and the second main chord plate (2). The second pressure-bearing stiffening plate (10) is connected to the third main chord plate (3) and the fourth main chord plate (4).

5. The structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 4, characterized in that, The longitudinal section of the first pressure-bearing stiffening plate (9) is U-shaped.

6. The structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 1, characterized in that, The tension of the steel tie rod (16) installed in the flat box (5) on the first main chord plate (1) is greater than the tension of the steel tie rod (16) installed in the flat box (5) on the second main chord plate (2).

7. The structure applicable to the arch foot joint section of a steel truss arch bridge according to any one of claims 1-6, characterized in that, Each of the flat boxes (5) includes two vertical plates (12) arranged opposite each other. One end of each of the two vertical plates (12) is connected to a horizontal plate (13), and the other end is connected to the first main chord plate (1), the second main chord plate (2), the third main chord plate (3), or the fourth main chord plate (4). The top of the vertical plates (12) and the horizontal plates (13) is connected to a top plate (14).

8. A steel truss arch bridge, characterized in that, Includes an arch base, on which a structure as described in any one of claims 1-7, applicable to the arch foot joint section of a steel truss arch bridge, is provided.

9. A method for manufacturing a structure applicable to the arch foot joint section of a steel truss arch bridge as described in claim 7, characterized in that, The flat box (5) on the third main chord plate (3) is asymmetrically arranged about the central axis of the third main chord plate (3), and the flat box (5) on the fourth main chord plate (4) is asymmetrically arranged about the central axis of the fourth main chord plate (4). The flat boxes (5) on the third main chord plate (3) and the fourth main chord plate (4) are closer to the side of the second main chord plate (2). The method includes the following steps: The flat box (5) on the third main chord plate (3) and the fourth main chord plate (4) is connected to the vertical plate (12) in sequence from the side of the second main chord plate (2) to the side of the first main chord plate (1). Each vertical plate (12) is connected to the third main chord plate (3) or the fourth main chord plate (4) and then immediately connected to the top plate (14). The vertical plate (12) closest to the first main chord plate (1) has a reserved space between it and the first main chord plate (1). Then the horizontal plate (13) is connected to the vertical plate (12) and the top plate (14).

10. The manufacturing method of the structure applicable to the arch foot joint section of a steel truss arch bridge according to claim 9, characterized in that, Each of the vertical plates (12) is welded to the third main chord plate (3) or the fourth main chord plate (4) by a single-sided bevel weld, and the range of the single-sided bevel of the vertical plate (12) closest to the first main chord plate (1) that is less than or equal to 50° is the reserved space.

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