A through plane bending steel arch bridge structure

Abstract

This invention discloses a planar curved steel arch bridge structure with a lower deck. The bridge consists of arch ribs, cross braces, and arch foot sections. The bridge plane is located on a curved section of the road. The arch rib axis is curved in both the plane and elevation. There are two arch ribs in the transverse direction, which are arranged parallel to each other or inclined inward along the longitudinal direction of the bridge. The cross braces are in a mesh-like shape on the horizontal projection plane, forming a truss structure with the two arch ribs. The arch foot sections are located between the ends of the arch ribs and the first cross brace, with a total of four arch foot sections. Each arch foot section consists of a box-shaped closed structure composed of the web plates on both sides, the end plates on the end face, and internal stiffening plates, connecting the arch ribs and steel beams into a whole. In this invention, the arch ribs and mesh cross braces form a truss structure on the horizontal projection, jointly bearing the out-of-plane bending of the arch and converting the transverse bending moment of the arch into the axial force of the arch ribs and cross braces. The arch foot section uses a large arch foot section, connecting the arch ribs and steel beams into a whole, extending the support length of the arch ribs, and reducing the transverse bending moment of the arch foot.

Description

Technical Field

[0001] This invention belongs to the field of bridge design technology, and more particularly to the field of steel structure bridge design technology. Specifically, it relates to a planar curved steel arch bridge structure with a lower deck in steel structure bridge design. Background Technology

[0002] A planar curved arch bridge is a beautiful bridge structure. The curved shape of the arch on the facade and plane gives the structure a strong visual impact.

[0003] like Figure 1 As shown in the figure, F represents the horizontal thrust. From a force perspective, the planar curved shape causes the arch to bear a large out-of-plane bending moment, transforming the arch from a primarily compression-bearing member to a primarily bending member. For through-arch bridges, the out-of-plane bending moment bearing capacity can be improved by increasing the transverse width of the arch cross-section. However, for large-span through-arch bridges, the transverse width of the arch cross-section is limited due to vehicle traffic and aesthetic requirements, resulting in a low out-of-plane bending moment bearing capacity and restricting the application of this structural form. Summary of the Invention

[0004] This invention discloses a through-type planar curved steel arch bridge structure to address the aforementioned technical problems. The problem this invention aims to solve is the out-of-plane bending of the arch ribs in through-type planar curved arch bridges, and it provides a lightweight, aesthetically pleasing through-type planar curved steel arch bridge structure that further enriches the structural forms of curved arch bridges.

[0005] The present invention is achieved by the following technical solution:

[0006] A type of under-bearing planar curved steel arch bridge structure, wherein the planar curved steel arch bridge is a steel arch bridge whose bridge plane is located on a curved section of a road, characterized in that: the bridge is composed of arch ribs, cross braces, and arch foot areas;

[0007] The arch ribs are steel pipes with a flat or circular cross-section, and the arch axis is curved in both the plane and elevation. There are two arch ribs in the transverse direction of the bridge, and the two arch ribs are arranged parallel to each other or inclined inward along the longitudinal direction of the bridge.

[0008] The cross brace is a steel pipe with a circular cross-section; the cross brace has a mesh-like shape on the horizontal projection plane and forms a truss structure with the two arch ribs. The arch ribs are the upper and lower chords of the truss structure, and the mesh-like cross brace is the web member of the truss structure.

[0009] The arch foot area is located between the end of the arch rib and the first cross brace, with a total of four arch foot areas. Each arch foot area consists of a box-shaped closed structure composed of the web plate of the arch foot area on both sides, the end plate of the arch foot area on the end face, and the internal stiffening plate, which connects the arch rib and the steel beam into a whole.

[0010] The preferred cross bracing is a circular cross-section steel pipe structure with a spatial mesh shape. The intersection of the cross bracing and the arch rib is the anchor point on the cable arch. The included angle (a) of the horizontal projection of the cross bracing is 30° to 60°. There are multiple sets of cables, with the upper end connected and fixed to the arch rib and the lower end connected and fixed to the steel beam.

[0011] The distance (L1) between the upper end of the arch foot area and the connection point of the first cross brace along the axial direction of the arch rib is 1 to 2 times the width (b) of the arch rib section.

[0012] The box-shaped enclosed structure is also equipped with internal stiffening plates arranged in a cross pattern, both horizontally and vertically.

[0013] The upper end of the web of the arch foot area is welded to the arch rib, and the lower end is welded to the steel beam; the end of the arch foot area is provided with a rounded chamfer and welded to the end plate of the arch foot area, and the end plate of the arch foot area is welded to the arch rib and the steel beam; the internal stiffening plate arranged longitudinally in the arch foot area is welded to the web of the arch foot area, the arch rib and the steel beam, and the internal stiffening plate arranged transversely in the arch foot area is welded to the web of the arch foot area, the arch rib and the end plate of the arch foot area.

[0014] The advantages of this invention are: the two transverse arch ribs and the mesh cross bracing form a truss structure on the horizontal projection, jointly bearing the out-of-plane bending of the arch, converting the transverse bending moment of the arch into the axial force of the arch ribs and cross bracing; the arch foot section adopts a large arch foot area, connecting the arch ribs and steel beams into a whole, extending the support length of the arch ribs, and reducing the transverse bending moment of the arch foot. This invention can effectively solve the transverse bending problem of under-deck planar curved arch bridges, with a lightweight and aesthetically pleasing structure, enriching the structural forms of curved arch bridges. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the lateral bending effect of a planar bending arch;

[0016] Figure 2 Plan view of the curved arch in the embodiment;

[0017] Figure 3 This is an elevation view of a curved arch in plan view as an example.

[0018] Figure 4 for Figure 3 Section 1-1;

[0019] Figure 5 This is a schematic diagram of the arch foot area of ​​the planar curved arch in the embodiment;

[0020] Figure 6 for Figure 5 Section 2-2;

[0021] Figure 7 for Figure 5 Section 3-3.

[0022] In the diagram, 1—arch rib, 2—cross brace, 3—suspension cable, 4—arch foot area, 5—steel beam, 6—arch foot area web, 7—arch foot area end plate, 8—arch foot area vertical stiffener, 9—arch foot area horizontal stiffener, section A—arch foot section, section B—truss section, a—horizontal projection angle of the cross brace, b—arch rib cross-section width, L1—longitudinal distance between the arch foot area and the first cross brace. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments. These specific embodiments are further explanations of the principles of the present invention and are not intended to limit the present invention in any way. Any technology that is the same as or similar to the present invention does not exceed the scope of protection of the present invention.

[0024] Refer to the attached diagram.

[0025] This embodiment provides a planar curved steel arch bridge structure with a lower deck, such as... Figures 2-7 It should be understood that the diagram only shows the arch structure itself and does not show the steel beam 5 structure.

[0026] Arch rib 1 is a steel tube structure, with a flattened circular cross-section in this example. It has good torsional and transverse bending resistance. The two arch ribs 1 are arranged in parallel or inwardly inclined transversely. Inwardly inclined arrangement means that both arch ribs are inclined towards the centerline of the bridge cross-section.

[0027] The cross brace 2 is a steel pipe structure with a circular cross-section. It has a spatial mesh-like shape. The intersection of the cross brace 2 and arch rib 1 is the anchorage point of the suspension cable 3 on the arch. The included angle α of the horizontal projection of the cross brace 2 should preferably be 30°-60°, specifically determined based on the transverse spacing of the two arch ribs 1 and the longitudinal spacing of the suspension cables 3. Vertically, the cross brace 2 and arch rib 1 are in the same plane. Figures 3-4 As shown.

[0028] like Figure 2 As shown, in this embodiment, the arch rib 1 and cross brace 2 of section B are in a mesh shape on the horizontal projection plane and form a truss structure with the two arch ribs. The two arch ribs 1 are the upper and lower chords of the truss structure, and the cross brace 2 is the web member of the truss structure, which converts the lateral bending moment of the arch of section B into the axial force of the arch rib 1 and cross brace 2.

[0029] like Figure 2 As shown, in this embodiment, since the vehicle passage limit cannot be set for the horizontal brace 2, the problem of the lateral bending of the arch rib 1 is solved by setting the arch foot area 4. The arch foot area 4 extends the support length of the arch rib, shortens the lever arm length of the lateral bending moment of the arch foot arch rib, and reduces the lateral bending moment of the arch rib 1.

[0030] The following combination Figure 3 , Figures 5-7 The arch foot area 4 of the embodiment will be described as follows: Figure 3As shown, the distance L1 between the arch foot 4 in the longitudinal direction and the first transverse brace is 1 to 2 times the width b of the arch rib 1 section. Figures 5-7 As shown, the arch foot region 4 adopts a box-shaped section, consisting of the arch foot region web plate 6, the arch foot region end plate 7, the arch foot region vertical stiffener 8, and the arch foot region horizontal stiffener 9. The arch foot region web plate 6 is welded to the arch rib 1 and the steel beam 5, and the end is provided with a rounded chamfer and welded to the arch foot region end plate 7. The arch foot region end plate 7 is welded to the arch rib 1 and the steel beam 5. The arch foot region vertical stiffener 8 is welded to the arch foot region web plate 6, the arch rib 1, and the steel beam 5. The arch foot region horizontal stiffener 9 is welded to the arch foot region web plate 6, the arch rib 1, and the arch foot region end plate 7.

Claims

1. A planar curved steel arch bridge structure, wherein the planar curved steel arch bridge is a steel arch bridge whose bridge plane is located on a curved section of a road, characterized in that: A bridge consists of arch ribs, cross braces, and arch foot areas; The arch ribs are steel pipes with a flat or circular cross-section, and the arch axis is curved in both the plane and elevation. There are two arch ribs in the transverse direction of the bridge, and the two arch ribs are arranged parallel to each other or inclined inward along the longitudinal direction of the bridge. The cross brace is a steel pipe with a circular cross-section; the cross brace has a mesh-like shape on the horizontal projection plane and forms a truss structure with the two arch ribs. The arch ribs are the upper and lower chords of the truss structure, and the mesh-like cross brace is the web member of the truss structure. The arch foot area is located between the end of the arch rib and the first cross brace, and a total of four arch foot areas are set. Each arch foot area consists of a box-shaped closed structure composed of the web plate of the arch foot area on both sides, the end plate of the arch foot area on the end face, and the internal stiffening plate, which connects the arch rib and the steel beam into a whole. The distance (L1) between the upper end of the arch foot area and the connection point of the first cross brace along the axial direction of the arch rib is 1 to 2 times the width (b) of the arch rib section.

2. The under-deck planar curved steel arch bridge structure according to claim 1, characterized in that: The cross bracing is a circular cross-section steel pipe structure with a spatial mesh shape. The intersection of the cross bracing and the arch rib is the anchor point on the cable arch. The horizontal projection angle (a) of the cross bracing is 30° to 60°. There are multiple sets of cables, with the upper end connected and fixed to the arch rib and the lower end connected and fixed to the steel beam.

3. The under-deck planar curved steel arch bridge structure according to claim 2, characterized in that: The box-shaped enclosed structure is also equipped with internal stiffening plates arranged in a cross pattern, both horizontally and vertically.

4. The under-deck planar curved steel arch bridge structure according to claim 2, characterized in that: The upper end of the web of the arch foot area is welded to the arch rib, and the lower end is welded to the steel beam; the end of the arch foot area is provided with a rounded chamfer and welded to the end plate of the arch foot area, and the end plate of the arch foot area is welded to the arch rib and the steel beam; the internal stiffening plate arranged longitudinally in the arch foot area is welded to the web of the arch foot area, the arch rib and the steel beam, and the internal stiffening plate arranged transversely in the arch foot area is welded to the web of the arch foot area, the arch rib and the end plate of the arch foot area.

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