Arch bridge main arch structure

Abstract

The utility model belongs to the technical field of arch bridge design, and particularly relates to an arch bridge main arch structure. Comprising an arch springing reinforcing section arch rib, a transition section arch rib and a midspan section arch rib, the arch springing reinforcing section arch rib comprises a plurality of single-chamber reinforced concrete boxes, the midspan section arch rib is a double-chamber steel box, the transition section arch rib comprises a left stiffening piece, a thick steel plate and a right stiffening piece, the transition section stiffening piece is welded to the thick steel plate, and the right stiffening piece is welded to the thick steel plate. The left stiffening piece is arranged at the joint of the single-chamber steel-concrete box and the thick steel plate, and the right stiffening piece is arranged at the joint of the double-chamber steel box and the thick steel plate. The single-chamber steel mixing box is a double-thin-wall steel jacket box, and the outer layer of the double-chamber steel mixing box is of a single-layer structure. The combined section structure can reduce the dead weight of the arch bridge, improve the rigidity of the arch rib and improve the integrity of the arch bridge.

Description

Technical Field

[0001] The utility model belongs to the technical field of arch bridge design, in particular to a structure applied to a main arch of a large-span arch bridge. Background Art

[0002] As a traditional bridge structure, arch bridges occupy an important position in bridge engineering. First, as the span of the arch bridge increases, its deadweight also increases. In the traditional reinforced concrete arch bridge structure, the deadweight of the arch bridge will affect the bearing capacity and economy of the entire structure. Especially when the span reaches 500 meters or more, the economy of the arch bridge deteriorates or even becomes difficult to construct due to the excessive deadweight of the structure. This is mainly because the heavy deadweight of the arch bridge will lead to increased construction costs and increased material consumption, thus affecting the economy of the arch bridge. Secondly, traditional arch bridges also have certain deficiencies in ductility and stiffness. In the design of arch bridges, ductility refers to the ability of materials to be able to extend and deform without breaking when subjected to external forces, while stiffness refers to the bending resistance of the structure when subjected to force. However, due to the particularity of the arch bridge structure, traditional reinforced concrete arch bridges often cannot meet the requirements of large-span arch bridges in terms of ductility and stiffness. Especially in extreme environments such as earthquakes, the ductility and stiffness of traditional arch bridges may not provide sufficient protection, thus affecting the safety and reliability of arch bridges.

[0003] In addition, the joint problems existing in traditional arch bridge structures will also affect their integrity. In traditional reinforced concrete arch bridges, due to the large span of the arch bridge, the main arch needs to be constructed in sections, which requires a large number of joint connections. However, the connection quality at the joints is often difficult to guarantee, and there may be problems such as loose joints and cracks, which affects the integrity and stability of the arch bridge structure. Utility Model Content

[0004] In order to comprehensively solve the above problems, the utility model adopts a double thin-walled steel casing filled with ultra-high performance concrete composite structure arch bridge section, which can reduce the deadweight of the arch bridge, increase the stiffness of the arch ribs, and improve the integrity of the arch bridge.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A main arch structure of an arch bridge comprises: arch ribs of an arch foot reinforcement section, arch ribs of a transition section and arch ribs of a mid-span section, wherein the arch ribs of the arch foot reinforcement section comprise a plurality of single-chamber steel-concrete boxes, the arch ribs of the mid-span section are double-chamber steel boxes, the arch ribs of the transition section comprise left-side stiffening plates, thick steel plates and right-side stiffening plates, the stiffening plates of the transition section are welded to the thick steel plates, the left-side stiffening plates are arranged at the junction of the single-chamber steel-concrete box and the thick steel plates, and the right-side stiffening plates are arranged at the junction of the double-chamber steel box and the thick steel plates.

[0007] Furthermore, the single-chamber steel-concrete box is a double-thin-wall steel casing box, the two layers of thin walls of the double-thin-wall steel casing box are connected by connecting angle steels, and steel casing ribs are provided between the upper thin wall and the lower thin wall. The double-thin-wall steel casing box is filled with ultra-high performance concrete, and the concrete and the wall panels are connected by angle steels and steel casing ribs to increase connectivity.

[0008] Furthermore, the outer layer of the double-chamber steel box is a single-layer structure, a web is provided between the upper and bottom parts of the steel box, and a mid-span steel box is provided inside the double-chamber steel box for reinforcement.

[0009] Furthermore, the transition section arch ribs may be made of low alloy steel, and the force transmission transition between the steel box arch ribs and the composite section arch ribs may be achieved through variable height stiffening plates.

[0010] Compared with the prior art, the utility model has the following advantages:

[0011] The combination of steel and concrete, especially ultra-high performance concrete, can reduce the amount of materials used while ensuring structural strength and stability, thereby reducing the weight of the structure. Through reasonable structural design, such as double-walled steel jackets and double-chamber steel boxes with single-layer structures, the number and weight of structural components can be reduced, thereby reducing the overall weight.

[0012] The steel box in the arch foot section is filled with concrete in the cross-sectional form, which can prevent the lateral expansion of concrete and resist the Poisson effect under the action of axial force to maintain the integrity of the core concrete, while the hoop effect further increases the ultimate compressive stress and ultimate compressive strain capacity of the concrete, thereby improving the ductility of the main arch; the double-chamber steel box is equipped with a mid-span steel box reinforcement. When subjected to external loads, the steel box structure can absorb and disperse the load to a certain extent, thereby slowing down the deformation speed of the structure and improving the ductility of the structure, that is, it can maintain a relatively large deformation capacity without being destroyed when subjected to external loads.

[0013] The joints in steel-box concrete composite arch bridges are mainly steel-box joints, which can be connected by welding. Their quality is controlled by a ready-made quality assurance system. Therefore, steel-box concrete composite arch bridges are significantly superior to conventional concrete arch bridges in terms of structural integrity. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic elevation view of a specific embodiment of the utility model;

[0015] Figure 2 It is a plan view of a specific embodiment of the utility model.

[0016] Figure 3 This is the large-scale structural drawing of the arch rib transition section.

[0017] Figure 4This is a cross-sectional view of the arch rib (AA) of the arch foot reinforcement section of the utility model;

[0018] Figure 5 It is a cross-sectional view of the transition section arch rib (BB) of the utility model;

[0019] Figure 6 It is a cross-sectional view of the middle section (CC) of the mid-span of the utility model.

[0020] The numbers in the figure are: 1. Arch rib of the arch foot reinforcement section; 2. Arch rib of the transition section; 3. Arch rib of the mid-span section; 4. Thin wall; 5. Connecting angle steel; 6. Steel box radial rib; 7. Ultra-high performance concrete; 8. Thick steel plate; 9. Right-side stiffener; 10. Mid-span steel box stiffener; 11. Web plate; 12. Left-side stiffener. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments, but is not intended to be limiting of the present invention. It should be noted that the accompanying drawings are all in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0022] The technical scheme adopted by the utility model is as follows: the arch ribs of the arch rib reinforcement section use double thin-walled 4 steel casings, steel casing diameter-increasing ribs 6 are arranged on the steel casing wall plate, the two steel casings are connected by angle steels, and the steel casings can be filled with self-compacting ultra-high performance concrete 7; the arch ribs 3 in the mid-span section use steel box sections, and the transition section arch ribs are between the steel box and the double thin-walled 4 steel casings of the arch rib reinforcement section, thereby completing the lightweight large-span arch rib section design.

[0023] See also Figure 1 to Figure 6 As shown, the main arch structure of the double thin-walled 4-steel-cased steel-concrete composite arch bridge mainly includes two single-box single-chamber steel-concrete composite section arch ribs 1, transition section arch ribs 2, mid-span arch ribs 3, a single-chamber steel-concrete box and a double-chamber steel box.

[0024] In this embodiment, the arch rib 1 of the arch foot reinforcement section is composed of two single-chamber steel-concrete boxes. The single-chamber steel-concrete box adopts a double-thin-wall 4 steel casing structure, the two thin walls 4 are connected by connecting angle steels 4, and steel casing diameter ribs 6 are provided to increase connectivity. Ultra-high performance concrete 7 is filled in the steel casing to increase overall strength and rigidity.

[0025] In this embodiment, the transition section arch rib is composed of a left stiffener 12, a thick steel plate 8 and a right stiffener 9. The transition section stiffener is welded to the thick steel plate 8, the left stiffener 12 is arranged at the junction of the single-chamber steel-concrete box and the thick steel plate 8, and the right stiffener 9 is arranged at the junction of the double-chamber steel box and the thick steel plate 8. The transition section arch rib can be made of low alloy steel, and the force transmission transition between the steel box arch rib and the combined section arch rib is achieved through the variable height stiffener.

[0026] In this embodiment, the mid-span arch rib 3 is a double-chamber steel box structure, the outer layer is a single-layer structure, and a web 9 is provided between the upper and bottom parts. A mid-span steel box stiffener 10 is provided inside the double-chamber steel box to enhance the overall rigidity and bearing capacity.

[0027] In the structural design, the steel box thin wall 4 is made of low alloy steel with a plate thickness of 16mm to 30mm, and the connecting angle steel 4 is selected to be L12x6mm. The design of separated box-shaped rib arches can save engineering usage and provide construction flexibility.

[0028] The transition from single-box single-chamber to single-box multi-chamber, with steel structure in the middle of the span and UHPC material in the arch foot section. Ultra-high performance concrete 7 is a high-density cement-based composite material prepared according to the principle of maximum packing density and low water-cement ratio. Since UHPC has high compressive strength and flexural strength, the use of combined sections can reduce the cross-sectional size and steel plate thickness, and reduce the amount of steel used in the arch ribs. The design of lightweight structure has enabled the arch bridge to achieve a larger span breakthrough, which is of great significance.

Claims

1. A main arch structure of an arch bridge, characterized in that: include: The invention relates to an arch foot reinforcement section arch rib (1), a transition section arch rib (2) and a mid-span section arch rib (3), wherein the arch foot reinforcement section arch rib (1) comprises a plurality of single-chamber steel-concrete boxes, the mid-span section arch rib (3) is a double-chamber steel box, the transition section arch rib (2) comprises a left stiffening sheet (12), a thick steel plate (8) and a right stiffening sheet (9), the transition section stiffening sheet is welded to the thick steel plate (8), the left stiffening sheet (12) is arranged at the junction of the single-chamber steel-concrete box and the thick steel plate (8), and the right stiffening sheet (9) is arranged at the junction of the double-chamber steel box and the thick steel plate (8).

2. The main arch structure of the arch bridge according to claim 1, characterized in that: The single-chamber steel-concrete box is a double-thin-wall steel casing box, wherein two thin walls (4) of the double-thin-wall steel casing box are connected by connecting angle steels (5), a steel casing box radial rib (6) is provided between the upper thin wall and the lower thin wall, and the double-thin-wall steel casing box is filled with ultra-high performance concrete (7).

3. The main arch structure of the arch bridge according to claim 1, characterized in that: The outer layer of the double-chamber steel box is a single-layer structure, a web (11) is provided between the upper part and the bottom part of the steel box, and a mid-span steel box reinforcement (10) is provided inside the double-chamber steel box.

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