Triangle Bridge

Abstract

The present invention discloses a triangular bridge, which is mainly composed of rigid diagonal bars (1), piers (2), main beams (3), and rigid connecting bars (4); the rigid diagonal bars (1) are arranged between the bridge spans, with the upper ends connected and the lower ends connected to the piers (2), respectively. The rigid diagonal bars (1) and the main beams (3) are fixed at the intersection; the rigid connecting bars (4) are arranged between the main beams (3) and the rigid diagonal bars (1). The present invention uses the rigid diagonal bars (1) and the ground to form a stable triangular frame as the load-bearing structure of the bridge, and uses the triangle stability principle to constrain the center point of the main beam with the largest deformation to make it close to rigidity. At the same time, two rigid diagonal bars (1) are used to strongly constrain the main beam (3), so that the calculated span is greatly reduced. The triangular bridge has scientific and reasonable force, economical cost, high bearing capacity, high rigidity, good stability, etc., and is a new type of bridge worthy of promotion and application.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge engineering, and in particular relates to a triangular bridge. Background Art

[0002] As an essential component of roads and a key hub in transportation engineering, bridges play a vital role in transportation and transportation development. Bridges are also crucial infrastructure for national economic and social development, reflecting a country or region's comprehensive national strength, including its economic strength, science and technology, and productivity.

[0003] Beam bridges are the oldest and simplest structural form in the history of bridge development. Stone beam bridges were widely constructed in my country as early as the Qin and Han dynasties. The Wan'an Bridge in Quanzhou, Fujian Province, built in 1053 AD, is 834 meters long, 7 meters wide, and has a clear span of 8 meters between piers, making it the world's longest existing stone beam bridge. Arch bridges have a long history in my country, with the world-renowned Zhaozhou Bridge in Zhao County, Hebei Province, a prominent example of ancient Chinese arch bridges. Rigid frame bridges, cable-stayed bridges, and suspension bridges are more recent bridge types, their development benefiting from advances in construction technology and material properties.

[0004] Existing bridge structures differ not only in their structural form but also in their fundamental mechanical principles. To more effectively perform their spanning function, beam bridges have their structural axis parallel to the horizontal. However, because the direction of the moving load is nearly perpendicular to the structural axis, beam bridges are primarily subjected to bending and do not generate horizontal thrust under vertical loads. Therefore, beam bridges place high demands on the bending resistance of the material, and due to the uneven distribution of bending moments, they sometimes require variable cross-section designs. Arch bridges, due to the unique shape of their arch axis, generate horizontal thrust at the arch foot when subjected to vertical loads. However, this significantly offsets the bending moments in the arch ribs, resulting in the arch ribs being primarily subjected to compression. Compared to beam bridges of the same span, arch bridges experience much less bending deformation. Rigid frame bridges operate in a load regime intermediate between beam and arch bridges, primarily borne by rigid connections between beams and columns to form a rigid frame structure. They are characterized by negative bending moments at the beam-pier connections. Compared to simply supported beam bridges of the same span, rigid frame bridges experience less bending moment, but there are horizontal reactions at the column base. Cable-stayed bridges utilize cables to provide multi-point elastic support for the main beam, transferring the load through the towers to the foundation. This reduces the bending moment of the main beam, but the presence of the horizontal component of the cable forces causes the main beam to be eccentrically compressed. Suspension bridges utilize main cables, supported by towers and anchored on both banks, as their primary load-bearing components. Hangers transfer the main beam's dead load and live loads, such as vehicles, to the cables, which then transmit the load to the foundation via anchors and towers.

[0005] With the continuous advancement of research in bridge engineering, new bridge structures, new processes, and new materials are constantly emerging, and the application and research of new technologies have reached unprecedented breadth and depth. In the construction of small and medium-span bridges, beam bridges have become the preferred bridge type due to their simple structure, clear load-bearing characteristics, mature construction techniques, short construction periods, and easy maintenance. Rigid frame bridges offer superior spanning performance compared to beam bridges, especially in areas with steep riverbanks and deep canyons, where slanted-legged rigid frame bridges are often used to span the entire span. Currently, the world's largest prestressed concrete continuous rigid frame bridge is the Chongqing Shibanpo Yangtze River Bridge, completed in 2006, with a main span of 330 meters. Arch bridges offer significantly superior load-bearing performance and high spanning capacity, making them widely used on my country's highways and railways. Currently, the world's largest arch bridge is the Pingnan Third Bridge in Guangxi, with a main span of 575 meters. Cable-stayed bridges and suspension bridges are recognized as large-span and extra-large-span bridges. For example, the Changtai Yangtze River Bridge currently under construction has a main span of 1,176 meters. After completion, it will be the cable-stayed bridge with the longest main span in the world. The Yangsigang Yangtze River Bridge, which was completed in 2019, has a main span of 1,700 meters, and its construction level is at the forefront of the world.

[0006] Given my country's transportation development needs, bridge construction remains essential. As a major bridge nation, innovation in bridge design, construction, and maintenance is crucial for China's continued progress on the path to becoming a bridge power. In particular, seeking bridge structures with improved mechanical properties and lower costs is crucial for conserving resources and achieving sustainable development. Currently, my country's high-speed railways are experiencing rapid development. As train speeds continue to increase, increasingly stringent requirements are being placed on the mechanical properties of bridges. Innovating bridge structures to make them safer, more economical, more practical, more durable, and more aesthetically pleasing has become a pressing concern for bridge builders in recent years. Summary of the Invention

[0007] This invention innovates existing bridge structures. Beyond existing beam-, arch-, cable-stayed, and suspension-type bridges, it proposes a new type of bridge using a tripod as its load-bearing structure: the triangular bridge. This invention utilizes the principle of triangular stability to constrain the main beam at its mid-span, where deformation is greatest, making it nearly rigid. Simultaneously, rigid diagonal rods provide strong constraints on the main beam, significantly reducing the calculated span. Consequently, both the structural load-bearing capacity and rigidity are significantly improved.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A tripod bridge mainly consists of rigid diagonal bars, piers, main beams, and rigid connecting rods; the main beams are installed on the piers; two rigid diagonal bars are arranged obliquely on the same side between a bridge span, and the upper ends of the two rigid diagonal bars are connected, and the lower ends are respectively connected to the piers at both ends of the bridge span, forming a tripod with the ground as the bottom edge; the rigid diagonal bars and the main beams are consolidated at the intersection; the rigid connecting rods are arranged between the main beams and the rigid diagonal bars.

[0010] In the present invention, two rigid diagonal rods and the ground form a stable tripod, which serves as a load-bearing structure to support the main beam. This can effectively constrain the main beam and reduce the calculated span, thereby greatly improving the bearing capacity and rigidity of the structure.

[0011] As a further illustration of the present invention, single-span and multi-span bridges can be constructed.

[0012] As a further illustration of the present invention, a double-deck or even multi-deck bridge can be made.

[0013] As a further illustration of the present invention, the rigid diagonal rods and rigid connecting rods are steel structures, steel-concrete composite structures or concrete structures.

[0014] As a further illustration of the present invention, the tripod bridge may further be provided with auxiliary diagonal bars; the upper ends of the auxiliary diagonal bars are connected to the main beams, and the lower ends are connected to the piers or the junction of the piers and the rigid diagonal bars.

[0015] As a further explanation of the present invention, there are several rigid connecting rods. When the rigid diagonal rod passes above the main beam, at least one rigid connecting rod is arranged vertically, with the upper end connected to the connection point of the two rigid diagonal rods and the lower end connected to the main beam; when the rigid diagonal rod is located below the main beam, the rigid connecting rods are connected to each other to form a truss structure.

[0016] Advantages of the present invention:

[0017] 1. High bearing capacity. The present invention uses a tripod as the load-bearing structure of the bridge, and the structure has a high bearing capacity.

[0018] 2. High rigidity. The present invention sets a rigid constraint at the maximum deformation point of the main beam, and the two rigid diagonal bars can strongly constrain the main beam, reducing the calculated span of the main beam, so the rigidity of the structure is high.

[0019] 3. Good stability. The two rigid oblique rods of the present invention and the ground form a triangular structure, which can be seen to have good stability, especially in-plane stability.

[0020] 4. High natural frequency. Due to the high rigidity of the present invention, the natural frequency of the structure is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is the arrangement form 1 of the present invention.

[0022] Figure 2 This is arrangement form 2 of the present invention.

[0023] Figure 3 This is arrangement form 3 of the present invention.

[0024] Figure 4 This is arrangement form 4 of the present invention.

[0025] Figure 5 This is arrangement form 5 of the present invention.

[0026] Figure 6 This is arrangement form 6 of the present invention.

[0027] Figure 7 This is arrangement form 7 of the present invention.

[0028] Figure 8 This is the arrangement form 8 of the present invention.

[0029] Reference numerals: 1-rigid diagonal rod, 2-pier, 3-main beam, 4-rigid connecting rod, 5-auxiliary diagonal rod. DETAILED DESCRIPTION

[0030] While innovation in bridge structures is a perennial topic, achieving both improved mechanical performance and economic efficiency through structural changes is challenging. This invention utilizes a highly stable tripod as the bridge's load-bearing structure. The principle of triangular stability is leveraged to constrain the center of the main beam, where deformation is greatest, to achieve near-rigidity. Simultaneously, two rigid diagonal rods are employed to provide strong constraints on the main beam, significantly reducing the calculated span and improving the structure's load-bearing efficiency, thereby enhancing the bridge's load-bearing capacity and rigidity.

[0031] Example:

[0032] The arrangement form 1 of the present invention was applied to the design of a newly built double-deck bridge. The bridge has a span of 70m and a deck width of 30m. Both the upper and lower decks are equipped with four lanes in both directions, and the top of the tripod is 15m away from the upper deck. The entire bridge is constructed with C30 concrete. The rigid diagonal bars are box-sectioned and come in two sizes (1.0m×0.5m above the deck, with a wall thickness of 0.15m; 1.5m×0.8m below the deck, with a wall thickness of 0.2m); the rigid connecting bars are box-sectioned (1.0m×0.5m, with a wall thickness of 0.15m); the main beams are longitudinal and transverse beam structures, and the main longitudinal beams are box-sectioned (1.2m×0.6m, with a wall thickness of 0.1m). The secondary longitudinal beams are solid sections (0.65m×0.3m), the primary and secondary transverse beams are box sections (1.6m×0.9m, upper and lower wall thickness 0.3m, left and right wall thickness 0.2m; 1.6m×0.8m, upper and lower wall thickness 0.25m, left and right wall thickness 0.15m), the bridge deck thickness is 0.2m; the upper and lower main beams are connected by solid truss members (0.6m×0.3m); the bridge piers are also solid sections (1.2m×0.6m).

[0033] The bridge designed with this scheme has excellent mechanical properties and economical cost, with the concrete consumption per square meter being only 0.4m 3 .

[0034] Obviously, the above embodiments are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will readily appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all possible implementations here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A triangular bridge, characterized in that: It is mainly composed of a rigid diagonal rod (1), a pier (2), a main beam (3), and a rigid connecting rod (4); The main beam (3) is mounted on the pier (2); two rigid diagonal rods (1) are arranged obliquely on the same side between a bridge span, and the upper ends of the two rigid diagonal rods (1) are connected, and the lower ends are respectively connected to the piers (2) at both ends of the bridge span, forming a tripod with the ground as the bottom side; the rigid diagonal rod (1) and the main beam (3) are fixed at the intersection; the rigid connecting rod (4) is arranged between the main beam (3) and the rigid diagonal rod (1); An auxiliary diagonal rod (5) is also provided; the upper end of the auxiliary diagonal rod (5) is connected to the main beam, and the lower end is connected to the pier (2) or the connection between the pier (2) and the rigid diagonal rod (1); The rigid connecting rods (4) are provided with a plurality of them. When the rigid diagonal rods (1) pass above the main beam (3), at least one rigid connecting rod (4) is arranged vertically, with its upper end connected to the connection point of the two rigid diagonal rods (1) and its lower end connected to the main beam (3); when the rigid diagonal rods (1) are located below the main beam (3), the rigid connecting rods (4) are connected to each other to form a truss structure.

2. The triangular bridge according to claim 1, characterized in that: The tripod bridge is a single-span bridge or a multi-span bridge.

3. The triangular bridge according to claim 1, characterized in that: The tripod bridge is a double-deck bridge or a multi-deck bridge.

4. The triangular bridge according to claim 1, characterized in that: The rigid diagonal rods (1) and rigid connecting rods (4) are steel structures, steel-concrete composite structures or concrete structures.

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