Vortex vibration suppression structure for large-span parallel bridge

Abstract

The invention relates to the technical field of bridge engineering wind tunnel tests, in particular to a large-span parallel bridge vortex-induced vibration suppression structure which comprises an air nozzle and a first inclined guide plate. The tuyere is installed on the side face of a lower chord on the windward side of the truss girder, the section of the tuyere is triangular, and the conical portion of the tuyere faces the windward side to guide airflow on the windward side to flow towards the two sides of the tuyere. The first inclined flow guide plate is located below the lower chord member, and a first flow guide channel is formed between the first inclined flow guide plate and the lower chord member; the end, facing the windward side, of the first diversion channel is wider than the end, facing the bridge, of the first diversion channel, and wind is guided to the bridge bottom. According to the invention, the distribution and flowing path of airflow can be effectively changed, so that the impact force of wind on the bridge is reduced, and the risks of wind-induced vibration and wind-induced fatigue are reduced. The problem that in the background technology, an existing bridge wind-resistant structure is poor in adaptability and effectiveness is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind tunnel tests for bridge engineering, and particularly to a vortex-induced vibration suppression structure for long-span parallel bridges. Background Art

[0002] The long span in long-span parallel bridges refers to parallel bridges with a single-span greater than 100 meters.

[0003] The wind resistance performance of bridges is one of the key factors affecting the structural safety and service life of bridges. Especially under complex climatic conditions, the wind resistance design of bridges needs to fully consider the action of wind and its impact on the bridge structure. Traditional wind resistance design methods often focus on the wind resistance optimization of a single structure. However, in the special structure of parallel bridges, due to their different main girder forms and wind force characteristics, the improvement of wind resistance performance is more complex and important.

[0004] Vortex-induced vibration, that is, Vortex-Induced Vibration (VIV), is a vibration phenomenon caused by the interaction between fluid and structure, commonly occurring when fluid flows around bluff bodies (such as cylinders, bridges, chimneys, etc.). Its core mechanism is that the periodically shed vortices in the fluid exert an alternating force on the structure. When the vortex shedding frequency is close to the natural frequency of the structure, resonance will be triggered, resulting in large-amplitude vibration and even damage to the structure. Vibration suppression refers to suppressing vibration and reducing the vibration amplitude.

[0005] In the structure of parallel bridges, a common design is a combination of a truss bridge and a steel box girder bridge. The truss bridge is on the windward side, and the steel box girder bridge is on the leeward side. This structural form of parallel bridges has a complex response to wind. The open form of the truss bridge and the closed structure of the steel box girder bridge result in significant differences in wind force distribution and aerodynamic performance between the two. Therefore, traditional wind resistance design methods cannot effectively meet the aerodynamic optimization requirements of parallel bridges, especially in terms of wind pressure, wind load distribution, and wind-induced vibration, there are significant potential safety hazards. In the design of parallel bridges, how to balance the aerodynamic characteristics between the two cross-sectional forms is an urgent problem to be solved.

[0006] Existing bridge wind resistance structures are difficult to balance the wind resistance effects under different wind forces. Especially in bridge structures such as parallel bridges with complex structures and wind force distributions, the adaptability and effectiveness of existing bridge wind resistance structures are poor. Summary of the Invention

[0007] The purpose of the present invention is to provide a vortex-induced vibration suppression structure for long-span parallel bridges, which can effectively change the distribution and flow path of airflows, thereby reducing the impact force of wind on the bridge, and reducing the risks of wind-induced vibration and wind-induced fatigue, so as to solve the problem of poor adaptability and effectiveness of existing bridge wind resistance structures in the background art.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A vortex-induced vibration suppression structure for a long-span parallel bridge, comprising a wind nozzle and a first inclined deflector; the wind nozzle is installed on the side of the lower chord of the windward side of the truss beam, the cross-section of the wind nozzle is triangular, the conical part of the wind nozzle faces the windward side, guiding the airflow on the windward side to flow towards both sides of the wind nozzle; the first inclined deflector is located below the lower chord, and a first diversion channel is formed between the first inclined deflector and the lower chord; the side of the first diversion channel facing the windward side is wider than the side facing the bridge, guiding the wind towards the bottom of the bridge.

[0009] Further, hooks are respectively installed on both sides of the lower chord, and the hooks on both sides are connected by a first connecting rod; the left end of the first inclined deflector is connected to the hook on the left side of the lower chord through a second connecting rod, and the right end of the first inclined deflector is connected to the hook on the right side of the lower chord through another second connecting rod.

[0010] Further, it further comprises a first inclined connecting rod; in the width direction of the truss bridge, the second connecting rods at the left end and the right end of the first inclined deflector are connected by the first inclined connecting rod; in the length direction of the truss bridge, the second connecting rods on the same side are connected by another first inclined connecting rod.

[0011] Further, a second inclined deflector is arranged below the first inclined deflector, and a second diversion channel is formed between the second inclined deflector and the first inclined deflector; the side of the second diversion channel facing the windward side is larger than the side of the first diversion channel facing the bridge, guiding the wind towards the bottom of the bridge.

[0012] Further, the left end of the second inclined deflector is connected to the left end of the first inclined deflector through a third connecting rod, and the right end of the second inclined deflector is connected to the right end of the first inclined deflector through another third connecting rod.

[0013] Further, it further comprises a second inclined connecting rod; in the width direction of the truss bridge, the third connecting rods at the left end and the right end of the second inclined deflector are connected by the second inclined connecting rod; in the length direction of the truss bridge, the third connecting rods on the same side are connected by another second inclined connecting rod.

[0014] Further, the cross-section of the wind nozzle is an isosceles triangle.

[0015] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The conical part of the wind nozzle faces the windward side, guiding the airflow on the windward side to flow towards both sides of the wind nozzle, smoothing the wind pressure by guiding the airflow, reducing the concentration of local wind pressure, optimizing the airflow distribution, and reducing the direct impact of the wind on the bridge.

[0016] 2. By changing the air flow path, the first inclined deflector and the second inclined deflector optimize the air flow guidance, reduce the concentration of wind pressure, avoid the wind accumulation on various parts of the bridge, reduce the direct impact of the wind on the lower chord of the truss bridge, stabilize the air flow, reduce the wind-induced vibration, and thus extend the service life of the bridge. The design of the wind nozzle and the double-layer deflector effectively reduces the air flow disturbance of the bridge under the action of wind, reduces the wind pressure fluctuation, and ensures the stability of the bridge under various climatic conditions. Description of the Drawings

[0017] Figure 1 It is a sectional view of a steel box girder bridge.

[0018] Figure 2 It is a layout diagram of the present invention.

[0019] Figure 3 A structural schematic diagram of the present invention.

[0020] Figure 4 It is a layout diagram of the first inclined deflector and the second inclined deflector.

[0021] Figure 5 It is Figure 3 View A of

[0022] Figure 6 It is Figure 3 View B of

[0023] Figure 7 It is a comparison diagram of the torsional amplitude of the truss bridge.

[0024] Figure 8 It is a comparison diagram of the vertical amplitude of the truss bridge.

[0025] Figure 9 It is a comparison diagram of the torsional amplitude of the steel box girder bridge.

[0026] Figure 10 It is a comparison diagram of the vertical amplitude of the steel box girder bridge.

[0027] The definitions of the reference numerals in the drawings are as follows: 1 - Truss bridge, 2 - Lower chord, 3 - Wind nozzle, 4 - First inclined deflector, 5 - Second inclined deflector, 6 - Hook, 7 - First connecting rod, 8 - Second connecting rod, 9 - Third connecting rod, 10 - First inclined connecting rod, 11 - Second inclined connecting rod. Detailed Implementation Modes

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention, so as to have a further understanding of the concept of the present invention, the technical problems to be solved, the technical features constituting the technical solutions, and the technical effects brought.

[0029] AsFigures 1 - 5 As shown in the figure, a vortex-induced vibration suppression structure for a long-span parallel bridge includes a wind nose 3 and a first inclined deflector 4; the wind nose 3 is installed on the side of the lower chord 2 on the windward side of the truss beam, the cross-section of the wind nose 3 is triangular, and the conical part of the wind nose 3 faces the windward side, guiding the airflow on the windward side to flow towards both sides of the wind nose 3; the first inclined deflector 4 is located below the lower chord 2, and a first diversion channel is formed between the first inclined deflector 4 and the lower chord 2; the side of the first diversion channel facing the windward side is wider than the side facing the bridge, guiding the wind towards the bottom of the bridge.

[0030] The wind nose 3 of the present invention is installed on the side of the lower chord 2 on the windward side of the truss beam and is continuously distributed longitudinally along the lower chord 2. The conical part of the wind nose 3 faces the windward side, guiding the airflow on the windward side to flow towards both sides of the wind nose 3, smoothing the wind pressure by guiding the airflow, reducing the concentration of local wind pressure, optimizing the airflow distribution, and reducing the direct impact of the wind on the bridge. The first inclined deflector 4 is inclined relative to the lower chord 2, and a first diversion channel is formed between the first inclined deflector 4 and the lower chord 2. Due to the inclined setting of the first inclined deflector 4, one end of the first diversion channel has a larger opening and the other end has a smaller opening. The side with the larger opening of the first diversion channel faces the windward side, and the smaller side faces the bottom of the bridge. This design optimizes the guidance of the airflow by changing the airflow path, reduces the concentration of wind pressure, avoids the accumulation of wind force on each part of the bridge, reduces the direct impact of the wind on the lower chord 2 of the truss bridge 1, stabilizes the wind flow, reduces wind-induced vibration, and thus extends the service life of the bridge. The design of the wind nose 3 and the double-layer deflector effectively reduces the airflow disturbance of the bridge under the action of the wind, reduces the wind pressure fluctuation, and ensures the stability of the bridge under various climatic conditions.

[0031] Further, hooks 6 are respectively installed on both sides of the lower chord 2, and the hooks 6 on both sides are connected by a first connecting rod 7; the left end of the first inclined deflector 4 is connected to the hook 6 on the left side of the lower chord 2 through a second connecting rod 8, and the right end of the first inclined deflector 4 is connected to the hook 6 on the right side of the lower chord 2 through another second connecting rod 8. The connection of the hooks 6 on both sides by the first connecting rod 7 makes the hooks 6 more stable, and the second connecting rod 8 completes the connection and fixation between the lower chord 2 and the first inclined deflector 4.

[0032] Further, it also includes a first inclined connecting rod 10; in the width direction of the truss bridge, the second connecting rods 8 at the left end and the right end of the first inclined deflector 4 are connected by the first inclined connecting rod 10; in the length direction of the truss bridge, the second connecting rods 8 on the same side are connected by another first inclined connecting rod 10. The first inclined connecting rod 10 is to increase the connection strength between the second connecting rods 8 in the width direction and the length direction of the truss bridge.

[0033] Further, a second inclined deflector 5 is provided below the first inclined deflector 4. A second diversion channel is formed between the second inclined deflector 5 and the first inclined deflector 4. The end of the second diversion channel facing the windward side is wider than the end of the first diversion channel facing the bridge, guiding the wind towards the bottom of the bridge. The second inclined deflector 5 is provided to form the second diversion channel, and the function of the second diversion channel is the same as that of the first inclined deflector 4, but the inclination angle is larger, guiding the airflow at the bottom of the first inclined deflector.

[0034] Further, the left end of the second inclined deflector 5 is connected to the left end of the first inclined deflector 4 through a third connecting rod 9, and the right end of the second inclined deflector 5 is connected to the right end of the first inclined deflector 4 through another third connecting rod 9. The third connecting rod 9 completes the connection and fixation between the first inclined deflector 4 and the second inclined deflector 5.

[0035] Further, it further includes a second inclined connecting rod 11; in the width direction of the truss bridge, the third connecting rod 9 at the left end of the second inclined deflector 5 and the third connecting rod 9 at the right end are connected through the second inclined connecting rod 11; in the length direction of the truss bridge, the third connecting rods 9 on the same side are connected through another second inclined connecting rod 11. The second inclined connecting rod 11 is to increase the connection strength between the third connecting rods 9 in the width direction and the length direction of the truss bridge.

[0036] As Figure 6 shown, preferably, the cross-section of the wind nozzle 3 is an isosceles triangle. The cross-section is set as an isosceles triangle, which can more evenly separate and guide the airflow when facing the oncoming airflow.

[0037] In this embodiment, the amplitudes of a conventional truss bridge, the truss bridge 1 with the wind nozzle 3, the first inclined deflector 4 and the second inclined deflector 5 added in the present invention, and a steel box girder bridge are compared.

[0038] Figure 7 is a comparison table of the torsional amplitudes of the truss bridge at different wind speeds, Figure 8 is a comparison table of the vertical amplitudes of the truss bridge at different wind speeds, Figure 9 is a comparison table of the torsional amplitudes of the steel box girder bridge at different wind speeds, Figure 10 is a comparison table of the vertical amplitudes of the steel box girder bridge at different wind speeds. From Figures 7 - 10 the data in it, it can be seen that both the truss bridge 1 and the steel box girder bridge have relatively large amplitudes in torsion and vertical directions without any measures. After the wind nozzle 3, the first inclined deflector 4 and the second inclined deflector 5 are added in the present invention, the vertical and torsional amplitudes of the truss bridge 1 and the steel box girder bridge are significantly reduced. The present invention optimizes the aerodynamic performance of the parallel bridge, significantly improves the wind resistance of the bridge, and solves the problems of wind pressure concentration and wind-induced vibration in traditional designs.

[0039] The terms "connection" and "fixation" appearing in the description of the present invention may be fixed connection, machining, welding, or mechanical connection. The specific meanings of the above terms in the present invention should be understood according to the specific circumstances.

[0040] In the description of the present invention, terms such as "center", "upper", "lower", "horizontal", "inner", "outer", etc. indicate the orientation or positional relationship only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying a specific orientation that the indicated device or element must have. Therefore, it should not be construed as a limitation to the present invention.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vortex-induced vibration suppression structure for a long-span parallel bridge, characterized in that: It includes a nozzle (3) and a first inclined deflector (4); The nozzle (3) is installed on the side of the lower chord (2) on the windward side of the truss beam. The cross-section of the nozzle (3) is triangular, and the tapered part of the nozzle (3) faces the windward side, guiding the airflow on the windward side to flow towards both sides of the nozzle (3); The first inclined deflector (4) is located below the lower chord (2), and a first diversion channel is formed between the first inclined deflector (4) and the lower chord (2); The side of the first diversion channel facing the windward side is wider than the side facing the bridge, guiding the wind towards the bottom of the bridge.

2. The vortex-induced vibration suppression structure for a long-span parallel bridge according to claim 1, characterized in that: Hooks (6) are respectively installed on both sides of the lower chord (2), and the hooks (6) on both sides are connected by a first connecting rod (7); The left end of the first inclined deflector (4) is connected to the hook (6) on the left side of the lower chord (2) through a second connecting rod (8), and the right end of the first inclined deflector (4) is connected to the hook (6) on the right side of the lower chord (2) through another second connecting rod (8).

3. The vortex-induced vibration suppression structure of a long-span parallel bridge according to claim 2, characterized in that: It further includes a first inclined connecting rod (10); In the width direction of the truss bridge, the second connecting rods (8) at the left end and the right end of the first inclined deflector (4) are connected by the first inclined connecting rod (10); In the length direction of the truss bridge, the second connecting rods (8) on the same side are connected by another first inclined connecting rod (10).

4. A vortex-induced vibration suppression structure for a long-span parallel bridge according to claim 1, characterized in that: A second inclined deflector (5) is arranged below the first inclined deflector (4), and a second diversion channel is formed between the second inclined deflector (5) and the first inclined deflector (4); The side of the second diversion channel facing the windward side is larger than the side of the first diversion channel facing the bridge, guiding the wind towards the bottom of the bridge.

5. A vortex-induced vibration suppression structure for a long-span parallel bridge according to claim 4, characterized in that: The left end of the second inclined deflector (5) is connected to the left end of the first inclined deflector (4) through a third connecting rod (9), and the right end of the second inclined deflector (5) is connected to the right end of the first inclined deflector (4) through another third connecting rod (9).

6. A vortex-induced vibration suppression structure for a long-span parallel bridge according to claim 5, characterized in that: It further includes a second inclined connecting rod (11); In the width direction of the truss bridge, the third connecting rods (9) at the left end and the right end of the second inclined deflector (5) are connected by the second inclined connecting rod (11); In the length direction of the truss bridge, the third connecting rods (9) on the same side are connected by another second inclined connecting rod (11).

7. A vortex-induced vibration suppression structure for a long-span parallel bridge according to claim 1, characterized in that: The cross-section of the nozzle (3) is an isosceles triangle.

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