Water damping device and method for controlling vortex-induced vibration and fluttering of sea-crossing or river-crossing bridges

Abstract

A water damping device includes a steel frame and a water-blocking cup; the device is immersed in the water and connected under the main bridge girder by wire ropes. One end of the water-blocking cup is provided with a blocking ring and a cover. The water-blocking cup cover is mounted between the cup and the blocking ring and is movably connected to the water-blocking cup. The blocking ring is used to prevent the water-blocking cup cover from opening towards the outside of the cup; an array of water-blocking cups is mounted on the steel frame along the downward direction of the water-blocking cup cover.

Claims

1. A water damping device for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges, comprising a water damping device, wherein the water damping device is connected under a main girder by wire ropes and immersed in the water; the water damping device comprises a steel frame and a water-blocking cup, one end of the water-blocking cup is provided with a blocking ring and a water-blocking cup cover, the water-blocking cup cover is mounted between the water-blocking cup and the blocking ring and is movably connected to the water-blocking cup, the blocking ring is used to prevent the water-blocking cup cover from opening towards the outside of the water-blocking cup; an array of water-blocking cups is mounted on the steel frame along the downward direction of the water-blocking cup cover; further comprising a displacement stroke amplifier, wherein the displacement stroke amplifier is mounted on the bridge tower adjacent to both ends of the main girder and is connected to the water damping device; the displacement stroke amplifier comprises a reinforced rigid arm, a solid steel shaft, a small-radius roller, and a large-radius hub; one end of the reinforced rigid arm is connected to the bridge tower, and the other end is connected to the small-radius roller; the solid steel shaft is embedded in the small-radius roller through balls; the large-radius hub and the small-radius roller are coaxially fixed; and a groove is provided on the outer side of the small-radius roller; one end of the wire ropes is wound in the groove on the outer side of the small-radius roller, and the other end is connected to the main girder; a groove is provided on the outer side of the large-radius hub; one end of the wire ropes is wound in the groove on the outer side of the large-radius hub and the other end is connected to the water damping device.

2. The water damping device for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges according to claim 1, wherein the water damping devices are mounted at points ½, ¼, and ⅛ of a length of the main girder.

3. The water damping device for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges according to claim 1, further comprising an anchoring hole opened at the bottom of main girder; wherein the water damping device is connected to the anchoring hole through the wire ropes.

4. The water damping device for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges according to claim 1, wherein the water damping devices are mounted on both sides of the bridge.

5. The water damping device for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges according to claim 1, wherein the water-blocking cup cover is made of lightweight materials; the steel frame and the water-blocking cup are made of high-density materials.

6. A method for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges, wherein the method makes use of the water damping device according to claim 1 and comprises following steps: S1: placing the device into the water and connecting the water damping device under the main girder through the wire ropes when the Vortex Induced Vibration and fluttering of a bridge occurs; S2: suppressing the Vortex Induced Vibration and fluttering of bridges using the water damping device; and S3: removing the water damping device and putting it away after the Vortex Induced Vibration and fluttering of bridges disappear.

7. The method for controlling vortex-induced vibration and flutter of sea-crossing or river-crossing bridges according to claim 6, wherein S2 comprises: S2.1: during an upward movement of the main girder, the water damping device conducting the upward movement under the action of pulling force, and the water flow causing the water-blocking cup cover to seal the bottom of the water-blocking cup so as to increase the resistance and damping force to the upward movement of the main girder and dissipate partial kinetic energy of the upward movement of the main girder; and S2.2: during a downward movement of the main girder, the water damping device moving downward under the action of gravity, the water flow causing the water-blocking cup cover to open towards the inside of the water-blocking cup and the water flowing through the water-blocking cup so that the resistance to the downward movement of the steel frame is reduced and falls rapidly under the action of gravity; the stroke of the water damping device being reserved for the next round of upward movement of the main girder so that the water damping device has a strong enough stroke to dissipate the vibration energy of the main girder during the next round of upward movement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to elaborate the specific embodiments of the present application and the technical solutions more explicitly, the accompanying drawings are briefly introduced below.

(2) FIG. 1 is a front view of the water damping device for controlling VIV and flutter of sea-crossing or river-crossing bridges provided by the application connected to the bridge.

(3) FIG. 2 is a side view of the water damping device for controlling VIV and flutter of sea-crossing or river-crossing bridges as provided by the application connected to the bridge.

(4) FIG. 3 is a structural representation of the water damping device provided by the application.

(5) FIG. 4 is a structural representation of the displacement stroke amplifier provided by the present application.

(6) FIG. 5 is a flowchart representation of the method for controlling VIV and flutter of sea-crossing or river-crossing bridges.

(7) FIG. 6 is a flowchart representation of the Step S2.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(8) The technical solutions of the present application will be explicitly elaborated in their entirety below in conjunction with the accompanying drawings. Obviously, the stated embodiments are a part of rather than the entire embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the application.

(9) In the description of the present application, it should be noted that the terms that indicate the relationship of orientations or positions such as “center,” “upper,” “lower,” “left,” “right,” “vertical,” “horizontal,” “inside,” and “outside” are based on the relationship of orientation or position as shown in the accompanying drawings. This intends solely to facilitate and simplify the description of the present application rather that to indicate or imply that the described device or element shall have a specific orientation or shall be constructed and operated in a particular fashion. Therefore, it shall not be interpreted as a limitation of the present application. Furthermore, the terms “first,” “second,” and “third” are used for description only and shall not be construed to indicate or imply relative importance.

(10) In the description of the present application, it should be noted that, unless otherwise expressly specified and limited, the terms “mount,” “connect,” and “link” shall be understood in a broad sense. For instance, they may be construed to indicate a fixed connection, a detachable connection, an integral connection, a mechanical connection, or an electrical connection; they may also refer to a direct connection or an indirect connection through an intermediate medium or through internal linkage of two components. For those of ordinary skill in the art, the specific connotation of the aforesaid terms in the present application should be understood on a case-by-case basis.

(11) In addition, the technical features stated in the various embodiments of the present application as described below can be combined with each other, as long as they do not conflict with one another.

Embodiment 1

(12) The present embodiment provides a water damping device that controls the VIV and flutter of sea-crossing and river-crossing bridges, as shown in FIGS. 1 to 4. It includes the water damping devices 1 that are connected to the anchoring hole opened at the bottom of the main girder 3 by wire ropes 2 and are immersed in the water. The water damping devices 1 are mounted at points ½, ¼, and ⅛ of the length of the main girder 3. The water damping devices 1 include a steel frame 11 and a water-blocking cup 12. One end of the water-blocking cup 12 is provided with a blocking ring 13 and a water-blocking cup cover 14. The water-blocking cup cover 14 is mounted between the water-blocking cup 12 and the blocking ring 13 and is movably connected to the water-blocking cup 12. The blocking ring 13 is used to prevent the water-blocking cup cover 14 from opening towards the outside of the water blocking cup 12; the water-blocking cup 14 is made of light materials, such as aluminum alloy. The steel frame 11 and the water-blocking cup 12 are made of high-density materials, such as stainless steel. A plurality of water-blocking cups 12 is mounted on the steel frame 11 according to the downward direction of the water blocking cup cover 14. The water damping device 1 adjacent to the two ends of the main girder 3 is connected to a displacement stroke amplifier 4. The displacement stroke amplifier 4 is mounted on the bridge tower 5.

(13) The displacement stroke amplifier 4 comprises a reinforced rigid arm 41, a solid steel shaft 42, a small-radius roller 43, and a large-radius hub 44; one end of the reinforced rigid arm 41 is connected to the bridge tower 5, and the other end is connected to the small-radius roller 43; the solid steel shaft 42 is embedded in the small-radius roller 43 through balls; the large-radius hub 44 and the small-radius roller 43 are coaxially fixed; a groove is provided on the outer side of the small-radius roller 43, one end of the wire ropes 2 is wound in the groove on the outer side of the small-radius roller 43, and the other end is connected to the main girder 3; a groove is provided on the outer side of the large-radius hub 44; one end of the wire ropes 2 is wound in the groove on the outer side of the large-radius hub 44, and the other end is connected to the water damping device 1.

(14) In this embodiment, based on the configuration of the blocking ring 13, the water-blocking cup cover 14 can be opened towards the inside of water-blocking cups 12 but cannot open towards the outside of the water-blocking cups 12. When the main girder 3 moves upward, the water damping device 1 conducts the upward movement under the action of pulling force, and the water flow causes the water-blocking cup cover 14 to seal the bottom of the water-blocking cups 12. This increases the resistance and damping to the upward movement of the main girder 3 and dissipates partial kinetic energy of the upward movement of the main girder 3. When the main girder 3 moves downward, the water damping device 1 moves downward under the action of gravity, and the water flow causes the water-blocking cup cover 14 to open towards the inside of the water-blocking cup 12; as the water flows through the water-blocking cup 12, the resistance to the downward movement of the steel frame 11 is reduced and falls rapidly under the action of gravity, and the stroke of the water damping device 1 is reserved for the next round of upward movement of the main girder 3.

(15) Based on the configuration of water damping device 1 on both sides of the main girder 3, when the torsional vibration of the main girder 3 occurs, the water damping device at the raised end of the main girder 3 hinders the torsion of the main girder 3, so as to control the torsional VIV and soft flutter. The setting of the water damping devices 1 at points ½, ¼, and ⅛ of the length of the main girder 3 achieves the effect of controlling the first-order, second-order, and third-order VIVs. Based on the configuration of anchoring holes at the bottom of the main girder 3, the water damping device is placed into the water and is connected by wire ropes 2 to exert the effect of suppressing VIV of the bridge; when the VIV of the bridge disappears and the wind environment of bridge deck is stabilized, wire ropes 2 are removed through the anchoring holes of the main girder 3, and the water damping devices 1 are detached and put away. This will not affect the underwater navigation or the aesthetics of the bridge.

(16) Because the vibration displacement of the main girder 3 adjacent to the side span of the bridge tower 5 is relatively small, the displacement stroke of the water damping device 1 is too few to achieve a great control effect. Therefore, the stroke of the water damping device 1 is amplified by installing the displacement stroke amplifier 4 onto the bridge tower 5. This can achieve the effect of suppressing the vibration of the main girder 3. The displacement stroke amplifier 4 is connected to the bridge tower 5 through a reinforced rigid arm 41, and the solid steel shaft 42 is embedded in the small-radius roller 43 through balls. In this way the small-radius roller 43 and the solid steel shaft 42 can rotate coaxially. A groove is provided outside the small-radius roller 43. One end of the wire rope 2 is wound around and connected to the groove, and the other end is connected to the main girder 3. Moreover, the vertical displacement of the main girder 3 is converted into the circumferential displacement of the small-radius roller 43. The large-radius hub 44 is securely mounted on the small-radius roller 43. One end of wire rope 2 is wound in the groove on the outer side of the large-radius hub 44, and the other end of wire rope 2 is connected to the water damping device 1. Under the same angular displacement, the vibration displacement of the main girder 3 is amplified by the multiple between the large-radius hub 44 and the small-radius roller 43. This enables the water damping device 1 to exert the damping effect, thereby suppressing VIV and soft flutter of the bridge. It should be noted that the present application is mainly used to control VIV and flutter but is not limited thereto and can control other forms of vibration with large amplitudes, such as wind-induced buffeting.

Embodiment 2

(17) The embodiments provide a method for controlling VIV and flutter of sea-crossing or river-crossing bridges. The method is implemented using the aforesaid water damping device 1 as a tool and comprises the following steps:

(18) S1: Placing the device into the water and connecting the water damping device 1 under the main girder 3 through the wire ropes 2 when the Vortex Induced Vibration and fluttering of a bridge occurs.

(19) S2: Suppressing the VIV and flutter of bridges using the water damping device 1.

(20) S3: Removing the water damping device 1 and putting it away after the VIV and flutter of bridges disappear.

(21) Step S2 is specifically implemented as below:

(22) S2.1: During the upward movement of the main girder 3, the water damping device 1 conducts the upward movement under the action of pulling force, and the water flow causes the water-blocking cup cover 14 to seal the bottom of the water-blocking cup 12. This increases the resistance and damping to the upward movement of the main girder 3 and dissipates partial kinetic energy of the upward movement of the main girder 3;

(23) S2.2: During the downward movement of the main girder, the water damping device 1 moves downward under the action of gravity, and the water flow causes the water-blocking cup cover 14 to open towards the inside of the water-blocking cup 12; as the water flows through the water-blocking cup 12, the resistance to the downward movement of the steel frame 11 is reduced and falls rapidly under the action of gravity, and the stroke of the water damping device 1 is reserved for the next round of upward movement of the main girder 3. Accordingly, the water damping device 1 has a strong enough stroke to dissipate the vibration energy of the main girder 3 during the next round of upward movement.

(24) In the present embodiment, based on the damping effect of water, the process of energy dissipation is ongoing as long as the main girder 3 moves upward. Therefore, the device has great control robustness and can effectively control the multi-order VIVs by the configuration of multi-span positions. The device provided by the present application is mounted directly outside the main girder 3 and can be detached when not in use. The device neither increases the weight of the main girder 3 nor affects the aesthetics of the main girder 3 and is easy to install if required. Moreover, its maintenance cost is low, and it is suitable for controlling various types of sections of the main girder 3. The device can dissipate the vibration energy of the main girder 3 as long as it moves upward. Hence the vibration of the main girder 3 can be controlled at any order and frequency, and the vibration in the torsional direction of the main girder 3 can be well controlled. The device provided by the application is featured by a simple structure and cost-effectiveness and makes full use of the damping and energy dissipation effects of the water environment. The device can be installed and removed at the position where the vibration of the main girder 3 is the most obvious. Due to its convenience and flexibility, the device has the value of extensive popularization and application and can control any significant vibration of the main girder 3 in the vertical and torsional directions. In particular, it can well control the vibration behavior in complex and extreme wind environments.

(25) Obviously, the foregoing embodiments are intended only to elaborate the examples listed, rather than to restrict the mode of implementation. For those of ordinary skill in the art, changes or modifications in other forms can also be made on the basis of the foregoing description. It is not necessary to give an exhaustive list of all implementation modes. Any obvious changes or modifications derived therefrom still fall within the protection scope of the present application.