JP2850662B2 - Damping device for diagonal cable in cable-stayed bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for a diagonal cable in a cable-stayed bridge, which attenuates the vibration of a diagonal cable installed in parallel by wind.

[0002]

2. Description of the Related Art In a parallel cable type cable-stayed bridge in which a diagonal cable is laid in parallel between a main tower and a bridge girder, when a diagonal cable receives a horizontal wind, a leeward wind is generated. In the diagonal cable on the side, forced vibrations are caused in the direction perpendicular to the direction of the wind and the axis of the diagonal cable by Karman vortices opposite to each other that occur alternately on the back side of the diagonal cable on the windward side, It is necessary to take measures to reduce this vibration.

Conventionally, a spacer is straddled between parallel diagonal cables to connect them, and at the same time, diagonal cables parallel in the height direction are connected to each other by wires to restrain the vibration of the diagonal cables. Alternatively, a damper is installed on the main tower or bridge girder at the end of the diagonal cable to reduce the vibration of the diagonal cable to reduce the vibration. In addition to causing subspan vibration in the diagonal cable, the crossing of the cable with the diagonal cable causes the appearance of the cable-stayed bridge to deteriorate. In the latter method, viscous dampers and oil dampers are usually used for the dampers, so that maintenance is required in addition to the fact that the dampers need to be arranged in the plane of vibration of the diagonal cable,
It is difficult to connect the diagonal cable to the main tower or bridge girder, and the installation cost is increased.

[0004] The present invention has been made in view of the actual situation of the conventional vibration reduction method, and aims to newly propose a device that effectively attenuates vibration with a simple structure.

[0005]

According to the present invention, at the same time, the projecting members facing each other are connected to the respective oblique material cables arranged in parallel, and at the same time, a high-damping rubber is provided between the projecting members and adhered to both of them. When vibration of the material cable occurs, the overhanging members are relatively moved to shear-deform the high-damping rubber, and the high-damping rubber attenuates the vibration, thereby simplifying the structure for vibration suppression and reducing manufacturing costs. While eliminating the problem of aesthetics and the need for maintenance, it also prevents the occurrence of subspan vibration.

The overhanging members are connected to the respective oblique material cables and overhang toward the oblique material cables facing each other, and the high damping rubber straddles the two overhanging members and is adhered to both so as to follow the relative movement thereof. The high-damping rubber is bonded to the overhang members so that it is sheared and deformed at the time of axial relative movement between the overhang members due to the vibration of the leeward cable, thereby damping this relative movement. Damping the vibration of

[0007] The high damping rubber attenuates the vibration of one of the diagonal cables on the leeward side, and thus also functions when sub-span vibration occurs when spacers are installed between the parallel diagonal cables.

[0008] Since the vibration damping device is composed only of the overhanging member and the high damping rubber, the structure is simplified and the manufacturing cost is reduced. In addition, the high damping rubber damps the vibration, thereby eliminating the need for maintenance. Further, since there is no wire between the diagonal cables in the height direction, it is possible to prevent the appearance from being deteriorated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing one embodiment.

A vibration-damping device 1 according to the present invention is applied to a cable-stayed bridge in which diagonal cables 5 and 5 installed between a main tower and a bridge girder are arranged in parallel as shown in FIG. Overhang members 2, 2 connected to the respective diagonal cables 5, 5
And a high-attenuation rubber 3 bonded between the overhang members 2, 2, and the wind shown by the arrow of the leeward side diagonal cable 5 generated by the wind shown by the white arrow in FIG. 1. This is a device that suppresses vibration in the direction perpendicular to the axis of the diagonal cable 5 and the direction of the cable 5.

As shown in FIG. 1, the overhanging members 2, 2 are connected to the respective diagonal cables 5, 5 to face the diagonal cables 5, 5 facing each other.
5 and are opposed to each other so as to be relatively movable on the same axis. In the embodiment shown in FIG. 1, sleeves 4, 4 are provided around diagonal cables 5, 5 in which projecting members 2, 2 are arranged in parallel.
Are connected to the diagonal cables 5, 5, but the method of connecting the projecting members 2, 2 to the diagonal cables 5, 5 is arbitrary.

As shown in FIG. 3, the overhang member 2 is inclined with respect to the normal state when one of the oblique member cables 5 vibrates, so that the overhang member 2 can rotate with respect to the oblique member cable 5 within the range of the inclination. Connected. In the case of the embodiment shown in FIG. 1, the sleeves 4, 4 are connected rotatably around the diagonal cables 5, 5.

As shown in FIG. 2, which is a sectional view of the diagonal cable 5 in the axial direction of FIG.
It straddles between the two and is adhered to both so as to follow the relative movement between the two.

FIG. 1 shows an embodiment in which the overhanging members 2 and 2 are tubular. In this case, as shown in FIG. inner tube 2 ₁ to be inserted is protruded within, high damping rubber 3 is bonded to both across between the inner circumferential surface of the outer peripheral surface and the other overhanging member 2 of the inner tube 2 _1.

FIG. 4 shows an embodiment in which the overhanging members 2 and 2 are plate-shaped. In this case, one of the overhanging members 2 is continuous in a plate-like shape and at least the other overhanging member 2 is opposed to the other. The portion to be formed has a groove shape that sandwiches one of the overhanging members 2, and the high damping rubber 3 is sandwiched between the two overhanging members 2, and is bonded to both. The two overhanging members 2 and 2 are combined so as to overlap with each other while being relatively movably opposed in the axial direction, and the high damping rubber 3 is attached to the overlapping portion of the two overhanging members 2 and 2 as shown in FIG. What is necessary is just to adhere | attach in the state which carries out a shear deformation following both at the time of relative movement between them, and the shape of the overhang members 2 and 2 and the way of adhesion | attachment of the high attenuation rubber 3 corresponding to it are not limited to an Example.

As shown in FIG. 3, the high-attenuation rubber 3 is provided with the overhanging members 2 and 2 when the leeward cable 5 is vibrated.
Following the relative movement of the two members, the overhang members 2, 2 are subjected to shear deformation and retained by the hysteresis energy retained.
The vibration of the diagonal cable 5 is attenuated by attenuating the relative movement between them and reducing the amplitude without restraining the vibration.

Since the vibration damping device 1 also has a role of restraining relative movement of a certain amount or more between the parallel diagonal cables 5, 5 by connecting the overhang members 2, 2 with the high damping rubber 3, It is also used as a spacer connecting the material cables 5 and 5. Further, since the damping effect of the high damping rubber 3 is higher as the amount of shear deformation is larger, when the diagonal cables 5 and 5 are connected to each other by spacers (not shown) in addition to the damping device 1, the damping device 1 It is installed at the position of the antinode of the vibration having the maximum amplitude between the spacers, and in this case, the subspan vibration generated between the spacers is also suppressed.

[0018]

The present invention is as described above. An overhanging member connected to each of the parallel diagonal member cables and overhanging to the opposite overhanging member side is provided. The high damping rubber is configured to attenuate the relative movement between the overhanging members by shearing deformation of the high damping rubber due to the shear deformation of the high damping rubber. Can be suppressed at the same time as the occurrence.

In particular, the use of high-damping rubber simplifies the structure of the device, reduces the manufacturing cost, makes maintenance unnecessary, and does not use wires for connecting the diagonal cables in the height direction. The beauty of the cable-stayed bridge is maintained.

Further, in order to attenuate the vibration of one of the diagonal cables on the leeward side by the high damping rubber, if a diagonal cable is connected by installing a spacer between the parallel diagonal cables, sub-span vibration will occur. Can also be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an installation example of a vibration damping device.

FIG. 2 is an axial sectional view of the diagonal cable of FIG. 1;

FIG. 3 is an axial cross-sectional view of the diagonal cable, showing a state in which the diagonal cable on the leeward side vibrates.

FIG. 4 is a perspective view showing an example of bonding high-damping rubber when the overhanging member has a plate shape.

FIG. 5 is a perspective view showing a cable stayed bridge in which the vibration damping device is used.

[Explanation of symbols]

1 ... damping device, 2 ... overhang member, 2 ₁ ... inner tube, 3 ...
High attenuation rubber, 4 ... Sleeve, 5 ... Diagonal cable.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) E01D 1/00 E01D 11/00

Claims (1)

(57) [Claims] The present invention is a device installed between a pair of parallel diagonal cables installed between a main tower and a bridge girder to suppress vibration in the height direction of the diagonal cables due to wind. An overhanging member that connects and overhangs to the diagonal cable side facing each other, and is bonded to both over the two overhanging members, and is attached between the two overhanging members in the axial direction between the two overhanging members due to vibration of the leeward side diagonal cable. A damping device for a diagonal cable in a cable-stayed bridge composed of high-damping rubber that attenuates the relative movement by shear deformation during relative movement.