JP2520564B2 - Damper device for cable-stayed cable - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper device for suppressing cable vibration in a cable-stayed bridge or the like.

[0002]

2. Description of the Related Art Conventionally, the vibration of a cable caused by wake galloping, rain vibration, vortex excitation, and live load is (a) a method of connecting ropes to interfere with each other and suppressing the vibration.

(B) A method of installing an oil damper.

(C) A method in which rubber is wound around the rope at the rope fixed end and the vibration energy is absorbed by the compression action of the rubber.

(D) A method of encapsulating a viscous substance in a fixed end and absorbing vibration energy as heat energy of the viscous substance.

And so on.

[0007]

The method of tying ropes together and interfering with each other to suppress vibrations has a problem in terms of appearance because a sufficient vibration suppressing effect cannot be obtained.

The method of attaching the oil damper to the fixed end has only a one-way damping effect and uses two or more oil dampers, which is aesthetically problematic and the damping characteristic depends on the oil viscosity coefficient. Depends on temperature, the damping effect is greatly influenced. In addition, the optimum viscosity coefficient varies depending on the vibration order, and stable damping cannot be obtained.

In the damping method in which rubber is sandwiched between the protective tube and the jacket tube of the cable to absorb the vibration energy by the compression action of the rubber, the rubber does not exert a sufficient damping effect against the compression vibration. There was a flaw.

The method of encapsulating the viscous substance in the fixed end of the cable for damping has a problem in sealing when encapsulating the viscous substance, and the viscous coefficient of the viscous substance greatly fluctuates with temperature, resulting in a constant damping effect. Was difficult to secure.

The present invention has been devised to solve the above problems.

[0012]

At the fixed end of a cable-stayed cable 1 covered with a protective tube 2, an outer tube 3 is provided so that the fixed end can be housed inside, and one end of the outer tube 3 is fixed to an anchor. Then, the other end of the outer tube 3 forms a flange, and a sleeve portion 4'covering the protective tube 2 is projected at the center of the flange, and the high damping rubber mounting flange 4 is fastened to the flange portion with a bolt. Around the sleeve 4'of the high-damping rubber mounting flange 4, a high-damping rubber 5 having a substantially trapezoidal shape obtained by dividing a thick disk into a plurality of pieces is adhered at intervals, and from above the high-damping rubber 5, A half-cracked disk that covers the entire surface of the high-damping rubber 5,
The cable protection tube 2 is wrapped while the high damping rubber 5 is adhered to the disc portion of the high damping rubber pressure fitting 6 formed of a half-cracked pressure fitting that holds the cable protection tube 2. The half-cracked high-damping rubber pressure fitting 6 is fastened with a bolt, and the outer tube 3
The purpose of the invention is to provide a damper device for a cable-stayed cable, characterized in that the high-damping rubber 5 attachment portion is closed with a protective cover 7 between the protective tube 2 and the protective tube 2.

[0013]

When the cable vibrates in all directions, a shearing force is generated between the high damping rubber mounting flange 4 side and the high damping rubber pressure fitting 6, and the vibration energy of the rope is absorbed by the shearing action of the high damping rubber. To be done.

An example of the damper analysis model of the present invention is shown in FIG.
Shown in When the damper is installed at a rope total length of 200 m and an initial tension of 300 t at a distance of 8 m from the rope fixed end, there is a relation between the elastic spring constant and the logarithmic decrement. The damping characteristics are determined by the internal friction coefficient of the rubber and are not related to the vibration order. In this example, when using a rubber with an internal friction coefficient of rubber γ = 1.0, if the spring constant is designed to be 35 t / m, Equivalent damping characteristics are obtained for all vibration orders. On the other hand, an analytical model of a conventional viscous damper is shown in FIG. The optimum damping coefficient differs depending on the vibration order. In this example, the damping coefficient is usually set to about 10 ts / m for design. Further, the viscous damper is easily affected by temperature, and the damping effect is not constant depending on temperature.

[0015]

FIG. 1 shows an embodiment of the present invention. At the fixed end of the cable-stayed cable 1 covered with the protection tube 2, an outer tube 3 is provided so that the fixed end can be housed inside, and one end of the outer tube 3 is fixed to an anchor. The other end of the outer tube 3 forms a flange, and a sleeve portion 4'covering the protective tube 2 is projected at the center of the flange. A high damping rubber mounting flange 4 is fastened to the flange portion of the outer tube 3 with a bolt, and a disc having a thickness is divided into several pieces around a sleeve 4 ′ of the high damping rubber mounting flange 4 to form a substantially trapezoidal shape. The damping rubber 5 is adhered at intervals. FIG. 1B shows an AA cross section of FIG. A circle of a high-damping rubber pressure-fitting metal fitting 6 formed from a half-cracking disk that covers the entire surface of the high-damping rubber 5 from above the high-damping rubber 5 and a half-breaking pressure metal fitting that wraps the cable protection tube 2. The cable protection tube 2 is wrapped while the high damping rubber 5 is bonded to the plate portion, and the half-cracked high damping rubber pressure fitting 6 is fastened with a bolt. FIG. 1C shows a BB cross section of FIG. With the protective cover 7 between the outer tube 3 and the protective tube 2, the high damping rubber 5
The mounting portion is closed to protect the high damping rubber portion 5 from wind and rain and external force. Further, since the high-damping rubber mounting flange 4, the high-damping rubber 5, and the half-damped high-damping rubber pressure fitting 6 are unitized, the structure is simple for replacement and maintenance.

[0016]

The effects of the present invention are as follows.

(A) In the design of the damper, since the optimum spring constant does not depend on the vibration order, the vibration damping effect is great for vibrations of any vibration order.

(B) The damping characteristic is slightly lower than that of the viscous damper, but the fact that the temperature characteristic is constant in addition to the fact that it responds to vibrations of any of the above-mentioned vibration orders makes the design easy and effective. large.

(C) Since the structure is unitized,
The area and length of the high-damping rubber can be freely changed, and the damping effect can be properly designed, and maintenance is easy.

(D) With a damper made of a compression rubber sandwiched between a protective tube and a jacket tube, it is difficult to set the spring constant as a compression spring, and almost no damping is expected for compression. On the other hand, in the present invention, damping due to internal shear friction is applied and effectively contributes to damping.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view of the present invention. (B) It is an AA sectional view of (a). (C) It is a BB view of (a).

FIG. 2 is a diagram showing an example of an elastic spring constant and a logarithmic damping rate of the present invention.

FIG. 3 is a diagram showing an example of a damping coefficient and a logarithmic damping rate of a viscous damper.

[Explanation of symbols]

1 ... Cable-stayed cable, 2 ... Protective tube, 3 ... Outer tube, 4 ... High damping rubber mounting flange, 5 ... High damping rubber, 6 ... High damping rubber pressure fitting , 7 ... Protective cover

Claims (1)

(57) [Claims] 1. A fixed tube of a cable-tensioned cable 1 covered with a protective tube 2 is provided with an outer jacket tube 3 such that the fixed end can be housed therein, and one end of the outer jacket tube 3 is fixed to an anchor. The other end of the pipe 3 forms a flange, and a sleeve portion 4'covering the protective pipe 2 is projected at the center of the flange, and the high damping rubber mounting flange 4 is fastened to the flange portion with a bolt,
Around the sleeve 4'of the high-damping rubber mounting flange 4, a substantially trapezoidal high-damping rubber 5 obtained by dividing a thick disc into a plurality of pieces is adhered with a space, and the high-damping rubber 5 is elevated from above. The high-damping rubber 5 is attached to the disk portion of the high-damping rubber pressure-fitting metal fitting 6 formed of a half-cracking disk that covers the entire surface of the damping rubber 5 and a half-breaking pressure-fitting metal fitting that wraps the cable protection tube 2. While adhering, the cable protection tube 2 is wrapped, and the half-cracked high-damping rubber pressure fitting 6 is bolted, and the high-damping rubber 5 is attached with the protective cover 7 between the outer tube 3 and the protective tube 2. A cable-damped cable damper device characterized in that the portion is closed.