JP2004183379A - Vibration control structure of expansion device for bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control structure of an expansion device for a bridge, which suppresses vibrations generated at the time of collision of wheels with middle beams, over the entire body of the beam, thereby reducing noises. <P>SOLUTION: In a joint 1 for the bridge, which is set between edges of girders 2, 2 or in an expansion gap 30 between the girder edge and an abutment, and includes a plurality of support beams 3 which have both ends thereof borne at intervals in a direction at right angles to a bridge axial direction, and the plurality of middle beams 4 which are borne on the support beams 3 at intervals in the bridge axial direction, a vibration control member 21 which is elastically deformable and held between the mutually adjacent middle beams 4, 4 by a backup member 22, to thereby block a cavity between the middle beams, is installed. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vibration damping structure for a telescopic device for a bridge, and more particularly to a technique for preventing vibration and noise generated when a vehicle runs on the telescopic device.
[0002]
[Prior art]
As one type of a telescopic device (joint) for a bridge, a modular joint is known. This modular joint can follow the expansion and contraction due to the temperature change of the girder, the rotation due to the live load, and the three-dimensional movement at the time of the earthquake. It is increasingly being used.
[0003]
However, in such a modular joint, when the vehicle passes over the joint, the wheels collide with the middle beam and the beam vibrates. For this reason, the vibration propagates as sound and spreads out from the gap between the upper and lower girders of the joint, thus causing a problem of noise. In particular, it has been observed that the frequency of the sound from the girder under the joint almost coincides with the vibration frequency of the middle beam in the vertical direction, and it is an issue how to suppress the vibration of the entire middle beam.
[0004]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following objects.
An object of the present invention is to provide a vibration damping structure for a telescopic device for a bridge capable of suppressing vibration when a wheel collides with a middle beam over the entire beam and reducing noise.
[0005]
[Means for Solving the Problems]
The present invention employs the following means to achieve the above object.
That is, the present invention provides a plurality of support beams whose both ends are supported at intervals in the direction perpendicular to the bridge axis, between the girder ends or in the play between the girder ends and the abutment, and on these support beams. In a bridge joint having a plurality of middle beams supported at intervals in the bridge axis direction,
The vibration damping structure of a telescopic device for a bridge, wherein elastically deformable vibration damping materials for closing the gap are provided between middle beams adjacent to each other.
[0006]
More specifically, the vibration damping material is held on an elastically deformable backup material installed between the middle beams. Further, the vibration damping material is filled between the middle beams on the backup material in a flowing state and hardened. A water shutoff gutter may be provided in the play below the middle beam.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an embodiment of the present invention and is a sectional view in the bridge axis direction showing a modular joint (hereinafter, simply referred to as a joint). In the illustrated example, the joint 1 is installed in a girder gap 30 formed between opposing ends of the girder (concrete girder) 2. The joint 1 has a plurality of support beams 3 whose both ends are supported at intervals between the ends of the girders 2 and 2 at right angles to the bridge axis, and supports on the support beams at intervals in the bridge axis direction. And a plurality of middle beams 4.
[0008]
A box 5 is buried at each end of the beams 2, 2, and the support beam 3 is supported by the boxes 5, 5 via sliding bearings 8 with both ends inserted into the boxes 5, 5. I have. A sliding spring 9 is interposed between the upper surface of the support beam 3 and the inner surface of the box 5.
[0009]
Each of the sliding bearing 8 and the sliding spring 9 is made of a columnar rubber, and is fixed to the inner surface of the box 5. The sliding bearing 8 and the sliding spring 9 are provided with a sliding member (not shown) on the contact surface with the support beam 3 so that the support beam 3 can move relative to the beams 2 and 2 in the bridge axis direction. Has become.
[0010]
Each middle beam 4 is provided with a number of frame-shaped brackets 10 corresponding to the number of the support beams 3 at a lower portion, and the support beams 3 are passed through the brackets 10. The middle beam 4 is supported by the support beam 3 via a sliding bearing 11 provided between the bracket 10 and the upper surface of the support beam 3. A sliding spring 12 is interposed between the lower surface of the support beam 3 and the inner surface of the bracket 10.
[0011]
The sliding bearing 11 and the sliding spring 12 are both made of cylindrical rubber, and are fixed to the inner surface of the bracket 10. The sliding bearing 11 and the sliding spring 12 are provided with a sliding member (not shown) on the contact surface with the support beam 3 so that the middle beam 4 can move relative to the support beam 3 in the bridge axis direction. ing. A waterproof rubber 13 is provided between the middle beams 4 and 4. An end beam 14 is provided at the upper edge of the end of the spar 2, and the waterproof rubber 13 is also provided between the end beam 14 and the middle beam 4. In the figure, reference numeral 15 indicates a road surface.
[0012]
The middle beam 4 includes upper and lower flanges 16 and 17 and a web 18 formed between the upper and lower flanges 16 and 17. Protrusions 19 formed on the upper side of both sides of the web 18 are for holding the waterproof rubber 13 between the web 18 and the upper flange 16. The configuration up to this point is the same as the conventional one.
[0013]
According to the present invention, the elastically deformable damping material 21 is provided between the middle beams 4 adjacent to each other below the waterproof rubber 13, and the gap between the middle beams 21 is closed by the damping material 21. . Specifically, an elastically deformable backup material 22 is installed between the webs 18 while being mounted on the lower flange 17 of the middle beam 4, and the vibration damping material 21 is held by the backup material 22. It is installed between the webs 18. The damping material 21 and the backup material 22 are installed over the entire effective width of the joint 1 in the direction perpendicular to the bridge axis, and are also installed between the end beam 14 and the middle beam 4.
[0014]
As the damping material 21, an elastic seal material used for non-drainage in a well-known finger joint can be applied. This elastic sealing material contains a hydroxyl-terminated polybutadiene or the like as a main component and an isocyanate prepolymer or the like as a curing agent, and the two are mixed and stirred. Although it has fluidity at first, it hardens when left overnight, and exhibits high elasticity after hardening. Further, as the backup material 22, a highly elastic urethane foam can be used. As described above, both the vibration damping material 21 and the backup material 22 have elasticity, and therefore can follow the expansion and contraction of the joint 1, that is, the movement of the middle beam 4 in the bridge axis direction.
[0015]
When installing the damping material 21, first, the backup material 22 is installed between the webs 18 of the middle beam 4. Then, the vibration damping material 21 is filled between the webs 18 on the backup material 22 in a flowing state and hardened. That is, the backup material 21 functions as a mold when the vibration damping material 21 is filled between the webs 18 before the vibration damping material 21 is hardened. Such an installation operation involving filling and hardening of the vibration damping material 21 in a fluidized state may be performed at the construction site of the joint 1 or at a factory.
[0016]
FIG. 2 is a cross-sectional view in the bridge axis direction showing another embodiment. In this embodiment, the waterproof rubber 13 shown in FIG. 1 is eliminated. Therefore, the damping material 21 can be filled up to the upper flange 16 of the middle beam 4, and the volume of the damping material 21 can be increased, so that the damping effect can be enhanced. In this case, the water stopping gutter 23 may be provided in the play space 30 below the middle beam 4 over the entire effective width in the direction perpendicular to the bridge axis.
[0017]
FIG. 3 is a cross-sectional view at right angles to the bridge axis, showing still another embodiment. In this embodiment, the backup member 22 is provided between the lower flanges 17 of the middle beams 4 adjacent to each other. As a result, the damping material 21 can be filled from the lower flange 17 to the upper flange 16 of the middle beam 4, and the volume of the damping material 21 can be further increased, so that the damping effect can be further enhanced. Can be. In the case of this embodiment as well, the installation work involving the filling and hardening of the damping material 21 in the flowing state can be performed at either the construction site of the joint 1 or the factory, but the damping material 21 is hardened. Thereafter, the backup material 22 may be removed.
[0018]
【The invention's effect】
As described above, according to the present invention, the vibration when the wheel collides with the middle beam can be suppressed over the entire beam without largely changing the conventional structure, and the noise can be reduced. it can.
[Brief description of the drawings]
FIG. 1 is a sectional view in the bridge axis direction showing an embodiment of the present invention.
FIG. 2 is a sectional view in the bridge axis direction showing another embodiment of the present invention.
FIG. 3 is a sectional view in a bridge axis direction showing still another embodiment of the present invention.
[Explanation of symbols]
1: joint 2: beam 3: support beam 4: middle beam 10: bracket 13: waterproof rubber 14: end beam 15: road surface 16: upper flange 17: lower flange 18: web 21: damping material 22: backup material 23 : Stop water gutter 30: Girder play

Claims (4)

A plurality of support beams, both ends of which are supported at intervals in the direction perpendicular to the bridge axis, between the girder ends or in the play between the girder end and the abutment. In a bridge joint having a plurality of middle beams supported by placing,
A vibration damping structure for a telescopic device for bridges, wherein elastically deformable damping materials for closing a gap are provided between middle beams adjacent to each other. The vibration damping structure for a telescopic device for a bridge according to claim 1, wherein the vibration damping material is held on an elastically deformable backup material provided between the middle beams. The vibration damping structure for a telescopic device for a bridge according to claim 2, wherein the vibration damping material is filled in a fluid state between the middle beams on the backup material and is hardened. The vibration damping structure of a telescopic device for a bridge according to claim 1, 2, or 3, wherein a water stop gutter is installed in a play under the middle beam.

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