JPS5821041B2 - Wind stabilization device when constructing long bridges - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for stabilizing wind resistance during construction of a long bridge such as a bridge having a truss structure stiffening girder.

Long bridges have the problem of vertical undulation due to wind loads.

Therefore, as a measure to stabilize the wind resistance of a long suspension bridge in its completed state, it has been proposed to prevent the above-mentioned vertical waving by providing a band-shaped drift wall along the length of the bridge at the center of the bridge width direction. ing.

Further, in the completed state, the structure may be designed to have sufficient wind resistance without providing the drift wall.

However, in either case, the structural system in the middle of construction may not have sufficient wind resistance stability for a period of time, and as a countermeasure for this, it is not possible to install the above-mentioned drift walls first.
Further, it is not preferable to provide the drift wall because it increases the weight of the structural system during construction.

That is, it is desirable that the wind-resistant stabilizing means in this case be easily installed during a period when a dynamic instability phenomenon is expected, be easily removed after the bridge is completed, and be lightweight.

The present invention provides a wind-resistant stabilizing device that satisfies such requirements.

An embodiment of the present invention will be described below based on the drawings.

1 is a stiffening girder of a truss structure of a long suspension bridge, and 2 is a pair of floors provided on the stiffening girder 1 and forming a reciprocating road surface.

In such a bridge, a wind-resistant stabilizing device is installed as follows during construction.

That is, by effectively utilizing the space in the middle of the stiffening girder 1 in the width direction, for example, below the median strip 2a of the floor 2, the two cable members 3 and 4 are vertically separated from each other and attached to the stiffening girder 1. It is stretched along the length.

The cable members 3 and 4 are made of prestressed wire ropes, for example, and are fixed at both ends to the stiffening girder 1 or a bridge pier.

The upper and lower cable members 3 and 4 are arranged with the main truss upper chord member 5 of the stiffening girder 1 interposed therebetween.

6 is a small truss.

Between the upper and lower cable members 3 and 4 stretched in this manner, a large number of rectangular flow plates 7 are arranged in a band-like manner in the longitudinal direction of the cable members 3 and 4.

The drifting plate 7 is preferably light in weight.

The deflection plate 7 can be attached to the rope members 3 and 4 by sandwiching each cable member 3 and 4 between the U-shaped folded parts 7a and 7b provided at the upper and lower ends of the deflection plate I and tightening them with bolts 8. It will be done.

The appropriate vertical width of the drift plate 7 is about 1 to 1.5 m.

The arrangement of the drift plates 7 does not necessarily have to be continuous, and gaps may be provided at the intersections with the upper chord members 5 of the main structure truss, the sub-trusses 6, and the like.

In this manner, by providing the drift plate 7 in a band shape, the stiffening girder 1 is prevented from waving in the vertical direction due to wind loads, and stabilization is achieved.

The deflection plate T does not have to be installed over the entire length of the bridge, but it can be installed only in the part where the aerodynamic force that is trying to generate vibration acts predominantly, and the aerodynamic force in this part can be converted so that it acts as a damping force. , it is possible to stabilize the wind resistance of the entire bridge.

In this way, wind resistance can be stabilized, but the structure is simply that the deflection plate 7 is attached to the cable members 3.4, and the deflection plate 7 is attached to the upper and lower cable members 3, 4 by bolts 8 etc. as in this embodiment. Since it can be easily attached and detached, it can be easily installed during the construction of a long bridge, and it can also be easily removed after the long bridge is completed.

Furthermore, it is possible to reduce the weight, and there is no problem of weight increase during construction due to installing this device.

As explained above, the present invention is composed of a material and a drifting plate that can be easily attached to and detached from the material, so it is lighter than conventional ones and is effective for stabilizing wind resistance when constructing long bridges. can be achieved.

Since it is easy to install and remove once, it is possible to provide a weatherproofing stabilizer with good workability that is removed after the construction is completed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, FIG. 1 is an explanatory diagram showing a cross section of a long bridge to which the present invention is applied, FIG. 2 is a perspective view of the same part, and FIG. 3 shows the relationship between the material and the drift plate. FIG. 1... Stiffening girder, 2... Floor, 3, 4... Rope material, 5...
・・Main structure truss top chord, 7... Stray plate, 8... Bolt.

Claims (1)

[Claims] 1. In a long bridge with a truss structure stiffening girder, multiple pieces of material are strung vertically apart from each other in the widthwise middle position of the stiffening girder, and multiple pieces of cable material are arranged side by side in the length direction. A wind-resistant stabilizing device for the construction of a long bridge, in which a drifting plate is removably installed between upper and lower materials, and the drifting plate is removed after the long bridge is completed.