JPS5833324B2 - pipe bridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe bridge installed as a suspension bridge for transporting water, gas, oil, etc.

When an object with a circular cross section is placed in a fluid such as water or air, Karman vortices are periodically generated on the downstream side of the object, and the forcing force of these vortices can cause the object to vibrate. This is known and has been experimentally confirmed.

Examples of the object include the above-mentioned pipe bridge.

Since the pipe bridge is installed at a relatively high place, it is extremely susceptible to the influence of wind, and the vibrations caused by the aforementioned vortices are significant.

Therefore, in the past, a major problem in pipe bridges was how to suppress the influence of wind, that is, the vibration caused by wind.

This invention was made to solve the above-mentioned problem, and includes a plurality of rectangular flat plates arranged on the same horizontal plane at intervals along the axial direction of the pipe bridge on both sides of the pipe bridge. The flat plates are fixed horizontally and are arranged in a staggered manner.

The present invention will be described by way of examples with reference to the drawings.

FIG. 1 is a partial perspective view of an embodiment of the invention, and FIG. 2 is a front view of the same.

As shown in FIGS. 1 and 2, the pipe bridge 1 of this embodiment has a plurality of rectangular flat plates 2 (width a, length b) along the central axis 3 of the pipe bridge 1 on both sides. are fixed horizontally at intervals on the same horizontal plane that is a distance e down from the horizontal line X- passing through the central axis 3, and the flat plates 2 are arranged in a staggered manner.

FIG. 3a shows that the pipe bridge 1 configured as described above has a first
Pipe bridge 1 when wind is blown from the direction indicated by the arrow in the figure
The results of the flexural vibrations that occur in the conventional example, that is, the results of the flexural vibrations that occur in a pipe bridge in which a net-like walkway member is continuously provided along the pipe axis direction on the top of the pipe bridge, are shown together with the results of the flexural vibrations that occur in the pipe bridge. The figure shows the results of torsional vibration.

In this experiment, the diameter d of the pipe bridge 1, the distance e between the rectangular flat plate 2 and the horizontal line X-y passing through the central axis 3 of the pipe bridge 1, the width a and length b of the rectangular flat plate 2, and the interval between the rectangular flat plates 2 The relationship between the two was as follows.

e/d:0. O, a/d: 083, b/d:
As is clear from FIGS. 3a and 3b of 8.2, the flexural vibration and torsional vibration occurring in the pipe bridge of the present invention are significantly reduced compared to the conventional example.

This is because the direction of vibration of the pipe bridge in the part where the flat plate is located and the direction of vibration of the pipe bridge in the part without the flat plate are opposite to each other, so that the vibrations are canceled out.

The flat plate 2 may be fixed at an appropriate distance from the side surface of the pipe bridge 1.

Actually, as shown in FIG. 4, a net-shaped walkway floor member 4 is attached between adjacent flat plates 2.

In this way, it has been confirmed through experiments that even when the floor member 4 is attached between the flat plates 2, it does not cause flexural vibration or torsional vibration.

As explained above, according to the present invention, bending vibrations and torsional vibrations caused by wind are greatly reduced, and since a rectangular flat plate for vibration prevention can be used as a part of the floor member for the walkway, installation of the walkway is possible. This brings about useful effects such as making it easier to perform the following tasks.

[Brief explanation of drawings]

FIG. 1 is a partial perspective view of an embodiment of the invention, and FIG.
The same front view, FIG. 3a is a diagram showing the relationship between wind speed and deflection, the same diagram is a diagram showing the relationship between wind speed and twist angle, and FIG. 4 is a diagram showing another embodiment of the present invention. FIG. In the drawings, 1...pipe bridge, 2...flat plate, 3...
Center axis line, 4...floor member.

Claims (1)

[Claims] 1. A plurality of rectangular flat plates are horizontally fixed on the same horizontal plane at intervals along the axial direction of the pipe bridge on both sides of the pipe bridge, and the flat plates are arranged in a staggered manner. Kanbashi.