JPH05156606A - Suspension bridge type pipeline bridge - Google Patents

Abstract

PURPOSE:To provide a pipeline bridge which is excellent in wind-proof stability without using a supplementary rigidity stringer by setting up a handrail passage way at a preset height above a suspension bridge fluid transporting pipe, a column at a preset size thereunder or the handrail passageway at a preset position on the face side of the pipe. CONSTITUTION:A handrail passageway 3 is set up on the upper face of a fluid transporting pipe 1 for water, gas, etc., supported by a cable extended over between main towers, so that the setup height (h) of a passageway plate 32 may be 5% or less of the diameter. D of the pipe 1. Columns 4, 4-8% of the pipe indiameter, are set up in parallel to the pipe 1. under the pipe 1. Otherwise, the handrail passageway 3 is set up where it is 4% or less of the diameter. D of the pipe above a position equal to the lower face of the pipe on both sides of the pipe 1. In this way, a pipeline bridge can be easily obtained which is excellent in wind-proof stability and lighter without using a supplementary rigidity stringer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension bridge type pipeline bridge in pipelines for transporting fluids such as water, gas and oil.

[0002]

2. Description of the Related Art In a conventional suspension bridge type pipeline bridge, a main cable is laid over a main tower standing on both banks, and both ends of the main cable are fixed to the foundation ground further outside the main tower by anchors or the like. In a publicly known suspension bridge in which a stiffener girder such as a truss structure is supported by a hanger rope suspended from a cable and is connected to the stiffener girder, a pipe is usually laid on the stiffener girder. However, the applicant of the present invention has previously developed a suspension bridge type pipeline bridge having a novel structure in which the stiffening girder is omitted and the pipeline is directly supported by the main cable and the wind resistant cable, and is disclosed in Japanese Patent Laid-Open No. 3-63306. ing. That is, as shown in FIG. 12, the main tower on the abutment 11
In a suspension bridge type pipeline bridge 10 constructed by constructing a pipeline 1 for transportation between 12 main cables 14, a main cable 14 is stretched between the main towers 12 and wind resistant cables 15 are provided between abutments 11 or between the bases of the main towers 12.
The main cable 14 and the wind resistant cable 15 are extended around the pipeline so as to extend along the pipeline 1, and the pipeline 1 is passed through the main hanger rope 16 to extend the main cable 14
It is a suspension bridge type pipeline bridge characterized by being suspended in.

[0003]

By the way, the suspension bridge type conduit bridge of this new structure has a reduced weight due to the omission of the stiffening girder, and the projected area is reduced. Therefore, when an accessory such as a corridor is attached to the pipeline, there is a problem that wind stability may be reduced depending on the position. It is an object of the present invention to provide a method of installing a corridor that does not cause such a problem.

[0004]

The present invention is a suspension bridge type pipeline bridge constructed by constructing a pipeline for transportation between main towers on an abutment, and a main cable is stretched between the main towers. By stretching a wind resistant cable between abutments or between main tower bases, the main cable and the wind resistant cable are extended along the pipeline around the pipeline, and the pipeline passes through the main hanger rope. In the suspension bridge type pipeline bridge, which is suspended from the main cable and suspended from the wind resistant cable via a wind resistant hanger rope, a corridor is installed just above the pipe body forming the pipeline and close to the pipe body. However, a plurality of cylinders are attached to the lower part of the tubular body in parallel with the tubular body, or a corridor is installed on both sides of the tubular body forming the pipeline at a height substantially equal to the lower surface of the tubular body It is characterized by having done.

[0005]

[Operation] According to the present invention, since the corridor is directly attached to the pipe body by selecting a position where vortex excitation is less likely to occur, the structure is simple without stiffening girders, but excellent in wind resistance stability. A suspension bridge type pipeline bridge can be realized.

[0006]

【Example】

Example 1 In a pipeline bridge, it is necessary to provide a walkway along the pipeline for the purpose of maintenance and inspection of the pipeline, and in a normal suspension bridge type pipeline bridge, the walkway can be installed on a stiffening girder. In the pipeline bridge of the invention, since there is no stiffening girder and the pipe body is directly hung by the hanger rope, a corridor must be attached to the pipe body itself. The installation position may be right above the pipe body or on both sides, but the first embodiment of the present invention is a case where the walkway is installed directly above the pipe body, and FIG. 1 is a perspective view thereof. is there. Reference numeral 1 is a tubular body, 2 is a handrail, 3 is a walkway, and the walkway 3 is further composed of a walkway mounting steel material 31 such as chevron steel and a walk board 32 such as expanded metal. The cylindrical body of No. 4 will be described later.

First, as shown in the sectional view of FIG.
As for the test body in which only the handrail 2 and the corridor 3 are attached to the upper surface of the, That is, FIG. 3 shows the results of wind tunnel tests with various changes in h / D.
Shown in. The minimum value of the dimensionless multiple response amplitude 2A / D in the vortex excitation region is about 0.45 when h = 0. The maximum amplitude in a vortex-excited region of a simple cylinder without a corridor is about 0.9, which indicates that the smaller the mounting height h of the corridor, the smaller the damping effect of the corridor. .. However, at this level, vortex excitation is unavoidable under actual wind action. Therefore, for the purpose of disturbing the flow at the separation point of the laminar flow, a thin cylindrical body 4 was attached near the surface of the tubular body in parallel with the tubular body, and the effect was observed. As shown in FIG. 4, the installation height of the corridor 3 is constant (h = 0.2D), and (a) a U-shape in which two cylinders are attached above the pipe,
(B) L-shape in which two cylinders are attached below the pipe, (c)
Table 1 shows the results of a wind tunnel test performed on three W-shaped cylinders each having two cylinders attached above and below the tube, while changing the diameter d of the cylinders. Note that FIG. 5 shows an example of optimum values obtained by a wind tunnel test for the mounting position of the cylindrical body and the distance from the pipe body.

[0008]

[Table 1]

As can be seen from Table 1, the U-type, L-type, and W-type all have the best results when the diameter d of the cylindrical body 4 is 0.06D. U-type is not so much, but L-type and W-type. The mold has about half the amplitude of the one without the cylinder. From this, the lower cylinder is effective,
Even if installed up and down, there is almost no difference from the case where it is installed only underneath, so the L type is the most effective from an economic point of view. The diameter of the cylinder is around 6% of the diameter of the tube and exceeds 4% 8
Less than% is good.

FIG. 6 is a graph showing the measurement results of the dimensionless reduced wind velocity Vr and the response amplitude 2A / D for the L-shaped cylinder 4 having a diameter d = 0.06D. Fig. 7 shows the results of wind tunnel tests conducted in this case by changing the installation height of the corridor.
Shown in. As can be seen from this figure, when the value of h / D was 0.05 or less, the response amplitude was close to zero and the result was good.

It is needless to say that a steel pipe or the like having a predetermined size may be used as the columnar body 4 described above, but in the suspension bridge type pipeline bridge 10 of the present invention, as shown in FIG. Uses a suspension ring 20 that connects the wind-resistant hanger rope 17, and there is a cable that is stretched in parallel with the pipeline by connecting this suspension ring, so adjust the diameter and position of this cable to the damping conditions. The effect described in the present embodiment can be exerted by installing them.

Embodiment 2 In the second embodiment, walkways are installed on both sides of a tubular body. FIG. 8 is a perspective view and FIG. 9 is a sectional view. 1 is a tubular body, 2 is a handrail, 3 is a walkway, 5 is a strip, and 6 is a cross beam. The corridor 3 is further composed of a corridor mounting steel material 31 such as angle steel and a walk board 32 such as expanded metal.

As shown in FIG. 9, the diameter of the tubular body is D, the installation height of the corridor is h from the lower surface of the tubular body to h, and the height of the corridor, that is, h / D is changed to conduct a wind tunnel test. The results obtained are shown in FIG. Dimensionless double response amplitude 2A /
Also in this case, the minimum value of D is h = 0, which is about 0.12, and the preferable value of h is 0.04 or less at most. In this range, the corridor is installed right above the pipe body. Compared with the first embodiment, the damping effect is large. For the reasons described below, the negative side of h is not preferable.

FIG. 11 is a graph showing the measurement results of the converted wind speed Vr and the response amplitude 2A / D at h = 0, which is quite stable except that a small vortex excitation occurs near Vr = 6.0. Although not shown in the figure, when h = -0.2D, not only the large-amplitude vortex excitation occurred but also the converted wind speed Vr
= Galloping from around 12 (self-excited vibration in the vertical direction)
It was also found that the response characteristics could change drastically depending on the height of the corridor, such as the occurrence of a.

[0015]

According to the present invention, the wind resistance stability can be improved by properly selecting the installation position of the corridor even in the case of the pipeline bridge without the stiffening girder, so that the weight of the steel material is reduced. In addition, there is an effect that the reliability of an economical pipeline bridge that does not have a stiffening girder that facilitates erection work is enhanced.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

FIG. 2 is a sectional view of the first embodiment of the present invention.

FIG. 3 is a graph showing the results of a wind tunnel test in which the corridor mounting height of the first embodiment of the present invention is changed.

FIG. 4 is a cross-sectional view in which a cylindrical body is installed in the first embodiment of the present invention.

FIG. 5 is a cross-sectional view showing an optimum installation position of a cylindrical body in the first embodiment of the present invention.

FIG. 6 is a graph showing the results of a wind tunnel test in which the wind speed was changed for the L type in the first embodiment of the present invention.

FIG. 7 is a graph showing the results of a wind tunnel test in which the corridor mounting height was changed for the L type in the first example of the present invention.

FIG. 8 is a perspective view of a second embodiment of the present invention.

FIG. 9 is a sectional view of a second embodiment of the present invention.

FIG. 10 is a graph showing the results of a wind tunnel test in which the corridor mounting height of the second embodiment of the present invention is changed.

FIG. 11 is a graph showing the results of a wind tunnel test in which the wind speed was changed for the second example of the present invention.

FIG. 12 is a perspective view of a suspension bridge type pipeline bridge without a known stiffening girder according to the present invention.

[Explanation of symbols]

 1 Tubular body 2 Handrail 3 Walkway 4 Cylindrical body 5 Band material 6 Cross girder

Claims (5)

[Claims] 1. A suspension bridge type pipeline bridge constructed by constructing a pipeline for transportation between main towers on an abutment, in which a main cable is stretched between the main towers and between abutments or between main tower bases, etc. By straddling the wind resistant cable to, the main cable and the wind resistant cable are extended around the pipeline along the pipeline,
In a suspension bridge type pipeline bridge in which the pipeline is suspended on the main cable via a main hanger rope and is suspended on the wind resistant cable via a wind resistant hanger rope, directly above the pipe body forming the pipeline. A suspension bridge type pipeline bridge characterized in that a walkway is installed close to the pipe body, and a plurality of columnar bodies are attached to the lower part of the pipe body in parallel with the pipe body. 2. The suspension bridge type pipeline bridge according to claim 1, wherein the installation height of the walkway is 5% or less of the diameter of the tubular body from the upper surface of the tubular body. 3. The diameter of the cylindrical body exceeds 4% of the diameter of the tubular body and 8%
The suspension bridge type pipeline bridge according to claim 1, which is less than. 4. A suspension bridge type pipeline bridge constructed by laying a pipeline for transportation between main towers on an abutment, wherein a main cable is stretched between the main towers and between abutments or between main tower bases, etc. By straddling the wind resistant cable to, the main cable and the wind resistant cable are extended around the pipeline along the pipeline,
In the suspension bridge type pipeline bridge in which the pipeline is suspended on the main cable via a main hanger rope and is suspended on the wind resistant cable via a wind resistant hanger rope, both sides of the pipe body forming the pipeline A suspension bridge type pipeline bridge characterized in that a walkway is installed on the lower surface of the pipe body at substantially the same height. 5. The installation height of the corridor is equal to the lower surface of the tubular body or 4% or less of the diameter of the tubular body above the lower surface of the tubular body.
Suspension bridge type pipeline bridge described.