JP2002138414A - Wind-resistant bridge and its inspection car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wind-resistant bridge solving the problem of an increase in the weight of a girder at a time when a wind-resistant stabilizing member is installed and efficiently improving wind resistance without increasing the weight of the girder and an inspection car proper to the bridge. SOLUTION: A plurality of windshield plates are installed along the bridge axial direction at regular intervals in the bridge axial direction on the underside of the bridge. Accordingly, since stream lines passing in the bridge axial direction converge in three dimensions, the conditions of a convergence are not equalized in the bridge axial direction, and exciting force vibrating the bridge can be inhibited low. The inspection car, in which the windshield plates are formed in intermittent guide rails for the inspection car and which has a fall preventive means for transferring to the intermittent sections, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind-resistant bridge having improved wind resistance and an inspection suitable for the wind-resistant bridge.

[0002]

2. Description of the Related Art FIG. 5 is a perspective view schematically illustrating the flow of wind under a floor slab in a conventional suspension bridge / cable stayed bridge. FIG.
1, the floor slab 1 is supported by main beams 2 and 3 having an I-shaped cross section. A guide rail 4 is installed on the lower flange of the main girder 2 in the bridge axis direction, and a guide rail 5 is installed on the lower flange of the main girder 3 in the bridge axis direction. Therefore, the wind from the lateral direction is indicated by arrows 91, 92, 93, 94,
As indicated by reference numeral 95, the fluid flows under the guide rail 4 and flows downward. That is, the flow of the wind became uniform in the bridge axis direction, causing a large vibrating force to vibrate the bridge.

[0003] Such vibration phenomena caused by wind include flutter that causes divergent vibration at a high wind speed, and vortex excitation generated at a relatively low wind speed. Measures to prevent such vibrations include increasing the torsional rigidity of the spar, changing the fairing shape, and installing dampers. Broadly speaking, it can be divided into the following methods. (Japan Road Association, Road Bridge Wind Resistant Design Handbook p.143 July 1991) ・ Increase the rigidity of the bridge girder ・ Increase the weight of the bridge girder ・ Change the aerodynamic force generated by wind (change in cross-sectional shape) ・ Damping Conventionally, from the viewpoint of economy, a method of improving the wind resistance by changing the cross-sectional shape is often adopted, and a method of installing a fairing, a flap, a side plate, or the like is often used. No.

FIG. 6 is an explanatory view showing a conventional method for improving wind resistance by changing the cross-sectional shape. FIG. 6 (a)
6 (b) is a flap, FIG. 6 (c) is an edge plate, FIG. 6 (d) is a side plate, FIG. 6 (e) is a baffle plate, and FIG. 6 (f) is The grating, FIG. 6 (g) shows a tip plate (Kawasaki Heavy Industries Technical Report No. 113, April 1992).

[0005]

However, the conventional method for improving the wind resistance, for example, the method of installing a wind-resistant stabilizing member such as a fairing or a flap, increases the weight of the girder. And the rigidity of the main tower increased, causing a problem in economics. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem of wind stabilization measures, and does not increase the weight of a girder and efficiently improves wind resistance, and a test vehicle suitable for the wind bridge. The purpose is to provide.

[0006]

A wind-resistant bridge according to the present invention has the following features. [1] A plurality of wind shields are provided along the bridge axis direction at predetermined intervals in the bridge axis direction on the lower surface of the bridge. [2] In the above [1], the wind shield plate is a member having a T-shaped cross section, an L-shaped cross section, an H-shaped cross section, or an I-shaped cross section, and forms an intermittent inspection vehicle guide rail;
An inspection vehicle provided with a fall prevention means for moving over the intermittent part is guided by the inspection vehicle guide rail.

Further, the inspection vehicle according to the present invention has the following features. [3] A T-shaped or L-shaped or H-shaped or I-shaped cross section intermittently installed along the bridge axis direction at predetermined intervals in the bridge axis direction on the lower surface of the bridge. An inspection vehicle guided by an inspection vehicle guide rail, comprising: a fall prevention means for moving over the intermittent portion extending in the bridge axis direction; two or more wheels installed in the bridge axis direction; And a scaffold for an inspection device or an inspector.

[0008]

[First Embodiment] FIG. 1 is a perspective view illustrating an embodiment of a wind-resistant bridge according to the present invention.
In FIG. 1, a floor slab 1 is supported by main beams 2, 3 having an I-shaped cross section. At the lower flange of the main girder 2, at predetermined intervals in the bridge axis direction, guide rail members 41, 42, 43,
44 are provided to form intermittent guide rails. Further, guide rail members 51, 52, 53, 5 are provided on the lower flange of the main girder 3 at predetermined intervals in the bridge axis direction.
4 are provided to form intermittent guide rails.
Therefore, the inspection vehicle described later can run across the gap between the intermittent guide rails by locking a plurality of wheels on the flange of one of the guide rail members. Arrows in FIG. 1 (hereinafter, referred to as streamlines) schematically illustrate the flow of wind. For example, streamline 61
The streamline 62 passes through the gap between the guide rail member 41 and the guide rail member 43, and the streamline 63 passes through the gap between the guide rail member 41 and the guide rail member 44. The streamline 64 passes through the gap, while the streamline 64 passes under the guide rail member 44. Therefore, the streamline after passing through the bridge does not become uniform in the bridge axis direction. For example, the guide rail member 42
On the leeward side, the streamline 61 and the streamline 62 merge in a substantially horizontal plane, whereas on the leeward side of the guide rail member 44, the streamline 6
3 and the stream line 64 merge three-dimensionally, and the manner of the merge differs. Furthermore, the same is true when passing through the guide rail members 51, 52, 53, 54 on the leeward side, and the streamline when passing is not uniform in the bridge axis direction. Therefore, the vibrating force for vibrating the bridge can be reduced. FIG. 2A shows a case where the guide rail is installed on a box-shaped bridge instead of an I-girder bridge.
(B) shows an example in which the guide rail is installed on a box-shaped bridge with a fairing, instead of an I-girder bridge. [Embodiment 2] FIGS. 3 and 4 are side views illustrating an embodiment of an inspection vehicle according to the present invention. In FIGS. 3 and 4, the inspection vehicle 7 includes a scaffold 71 and a scaffold connecting portion 72.
, A wheel support portion 73 and three wheels 81, 82, 83, and travels while being supported by the upper surface of the lower flange of the guide rail. The wheels 81 and 83 are rotated by wheel driving means (not shown). Further, the wheel 82 is freely rotatable, and functions as a fall prevention means for preventing the inspection car 7 from falling when the inspection car 7 runs across the intermittent guide rail gap.

At this time, the guide rail members 41, 42 are installed at a distance x, and the wheels 81, 82, 83 are at a distance d (L>d> x).

Therefore, the wheels 81, 83,
At least two of the rails 83 are engaged with one of the guide rails, so that the test vehicle 7 can run over the intermittent guide rail without derailing.

The number of the wheels is not limited to three, but may be one pair on each side of the web of the guide rail member, a total of three pairs, or a total of five wheels with additional wheels therebetween. A total of 5 pairs may be used. Further, the number of wheels may be larger than this.

FIG. 4A shows an example in which tracks are installed in place of wheels. FIG. 4B shows that the overturn preventing means contacts the lower surface of the upper flange of the guide rail. FIG. 4C shows that the overturn prevention means contacts the lower surface of the lower flange. Furthermore, the fall prevention means is not limited to wheels, but may be an arc-shaped cross section or a ski having a sliding surface. Further, FIG.
(D) is one in which a hydraulic damper or the like for reducing the vibration of the inspection vehicle is arranged.

[0013]

The wind-resistant bridge and the inspection vehicle according to the present invention are:
Since the inspection guide rails are provided intermittently, the following remarkable effects can be obtained. (1) Since the weight of the inspection guide rail is reduced, the weight of the entire bridge including the cable can be reduced. (2) Since the flow of the wind passing under the girder is not uniform in the bridge axis direction, the vibrating force can be suppressed low, so that it is not necessary to install a conventional wind-resistant stabilizing member. (3) Since the inspection vehicle has three or more wheels in the bridge axis direction, it can run on the intermittent guide rails.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an embodiment of a wind-resistant bridge according to the present invention.

FIG. 2 is a perspective view illustrating an embodiment of a wind-resistant bridge according to the present invention.

FIG. 3 is a side view illustrating an embodiment of the inspection vehicle according to the present invention.

FIG. 4 is a side view illustrating an embodiment of the inspection vehicle according to the present invention.

FIG. 5 is a perspective view schematically illustrating a flow of wind under a floor slab in a conventional suspension bridge / cable stayed bridge.

FIG. 6 is an explanatory view showing a conventional method for improving wind resistance by changing a cross-sectional shape.

[Explanation of symbols]

 Reference Signs List 1 floor slab 2 main girder 3 main girder 4 guide rail 5 guide rail 7 inspection vehicle 41 guide rail member 42 guide rail member 43 guide rail member 44 guide rail member 51 guide rail member 52 guide rail member 53 guide rail member 54 guide rail member 61 Streamline 62 Streamline 63 Streamline 64 Streamline 71 Scaffolding 72 Scaffolding Connection 73 Wheel Support 81 Wheel 82 Wheel 83 Wheel 91 Streamline 92 Streamline 93 Streamline 94 Streamline 95 Streamline

Claims (3)

[Claims] 1. A wind-resistant bridge, wherein a plurality of wind shields are provided along a bridge axis direction at predetermined intervals in a bridge axis direction on a lower surface of the bridge. 2. A cross-section of a T-shaped or L-shaped or H-shaped or I-shaped section, wherein the intercepting section forms a guide rail for an inspection vehicle. 2. The wind-resistant bridge according to claim 1, wherein an inspection vehicle provided with a fall prevention means for transferring is guided by the inspection vehicle guide rail. 3. A T-shaped or L-shaped or H-shaped or I-shaped cross section intermittently installed along the bridge axis direction at predetermined intervals in the bridge axis direction on the lower surface of the bridge. Inspection car guided by a guide rail for inspection car,
A fall prevention means for moving over the intermittent portion extending in the bridge axis direction, two or more wheels installed in the bridge axis direction, wheel driving means for driving at least two of the wheels, An inspection vehicle comprising a scaffold for an inspector.