JP2007154576A - Bridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently improve the shielding property of a bridge girder part, particularly the shielding property of its end, with simple construction. <P>SOLUTION: When covering a side face, a lower face and the end of the bridge girder part 12 of a bridge 10 with shielding plates 13, the end shielding plate 13 is installed inward by 0.5-5 m from a bearing 16. In this manner, a large working space can be secured in installing the end shielding plate 13 to permit excellent construction. Further, since rainwater or the like does not infiltrate into the bridge girder part 12 even if there is a water leakage from an expansion device 17, there is no need to separately close up the lower face or the like of the expansion device 17, and in consequence, structure is simplified. Furthermore, even if clearances are formed at joint parts between the side face and lower face shielding plates 13 and the end shielding plate 13, the clearances are not directly exposed to the outside, which makes it hard for impurities to enter. In carrying out inspection work, it is convenient to use a maintenance hatch provided at the end shielding plate 13. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a bridge in which a bridge girder is covered with a shielding plate.

Bridges are usually installed outdoors, and are always exposed to solar radiation, wind, snow, and rain. Especially, bridges in the coastal area are transported by the wind and have a large amount of salt, so they are exposed to severe corrosive environments. It is in.
For this reason, various countermeasures have been taken in steel bridges, such as applying corrosion resistance by coating or metal plating, or using a corrosion-resistant member.
Similarly, in concrete bridges, measures are taken such as securing sufficient concrete covering on the reinforcing bars or painting the reinforcing bars and the concrete surface.

However, anti-corrosion measures such as painting of steel bridges must be repainted regularly, and anti-corrosion measures using corrosion-resistant members are difficult to select appropriately according to the installation environment. It is apt to abuse a highly corrosion-resistant member, and in any case, the efficiency is poor.
On the other hand, in concrete bridges, it is difficult to grasp the corrosion status of internal rebars, so it is difficult to take countermeasures according to the situation, and if internal rebars are corroded, they are covered with concrete during repairs. Is accompanied by a large amount of cost, which is also inefficient.

  In view of such circumstances, in order to increase the anticorrosion properties of the bridge over a long period of time at low cost, the side and bottom surfaces of the bridge girder portion of the bridge are covered with a shielding plate (see Patent Documents 1 and 4) and the shielding sheet. Technology (see Patent Documents 2 and 3) has already been disclosed.

However, in the case where the bridge girder is covered with a shielding sheet, since the sheet deteriorates at an early stage when it is blown by the wind, a means is provided to stabilize the shape by tensioning the sheet (Patent Document 2,). 3), it is not preferable from the viewpoint of inspection work or the like that the structure of the bridge girder is complicated by adding a member that gives tension.
Further, such a sheet is weak against an external impact and easily breaks. Further, when the sheet is partially damaged in this way, it is usually necessary to replace the entire sheet, so that a large installation work is required again.
In addition, when inspecting a bridge, the seat cannot be used as a scaffold, or even if it can be used, it is unstable and a problem remains in terms of safety. Therefore, it is troublesome to temporarily install the scaffold during inspection, or the sheet becomes obstructive, and it is necessary to remove it once.

On the other hand, when the bridge girder is covered with a shielding plate, it does not have a very complicated structure. Further, since such a shielding plate is strong, it is difficult to break, and even if breakage occurs, it is shielded. In the case where the plate is composed of a plurality of panels (see Patent Documents 1 and 4), only the damaged panel needs to be replaced, so the cost can be relatively low.
In addition, it is convenient because the shielding plate can be used as a scaffold during inspection of the bridge.

  However, none of these patent documents disclose a technique for covering the end portion of the bridge girder portion with a shielding plate, and it is considered that the end portion is opened without being covered. In such a case, impurities or the like enter from this end portion and the bridge girder portion is corroded, so that the shielding property is insufficient.

Therefore, as shown in FIG. 7, it is conceivable to improve the shielding property by covering the open ends of the side shield plate 20a and the bottom shield plate 20b covering the bridge girder with the end shield plate 20c (see Japanese Patent Application No. 2004-305173).
However, in such a case, the distance between the open ends facing each other on the pier 18 or the distance between the open end and the wall surface of the abutment 15 is 150 mm to 300 mm, and the distance between the open end and the wall surface of the abutment 15 is 100 mm to 200 mm. Since they are close to each other, it is difficult to attach the end face shielding plate 20c in such a narrow portion.
In addition, when a gap exists due to poor construction in the joint portion with the side shield plate 20a, the bottom shield plate 20b, or the end shield plate 20c, the joint portion is directly exposed to the outside, so impurities such as salt And rainwater will enter the bridge girder through the gap. Therefore, there is still room for improvement in shielding performance.

Further, as shown in FIG. 8, the open ends facing the bridge piers 18 of the side shield plate 20a and the bottom shield plate 20b covering the bridge girder are connected by a side extension plate 20d, or the side extension plate 20d is extended to extend the open end and the abutment It is conceivable to improve the shielding property by reducing the gap with the 15 wall surface (see Japanese Patent Application No. 2004-305173).
Here, the telescopic device 17 is installed directly above the open end, which is designed to prevent water leakage, but will block water when exposed to the load and impact of vehicle traffic for many years. Wrinkles and flexible materials that play a role will deteriorate. With such deterioration of the telescopic device 17, water leakage often enters the inside of the bridge girder, and there is still room for improvement in shielding performance.
In this case, if the lower surface of the expansion / contraction device 17 is newly closed with a flexible material to prevent the intrusion of water from the expansion / contraction device 17 into the bridge girder, the structure becomes complicated. As with, construction is difficult because it is necessary to work in a narrow area.
Japanese National Publication No. 9-500698 JP 2000-129475 A JP 2004-183236 A JP 2004-324230 A

  Then, this invention makes it the subject to improve the shielding property of a bridge girder part efficiently, especially the shielding property of the edge part by simple construction.

  In order to solve the above-described problems, in the present invention, in a bridge having a floor slab and a bridge girder part that supports the floor slab from below, the side and lower surfaces and ends of the bridge girder part are covered with a shielding plate, and the end shielding plate Is installed inside from the open ends of the side shield plate and the bottom shield plate.

Since the end shield plate is installed on the inner side of the open end of the side shield plate and the lower shield plate, a wider work space can be secured compared to the case where the end shield plate is attached to the open end. Is possible.
Moreover, even if there is water leakage from the expansion / contraction device, the end shielding plate is inside the water leakage portion, so that this water leakage does not enter. Therefore, since it is not necessary to separately close the lower surface of the expansion device with a flexible material, the structure is simplified.
Further, the joint between the side shield plate, the lower shield plate and the end shield plate is surrounded by the space surrounded by the floor slab, the side shield plate and the lower shield plate, or the floor slab, the side shield plate and the abutment upper surface. Since it is inside any one of the space or the space surrounded by the floor slab, the side shielding plate, and the pier upper surface, even if there is a gap in this part due to poor construction, impurities are difficult to enter from the gap.

Here, if the end shielding plate is installed on the inner side of the support that supports the bridge girder, a sufficient space for securing the end shielding plate can be secured, so that the construction is further improved.
In addition, even when there is a gap in the joint between the side shield plate or the bottom shield plate and the end shield plate due to poor construction, impurities are less likely to enter the bridge girder because they are in the back.

Here, usually, in the vicinity of the abutment or the pier, the lower surface of the bridge girder is often opened without being covered by the lower shielding plate for the convenience of construction. Therefore, when the end shield plate is installed in the vicinity of the abutment etc. that are not covered with the bottom shield plate in this way, the bottom surface is open. There is a risk that impurities or the like may enter the part. Therefore, when the end shield plate is installed in the portion where the lower shield plate exists, the lower surface is not opened, so that impurities do not enter from below and the shielding property is higher.
On the other hand, if the end shielding plate is installed too far away from the abutment etc., the non-blocking part at the end of the bridge will be large, and the part of the bridge girder that will be directly exposed to the outside air will be large . For these reasons, it is appropriate to install the end shielding plate 0.5 to 5 m, more preferably 2 to 3 m from the support installed on the abutment or pier.

  When a maintenance hatch that can be opened and closed is provided on at least one of the side shield plate, the bottom shield plate, and the end shield plate, it is convenient because it allows easy access to the shield space of the bridge during inspection work, etc. is there. In particular, when a maintenance hatch is provided on the end shielding plate, the periphery thereof is covered with the side shielding plate and the bottom shielding plate, so that even when opened, the shielding space of the bridge is preferable because a certain airtightness is maintained. .

  In this invention, when covering the side, bottom and end of the bridge girder with the shielding plate, the end shielding plate is installed on the inner side of the open end of the side and bottom shielding plate, so that the construction is good and the structure is simple. Thus, there is an effect that the shielding property is increased.

  Embodiments of the present invention will be described below. First, an outline of a bridge 10 according to the present invention will be described with reference to FIGS. 1 to 3, and then the present invention will be described with reference to FIGS. 4 to 6. The main part of the bridge 10 will be described.

As shown in FIGS. 1 to 3, the bridge 10 according to the present invention includes a shielding plate 13 on the side surface, the lower surface, and the end portion of the bridge girder portion 12 of an existing or new bridge main body composed of a floor slab 11 and a bridge girder portion 12. It is attached with a cover.
Here, as will be described later, the shielding plate 13 is obtained by connecting a plurality of panels 13a to 13c to each other. As shown in the drawing, the lower surface and the side shielding plate 13 are bridge girder using a fixture 14. It is attached to the part 12.

To cover the side and bottom surfaces of the bridge girder 12 with the shielding plate 13, as shown in FIGS. 1 (a) to 1 (b), it is attached to the I-type main girder of the bridge girder 12 that supports the bottom of the floor slab 11. By attaching the tool 14 and attaching the lower surface and the side surface shielding plate 13 to the main girder of the bridge girder part 12 through the mounting tool 14 as shown in FIG.
At this time, the attachment of the attachment 14 to the main girder of the bridge girder 12 is appropriately spaced in the length direction of the main girder of the bridge girder 12 in consideration of the dead load of the shielding plate 13, the live load at the time of inspection, and other loads. And Moreover, the lower surface and side shielding plate 13, the fixture 14, the fixture 14, and the main girder of the bridge girder portion 12 are fixed by, for example, bolts and nuts.

  As shown in FIGS. 2A to 2C, when the main girder of the bridge girder portion 12 is a box girder, the fixture 14 corresponding to the shape of the box girder is provided as in the case of the I girder described above. By adopting, the shielding plate 13 can be covered.

  Further, as shown in FIG. 3, the end of the bridge girder 12 is closed by the end shielding plate 13. As illustrated, the end shielding plate 13 is attached to the inner side of the support 16 installed on the abutment 15 or the pier 18.

Details of the bridge 10 according to the embodiment when the main girder 12a is an I-girder are shown in FIGS. The structural members of the bridge will be described in order from the top.
First, the floor slab 11 is a concrete structure through which vehicles and the like pass on the upper surface, and asphalt pavement is applied to the vehicle-passing portion on the upper surface. As shown in FIGS. 4 and 5, both sides of the upper surface rise to form a ground cover 11a, and a guard rail 11b is installed on the upper surface of the ground cover 11a. Further, a notched drainer 11 c extends in the length direction of the floor plate 11 on both sides of the lower surface of the floor slab 11.

  As shown in FIGS. 4 and 5, an I-type main girder 12 a extending in the length direction of the floor slab 11 is arranged below the floor slab 11 in parallel with a predetermined interval in the width direction of the floor slab 11. The floor slab 11 is supported by the upper flange of the main beam 12a. Adjacent main girders 12a webs are connected and strengthened by horizontal girders (not shown).

Further, as shown in FIG. 4, the upper end of the hanging tool 14a is fixed to the lower flange of the main girder 12a, and the lower end of the hanging tool 14a is an I-type extending in the length direction of the floor slab 11. The upper flange of the lower vertical beam 14b is fixed.
The lower flange of the lower vertical beam 14b is in contact with the upper flange of the I-type lower surface support beam 14c that is arranged in parallel with a predetermined distance in the length direction of the floor slab 11 and extends in the width direction of the floor slab 11. The lower vertical beam 14b and the lower surface support beam 14c are fixed to each other.

On the other hand, one end of a pressing tool (not shown) heading obliquely upward is fixed to the upper end of the hanging tool 14a on both sides of the hanging tool 14a arranged in parallel in the width direction of the floor slab 11. As shown in FIG. 5, an I-type side longitudinal beam 14 d extending in the length direction of the floor slab 11 is fixed to the outer portions of the end and the hanging tools 14 a on both sides.
Then, as shown in FIG. 5, the I-shaped side surface that extends in the direction perpendicular to the surface of the floor slab 11 is arranged in parallel with the outer flange of the side longitudinal beam 14 d at a predetermined interval in the length direction of the floor slab 11. One flange of the support beam 14e is fixed. A stopper 14f made of L-shaped steel is provided at the upper end of the side support beam 14e.

The attachment 14 is comprised from the above members 14a-14f.
Here, the materials of the members 14a to 14f of the fixture 14 may be appropriately selected from lightweight steel, aluminum alloy, FRP, wood, and the like, but a great dead load (static load) is applied to the bridge 10. It is preferable to make the object as light as possible so as not to give it.
The size and number of the fixtures 14 are determined by taking into consideration the dead load of the shielding plate 13, the live load at the time of inspection and other loads, and the dimensions of the lower surface panel 13a and the side panel 13b constituting the shielding plate 13 described later. It shall be determined as appropriate.

  Further, as shown in FIGS. 4 and 5, the lower surface shielding plate 13 is attached to the lower flange of the lower surface support beam 14c, and as shown in FIG. 5, the other flange of the side surface support beam 14e is provided with a frame member 13d. A side shielding plate 13 is attached. Further, as shown in the figure, the end portion of the bridge girder portion 12 is blocked by the end shielding plate 13 attached to the inner side of the predetermined distance D from the support 16 installed on the upper surface 15a of the abutment 15 and supporting the bridge girder portion 12. ing. The distance D is preferably 0.5 to 5 m, and ideally 2 to 3 m.

  As shown in the figure, these shielding plates 13 are composed of a plurality of bottom panels 13a, side panels 13b, and end panels 13c.

  These bottom panel 13a, side panel 13b and end panel 13c are made of a material having corrosion resistance and durability, for example, stainless steel, galvanized steel sheet, aluminum alloy, reinforced, depending on the degree of corrosive environment in the area where the bridge is built. Glass, fiber reinforced plastic (FRP), acrylic resin plate, polycarbonate resin plate, vinyl chloride plate and the like may be selected as appropriate, but as much as possible so as not to give an excessive dead load (static load) to the bridge 10 It should be light.

For example, a stainless steel plate may be used, and color coating may be applied when considering the landscape.
When stainless steel is adopted, the type is selected according to the substance expected to come. For example, in the region where the amount of sea salt is 0.15 mdd or less, it is SUS304, in the region where 0.15 mdd to 0.4 mdd. SUS316 and SUS329J3 should be used in the area of 0.4 mdd or more.
Moreover, when using a galvanized steel sheet, it is good to consider a landscape and to use a fluororesin laminate specification.

  Moreover, in a very severe environment, a titanium plate can also be used for panels 13a-13c from a viewpoint of ensuring corrosion resistance. Furthermore, the corrosion resistance can be further improved by applying a photocatalyst to the outer surfaces of the panels 13a to 13c to decompose the dirt.

Further, if the lower surface panel 13a constituting the lower surface shielding plate 13 is formed in a box shape, the rigidity is increased, and it is easy to ensure sufficient strength to be used as a scaffold during inspection work and the like. Since the upper surface is flat, the trafficability is also good.
In this case, it is preferable to enclose a highly sound-absorbing material such as glass wool in the box-like lower surface panel 13a because noise generated when the vehicle passes under the bridge 10 can be reduced.

The end shielding plate 13 is supported and reinforced from the inside by a frame member (not shown).
Further, the end shielding plate 13 is provided with an opening, and the opening is covered with a maintenance hatch 13g as shown in FIG. As shown in the figure, the four corners of the maintenance hatch 13g are fixed to the end shielding plate 13 by a set bolt 13e, and handles 13f are attached to the top and bottom thereof.
When the retaining bolt 13e is removed and the maintenance hatch 13g is opened by holding the handle 13f, an opening appears, and the opening of the bridge 10 can be easily accessed through this opening. For this reason, if the maintenance hatch 13g is provided in this way, it is very convenient for maintenance, inspection, repair, and reinforcement.
When the maintenance hatch 13g is formed of a highly transparent material such as a transparent acrylic resin plate, a transparent polycarbonate resin plate, or a transparent vinyl chloride plate, light can easily enter the shielding space of the bridge 10 through the maintenance hatch 13g. Visibility inside the shielding space is improved.
If such a maintenance hatch 13g is provided not only on the end shielding plate 13 but also on the side shielding plate 13 and the lower shielding plate 13, it becomes easier to enter and exit the shielding space of the bridge 10 during inspection work. In this case, if the maintenance hatch 13g is provided at the end of the side shielding plate 13 or the lower shielding plate 13 and outside the end shielding plate 13, the airtightness of the shielding space of the bridge 10 is improved even when the maintenance hatch 13g is opened. It is preferable because it is kept above a certain level.

Further, as shown in FIG. 5, the end panel 13c adjacent to the lower vertical beam 14b and the side vertical beam 14d is cut into a square shape so as not to interfere with the lower vertical beam 14b and the side vertical beam 14d during installation. ing. For this reason, as shown in the drawing, gaps are formed on both sides of the web of the lower vertical beam 14b and the side vertical beam 14d.
Therefore, in order to further improve the shielding property, it is preferable to close both sides of the web with auxiliary plates 13h as shown in FIG.

  In order to further improve the shielding performance, the rubber plate 19 may be used to simply close the gap formed between the lower shielding plate 13 and the front surface 15b of the abutment 15 and the lower part of the telescopic device 17 as shown in FIG. . In addition, the gap formed between the side shielding plate 13 and the upper end portion of the abutment 15 may be easily blocked as well.

  In order to ventilate the inside of the bridge 10, when a ventilation window is provided, it is preferable to provide a filter on the ventilation window to prevent impurities from entering the bridge 10. An illumination lamp can also be provided for inspection work in the bridge 10. In the inspection work or the like, the mounting tool 14, the shielding plate 13 and the like serve as a scaffold.

  Further, B-type silica gel having a semi-permanent dehumidifying effect can be installed in the bridge 10 to prevent corrosion due to high humidity and condensation during rain. About the installation amount of this B type silica gel etc., it shall follow the Unexamined-Japanese-Patent No. 2003-089888 for which this applicant applied previously.

  As an installation method of the above silica gel, in order to enhance the moisture absorption effect, it is preferable that the silica gel molded and packaged in a sheet shape is attached to the inner surface of the shielding plate 13.

The figure which shows the assembly order of the bridge concerning one Embodiment The figure which shows the assembly order of the bridge concerning other embodiment Side view of a bridge according to one embodiment The longitudinal cross-sectional view of the bridge concerning one embodiment Cross-sectional view of a bridge according to one embodiment Partial enlarged view of a bridge according to one embodiment Side view of a conventional bridge Side view of a conventional bridge

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Bridge 11 Floor slab 11a Ground cover 11b Guard rail 11c Drainer 12 Bridge girder part 12a Main girder 13 Shielding board 13a Bottom panel 13b Side panel 13c End part panel 13d Frame material 13e Stop bolt 13f Handle 13g Maintenance hatch 13h Auxiliary board 14 Attaching board 14 Lowering tool 14b Lower vertical beam 14c Lower surface support beam 14d Side vertical beam 14e Side surface support beam 14f Stopper 15 Abutment 15a Abutment upper surface 15b Abutment front 16 Bearing 17 Expansion / contraction device 18 Abutment 19 Rubber plate 20a Side shielding plate 20b Lower surface shielding plate 20c End surface shielding plate 20c 20d Side extension plate D Distance from support

Claims (4)

In the bridge 10 having the floor slab 11 and the bridge girder portion 12 that supports the floor slab 11 from below,
The side surface, the lower surface and the end portion of the bridge girder portion 12 are covered with a shielding plate 13, and the end portion shielding plate 13 is installed inside from an open end formed by the floor slab 11, the side surface shielding plate 13 and the lower surface shielding plate 13. A bridge characterized by that.   The bridge according to claim 1, wherein the end shielding plate 13 is installed inside a support 16 that supports the bridge girder 12 from below.   The bridge according to claim 2, wherein the end shielding plate 13 is installed 0.5 m to 5 m from the support 16.   The bridge according to any one of claims 1 to 3, wherein a maintenance hatch 13g that can be opened and closed is provided on at least one of the side shield plate 13, the lower shield plate 13, and the end shield plate 13.

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