JP2008280683A - Bridge using reinforced concrete floor slab and a small number of main girders - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bridge using a small number of main girders, which can reduce construction costs. <P>SOLUTION: The pair of right and left main girders 2 and 2 is provided; a plurality of steel cross girders 3 are provided at predetermined intervals in the direction of a bridge axis between the main girders 2 and 2; a reinforced concrete floor slab 4 is installed on the main girders 2 and 2; and a floor framing member 5 in the direction of the bridge axis, which is composed of reinforced concrete leading to a top surface 3a of the cross girder 3 from an undersurface 4a of the reinforced concrete floor slab 4, is supported by the cross girder 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a plurality of steel cross girders at a predetermined interval in the bridge axis direction between a plurality of steel main girders, installs a reinforced concrete floor slab on the steel main girder, and supports the floor slab on the cross girder The present invention relates to a reinforced concrete floor slab minority main girder bridge provided with flooring members in the direction of the bridge axis.

  With the rationalization or labor saving at the time of designing and constructing steel bridges, PC floor slabs (pre-slabs) have been developed as an economically superior structure over conventional multi-main girder bridges for intermediate span bridges with spans of about 30m to 60m. Two main girder bridges using stress concrete floor slabs and synthetic floor slabs have been adopted. (For example, refer nonpatent literature 1.).

  As shown in FIG. 8, the PC floor slab 2 main girder bridge 100 is provided with a cross girder 102 having an H cross section or an I cross section between two main girders 101, and a PC floor slab 103 is constructed on the upper part thereof. ing. The PC floor slab 103 is fastened with a fixing nut 106 to a PC steel material 105 inserted into the sheath 104. An asphalt pavement 107 is provided on the PC floor slab 103.

  On the other hand, as shown in FIG. 9, the composite floor slab 2 main girder bridge 200 is provided with a cross girder 202 having an H cross section or an I cross section between two main girders 201, and the composite floor slab 203 is disposed on the upper part. Has been built. An asphalt pavement 204 is provided on the PC floor slab 203.

  However, PC floor slabs and synthetic floor slabs also have the following problems.

That is,
(1) The construction cost of the superstructure is lower than that of the conventional multi-main girder bridge due to the adoption of the 2-main girder bridge. It is more expensive than RC slabs (reinforced concrete slabs) that have been conventionally used.
(2) When it is necessary to replace the floor slab, the PC floor slab and the composite floor slab are supported by the main girder. The social loss in that case will be very large. Even in the case of three or more main girders, PC floor slabs are prestressed in the floor slabs, so replacement with the full width direction is necessary, and traffic is completely stopped.
(3) When the PC floor slab is adopted, the concrete design standard strength of the PC floor slab is 30 N / mm ² or more. Therefore, compared to RC floor slabs with a design standard strength of about 24 N / mm ² Sufficient management is required, and advanced construction techniques are required compared to RC floor slab construction.
(4) When a PC floor slab is used with a box girder structure, a problem of prestress loss occurs, and therefore sufficient consideration is required in introducing prestress.
“Birth of a New Steel Bridge II Revised Edition”, Japan Bridge Construction Association, Kiyoto Noda (Publisher), December 2004, p. 4

  The present invention has been made to solve such problems, and an object of the present invention is to provide a minority main girder bridge capable of reducing construction costs.

  In order to solve the above-described problem, a minority main girder bridge according to the invention described in claim 1 of the present application is provided with a plurality of steel cross beams at a predetermined interval in a bridge axis direction between a plurality of steel main girders. A reinforced concrete floor slab minority main girder bridge in which a reinforced concrete floor slab is installed on the main girder. The assembly member is provided.

  The minority main girder bridge according to the invention described in claim 2 of the present application is characterized in that, in claim 1, the cross section of the floor assembly member in the direction of the bridge axis is formed in an inverted T shape, an inverted trapezoidal shape, or a rectangle. To do.

  The minority main girder bridge according to the invention described in claim 3 of the present application is characterized in that, in claim 1, a rubber plate is inserted between the floor assembly member in the bridge axis direction and the cross beam.

  A minority main girder bridge according to claim 4 of the present application is the minority main girder bridge according to claim 1, wherein a gibber is erected on the upper surface of the cross beam, and a floor frame member in the bridge axis direction is fixed on the cross beam by the diver. It is characterized by this.

  A minority main girder bridge according to the invention described in claim 5 of the present application is that the rubber plate is bitten between the floor assembly member in the bridge axis direction and the cross beam in the first aspect, and is erected on the upper surface of the cross beam. The floor framing member in the bridge axis direction is fixed on the cross beam by the above-mentioned dowel.

  As described above, in the invention according to claim 1 of the present application, a plurality of steel cross girders are provided at a predetermined interval in the bridge axis direction between a plurality of steel main girders, and a reinforced concrete floor slab is installed on the steel main girders. In the reinforced concrete floor slab minority main girder bridge, the reinforced concrete floor slab is provided with a floor frame member in the bridge axis direction made of reinforced concrete or prestressed concrete that reaches the upper surface of the transverse girder from the lower surface of the reinforced concrete floor slab. This type of floor assembly can absorb bridge surface alignment and construction errors of reinforced concrete floor slabs. For this reason, applicability and workability are improved.

  Reinforced concrete floor slabs can be adopted by appropriately arranging the floor framing members in the bridge axis direction for existing minority girder bridges using PC slabs or composite slabs. The plate thickness can be reduced. In other words, the floor slab thickness can be reduced to about 200 mm to 250 mm, and the cost can be reduced by about 10 to 20% in total by forming the floor assembly in the bridge axis direction with inexpensive concrete members. Is possible.

  Further, as in the invention according to claim 2 of the present application, the cross section of the floor assembly member in the bridge axis direction is formed in an inverted T shape, an inverted trapezoidal shape, or a rectangle with respect to the cross sectional force of the floor assembly in the bridge axis direction. As a result, it is possible to select an optimum cross-sectional shape, which can reduce costs and easily absorb bridge surface alignment and construction errors of reinforced concrete floor slabs.

  Further, as in the invention according to claim 3 of the present application, the rubber plate is bitten between the floor assembly member in the bridge axis direction and the cross beam, so that the floor assembly member in the bridge axis direction and the horizontal assembly caused by rainwater or condensation are formed. Corrosion of the steel material on the upper surface of the cross beams between the beams can be prevented.

  Further, as in the invention according to claim 4 of the present application, a floor set in the bridge axis direction is provided by erecting a gibber on the upper surface of the cross beam and fixing the floor set member in the bridge axis direction on the cross beam with the gibber. The joint strength between the member and the cross beam can be increased.

  Further, as in the invention according to claim 5 of the present application, the rubber plate is bitten between the floor assembly member in the bridge axis direction and the cross beam, and the floor assembly in the bridge axis direction is provided by a dowel erected on the upper surface of the cross beam. By fixing the member on the cross girder, it is possible to prevent the corrosion of the steel frame on the top surface of the cross beam between the cross beam and the bridge axis direction due to rainwater and condensation, and the floor frame in the bridge axis direction. The joint strength between the member and the cross beam can be increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view of a first embodiment of a minority main girder bridge according to the present invention. The minority main girder bridge 1 includes a pair of left and right main girders 2, 2 and two main girder 2, A plurality of steel cross girders 3 are provided between the two at a predetermined interval in the bridge axis direction, a reinforced concrete floor slab 4 is installed on the main girders 2 and 2, and a lower surface 4a of the reinforced concrete floor slab 4 is connected to an upper surface 3a of the cross girder 3 The cross beam 3 supports the floor assembly member 5 in the direction of the bridge axis made of reinforced concrete that reaches the center.

  In this case, the main girder 2 and the cross girder 3 are each made of steel having an I-shaped cross section. Further, the horizontal beam 3 is located on the neutral axis (not shown) of the main beam 2. The reinforced concrete floor slab 4 includes a plurality of, for example, three flooring members 5 in the bridge axis direction that reach the upper surface 3a of the cross beam 3 from the lower surface 4a. At that time, the floor framing members 5 in the bridge axis direction are provided at equal intervals in the width direction of the reinforced concrete floor slab 4. Further, the floor assembly member 5 in the bridge axis direction has a cross section formed in an inverted T shape.

  The cross-sectional shape of the floor assembly member 5 is a shape (see FIGS. 5B and 5C) provided with a rectangle (see FIG. 5A) and a haunch 8 in accordance with the cross-sectional force of the floor assembly in the bridge axis direction. See). Moreover, the structure of the floor assembly member can be prestressed concrete in addition to reinforced concrete.

  Furthermore, as a method of fixing the floor assembly member in the bridge axis direction, as shown in FIG. 2A, a method of engaging the rubber plate 6 between the floor assembly member 5 and the cross beam 3 in the bridge axis direction, FIG. As shown in FIG. 2B, a method of fixing a lower portion of the floor assembly member 5 in the bridge axis direction on the cross beam 3 by installing the gibber 7 on the upper surface 3a of the cross beam 3 or FIG. As shown in (c), the rubber plate 6 is engaged between the floor assembly member 5 and the cross beam 3 in the bridge axis direction, and on the cross beam 3 by a dowel 7 erected on the upper surface 3a of the cross beam 3. A method of fixing the floor assembly member 5 in the bridge axis direction can be exemplified.

  FIG. 3 is a cross-sectional view of the second embodiment of the minority main girder bridge according to the present invention. The minority main girder bridge 11 includes a pair of left and right main girders 12 and 12 and the two main girder 12, A plurality of steel cross girders 13 are provided at a predetermined interval in the bridge axis direction between 12 and a reinforced concrete floor slab 14 is installed on the main girders 12, 12, and the upper surface 13 a of the cross girder 13 from the lower surface 14 a of the reinforced concrete floor slab 14. The cross beam 13 supports the floor assembly member 15 in the direction of the bridge axis made of reinforced concrete that reaches the center.

  In this case, a steel material having an I-shaped cross section is used for each of the main beam 12 and the horizontal beam 13. Further, the cross beam 13 is located between the neutral shaft (not shown) of the main beam 12 and the upper flange 12 a of the main beam 12. The reinforced concrete floor slab 14 includes a plurality of, for example, three bridge assembly members 15 in the bridge axis direction that reach the upper surface 13a of the cross beam 13 from the lower surface 14a. At that time, the floor framing members 15 in the bridge axis direction are provided at equal intervals in the width direction of the reinforced concrete floor slab 14. Moreover, the floor assembly member 15 in the direction of the bridge axis is formed in an inverted trapezoidal cross section.

  Furthermore, as a method of fixing the floor assembly member in the bridge axis direction, as shown in FIG. 4A, a method of engaging the rubber plate 16 between the floor assembly member 15 and the cross beam 13 in the bridge axis direction, FIG. As shown in FIG. 4B, a method of fixing a floor assembly member 15 in the bridge axis direction on the cross beam 13 by setting up a gibber 17 on the upper surface 13a of the cross beam 13 or FIG. ), The rubber plate 16 is engaged between the floor assembly member 15 and the cross beam 13 in the bridge axis direction, and the bridge axis direction is set on the cross beam 13 by a dowel 17 standing on the upper surface of the cross beam 13. And a method of fixing the floor assembly member 15 of the present invention.

  FIG. 6 is a cross-sectional view of a third embodiment of the minority main girder bridge according to the present invention, and FIG. 7 is a cross-sectional view taken along line AA of FIG. The minority main girder bridge 21 includes a pair of left and right main girders 22 and 22 and a plurality of steel cross girders 23 provided between the two main girders 22 and 22 at a predetermined interval in the bridge axis direction. , 22 is provided with a reinforced concrete floor slab 24, and a floor framing member 25 made of reinforced concrete joined to the cross beam 23 from the lower surface 24 a of the reinforced concrete floor slab 24 is provided.

  In this case, a steel material having an I-shaped cross section is used for each of the main beam 22 and the horizontal beam 23. Further, the cross beam 23 is located between the neutral shaft (not shown) of the main beam 22 and the upper flange 22 a of the main beam 22. The reinforced concrete floor slab 24 is provided with a plurality of, for example, three bridge assembly members 25 extending in the bridge axis direction from the lower surface 24a to the lower surface 3b of the cross beam 23. Further, the floor assembly member 25 is formed in a reverse trapezoidal shape or a shape shown in FIG.

  Further, as a method of joining the floor assembly member 25 and the cross beam 23, a perforated steel plate gibber or stud provided on the horizontal plate of the cross beam 23 is used.

It is a cross-sectional view of the first embodiment of the minority main girder bridge according to the present invention. (A) Explanatory drawing of the method of engaging a rubber plate between a floor girder member in the bridge axis direction and the cross beam, (b) A floor girder member in the bridge axis direction on the cross beam by a dowel standing on the upper surface of the cross beam. Explanatory drawing of the fixing method, (c) The rubber plate is engaged between the floor assembly member in the bridge axis direction and the cross beam, and the floor in the bridge axis direction is placed on the cross beam by a dowel erected on the upper surface of the cross beam. It is explanatory drawing of the method of fixing an assembled member. It is a cross-sectional view of the second embodiment of the minority main girder bridge according to the present invention. (A) Explanatory drawing of the method of engaging a rubber plate between a floor girder member in the bridge axis direction and the cross beam, (b) A floor girder member in the bridge axis direction on the cross beam by a dowel standing on the upper surface of the cross beam. Explanatory drawing of the fixing method, (c) The rubber plate is engaged between the floor assembly member in the bridge axis direction and the cross beam, and the floor in the bridge axis direction is placed on the cross beam by a dowel erected on the upper surface of the cross beam. It is explanatory drawing of the method of fixing an assembled member. (A)-(c) It is a cross-sectional view of the floor assembly member of a bridge axis direction. It is a cross-sectional view of a third embodiment of a minority main girder bridge according to the present invention. It is AA sectional drawing of FIG. It is a cross-sectional view of a conventional PC floor slab 2 main girder bridge. It is a cross-sectional view of a conventional composite floor slab 2 main girder bridge.

Explanation of symbols

1,11,21 Minor main girder bridge 2,12,22 Main girder 3,13,23 Cross girder 3a, 13a Top face of cross girder 3b Bottom face of cross girder 4,14,24 Reinforced concrete slab 4a, 14a Lower surface 5, 15, 25 Floor assembly member in bridge axis direction 6, 16 Rubber plate 7, 17 Dive

In order to solve the above-described problem, a minority main girder bridge according to the invention described in claim 1 of the present application is provided with a plurality of steel cross beams at a predetermined interval in a bridge axis direction between a plurality of steel main girders. in reinforced concrete slab few main girder bridge installing a reinforced concrete slab on a main girder, in the reinforced concrete slab, rebar concrete or Ranaru bridge with the lower surface of the reinforced concrete slab reaches the upper or lower surface of the steel crossbeams The floor assembly members in the axial direction are integrally provided seamlessly .

Few main girder bridge according to the invention of claim 2 of the present application, according to claim 1, characterized in that to form the cross-section of the floor assembly member in an inverted T-shaped or inverted trapezoidal or rectangular is there.

To solve the above problems, the inventions of claim 1 of the present application, reinforced concrete a plurality of steel cross beams between the plurality of steel main beam provided with a predetermined interval in Hashijiku direction, the steel main beam on In the reinforced concrete slab minority main girder bridge in which the slab is installed, the reinforced concrete floor slab is connected to the reinforced concrete floor slab from the lower surface of the reinforced concrete floor slab to the upper surface or the lower surface of the steel cross girder, and the bridge frame direction member made of reinforced concrete is connected to the seam. It is provided integrally, and the steel beam is supported by the steel beam .

Inventions of claim 2 of the present application resides in that in Claim 1, it is characterized in that to form the cross-section of the floor assembly member in an inverted T-shaped or inverted trapezoidal shape.

Claims (5)

  In the reinforced concrete floor slab minority main girder bridge in which a plurality of steel cross girders are provided at predetermined intervals in the bridge axis direction between a plurality of steel main girders and the reinforced concrete floor slab is installed on the steel main girder, A minority main girder bridge provided with a floor frame member made of reinforced concrete or prestressed concrete that extends from the lower surface of the reinforced concrete floor slab to the upper surface of the cross beam.   The minority main girder bridge according to claim 1, wherein a cross section of the floor assembly member in the bridge axis direction is formed in an inverted T shape, an inverted trapezoidal shape, or a rectangle.   2. The minority main girder bridge according to claim 1, wherein a rubber plate is inserted between the floor assembly member in the bridge axis direction and the cross beam.   2. A minority main girder bridge according to claim 1, wherein a dive is erected on the upper surface of the cross girder, and a floor assembly member in a bridge axis direction is fixed on the cross girder by the dive.   A rubber plate is bitten between the bridge assembly in the bridge axis direction and the cross girder, and the floor assembly member in the bridge axis direction is fixed on the cross girder by a dowel standing on the upper surface of the cross beam. The minority main girder bridge according to claim 1.

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