JP2006257634A - Corrugated-steel-plate web girder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a corrugated-steel-plate web girder which can obtain high buckling resistance while minimizing an increase in dead load. <P>SOLUTION: This corrugated-steel-plate web girder 10 is equipped with a corrugated-steel-plate web 13 where recesses 14 and projections 15, directed in a lengthwise direction, are alternately juxtaposed; a lower end of the web 13 is supported on a downside concrete structure 12; and an upside concrete structure 11 is joined to an upper end. In the web girder 10, a reinforcing steel plate 21 for countering a shear force acting in the vertical direction of the web 13 is fixed between both the upside and downside concrete structures 11 and 12 of the web 13. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a corrugated steel web girder mainly used for corrugated steel web PC bridges.

  Conventionally, a box girder constituting a prestressed concrete bridge (hereinafter referred to as a PC bridge) has an upper floor plate joined between upper end portions of both side walls raised from both edge portions of a lower floor plate supported by a bridge pier. It is integrally formed of concrete in shape, and prestress is introduced by inserting a PC tendon in the longitudinal direction of the lower floor board, both side wall boards, and the upper floor board, or by using an external cable.

  However, in the bridge girder formed entirely of concrete in this way, the total weight increases and the cost increases, and the lower structure such as the bridge pier needs to be a strong structure to support the weight. In order to solve this problem, there is known a corrugated steel web girder constituted by corrugated steel webs by changing the above-mentioned side wall portion to a concrete side wall.

  As shown in FIG. 4, the corrugated steel web girder 1 uses a corrugated steel web 2 in which longitudinal concave portions and convex portions are alternately arranged, and the lower ends of a pair of corrugated steel webs 2 and 2 are lowered. A box girder having a high buckling resistance is configured by supporting it on both sides of the floor plate 3 and joining the upper floor plate 4 to the upper ends of the corrugated steel webs 2 and 2 (for example, (See Patent Documents 1 and 2). In the figure, reference numeral 5 denotes a PC steel material, which is inserted along the longitudinal direction of the upper and lower floor boards 4 and 3, and prestress is introduced into the upper and lower floor boards 3 and 4 by tensioning them.

Further, in this corrugated steel web girder, pre-stress can be efficiently introduced only into the upper and lower concrete floor boards by the so-called accordion effect of the corrugated steel sheets that do not resist axial force.
JP 2000-345516 A JP 2001-115417 A

  However, in general, the buckling strength of the corrugated steel sheet web is inversely proportional to the square of the web height, and when the girder height is high, that is, when the girder height is 5 m or more, simply adjusting the height of the convex portion or the thickness of the steel sheet, There was a problem that the strength against buckling could not be secured.

  On the other hand, as a countermeasure for such a problem, there is a method of placing concrete called lining concrete on the back of the corrugated steel sheet web, but in this method, the weight of the bridge girder increases due to the concrete, and the dead load increases. In addition, there has been a problem that the construction period is increased due to an increase in the number of processes due to concrete placement, thereby increasing the cost.

  In view of the above-described problems of the prior art, an object of the present invention is to provide a corrugated steel web girder that can obtain a high resistance to buckling while minimizing an increase in dead load.

  The invention described in claim 1 for solving the conventional problems as described above and achieving the intended purpose includes a corrugated steel sheet web in which longitudinal concave portions and convex portions are alternately arranged, and the corrugated steel web is provided. In the corrugated steel web girder in which the lower end portion of the steel plate web is supported by the lower concrete structure and the upper concrete structure is joined to the upper end portion, the corrugated steel plate is disposed between the upper and lower concrete structures of the corrugated steel web. It is a corrugated steel sheet web girder in which a reinforcing steel sheet for fixing a shearing force acting in the vertical direction of the web is fixed.

  The invention according to claim 2 is characterized in that, in addition to the configuration of claim 1, a reinforcing steel plate is fixed vertically on the concave side surface and / or convex side surface of the corrugated steel plate web.

  In addition to the structure of Claim 1 or 2, the invention of Claim 3 has the uneven | corrugated | grooved part which a reinforced steel plate fits with the uneven | corrugated | grooved part of the said corrugated steel sheet web in the edge of one side, The reinforcing steel plates are fitted and fixed laterally to the central portion of the corrugated steel web.

  The corrugated steel sheet web girder according to the present invention includes a corrugated steel sheet web in which longitudinal concave portions and convex portions are alternately arranged, the lower end portion of the corrugated steel sheet web is supported by the lower concrete structure, and the upper end portion is provided. In the corrugated steel web girder joined with the upper concrete structure, a reinforcing steel plate is fixed between the upper and lower concrete structures of the corrugated steel web to counter the shearing force acting in the vertical direction of the corrugated steel web. As a result, even if the girder height is 5 m or more, while maintaining high resistance to the shearing force acting in the vertical direction, the increase in weight can be minimized and the increase in dead load can be suppressed. As a result, the span can be lengthened, the substructure can be simplified, the construction period can be shortened, and the cost can be reduced.

  Moreover, the resistance with respect to a shear can be improved suitably by fixing the reinforcement steel plate to the recessed part back side surface and / or convex part protrusion side surface of the said corrugated steel sheet web vertically.

  The reinforcing steel sheet has an uneven part that fits with the uneven part of the corrugated steel sheet web on one side edge part, the both uneven parts are fitted together, and the reinforcing steel sheet is fixed laterally to the central part of the corrugated steel sheet web Thus, the resistance to shearing can be improved suitably.

  Next, an embodiment of a corrugated steel web girder according to the present invention will be described with reference to the drawings.

  FIG. 1 shows an example of a corrugated steel web girder. In the figure, reference numeral 10 denotes a corrugated steel web box girder used for a PC bridge, reference numeral 11 denotes an upper concrete structure constituting an upper floor board, and reference numeral 12 denotes a lower floor board. A lower concrete structure, 13 is a corrugated steel web.

  In the corrugated steel web box girder 10, a pair of corrugated steel webs 13, 13 are supported on both sides of the lower concrete structure 12, as in the conventional example shown in FIG. 4. The upper concrete structure 11 is connected to the upper end.

  The corrugated steel web 13 is composed of corrugated steel, and as shown in FIG. 2, the concave portions 14, 14... And the convex portions 15, 15. , 14, 15... Are arranged in a cross-sectional wave shape. That is, the rear side surface (the bottom surface of the concave groove) of the concave portion 14 and the projecting side surface (the top surface of the convex mountain) of the convex portion 15 are connected via the common side wall plate portion 16, and irregularities appear alternately in the lateral direction. A cross-sectional wave shape is formed.

  Further, the corrugated steel web 13 is integrally provided with a pair of upper and lower flanges 17 and 18 arranged in parallel at the upper end and the lower end, the lower flange 18 is fixed to the lower concrete structure 12, and the upper flange 17 is By being fixed to the upper concrete structure 11, the lower concrete body 12 is supported at the lower end of the corrugated steel web 13, and the upper concrete structure 11 is joined to the upper end of the corrugated steel web 13. Yes.

  The upper and lower flanges 17 and 18 function as part of the formwork of the concrete structures 11 and 12.

  Further, a reinforcing steel plate 21 is fixed to the corrugated steel web 13 between the upper and lower concrete structures 11 and 12 to counter shear stress acting in the vertical direction of the corrugated steel web 13.

  The reinforcing steel plate 21 is formed into a long and thin plate shape with a steel plate, and its side edge is fixed to the projecting side surface of the convex portion 15 in the vertical direction by welding or the like. Further, the reinforcing steel plate 21 is fixed in an arrangement (a right angle arrangement) in which the plane intersects the protruding side surface of the convex portion 15, and protrudes vertically from the protruding side surface of the convex portion 15.

  In the upper concrete structure 11, pre-stress is introduced by inserting PC tension members 22, 22... In the longitudinal direction at intervals, and tensioning them, and the lower concrete structure 12 is similarly spaced. The pre-stress is introduced by inserting the PC tension members 22, 22... In the longitudinal direction and tensioning them.

  The corrugated steel web box girder 10 configured in this way is suitable for the shearing force and has a sufficiently high buckling resistance, even if the girder height is 5 m or more, by the reinforcing steel plate 21. As a result, the weight is reduced and the increase in dead load is kept to the minimum range compared to corrugated steel web box girders, etc., in which concrete is placed on the back side of concrete box girders and corrugated steel webs. It is possible to lengthen the span and slim the substructure such as the pier, thereby reducing the cost.

  In addition, since it is not necessary to place lining concrete or the like, the construction process is simplified, and the construction cost can be reduced by shortening the construction period.

  Further, in the corrugated steel web girder 10, the corrugated steel web 13 does not resist the axial force, that is, the force acting in the lateral direction (the insertion direction of the PC tension member 22), the so-called accordion effect, the upper and lower concrete structures 11, Prestress can be suitably introduced into only 12.

  In the above-described embodiment, an example in which the elongated plate-shaped reinforcing steel plate 21 is fixed vertically on the protruding side surface of the convex portion 15 is described. However, the elongated plate-shaped reinforcing steel plate 21 is fixed vertically on the back side surface of the concave portion 14. Alternatively, the reinforcing steel plate 21 may be fixed to both the concave and convex portions 14 and 15, or a plurality of reinforcing steel plates may be fixed to one convex portion 15 or the concave portion 14.

  Further, the reinforcing steel plate 21 may be provided only on a part of the uneven portions 14 and 15, for example, only in the vertical center of the uneven portions 14 and 15, or provided over the entire vertical length of the uneven portions 14 and 15, The upper and lower ends may be connected to the upper and lower flanges 17 and 18, respectively.

  As shown in FIG. 3, the reinforcing steel plate 30 alternately has concave portions 31, 31... And convex portions 32, 32. The reinforcing steel plate 30 is fitted to the concave portion 14 and the convex portion 32, and the convex portion 15 and the concave portion 32 are fitted to face the center portion of the corrugated steel web 13, that is, parallel to the upper and lower flanges 17 and 18. It may be fixed to.

  In addition, a plurality of reinforcing steel plates 30, 30... May be provided in parallel with each other, and the reinforcing steel plates 30, 30 may be installed on both front and back surfaces of the corrugated steel web 13.

  Further, the longitudinal reinforcing steel plate 21 and the lateral reinforcing steel plate 30 may be used in combination.

  Moreover, although the example applied to the box girder was described in the above-described embodiment, if the upper concrete structure 11 and the lower concrete structure 12 are joined to the upper and lower ends of the corrugated steel sheet web 13, respectively, Other structures such as a structure in which both side concrete structures are connected by one corrugated steel web 13 may be used.

  In the above-described embodiment, the upper concrete structure 11 and the lower concrete structure 12 are inserted into the upper and lower concrete structures 11 and 12 by inserting the PC tension member 22 in the longitudinal direction and tensioning it. Although an example in which prestress is introduced has been described, prestress may be introduced using an external cable.

It is a perspective view which shows an example of implementation of the corrugated steel web girder concerning this invention. It is sectional drawing which shows the corrugated steel sheet web in FIG. It is a perspective view which shows another example of the corrugated steel web girder which concerns on this invention. It is sectional drawing which shows the conventional corrugated steel web box girder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Corrugated steel sheet web (box) girder 11 Upper concrete structure 12 Lower concrete structure 13 Corrugated steel sheet web 14 Recess 15 Convex 16 Side wall plate 17 Upper flange 18 Lower flange 21 Reinforced steel 22 PC tension member 30 Reinforced steel 31 Recessed 32 Convex

Claims (3)

A corrugated steel sheet comprising corrugated steel sheet webs in which longitudinal concave and convex portions are alternately arranged, the lower end portion of the corrugated steel sheet web is supported by the lower concrete structure, and the upper concrete structure is joined to the upper end part. In the web girder
A corrugated steel web girder characterized in that a reinforcing steel plate for fixing a shearing force acting in the vertical direction of the corrugated steel web is fixed between the upper and lower concrete structures between the corrugated steel web.   The corrugated steel web girder according to claim 1, wherein a reinforcing steel plate is fixed in a vertical direction on a concave back surface and / or a convex protrusion side surface of the corrugated steel web.   The reinforcing steel sheet has an uneven part that fits with the uneven part of the corrugated steel sheet web on one side edge part, the both uneven parts are fitted together, and the reinforcing steel sheet is fixed laterally to the central part of the corrugated steel sheet web The corrugated steel web girder according to claim 1 or 2.

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