JPH0344807Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a tapered girder used in a tapered bridge or the like, and relates to a technique for manufacturing the tapered girder using H-beam steel.

[Prior Art] Conventionally, in a bridge 1 that does not use a tapered girder, the height of the embankments 2 at both ends of the bridge 1 is higher than the surface of the road 3 on the embankment, as shown in FIG. The embankment had become quite high, creating an obstacle for vehicles driving on the embankment. There was also the problem that the house 4 was lower than the embankment 2.

One way to solve this problem is to use a tapered bridge 5 as shown in FIG. In the tapered bridge 5, tapered girders 6 are used at both ends of the bridge 5, the height of which decreases toward the ends of the bridge, and as a result, the embankment 7
The height of the embankment is reduced, and the above-mentioned obstacles caused by the increased height of the embankment are alleviated. In this case, the embankment 7 may not be required depending on the location.

In order to manufacture a tapered girder used in a tapered bridge, conventionally, as shown in FIG. The plate 8 was cut out, and flanges 9 cut to a certain width as shown in FIG. 8 were welded to the top and bottom of the plate by welding 10 as shown in FIG. 10.

[Problems to be solved by the invention] However, when using a tapered girder as shown in Figs. 7 to 9, the wedge-shaped belly plate is usually cut out from a rectangular plate, so the diagonal lines in Fig. 7 are not applied. This resulted in the problem of poor material yield as the plate had to be discarded. Also, since the flanges are welded to the top and bottom of the belly plate,
There was a problem that two welding lines were required and the welding cost was high.

The purpose of the present invention is to achieve cost reduction by reducing material yield and welding lines in the production of tapered girders.

[Means for Solving the Problems] To achieve the above object, the tapered girder using the H-shaped steel of the present invention is constructed by cutting the H-shaped steel diagonally in the longitudinal direction at the belly plate and dividing it into two parts. The cutting part is fixed by inverting one side with respect to the other.

[Function] In the tapered girder using H-shaped steel according to the present invention configured as described above, commercially available H-shaped steel is used as the material. Taper beams having different heights in the longitudinal direction can be obtained by cutting the H-shaped steel obliquely at the belly plate in the longitudinal direction, inverting it, and fixing the cut part. Here, the area corresponding to the shaded area in Figure 7 disappears, so the material yield is approximately 100.
%.

In addition, since H-beam steel has a flange from the beginning, there is no need for two weld lines for welding the web of the tapered girder to the belly plate, and the weld line is the weld line 1 of the belly plate.
The number of welded parts is reduced compared to the conventional method. Further, the welding of the belly plate may be performed using rivets or bolts.

These will reduce the cost of the tapered girder and improve the reliability of the tapered girder by eliminating fillet welds.

[Example] Hereinafter, a preferred example of a tapered girder using H-shaped steel according to the present invention will be described with reference to FIGS. 1 to 4.

1 to 4 show tapered girders according to embodiments of the present invention.

In the figure, reference numeral 11 indicates a normal H-type steel (a member that integrally has flanges on the upper and lower sides of the belly plate, and includes I-type steel and the like). The H-shaped steel has a belly plate 1 in the longitudinal direction.
2 is cut diagonally in a straight line over the entire length.
The heights a ₁ and a ₂ at both ends of one cut piece 11a and the heights b ₁ and b ₂ at both ends of the other cut piece 11b are a ₁ + b _2.
b ₁ + a ₂ is the height that determines the taper of the tapered girder.

Next, the cut pieces 11a and 11b are reversed in the longitudinal direction relative to one another, so that the lower height parts and the higher height parts of the abdominal plate part 12 correspond to each other, as shown in FIG. , fix the cut.

The cut portion is fixed by butt welding 13 or lap welding as shown in FIG. 2, or by
As shown in FIG. 3, they are stacked one on top of the other and stitched together using rivets 13A or bolts. This allows the tapered beam 14 to vary in height in the longitudinal direction.
is obtained.

After fixing the cut portion, both ends of the tapered beam 14 are cut perpendicularly to the lower side 15 of the tapered beam 14, and the ears 16 and 17 (hatched portions in FIG. 2) at both ends are removed. In this way, the tapered girder 18 is completed.

FIG. 4 shows a cross section of the tapered girder 18, showing the upper and lower flanges 19, 20 and the belly plate (web).
12 is integrally formed from the beginning of the material and is not welded.

In conventional composite girders, it is possible to change the cross-sectional area of the upper and lower flanges, but if you want to change the cross-sectional area of the upper and lower flanges 19 and 20 in the tapered girder 18 of the present invention, you can combine H-beams of different sizes. good. In this case, normally only one girder is used for a bridge, but two or more girders are used, so if an even number of girders are arranged, all the parts cut from the H-shaped steel material will be used, and there will be no unused parts.

In the tapered girder 18 of the present invention having the above configuration, H
Almost all parts of the type steel 11 are tapered girders 18
Since only the ears 16 and 17 at both ends of the tapered girder are effectively used as raw materials for manufacturing, and the only parts to be removed are the ears 16 and 17 at both ends of the tapered girder, the material yield is approximately 100%. Improving yield leads to cost reduction.

Further, there is no need to weld the belly plate part 12 and the flanges 19, 20, and since they are integrated from the material stage, the only weld line required is the welding part 13 for fixing the cut part of the belly plate part 12. There will be several places. That is, welding, which conventionally required two locations, is now required at one location, and in this sense as well, costs can be reduced.
However, when engagement with rivets or bolts 13A is used to fix the cut portion, the above 1.
Welding in several places is no longer necessary. In this sense, costs can also be reduced.

[Effect of the invention] As explained above, when using the tapered girder using H-shaped steel according to the present invention, H-shaped steel (including I-shaped steel) is used as the material, and the belly plate is cut diagonally and then turned over. Since the cutting part is fixed, it is possible to improve the material yield and reduce the amount of welding.
Costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side view of the H-shaped steel in a taper girder using H-shaped steel according to an embodiment of the present invention, showing the state of cutting the belly plate of the H-shaped steel, and Fig. 2 is a side view of the H-shaped steel shown in Fig. 1 cut. Figure 3 is an enlarged side view of the vicinity of the cut part when the cut part is fixed with rivets in Figure 2; Figure 2 is a cross-sectional view of a tapered girder, Figure 5 is a side view of a bridge without a tapered girder, Figure 6 is a side view of a tapered bridge using a tapered girder, and Figure 7 is a belly plate of a conventional tapered girder. FIG. 8 is a plan view of the flange of a conventional tapered girder in a cut-out state, and FIG. 9 is a cross-sectional view of the conventional tapered girder. 11...H-shaped steel, 12...Body plate part, 13...Butt welding, 13A...Rivet or bolt, 1
4... Tapered beam, 18... Tapered girder, 19,
20...Upper and lower flanges.

Claims (1)

[Scope of utility model registration request] Cut the H-shaped steel diagonally in the longitudinal direction at the belly plate.
A tapered girder made of H-beam steel that is divided into sections, one of which is inverted relative to the other, and the cut portion is fixed.