JPH11158996A - Triangular truss - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify welding work and facilitate welding of studs by making a chord member being an upper chord and a lower chord to be a pentagonal steel pipe having a cross section of a pentagon. SOLUTION: The triangular truss comprises two upper chords 1 positioned under a floor board F and extending in the direction of a bridge axis, one lower chord 2 and an oblique material 3 connected to the upper chord 1 and the lower chord 2 to be applied to a triangular bridge. The upper chord 1 and the lower chord 2 are a pentagonal steel pipe, the same shape is made in the whole cross section to display a right and left symmetrically pentagon. Since the upper chord 1 and the lower chord 2 are the cross section pentagon, the beveling of the oblique material 3 makes a shape abutting on the same plane. Therefore, the beveling can be simplified. In addition, welding work can be simplified. Therefor welding defects can be reduced. In addition, since the welding face of studs can be made a plane, welding studding can be performed. Thus, execution of a triangular truss is improved, a construction period is shortened and elimination or reduction of labor can be contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a triangular truss and a chord used therefor, and more particularly to a triangular truss suitable for use in a triangular truss bridge.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a conventionally known triangular truss bridge (from LULLY Bridge, Bridge and Foundation, July 1997, Switzerland). In this triangular truss, round steel pipes are used as the upper chord members 20, 20, the lower chord member 21, and the diagonal members 22 located below the floor slab F. As shown in FIG. 10, studs S are cultivated on the upper surface of the upper chord material 20 and are combined with the precast concrete floor slab F. Since a tensile force acts on the floor slab F in the direction perpendicular to the bridge axis, in this example, P
Prestress is introduced in the direction perpendicular to the bridge axis by a C steel rod (not shown).

[0003]

However, the prior art has the following problems. In a conventional triangular truss, as shown in FIG. 9, a diagonal member 22, which is a round steel tube, is obliquely joined to an upper chord member (not shown in FIG. 9), which is also a round steel tube, and a lower chord member 21. As shown in FIG. 11, it was necessary to finish the groove 22a of the diagonal member 22 into a complicated shape.

[0004] In addition, welding of the upper and lower chord members 20, 21 and the oblique member 22 is a very troublesome operation because the welding is performed on curved surfaces, and there is a problem that welding defects are likely to occur. there were.

Further, since the upper chord material 20 is a round steel pipe, FIG.
As shown in (1), the swelling surface of the stud S became a curved surface, and swelling of the stud S was difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to simplify the shape of a groove, simplify welding work, and facilitate stud swelling. The point is to provide a triangular truss that can be used.

[0007]

Means for Solving the Problems In order to solve the above problems, the present invention has the following constitution. The gist of the invention according to claim 1 is a triangular truss provided with an upper chord material, a lower chord material, and a diagonal member connected to the chord material, wherein the upper chord material and the lower chord material are pentagons having a pentagonal cross section. A triangular truss characterized by being a steel pipe. The gist of the invention according to claim 2 resides in the triangular truss according to claim 1, wherein the pentagonal steel pipe has a cross-sectional shape having a side surface rising vertically from a bottom surface. The gist of the invention according to claim 3 is that, in the pentagonal steel pipe, when an angle between a diagonal member and a horizontal plane when the triangular truss is viewed from a bridge axis direction is x,
The inner angle is such that the vertex angle is 2x, the both end angles of the bottom surface are 90 °, and the upper chord material and the lower chord material are such that the bottom surface and the horizontal surface are parallel to each other and each slope is parallel to each other. 3. The triangular truss according to claim 1, wherein the vertices are arranged to face each other.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) A triangular truss according to Embodiment 1 is applied to a triangular truss bridge, and FIG.
As shown in FIG. 2, two upper chords 1 extending below the floor slab F and extending in the bridge axis direction, one lower chord 2 and an oblique connection to the upper chord 1 and the lower chord 2 are provided. And material 3.

The upper chord member 1 and the lower chord member 2 are pentagonal steel pipes, which have the same shape in all cross sections and have a symmetrical pentagon shape. As shown in FIG. 2, side surfaces 1d and 2d rise vertically from bottom surfaces 1b and 2b, and slopes 1c and 2c are joined at vertices 1a and 2a. In addition, in FIG. 2, since the upper chord material 1 and the lower chord material 2 are the same pentagonal steel pipe, both reference numerals 1 and 2 are given. In the erected state, the upper chord material 1
Is upside down from the state shown in FIG. Slope 1c, 2
c is an inclination angle such that the diagonal members 3 are vertically connected as viewed from the bridge axis direction as shown in FIG. When the inner angle is specifically described using the lower chord material 2, as shown in FIG.
X is the angle between the diagonal member 3 and the horizontal plane when viewed from the bridge axis direction.
In this case, the angle of the vertex 2a is 2x, the both end angles of the bottom surface 2b are 90 °, and the remaining angles are 180 ° -x and 180 ° -x. The upper chord material 1 has a similar shape.

FIG. 1 (reference numerals 1a to 1)
c, 2a to 2c are shown in FIG. 2), as shown in FIG.
Has a bottom surface 1b in contact with the lower surface of the floor slab F, and a vertex 1a faces downward. The lower chord 2 has a bottom surface 2b facing downward and a vertex 2a facing upward. Therefore, the upper chord material 1
And the slope 2c of the lower chord material 2 are parallel to each other.

The diagonal member 3 shown in FIGS. 1 and 3 is a round steel pipe. As shown in FIG. 4, the groove 3a has the groove 3a on the same plane. Such a round steel pipe is fixed to a slope 1c of the upper chord 1 and a slope 2c of the lower chord 2 separately.

In the first embodiment, as shown in FIG. 1, a tensile force acting on the floor slab F is applied to the P slab embedded in the floor slab F.
It is canceled by the prestress introduced into the C steel material 11.

Since the triangular truss according to the first embodiment is configured as described above, the following effects can be obtained. Since the joint between the diagonal member 3 and the upper and lower chord members 1 and 2 is flat,
Workability and weldability are improved, and automatic welding is also possible.

Further, since welding is performed on a flat surface, defects are less likely to occur.

Further, as for the stud S, the lysing surface is flat as shown in FIG. 5, so that the lysing property is improved.

Further, since the swelling surface is parallel to the floor slab F, stress is transmitted more smoothly between the upper chord material 1 and the floor slab F.

Further, since the slope 1c of the upper chord 1 and the slope 2c of the lower chord 2 are parallel to each other, each end of the diagonal 3 can be machined into the same shape without any upper and lower parts. Lower chord material 2
Any of the grooves 3a can be set up or down when mounting to the.

The slopes 1c, 1c, of the upper chord material 1 and the lower chord material 2
Since 2c is parallel to each other, welding of the diagonal member 3 is easy.

Further, since it is a pentagonal steel pipe, the number of bending press steps is smaller than that of a polygonal steel pipe such as a hexagonal steel pipe and a heptagonal steel pipe, so that the production cost can be reduced.

In addition, when the pentagonal steel pipe is arranged so that the top is directed upward, dust and the like do not accumulate on the upper surface.

(Embodiment 2) A triangle truss according to Embodiment 2 also constitutes a triangle truss bridge as shown in FIG. The difference from the triangular truss bridge according to the first embodiment is that two upper chord members 1 are connected by cross members 4 and the
Is that the PC steel material 11 as shown in FIG.
In such a case, since it is easy to connect the two upper chords 1 with the cross members 4, it is not necessary to introduce prestress into the floor slab F. The pentagonal steel pipe used here can be manufactured sufficiently by the current welding pipe manufacturing technology, and since the upper and lower chord materials 1 and 2 have the same shape, the number of members, the manufacturing cost, and the manufacturing time can be greatly reduced.

When the cross member 4 is installed between the upper chord members 1 and 1, the side surface 1d of the pentagonal steel pipe is vertical.
Easy to weld. Further, the processing of the end of the cross member 4 is unnecessary. Further, it is possible to prevent a force from acting on the cross member 4 in a direction other than the axial direction.

Although the present embodiment is applied to a triangular truss, the present invention is not limited thereto, and can be applied to a truss suitable for applying the present invention.

Although the triangular truss is used for a triangular truss bridge, in the present invention, a triangular truss beam used for a beam string and a triangular truss structure 30 shown in FIG. Can be used for truss structures.

Further, the construction of the triangular truss bridge can be easily performed by welding the diagonal members 3 and the cross members 4 to pentagonal steel pipes (upper and lower chords) manufactured at the factory, and the labor of the erection is reduced. It is possible to plan.

The upper chord member 1 and the lower chord member 2 according to the above-described embodiment are the same pentagonal steel pipe, but the present invention is not limited to this, and the pentagonal steel pipes of different sizes or different materials are not limited thereto. It is also possible to Furthermore, it is also possible to make a shape suitable for carrying out the present invention, such as a triangular steel pipe, a trapezoidal steel pipe, and a heptagonal steel pipe.

In the above embodiment, both the upper chord and the lower chord are pentagonal steel pipes. However, the present invention is not limited to this. In the present invention, only the upper chord and only the lower chord are pentagonal steel pipes. You can also.

The diagonal member 3 is made of an H-section steel or a square steel pipe.
A steel material having a suitable cross-sectional shape for implementing the present invention can be obtained. In such a case, the groove 3a is on the same plane, so that the above-described effect can be obtained. The cross member can be formed in any shape like the diagonal member.

The number, position, shape, and the like of the above-mentioned constituent members are not limited to the above-described embodiment, but can be set to a number, position, shape, and the like suitable for carrying out the present invention.

In the drawings, the same components are denoted by the same reference numerals.

[0032]

Since the present invention is configured as described above, the following effects can be obtained. Since the cross sections of the upper chord material and the lower chord material are pentagonal, the groove of the diagonal material has a shape that is in contact with the same plane. Therefore, the groove can be simplified. In addition, the welding operation can be simplified, so that welding defects can be reduced. In addition, since the swelling surface of the stud can be made flat, swelling can be facilitated. As a result, according to the present invention, the workability of the triangular truss and thus the triangular truss bridge is improved, the construction period is shortened,
Labor saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a triangular truss bridge according to Embodiment 1 of the present invention.

FIG. 2 is a longitudinal sectional view of a partially broken upper chord material and lower chord material shown in FIG.

FIG. 3 is a conceptual diagram showing an inner angle of the pentagonal steel pipe shown in FIG.

FIG. 4 is a longitudinal sectional view showing the stud according to the embodiment shown in FIG.

FIG. 5 is a perspective view showing a lower end of the diagonal member shown in FIG. 1;

FIG. 6 is a longitudinal sectional view of a triangular truss bridge according to Embodiment 2 of the present invention.

FIG. 7 is a longitudinal sectional view of a triangular truss according to another embodiment of the present invention.

FIG. 8 is a longitudinal sectional view of a triangular truss bridge according to a conventional example.

FIG. 9 is a perspective view of a partial cross section showing a portion where the diagonal member and the lower chord member shown in FIG. 8 are joined.

FIG. 10 is a partially longitudinal sectional view showing the stud of the triangular truss shown in FIG. 8;

FIG. 11 is a perspective view showing a lower end portion (groove) of the diagonal member shown in FIG. 8;

[Explanation of symbols]

 F Floor slab S Stud x Angle between diagonal and horizontal plane 1 Upper chord 1a Vertex 1b Bottom 1c Slope 1d Side 2 Lower chord 2a Vertex 2b Bottom 2c Slope 3 Diagonal 3a Groove 4 Horizontal rod 11 PC steel rod 20 Upper chord 21 lower chord material 22 diagonal material 22a groove 30 triangular truss

Claims (3)

[Claims] 1. A triangular truss comprising an upper chord material, a lower chord material, and an oblique material connected thereto, wherein the chord material, which is the upper chord material and the lower chord material, is a pentagonal steel pipe having a pentagonal cross section. Triangular truss featured. 2. The triangular truss according to claim 1, wherein the pentagonal steel pipe has a cross-sectional shape having a side surface rising vertically from a bottom surface. 3. The pentagonal steel pipe has an interior angle, a vertex angle of 2x, and an end angle of a bottom face, where x is an angle between a diagonal member and a horizontal plane when the triangular truss is viewed from a bridge axis direction. The upper chord material and the lower chord material are arranged so that their vertices face each other so that the bottom surface and the horizontal plane are parallel to each other and each slope is parallel to each other. Item 3. Triangular truss according to item 1 or 2.