JPS6147938B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of forming a plate-like space truss.

As shown in Japanese Patent Publication No. 50-14455, the conventional block-shaped three-dimensional truss has a plurality of upper chord members arranged at intervals, and a plurality of upper chord members arranged at intervals and located below the upper chord members. A lattice is provided between one upper chord member and two lower chord members adjacent to the upper chord member, but due to manufacturing, the lattice is placed within the inclined plane of the upper and lower chord members. Since the lattice must be welded to the surface of the lattice, it is difficult to manufacture and the work efficiency is low, and the welding of the lattice within an inclined surface makes it difficult to automate the operation.

Therefore, an object of the present invention is to facilitate the manufacture of a plate-shaped space truss, in other words, to provide a structure of a space truss that is easy to manufacture and a method for forming the same.

The method for forming a plate-like three-dimensional truss according to the present invention is to fabricate in advance a plurality of plane trusses, each consisting of an upper chord, a lower chord, and a lattice, so that the upper chords and lower chords of adjacent plane trusses are parallel to each other and close to each other. The planar trusses are arranged so as to be inclined in opposite directions, and then an upper connecting member and a lower chord member are arranged on the upper chord member of the planar truss in a direction perpendicular thereto so as to pass through the intersection of the upper chord member and the lattice. The method includes connecting the plurality of plane trusses by means of a lower connecting member disposed on the lower chord of the plane truss in a direction perpendicular to the lower chord of the plane truss so as to pass through the intersection with the lattice, and the plane truss is manufactured in advance and assembled. At times, the lattice is welded to the upper and lower chords in an inclined plane by closely joining the upper chord to any upper chord and similarly joining the lower chord closely to any lower chord. It is characterized by forming a plate-like three-dimensional truss without any problems.

According to the present invention, since lattice welding within an inclined plane, which is difficult to perform, is eliminated, it is possible to improve work efficiency and improve quality. Also,
According to the present invention, the production of a plane truss including a lattice can be carried out within a plane on a workbench, making it easy to automate the production.

The features of the invention will become more apparent from the following description of the illustrated embodiments.

First, the structure of the plate-like space truss formed by the method of the present invention will be described. The three-dimensional truss 10 shown in FIG. 1 includes a large number of planar trusses as constituent elements.

As shown in FIG. 2, the plane truss 12 consists of an upper chord member 14, a lower chord member 16, and a lattice 18 welded between the two chord members. This plane truss can be easily manufactured by applying a conventional wire mesh welding machine.

When assembling the space truss 10, the planar trusses 12 are arranged so as to be inclined in opposite directions alternately. That is, as shown in FIG. 3, adjacent planar trusses 12a,
12b are arranged so as to be inclined in left and right directions opposite to each other. Moreover, the upper chord member 14a of these plane trusses,
The lower chord members 14b are arranged close to and parallel to each other so as to almost touch each other, and the lower chord members 16a and 16b are also arranged close to and parallel to each other with the lower chord members of other planar trusses adjacent to each of the plane trusses 12a and 12b. At this time, the intersection points of the lattice and chord members of each planar truss are positioned on a line in the lateral direction on both upper and lower sides of the space truss.

Such arrangement of a large number of planar trusses 12 with alternating inclinations in opposite directions can be achieved by using a jig 2 as shown in FIGS. 4a and 4b.
This can be easily done by using 0 and 22. First, the jig 20 has concave grooves 2 at regular intervals in the square timber.
4 is provided. The groove 24 is formed between a pair of lower chord members 1
6 and has a width dimension equal to approximately twice the diameter of the lower chord. Next, the jig 22 is suitable for arranging the plane truss 12 with higher precision, and has a shape in which a plurality of triangular peaks are connected as a whole, and each vertex has an arc-shaped shape that receives the upper chord member 14. A pair of grooves 26 having a cross section are provided, and a groove 27 for receiving a pair of lower chord members 16 is provided in the trough. Each of the jigs 20 and 22 is a planar truss 12.
When arranging as described above, a plurality of them are arranged at intervals.

After arranging multiple planar trusses alternately tilting in opposite directions in the area adjacent to the factory or floor slab construction site,
The upper connecting member 28 passing through the intersection of the upper chord member 14 and the lattice 18 and the lower connecting member 30 passing through the intersection point of the lower chord member 16 and the lattice 18 are arranged in the arrangement direction of the plane truss 12, as shown in FIG. In addition, these connecting members are fixed to the upper and lower chord members 14 and 16, thereby connecting a large number of planar trusses together to complete a plate-shaped three-dimensional truss 10 of a desired size. Connecting material 28, 30
can be fixed to the chord members 14, 16 by welding.

The connecting members 28, 30 can also be fixed to the chord members 14, 16 by means other than welding. Fifth
In the example shown in Figures a and b, a stud bolt 32 is welded to the connecting member 28 in advance, and a metal fitting 34 with both ends bent and a nut 35 are fitted to the bolt, so that a pair of stud bolts 32 can be attached to the connecting member 28 in close proximity. This is to tighten and fix the string members 14 that are arranged in such a manner.
In addition, in the examples shown in FIGS. 6a, b, and c, the connecting member 28
A metal plate 36 with slits is welded to the metal plate 36, and each piece is bent in the opposite direction as shown in FIG. 6b when the string member 14 is fixed. 14. Furthermore, each of the chord members 14 and 16 and the connecting members 28 and 30 can be connected by a binding wire.

When the space truss 10 shown in FIG. 1 is used to support a concrete formwork, a formwork 38 is attached to one side of the space truss, that is, on the underside of the space truss as shown in FIG. The formwork 38 is attached to the three-dimensional truss through attachment fittings 40 that are inserted between adjacent lower chord members 16.

The three-dimensional truss with the formwork 38 attached thereto is then lifted by a crane (not shown),
It rests on the support edge or top of a beam or wall between pre-erected columns. Due to its integral steel nature, the space truss resting on the supporting edges can withstand subsequent concrete pouring without support.

After the concrete has hardened, remove the formwork. If ceiling finishing material or its base material is used in the formwork, it is not necessary to remove it.

The three-dimensional truss 10 undergoes slight flexural deformation due to the pouring of the slab concrete, and internal stress is generated in the reinforcing bars at various parts. A reinforced concrete floor slab that satisfies the conditions and the compatibility conditions for deformation can be obtained. Therefore, compared to the conventional floor slab construction method using shoring, it is possible to prevent deflection deformation when dismantling the shoring and cracking of concrete due to the deflection deformation.

Furthermore, the deflection of the deck slab due to the load during concrete placement or the normal load after concrete hardening is assumed as the amount of deformation, and the space truss is given in advance an initial deformation in the opposite direction according to the amount of deflection deformation. This not only allows for floor slab construction without support, but also enables active control of unavoidable deflection and cracking.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a plate-shaped space truss formed by the method of the present invention, FIG. 2 is an elevational view of a plane truss constituting the space truss, and FIG. 3 is a perspective view showing the arrangement of the plane truss. Fig. 4 is a perspective view of a jig used for arranging the plane truss, Figs. 5 and 6 are perspective views showing the fittings for connecting the chord members and the connecting members, respectively, and Fig. 7 is the installation state of the three-dimensional truss and the formwork. FIG. 10: Three-dimensional truss, 12: Plane truss, 14:
Upper chord material, 16: Lower chord material, 18: Lattice, 28,3
0: Connecting material, 38: Formwork.

Claims (1)

[Claims] 1 Prefabricating a plurality of plane trusses, each consisting of an upper chord member, a lower chord member, and a lattice, and tilting the plane trusses in opposite directions so that the upper chord members and lower chord members of adjacent plane trusses are parallel and close to each other. and then connecting the plurality of planar trusses by an upper connecting member and a lower connecting member, the upper connecting member being connected to the upper chord of the planar truss through the intersection of the upper chord and the lattice. , and the lower connecting member is arranged in a direction perpendicular to the lower chord member of the planar truss so as to pass through the intersection of the lower chord member and the lattice.