JPH0222820B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for introducing prestress into a beam in a steel structure.

<Prior art> Conventionally, when joining steel columns and beams, various structures have been implemented that use joining metal fittings such as gusset plates and split Ts and fastening fittings such as bolts, nuts, and rivets. In the structure,
It is required to improve the erection accuracy of columns and the dimensional accuracy of columns, beam members, and their bolt holes.

Furthermore, when a building is completed, stress is generated in the framework of columns and beams due to external forces such as self-weight, seismic force, wind force, etc., so the size of the beams must be increased.

<Purpose of the invention> This invention was devised in view of the above circumstances, and its purpose is to provide a method for introducing prestress into a steel beam that can offset stress caused by external forces. be.

<Structure of the Invention> The present invention uses a metal joint having a flat plate part with a male threaded bolt part formed at one end and a bolt insertion hole formed at the other end, and overlaps the flat plate part of the joint metal part on a steel beam flange. and tighten with bolts and nuts.
An adjustment nut is screwed together, this bolt part is inserted into the column flange, a tightening nut is then screwed into the bolt part, and prestress is introduced into the steel beam by rotating the tightening nut. be.

<Examples> The present invention will be described below based on illustrated examples. As shown in Figures 1 and 2, steel column A
and the upper and lower flanges of steel beam B,
The flange of the steel column A and the web center of the steel beam B are connected via a gusset plate 2 and a T-beam 3.

As shown in FIGS. 3 and 4, the joining hardware 1 is
A male-threaded bolt part 4 is formed at one end, and a flat plate part 6 with a plurality of bolt insertion holes 5 is formed at the other end. A shaded area is provided.

Using such a joining hardware 1, the bolt part 4 is inserted into the flange of the steel column A to which the reinforcing plate 8 is attached, and is fixed by the adjusting nut 9 and the tightening nut 10, and the flat plate part 6 is attached to the filler plate. 11, and is superimposed on the flange of the steel beam B and tightened with bolts and nuts. Here, the reinforcing plate 8
may be attached only to the outside or inside of the column flange, or may be unnecessary if the flange is sufficiently rigid. Furthermore, the reinforcing plate is not limited to a flat plate, but may also be an angle material or
As shown in the figure, a T-beam with only the web welded may be used.

Note that the bolt holes in the gusset plate 2 are elongated holes or loose holes so that the dimensions can be adjusted.

In such a configuration, the tightening nut 10 is rotated to introduce prestress into the bolt portion and the steel beam so as to offset stress due to self-weight, seismic force, wind force, etc. Here, depending on the purpose of the stress to be offset, it may be introduced into the upper flange, the lower flange, or both the upper and lower flange.

It should be noted that the gusset plate 2 is not required when the joining hardware 1 bears not only the axial force (tensile and compressive force) but also the shear force.

Fig. 5 shows an example of a gusset plate different from Fig. 2, in which two T-beams 3 are arranged one above the other to also function as a reinforcing plate. In this case, two gusset plates 2 will be arranged. Furthermore, as shown in FIG.
One is enough.

In the above configuration, when joining,
Among the joint hardware, if the two lower joint hardware at the lower flange of the beam are attached to the pillar in advance, they will serve as seats for receiving the beam material, and the work will be significantly improved.
Furthermore, if there is a gusset plate, the beam B is temporarily fixed using this plate. Next, the tightening nut 10 of the joining metal fitting 1 is rotated and tightened, and a predetermined prestress is introduced at the required location. Then, if there is a gusset plate,
Fully tighten the bolts and nuts of the gusset plate.

Although the case of a steel beam made of H-shaped steel has been described above, the present invention can also be applied to a truss beam, as shown in FIGS. 7, 8, and 9.

<Effects of the Invention> This invention uses a joint between a column and a beam and rotates a tightening nut to introduce prestress into the steel beam to offset the stress caused by external force, thereby reducing the size of the beam. It can be made smaller, which reduces the overall height of the building and improves economic efficiency.

Furthermore, even if the construction accuracy is a little poor, the dimensions can be adjusted using the adjusting nuts of the joint metal fittings, which improves workability and shortens the construction period.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a state in which an external force is applied to the joint between a column and a beam constructed according to the present invention;
The figures are front views showing similar joints, Figures 3 and 4 are plan views and side views showing joint hardware, Figure 5 is a front view showing another embodiment, and Figure 6 is a T-shaped steel. A front view showing another example, FIGS. 7 and 8 are cross-sectional views and front views showing still other embodiments, and FIGS. 9 and 10 are an overall view and a partial front view showing the case of a truss beam. , 11th
The figure is a front view showing another example of a truss beam. 1... Joining hardware, 2... Gusset plate, 3
...T-beam, 4... Bolt part, 5... Bolt insertion hole, 6... Flat plate part, 7... Curved part, 8... Reinforcement plate, 9... Adjustment nut, 10... Tightening nut, 11... Filler plate.

Claims (1)

[Claims] 1. Using a joint metal fitting having a flat plate part with a male threaded bolt part formed at one end and a bolt insertion hole formed at the other end, the flat plate part of this joint metal piece is stacked on the steel beam flange and tightened with bolts and nuts, A steel frame characterized by introducing prestress into a steel beam by inserting a bolt part into which an adjustment nut is screwed into a column flange, then screwing a tightening nut into the bolt part, and rotating the tightening nut. How to introduce prestress into beams.