JPH026898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for joining steel frames when an exterior finishing material is previously attached.

Traditionally, when constructing a steel frame ground frame for medium-sized and high-rise buildings, the exterior work was done only after the steel frames had been completely joined.
The most common method was to attach a PC board.

This is because once the steel frames are completely joined, the structure becomes sufficiently strong, and then by installing the exterior PC board in the correct position, highly accurate installation becomes possible.

However, recently, the method of attaching the exterior PC board after the temporary assembly of the steel frame has been attracting attention.

The exterior PC board, which is installed immediately after the steel frame has been temporarily assembled, acts as a protective wall, making it possible to ensure safety to the outside, making it possible to use a fixed type of scaffolding for joining steel frames, which was previously required for safety reasons. This is because the system can now be mobile, meeting the demands for prioritizing safety and reducing costs. However, this method has disadvantages. After the exterior PC board is installed,
As a result of welding and bolting of the main steel frame, the behavior of the steel frame as a structure due to shrinkage of the welded parts will affect the exterior PC board, and the PC board will be replaced again.
This requires work to adjust it to the correct position.

That is, in Figure 1, 1 in the figure is a steel column;
2 is the steel beam bracket, 3 is the steel beam, 4 is the exterior
Each PC board is shown, but in the method described above in which the exterior PC board is installed immediately after the temporary assembly of the steel frame, first the steel beam bracket 2 and the steel beam 3 are temporarily bolted together with the gusset plate 5 between the waves of both. After temporarily assembling the steel frame, the exterior PC board 4 is installed. After that, welding of the upper flange part a, main bolt connection of the wave, and welding of the lower flange part b are continued.

The pre-attached exterior PC board 4 is affected by the shrinkage of the welding steps a and b in the subsequent steps, causing positional deviation and must be adjusted.

When the inventor of the present invention analyzed the shrinkage phenomenon that is the cause of the need for such post-adjustment, the results as shown in the diagram of FIG. 2 were found.

In addition, in the diagram, 1, 2, 3, and 4 indicate welding points, that is, both sides of the upper flange and lower flange, as shown in the attached diagram, and 1, 2, 3, and 4 indicate the welding location of the upper flange and the lower flange through the main bolt connection. Showing the stages of welding.

As a result, the upper flange weld accounts for most of the total shrinkage (approximately
95%).

Therefore, after welding the upper flange part,
If you install the exterior PC board, you won't have to put the PC board in the correct position again later.

The present invention has been made based on this point of view, and its gist is to first attach a steel beam bracket and a steel beam to the receiving portions projecting from the upper and lower flanges of the steel beam bracket, respectively. The tips of the upper and lower flanges of the beam are placed on top of each other, and a temporary restraint piece is connected between the steel beam bracket and the upper flange of the steel beam to temporarily connect them, and then the upper flange portions are welded together. Wait for the shrinkage of the welded part to complete before installing the exterior PC board.
After that, the gusset plate between the steel beam bracket and the steel beam wave was bolted together, and the lower flange was welded together, thereby eliminating the need for post-adjustment of the exterior PC board. That's what I did.

This will be explained in detail below based on the drawings.

Figures 3a and 3b are schematic explanatory diagrams of the construction method of the present invention and enlarged detailed views of the main parts, and 6 in the figure shows the steel beam bracket 2,
This is a temporary restraining piece attached between the upper flanges of the steel beam 3, and as shown in detail in Figure b, this consists of cover plates 6a, 6b welded to the upper flanges and a splice plate 6c connecting the two. Receptacles 7 and 8 are protruded from the upper and lower flanges of the steel beam bracket 2, on which the upper and lower flange tips of the steel beam 3 are placed, and the cover plate 6 is mounted.
A and 6b are connected by a splice plate 6c to temporarily connect the steel beam bracket 2 and the steel beam 3.

Next, the upper flange part a is welded, and after the steel frame has contracted at the welded part, the exterior PC board 4 is attached, and the wave bolts are tightened by the gusset plate 5 on a movable scaffold while securing the protective wall. Join and weld the lower flange part b.

In the above procedure, since the wave bolts are joined after welding shrinkage, it is necessary to take into account the amount of welding shrinkage so that the workability of the wave bolts does not deteriorate.

According to the construction method of the present invention described above, the exterior PC board 4 is assembled after the welding of the upper flange, which accounts for most of the total shrinkage, is completed, so that no displacement occurs and post-adjustment is almost unnecessary.

In addition, when temporarily joining the steel beam flange 2 and the steel beam 3 before securing a curing wall, the steel beam 3 can be placed on the steel beam flange 2 and the restraint piece 6 can be connected to the beam without requiring a separate fixed scaffold. In the present invention, the welding of the upper flange portion a can also be performed on the beam.
There is no need for fixed scaffolding even at the stage before the formation of the curing wall.

The significance of the restraint piece 6 is that it can naturally eliminate the misalignment of the upper and lower flanges for welding in the case of forming a curing wall in the case of conventional wave bolt joining.
The beam could be temporarily fixed to the column, but the same effect can be achieved while restraining the welding shrinkage of the upper flange.

In the present invention, the main bolt connection of the gusset plate 5 and the welding of the lower flange are performed after the protective wall is formed after the exterior PC board is attached, so it is not safe to perform this work on a moving scaffold where there is a risk of tilting. As a result, the advantages of installing the exterior finishing material in advance are maintained without any loss, while eliminating the need for post-adjustment of the exterior finishing material, which is extremely significant in practice.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the conventional construction method, FIG. 2 is an analysis chart of shrinkage phenomena due to upper and lower flange welding, and FIG. 1... Steel column, 2... Steel beam bracket, 3...
... Steel beam, 4 ... Exterior PC board, 5 ... Gusset plate, 6 ... Restraint piece, 6a ... Cover plate, 6b ... Cover plate.

Claims (1)

[Claims] 1. First, hang the ends of the upper and lower flanges of the steel beam bracket onto the receiving parts protruding from the upper and lower flanges of the steel beam bracket, respectively, and then attach the steel beam bracket and the steel beam together. Temporarily connect the upper flanges by connecting a temporary restraining piece installed across the bridge, then weld the upper flanges together, and wait for the welding to complete shrinking before installing the exterior PC board. A steel frame joint in the case of prior installation of an exterior finishing material, characterized in that the gusset plate between the wave of the steel beam bracket and the steel beam is joined with bolts, and the lower flange portion is further welded. Method.