JPH047416B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to the structure of a multi-story building and its construction method.

(Prior Art) Conventional building structures include steel frame structures (S structures) and reinforced concrete structures (RC structures).

(Problem to be solved by the invention) When a building is a steel frame structure, the steel columns must be covered with a fireproof covering plate. In this case, the trolley etc. may hit the pillars and damage the fireproof covering plate, and since it is a steel structure, a large amount of steel material is required, which raises the cost of construction materials. In addition, if the building is made of reinforced concrete, it is necessary to assemble and dismantle the formwork during construction, but in particular for beam formwork, supports are required to support it along the entire length of the bottom surface of the formwork, so it is necessary to assemble and dismantle the formwork during construction. , it takes time and effort to remove it, prolonging the construction period accordingly, and it is inconvenient that work cannot be done on the floor supporting this support until all supports are removed.

(Means for solving problems) This means includes the structure of the building itself and its construction method. The former means that the columns are reinforced concrete columns and the beams are steel beams, and among the joints between columns and beams, the joints on the top floor are pin joints, and the joints on other floors are rigid joints. In the column-beam joint section, a predetermined main reinforcement of the column passes through the beam end, and the beam end is fixed to the column main reinforcement with a fixing nut. The latter method involves assembling column reinforcing bars on the ground in advance, passing the main bars at predetermined positions of the assembled column reinforcing bars through the beam ends of the steel beam, and attaching the beam ends to the column main bars via fixing nuts. This construction method involves erecting the existing structure, installing the prefabricated steel columns and steel beams, then erecting the column formwork and pouring the concrete.

(Example) In Fig. 1, the building is a three-story building in which column 1 is a reinforced concrete column and beams 2 and 12 are steel beams. Joints 3a ₁ and 3a ₂ are rigid joints, top floor joint 3a ₃
is a pin connection.

The column reinforcement 4 in the column 1 has a spiral hoop 4 attached to the column main reinforcement 4a (4a ₁ , 4a ₂ ), which is a deformed reinforcement.
This is an assembled column reinforcing bar formed by hanging the column main reinforcement at the sleeve joint 4c.
... to make a length of three layers, and fixing plates 4d and 4e are fixed to the main pillar reinforcements at the upper and lower ends with nuts 4f (Fig. 5).

Here, the configuration of the joint portion 3al between the assembly column reinforcing bar 4 and the beams 2, 12 on the second floor will be explained with reference to FIGS. 1 to 4.

The steel beams 2, 12 are made of H-beams, and the beam ends 2a, 1
The corner main reinforcements 4 with larger diameters among the column main reinforcements 4a are inserted into the reinforcing bar through holes pre-drilled in the upper and lower flanges of 2a.
A flange penetrating main reinforcement 4a ₂ arranged between reinforcements _{a 1} passes through the flange, and the beam end is fixed to this penetrating main reinforcement by tightening fixing nuts 5 from the outside of the flange. The level of the steel beams 2 and 12 can be adjusted with this fixing nut. Column 1 between flanges of beam ends 2a and 12a
Rib plates 6, which also serve as concrete closures, are installed to strengthen the steel beams 2. Therefore, the stress from the steel beam 2 is transmitted to the column 1 by the column main reinforcement 4a ₁ that penetrates the flange and the adhesive force of the beam end, making it possible to rigidly connect the column reinforced concrete and the beam reinforcement, and as a frame. A rigid frame is formed.

The joint 3a ₂ between the column and the third floor beam is also the same as the joint 3 above.
It has the same configuration as _a1 .

The joints 3a ₁ and 3a ₂ are the steel frames 2a and 12a at the beam ends.
Since the structure is such that the flange penetrating main reinforcement _4a2 is passed through the upper and lower flanges of the flange and fixed with the fixing nut 5,
Since the joint can be extremely simplified, and the steel frame processing for the joint only involves providing holes through the reinforcing bars in the flange, there is an advantage that there is less labor involved in processing the joint, and that the amount of steel in the joint is small.

Further, the structure of the joint _3a3 between the column 1 and the beam 2 on the top floor will be explained based on FIGS. 5 and 6. At this joint, the column reinforcing bars 4 are not connected to the beam ends 2a;
It is fixed under the beam, the end of the beam is received by the head of the column, and the lower flange of the end of the beam is fixed to the head of the column with a pin connection using an anchor bolt 7 and a double nut 8. Furthermore, the beam end 2a and the column capital are connected via a shear connector 9 that is vertically disposed from the lower flange of the beam end.

The method of installing the anchor bolt 7 is to attach it to the beam end 2a first, and then pour the concrete for the column 1 afterward. This will allow the anchor bolt to be set accurately and avoid resetting when setting the steel beam. be able to. Of course, depending on the construction method, the anchor bolt 7 may be set on the column head.
Then, after the column concrete has solidified, the lower flange of the beam end may be fixed to the fixed anchor bolts.

In FIG. 1, the column base is fixed by embedding a fixing plate 4e which also serves as a base plate in the foundation.
10 is an underground beam. The slab 11 is formed by pouring concrete onto a deck plate (not shown) placed on the beam 2.

In the structure of the building in the above example, the column-beam joints 3a ₁ and 3a ₂ on the middle floor are rigidly connected as a rigid frame frame, ensuring high earthquake resistance, and the joints 3a ₃ on the top floor are pin-jointed. Because of this, it has the ability to flexibly respond to stress in either the front or back or left or right direction, maintaining earthquake resistance, and the method of joining the joints can be selected according to the stress to create a rational structure.
Furthermore, each joint portion 3a ₁ to 3a ₃ is simplified to reduce the amount of steel material.

Next, the construction method will be explained.

The independent steel frames 2a and 12a at the beam ends of the steel beams 2 and 12 are attached to the assembled column reinforcing bars 4 in advance, and are erected vertically as shown in FIG.
(Fig. 1) is embedded and fixed in the foundation, the beam steel frame 2b is connected between the steel frames at the end of the beam at the joint of the beam, and after setting the column reinforcing bars and the steel beam, a deck plate is laid on the beam. , assemble formwork for columns and walls, and pour concrete for slabs, columns, walls, etc. To reach the upper floor, extend the sleep joints 4c of the main pillar bars 4a that rise about 1m above the floor line, and then erect them in the same manner as above.
At the top, temporary supports for supporting the beam ends 2a are placed on the third floor slab 11 along the assembly column reinforcing bars 4 to temporarily support the steel beams on the top floor. Work space is secured between the temporary supports so that the supports do not interfere with work. When temporarily receiving the anchor bolt 7 and shear connector 9, the anchor bolt 7 and shear connector 9 are suspended from the beam end 2a into the column reinforcing bar 4. After that, concrete for pillars, walls, etc. will be poured. When the predetermined concrete strength of column 1 is obtained, the temporary support is removed, a deck plate is laid on beam 2, and roof slab concrete is poured.

When attaching the beam end 2a to the assembled column main reinforcement 4 on the ground, it is possible to install an independent steel frame that will become the beam end as shown in Figure 7, erect the column reinforcement, and then set the beam steel frame 2b. As shown in FIG. 8, the column reinforcing bars may be erected after the beam end of the beam, which is made by integrating the beam steel frame and the end steel frame, is attached.

The reinforcements may be arranged and attached on site without assembling the column reinforcing bars 4 in advance or attaching the beam ends. That is, at the site, four corner main reinforcements 4a ₁ and eight flange penetrating main reinforcements 4a ₂ are hung and solidified with hoops 4b, and fixing plates 4e are attached to the column bases.
Install it, stand it up from the foundation, adjust the beam level by setting the nut 5 on the flange-penetrating main reinforcement at the level of the joint with the beam, then pass the flange-penetrating main reinforcement on the beam end 2a and fix it from the outside of the upper flange. Tighten nut 5 to fix the beam end to the main reinforcement.
Thereafter, a method may be adopted in which the beams 2 are set, deck plates are laid, formwork such as columns is assembled, and concrete is poured.

Also, as a construction method, as mentioned above, a layered construction method in which concrete is poured for each floor and extended to the upper floors may be used, but as long as the column reinforcing bars can support the steel beams, the column reinforcing bars and It is also possible to set the steel beams and then pour concrete later.

(Effects of the Invention) As explained above, according to the present invention, the columns are made of reinforced concrete and the beams are made of steel, so the amount of steel can be reduced compared to a steel-framed building structure, and the cost of construction materials can be reduced. This eliminates the need for fireproof covering plates for the columns, which eliminates the problem of damage, and eliminates the need for assembling and dismantling beam formwork and installing and removing supports for beam formwork, reducing construction time. It is possible to work under the beam. And pillars on floors other than the top floor
The beam joints are rigidly connected to ensure high seismic resistance, and the column-beam joints on the top floor are pin-jointed to provide earthquake resistance that can flexibly respond to stress in either the longitudinal or lateral direction of the building. You can maintain your sexuality. Furthermore, since the beam ends are connected to the column reinforcing bars via fixing nuts, the level of the beam ends can be adjusted during construction, ensuring accuracy in the position of the beam ends, and stress transmission from the beam ends to the column reinforcing bars. will be carried out reliably. In addition, the present invention is a construction method in which beam ends are attached to pre-assembled column reinforcing bars, so there is no need to attach beam ends at high places, which improves workability and ensures work safety. Columns and beams can be erected in the same way as for steel-framed buildings, and the construction method is superior to that for reinforced concrete buildings, and the construction period can be expected to be shortened.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view, Figure 2 is an enlarged cross-sectional view showing the joint between the second floor beam and column, Figure 3 is a cross-sectional view taken along the line shown in Figure 2, and Figure 4 shows how the beam end flange is attached. Fig. 5 is an enlarged front view, Fig. 5 is an enlarged cross-sectional view showing the joint between the top floor beam and column, Fig. 6 is a cross-sectional view taken along the line shown in Fig. 5, and Fig. 7 and Fig. 8 are the connection between the column reinforcement and the beam. It is an explanatory view showing each example of a construction procedure. 1... Column, 2, 12... Beam, 2a, 12a...
Beam end, 3a ₁ to 3a ₃ ... Column-beam joint, 4 ... Column reinforcement, 4a, 4a ₁ , 4a ₂ ... Column main reinforcement, 5 ... Fixing nut, 6 ... Rib plate, 7 ... Anchor bolt.

Claims (1)

[Claims] 1. The columns are reinforced concrete columns and the beams are steel beams. Among the joints between the columns and beams, the joints on the top floor are pin joints, and the joints on other floors are rigid joints. A structure of a multi-story building characterized by a joint between a column and a beam in which a predetermined main reinforcement of the column passes through the beam end, and the beam end is fixed to the column main reinforcement with a fixing nut. 2. The main reinforcement of the pre-assembled column reinforcement at a predetermined position is passed through the beam end of the steel beam, and the beam end is attached to the column main reinforcement via fixing nuts.Then, the assembled column reinforcement and steel beam are assembled. A construction method for multi-story building structures, which is characterized by erecting column formwork and pouring concrete after installation.