JPH1136449A - Column-beam joining part structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the erection with excellent accuracy by integratedly embedding a column-beam joining part of a steel structure in the vicinity of a top end of a columnar block of a PC structure in the joining part structure of a transition stair of the mixed structure where a lower stair is of PC structure and an upper stair of steel structure. SOLUTION: Three deformed bars which is a column main reinforcement 2 of a PC column 1 of a lower stair are arranged at each of four corners of the columnar section, a hoop reinforcement 3 is arranged so as to surround the column main reinforcement at four corners, and a reinforcement anchoring plate 4 is fixed to an upper end. A joining part steel 11 is built so that the column core of the lower stair and the upper stair surrounded by the upper end of the column main reinforcement 2 and the beam installation height for the upper stair slab are agreed with each other. The joining part steel 11 comprises a box joining part 12, a diaphragm 13, a beam bracket 15, and a steel column block 16, and concrete is placed in the box joining part 12 from a filling hole 13a in the diaphragm 13. A simple and economical structure can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam-column joint structure, and more particularly, to a precast reinforced concrete structure having a lower floor.
The present invention relates to a beam-column joint structure at a transitional floor of a structural type in a mixed structure in which an upper floor is made of a steel structure.

[0002]

2. Description of the Related Art For example, in order to realize a design demand for providing a space with a large beam span on an upper floor or to reduce the weight of the upper floor, a lower floor has a reinforced concrete (RC) structure and an upper floor. May have a mixed structure of steel (S) structure. In such a mixed structure,
When the entire building is designed as an integral ramen structure, it is necessary to ensure that stress is transmitted at a transition floor from the lower floor of the RC structure to the upper floor of the S structure, for example. In order to realize an S structure that is mechanically continuous with the RC structure, a steel column connected to the top end of the RC column is designed to have a rigid contact structure with the RC column. Various types of fixed pillar bases having a rigid contact structure, such as a conventional embedded pillar base and an exposed fixed pillar base, are known. Also,
In order to secure the construction accuracy of the steel frame on the upper floor, a design is often made in which a steel frame is buried in the RC column in advance, and the buried steel frame and the column base of the S column are rigidly connected at the transition floor.

[0003]

However, in the above-described design, it is necessary to embed a steel frame which is not considered in the design of the column in the RC column, so that the total amount of steel used increases and the R
There is a problem that the construction of the C column is complicated. Also, in the case of an exposed fixed column base with high rigidity, the column section of the lower floor is determined by the column dimensions to be built on the upper floor, so the column section of the lower floor must be larger than the required design dimension,
It is uneconomical.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, to provide an economical member structure, and to easily and accurately build a steel column on an upper floor. It is to provide a joint structure.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a transitional floor of a mixed structure in which the lower story is a precast reinforced concrete structure and the upper story laminated on the lower story is a steel frame structure. In the beam joint structure, a column-beam joint of the steel structure of the transition floor is integrally embedded at a predetermined position near the top end of the column block concrete of the precast reinforced concrete structure on which the steel column of the transition floor is erected. It is characterized by having been done.

Further, the column-to-column joint of the steel structure comprises a box joint, a connection of a steel beam block is joined to a side surface of the box joint, and a steel frame is attached to a diaphragm attached to an upper surface of the box joint. It is preferable that the column block be erected.

At this time, it is preferable to fill concrete into the inside of the box joint.

Further, the box joint is surrounded by a closing plate substantially equal to the outer dimensions of the precast reinforced concrete column block, and concrete is filled between the closing plate and the box joint. preferable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the beam-column joint structure according to the present invention will be described below with reference to the accompanying drawings.
1 to 3 are perspective views and front views showing a steel material unit 10 which is assembled in a factory in advance and is buried in a column portion of a precast concrete (hereinafter, referred to as PCa) and which is embedded in a column portion of a joint steel frame 11 and a column main bar 2. It is a top view. FIG.
As shown in the figure, three deformed reinforcing bars serving as the column reinforcing bars 2 of the PCa column 1 on the lower floor are arranged at the four corners of the column section, and three spiral hoop bars 3 are arranged so as to surround the column reinforcing bars 2 at the four corners. Has been streaked. On the other hand, a reinforcing bar fixing plate 4 is provided at the upper end of the column main bar 2.
Is fixed. The reinforcing bar fixing plate 4 holds the position of the column main bar 2 located near the top end of the PCa column 1. In the present embodiment, a steel plate having a side of 10 cm is fixed to a head of each main bar 2 with a nut (not shown).

The joint steel frame 11 shown in FIG. 4 is surrounded by the upper ends of the main pillars 2 so that the lower and upper pillar cores and the beam installation height for the upper floor slab coincide with each other. It is rare. The joint steel frame 11 has a box joint 12 equal to the outer dimensions of the upper story steel column 21 shown by phantom lines in FIG. 4, and two through-diaphragms 13 and 14 for closing upper and lower openings of the box joint 12. And a beam bracket 15 joined to the side connection of the box joint 12
Erected on the diaphragm 13 and the upper story steel column 21
And a steel column block 16 having the same external dimensions as the above. In the present embodiment, the external dimensions of the PCa column 1 are □
850 × 850, whereas the outer dimensions of the box joint 12 forming the panel zone are □ 500 × 5
00 is set. The box joint 12 is made of a steel plate processed material, but may be a pre-made square steel pipe having a predetermined dimension.
The beam bracket 15 is made of a built-up H-section steel, and the steel column block 16 is made of a ready-made box column (□ 5).
00 × 500). As the steel material, an SN material or the like that meets the design specifications is used.

In FIG. 1, the steel column block 16 is shown by imaginary lines in order to clearly show each configuration, but actually, it is welded to the upper diaphragm 13 as shown in FIGS. ing. In each figure, the box joint 12
Although the example of the T-shaped joint in which the beam bracket 15 is attached to the three side surfaces is shown, it goes without saying that a cross-shaped beam joint can be configured like a general inner pillar. At this time, the details of the connection of the beam bracket 15 on the beam joining side are not shown for the sake of simplicity of the drawing, but can take a known shape.

As shown in FIGS. 1 and 3, a concrete filling hole 13a is formed in the center of the upper diaphragm 13. Internal concrete is poured into the box joint 12 through the concrete filling hole 13a. In addition, air vent holes (not shown) are formed at the four corners of the diaphragm to ensure concrete filling.

Further, the box joint portion 12 as a panel zone has a quadrangular shape in plan view, and its side surface is covered with a rectangular tubular closing plate 20 having one side equal to the column outer dimension. The closing plate 20 is a steel plate with ribs. The ribbed steel plate has ribs of a predetermined shape continuously formed on the entire surface of one side, and is bent into a rectangular tube shape such that the surface on which the ribs are located is on the inner surface side. The height of the closing plate 20 is set equal to the web height of the connection part of the beam bracket 15. Since the ribs are arranged on the inner surface side of the closing plate 20, the concrete to be filled in the panel zone is surely integrated with the PCa column 1 and the column main bar 2 under the beam, and the bond between the concrete and the reinforcing bar is split and the reinforcing bar is broken. Prevent pulling out. In the present embodiment, a ribbed steel plate having a thickness of 12 mm is used. However, a steel plate having a thickness that does not deform even under the side pressure of the filled concrete can be used as appropriate.

FIG. 5 is a view showing a PCa pillar and a concrete pillar completed by casting concrete from the steel material assembled state of FIG. 1 in a factory.
It is the schematic perspective view which showed the structure of the joint part structure with a pillar and a beam. To perform concrete casting as shown in the figure,
First, concrete is cast into the box joint 12 from the above-described concrete filling hole 13a in a state where the steel material unit 10 incorporating the joint steel frame 11 at a predetermined position of the column is erected. Further, the steel unit 10 is placed horizontally and the PCa column 1
A mold (not shown) corresponding to the side surface and the top end surface of the PCa member is assembled on the outside of the steel material unit 10 to cast concrete on the entire PCa member. As a result, it is possible to complete a joint structure with high manufacturing accuracy in which the PCa column 1 portion, the joint panel panel portion, and the PCa column top end portion (steel column base portion) are integrated. At this time, the closing plate 20 functions as a side formwork of the joint panel zone, but a normal temporary formwork can be used instead of the closing plate 20.
In this case, it is preferable to design a panel zone that does not consider the confining effect of concrete by the closing plate 20.

In the above description, the so-called diaphragm-penetrating type is used as an example, and the diaphragm attached to the upper and lower ends of the box joint is welded to the beam flange. However, as the column-penetrating type, the diaphragm is placed at the upper flange position of the beam. The beam connection may be welded to the side of the column. Similarly, a stiffener type may be used.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional perspective view showing one embodiment of a beam-column joint structure according to the present invention.

FIG. 2 is a front view of the beam-column joint structure shown in FIG.

FIG. 3 is a plan view of the beam-column joint structure shown in FIG. 1;

FIG. 4 is a perspective view showing the overall shape of a joint steel frame.

FIG. 5 is a perspective view showing a shape of a column-beam joint structure in a completed state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Precast concrete column (PCa column) 2 Column main reinforcing bar 4 Reinforcing bar fixing plate 10 Steel unit 11 Joint section steel frame 12 Box joint section 13, 14 Diaphragm 13a Concrete filling hole 15 Beam bracket 16 Steel column block 20 Closure plate

Claims (4)

[Claims] In a beam-column joint structure of a transitional floor of a mixed structure in which a lower floor is a precast reinforced concrete structure and an upper floor laminated on the lower floor is a steel frame structure, a steel column of the transition floor is erected. A beam-column joint structure, wherein a beam-column joint portion of the steel structure of the transition floor is integrally buried at a predetermined position near a top end of the column block concrete of the precast reinforced concrete structure. 2. The beam-column joint of the steel structure comprises a box joint, a connection of a steel beam block is joined to a side surface of the box joint, and a steel frame is attached to a diaphragm attached to an upper surface of the box joint. The column-beam joint structure according to claim 1, wherein the column block is erected. 3. The beam-column joint structure according to claim 2, wherein the box joint portion is filled with concrete. 4. The method according to claim 1, wherein the box joint is surrounded by a closing plate substantially equal to an outer dimension of the precast reinforced concrete column block, and concrete is filled between the closing plate and the box joint. The column-beam joint structure according to claim 2 or 3, wherein: