JPH03235848A - Connecting structure of slab to steel pipe pillar in flat slab structure - Google Patents

Abstract

PURPOSE:To prevent generation of panting destruction by providing an engaging means in the periphery of a crossing part between a steel pipe and a slab and a plurality of reinforcing steel bars in the slab in such a manner as passing a hazardous section of the panting destruction in the engaging means. CONSTITUTION:A steel pipe pillar 2, formed of a steel pipe 2a whose section is formed in squared shape, is erected in a vertical direction in a slab 3 constructed in a horizontal direction. Next a bracket 2c is annularly provided in such a manner as horizontally surrounding a steel pipe peripheral surface 2b in an upper part position corresponding to a crossing part 1a where the four peripheral surfaces 2b of the steel pipe 2a are crossed with the slab 3. Further a plurality of engaging holes 2d are filled to penetrate in the bracket 2c. Next, an S-shaped reinforcing steel bar 5, in a shape such that its engaging part 5a is fit-engaged with the engaging hole 2d, is radially provided in such a manner as spreading diagonally downward with the steel pipe 2a serving as the center. Shear stress, correlated to shear destruction generated in the periphery of the steel pipe pillar 2, is supported by the reinforcing steel bar 5.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a joint structure between a steel pipe column and a slab in a flat slab structure in which the reinforcing material is lightweight and easy to construct.

(b), Conventional technology Conventionally, in flat slab structures, there is a risk of shear failure (punching failure) occurring near the joint between the column and the slab. A reinforcing steel frame was installed that penetrated the columns to provide shear reinforcement.

(C) 0 Problems to be Solved by the Invention However, when a steel pipe column is used as a column, it is difficult to install a reinforcing steel frame to penetrate the column, and it has been desired to develop some other method.

SUMMARY OF THE INVENTION In view of the above-mentioned circumstances, an object of the present invention is to provide a joint structure between a steel pipe column and a slab in a flat slab structure using a steel pipe column as a column.

(d) Means for solving the six problems, that is, the present invention has a slab (3), the slab (3)
In a flat slab structure (1) in which a steel pipe column (2) having a steel pipe (2a) is erected, the steel pipe (2a)
The engagement means (2
c), and the engagement means is constructed by providing a plurality of reinforcing reinforcing bars (5) within the slab (3) in a manner that passes through the critical cross section (CS) of punching failure.

Note that the numbers in parentheses are for convenience and indicate corresponding elements in the drawings, and therefore, this description is not limited to the descriptions on the drawings. r (e) below
The same applies to the column ``, action''.

(e) 6 Effects With the above configuration, the reinforcing reinforcing bars (5) of the present invention act to support the shearing force in the slab (3) surrounding the steel pipe column (2).

(f), Example Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a front view showing one embodiment of the joining structure of a steel pipe column and a slab in a flat slab structure according to the present invention, Fig. 2 is a plan view of Fig. 1, and Fig. 3 is a flat slab structure according to the present invention. It is a top view which shows another Example of the joint structure of the steel pipe column and slab in .

As shown in FIG. 1, the flat slab structure 1 has a horizontally constructed slab 3, and the slab 3 has a steel pipe column 2 made of a steel pipe 2a having a square cross section. A bracket 2c is provided in an annular shape horizontally surrounding the steel pipe outer periphery 2b at the upper position corresponding to the intersection 1a of the four outer peripheral surfaces 2b of the steel pipe 2a vertically installed with the slab 3. A plurality of engagement holes 2d are bored through the bracket 2C. In the engagement hole 2d, a reinforcing reinforcing bar 5 formed in an S-shape with a predetermined length is fitted into the engagement hole 2d with a bent engagement portion 5a formed at the tip thereof. As shown in Fig. 2, they are installed radially in the slab 3 with the steel pipe 2a at the center, spreading diagonally downward in Fig. It is installed so as to pass through the critical cross section CS where the risk of shear failure due to shear stress generated around the steel pipe columns of the slab structure 1 is highest.

Although not shown, at the column-slab intersection 1a of the slab 3 and the steel pipe column 2, there are also ordinary reinforcing bars that make up the slab 3.
There are many installed horizontally and perpendicularly to the paper in Figure 1.

Since the flat slab structure 1 has the above-described configuration, the shear stress that leads to shear failure occurring around the steel pipe column 2 is supported by the reinforcing reinforcing bars 5 provided so as to pass through the critical cross section CS, and the slab 3. Punching damage is prevented. Note that the number of reinforcing bars 5 to be installed is based on slab 3.
Since it can be adjusted appropriately according to the shear stress acting on the site, flexible construction is possible to suit the site. That is, it is possible to set a large number of engagement holes 2d of the bracket 2c and selectively install reinforcing bars 5 in the engagement holes 2d according to the needs of the site.
Of course, it is also possible to form the engagement holes 2d in the shape of continuous long holes as shown in FIG. .

In addition, as in this embodiment, steel pipes 2 are provided on both sides 5 of the reinforcing reinforcing bars 5.
Providing engaging portions 5a, 5a with side a.

It becomes possible to install the reinforcing reinforcing bars 5 on site without worrying about the top and bottom of the reinforcing bars 5, and the bar arrangement work can be carried out quickly.

(g) 1 As described in detail, according to the present invention, in the flat slab structure 1 which has a slab 3 and has a steel pipe column 2 having a steel pipe 2a erected on the slab 3, the steel pipe An engagement means such as a bracket 20 is provided on the outer periphery of the intersection of 2a with the slab 3, and a plurality of reinforcing reinforcing bars 5 are provided within the input slab 3 in a form that passes through the dangerous cross section C8 of punching failure. As a result, the shear stress generated in the slab 3 around the intersection 18 between the column 2 and the slab 3 of the flat slab structure 1 is effectively supported by the reinforcing reinforcing bars 5, and the occurrence of punching failure can be prevented. I can do it.

In addition, since the reinforcing reinforcing bars 5 are lighter than steel frames, they are easy to handle, and can be installed simply by engaging the reinforcing bars 5 with the engagement means, so no special temporary fixing means is required. It can be done.

In addition, the reinforcing reinforcing bars 5 do not block the slab part around the column-slab intersection 1a, unlike when reinforcing steel frames are used, and can be placed in the slab 3 part and the intersection 1a. When pouring concrete, pillars and
The concrete filling properties of the slab intersection 1a and its surroundings can be maintained in a good condition, and the construction is highly reliable.

[Brief explanation of drawings]

Fig. 1 is a front view showing one embodiment of the joining structure of a steel pipe column and a slab in a flat slab structure according to the present invention, Fig. 2 is a plan view of Fig. 1, and Fig. 3 is a flat slab structure according to the present invention. It is a top view which shows another Example of the joint structure of the steel pipe column and slab in . 1...Flat slab structure 1a...Intersection 2...Steel pipe column 2a...Steel pipe 2b...Outer periphery (outer peripheral surface) 2c...Engagement means (Bracket) 3...Slab 5...Reinforcement reinforcing bar CS...Dangerous section

Claims (1)

[Scope of Claims] A flat slab structure including a slab and a steel pipe column having a steel pipe erected on the slab, wherein an engagement means is provided on the outer periphery of the intersection of the steel pipe with the slab, and the engagement means A joint structure between a steel pipe column and a slab in a flat slab structure, wherein a plurality of reinforcing reinforcing bars are provided in the slab so as to pass through a cross section at risk of punching failure.