JPH03217542A - Jointing construction of steel pipe column and slab in flat slab structure - Google Patents

Abstract

PURPOSE:To prevent punching fracture from being generated by arranging reinforcing iron plates on the outer peripery of a crossed section between steel pipes and a slab in a state that the tip sections of the plates pass the dangerous cross-sectional areas of the punching fracture and the side surfaces of the plates are vertically arranged. CONSTITUTION:At positions confronted with a crossed section 1a between the outer peripheral surface 2b of four steel pipes 2a and a slab 3, reinforcing iron plates 5 are arranged via gusset plates 2c. After that, the plates 5 are arranged in a state that the tip sections of the respective reinforcing iron plates 5 are extended outside the steel pipes 2a and pass the dangerous cross-sectional areas CS of the high dangerous property of shear fracture due to shearing stress to be generated on the peripheries of the steel pipe columns of a flat slab structure l. After that, engaging holes 5c are arranged, and they are bored to be matched with each other between the iron plates 5, and inserting reinforcing bars 5d are arranged to be inserted into the holes 5c. As a result, the shearing stress to be generated on the slab 3 on the periphery of the crossed section 1a is effectively supported by the iron plates 5, and the fracture can be previously prevented from being generated.

Description

DETAILED DESCRIPTION OF THE INVENTION (a). INDUSTRIAL APPLICATION FIELD 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 was a risk of shear failure (punching failure) occurring near the joints between columns and slabs, so they were assembled in parallel cross-sections near the critical cross-section where shear failure would occur. Reinforced steel frames were installed to penetrate the columns to provide shear reinforcement.

(C). Problems to be Solved by the Invention However, when steel pipe columns are used as columns, it is difficult to install reinforcing steel frames to penetrate the columns, and there has been a desire for the development of some other method.

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 steel pipe columns as columns. (d). Means for solving the problem, 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)
A reinforcing iron plate (5) is installed around the outer periphery of the intersection with the slab (3), with its tip passing through the critical cross section (CS) of punching failure, and its side (5b) standing vertically. Ru.

Further, the present invention is configured by providing a concrete adhesion member (5d) on the reinforcing iron plate (5).

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 "Effect".

(e). Operation With the above-described configuration, the present invention operates so that the reinforcing iron plate (5) supports 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 between a steel pipe column and a slab in a flat slab structure according to the present invention, and FIG. 2 is a plan view of FIG. 1.

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. It is installed vertically. At the positions corresponding to the intersections 1a of the four outer peripheral surfaces 2b of the steel pipe 2a with the slab 3,
The reinforcing iron plate 5 formed into a strip shape is the gusset plate 2c.
There are 12 sheets in total, 3 sheets each. Each reinforcing iron plate 5 is installed with its side surface 5b vertically erected, and the tip of each reinforcing iron plate 5 extends outward from the steel pipe 2a and is placed around the steel pipe column of the flat slab structure 1. It is installed so that it passes through the critical cross section CS where the risk of shear failure due to the generated shear stress is highest. Also,
Each of the three reinforcing iron plates 5 provided on each side of the steel pipe 2a includes:
As shown in FIG. 1, each of the six engagement holes 5C is
Penetration holes are formed between the reinforcing iron plates 5 in a manner that they align with each other, and insertion reinforcing bars 5d are inserted into the engagement holes 5c so as to communicate between the reinforcing iron plates 5.

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 configuration, the shear stress that leads to shear failure occurring around the steel pipe column 2 is supported by the reinforcing iron plate 5 provided in a manner that passes through the critical cross section CS, and the slab 3. Punching damage is prevented. Since the reinforcing iron plate 5 is installed with its side surface 5b vertically erected, it can exhibit high rigidity against the shearing force generated in the slab 3.

In addition, although the above-mentioned embodiment described the case where a steel plate formed in a rectangular shape is used as it is as the reinforcing iron plate 5, in the present invention, the reinforcing iron plate 5 is installed with its side surface 5b vertically erected. Of course, the shape of the reinforcing iron plate 5 may be any shape as long as it is.

(g). Effects of the Invention As explained above, according to the present invention, the slab 3 is provided,
In a flat slab structure 1 in which a steel pipe column 2 having a steel pipe 2a is erected on the slab 3, a reinforcing iron plate 5 is provided on the outer periphery 2b of the intersection of the steel pipe 2a with the slab 3, and the tip thereof is at risk of punching failure. Passing through the cross section CS and its side 5
b is provided vertically, so 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 iron plate 5. It is possible to prevent punching damage from occurring.

In addition, since the reinforcing iron plate 5 is lighter than a steel frame, it is extremely easy to handle and install, and the reinforcing iron plate 5 can stand on its own simply by attaching it to the steel pipe 2a, so it is a special temporary material. It is also possible to eliminate the need for a stopping means.

In addition, since the reinforcing iron plate 5 is a plate-shaped member, the reinforcing iron plate 5 does not block the slab part around the column-slab intersection 1a unlike when a reinforcing steel frame is used, and the slab 3 part and Obstacles to the flow of concrete poured at the intersection 1a should be prevented as much as possible, and the fillability of the concrete in the column-slab intersection 1a and its surroundings should be maintained in a good condition when concrete is poured. The construction is highly reliable.

Furthermore, if a member for adhering concrete such as reinforcing bars 5d is provided on the reinforcing iron plate 5, the adhesion between the concrete placed in the slab 3 and the reinforcing iron plate 5 can be maintained in a good state.

[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, 1...Flat slab structure 1a...Intersection 2. ... Steel pipe column 2a ... Steel pipe 2b ... Outer periphery 3 ... Slab 5 ... Reinforcement iron plate 5b ... Side surface 5d. ...Concrete attachment member (inserted reinforcing bar) CS...Dangerous cross section

Claims (2)

[Claims] (1) In a flat slab structure having a slab and a steel pipe column having a steel pipe erected on the slab, a reinforcing steel plate is provided around the outer periphery of the intersection of the steel pipe with the slab, and the tip thereof is resistant to punching failure. A joint structure between a steel pipe column and a slab in a flat slab structure that passes through a dangerous cross section and has its sides vertically erected. (2) A joint structure between a steel pipe column and a slab in a flat slab structure according to claim 1, which is constructed by providing a concrete adhesion member on a reinforcing iron plate.