JPH07238637A - Steel/concrete composite structure having perforated stiffening steel plate - Google Patents

Abstract

PURPOSE:To provide a strong steel/concrete composite structure with a simple constitution. CONSTITUTION:In a concrete-filled steel/concrete composite structure in which concrete has been filled inside its steel shell, perforated stiffening plates 2 having a plurality of concrete-filling holes 1 are arranged and fixed inside a steel shell 4 constituting a composite structure 3 so as to be extended in the longitudinal direction of the steel shell. Then, concrete 5 is filled inside the steel shell 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel / concrete composite structure having a perforated stiffening steel plate used as a columnar structure such as a building, a bridge or an artificial ground support structure.

[0002]

2. Description of the Related Art Conventionally, steel / concrete composite structures have been described in “Synthetic bridge piers and their calculation examples / commentary”, issued on July 20, 1992 by Hyundai Science and Engineering Publishing Co., Ltd. Pages 44 and 45, Appendix-3. As described in "Detailed drawing of pier (No. 2)", a plurality of strip-shaped steel plates extending in the longitudinal direction of the steel shell are fixed to the inner surface of the steel shell constituting the columnar structure, and the strip-shaped steel plates are fixed to each other. A structure having a steel shell filled with concrete is known, that is, in the case of the conventional steel-concrete composite structure, as shown in Fig. 9, in order to suppress local buckling of the steel shell 4. In addition, a strip steel plate called a stiffening steel plate is vertically welded to the steel plate of interest in the axial direction of the steel shell 4 to form the steel shell 4
It uses a method to increase the rigidity of the.

[0003]

Even in a composite structure of the type in which the steel shell 4 is exposed to the outside as described above, the strip steel plate 7 is similarly welded on the basis of the same concept as that of a normal steel structure. Are designed to suppress local buckling of the steel shell 4. In the case of a steel structure, the stiffening cross section as shown in FIG. 9 is shown in FIG. 10 when the concrete 5 is filled with the lateral stiffening steel plates (diaphragms) 6 fixed at regular intervals as nodes. When the inside of the steel shell 4 is filled with concrete, the steel plate is not deformed toward the concrete side, and therefore the buckling mode changes as shown in FIG. The buckling strength is higher than that without filling, and the strip-shaped stiffening steel plate 8
Since the mode changes, the buckling strength is higher than when the concrete is not filled, and therefore the strip-shaped stiffening steel plate 8
However, since the strip steel plate 7 comes out of the concrete 5, it is not possible to suppress the buckling mode as shown in FIG. It is necessary to weld the steel plate 8 or reduce the design stress of the steel plate as much as necessary, which causes a problem that the amount of steel material used increases and the welding process cost increases.

[0004]

In order to advantageously solve the above-mentioned problems, in a steel / concrete composite structure having a stiffening steel plate with holes according to the present invention, concrete filling is performed by filling concrete inside a steel shell. In a steel-concrete composite structure of the type, a perforated stiffening steel plate 2 having a plurality of concrete filling holes 1 is arranged on the inner surface of a steel shell 4 constituting the composite structure 3 so as to extend in the longitudinal direction of the steel shell. Then, the steel shell 4 is fixed, and the inside of the steel shell 4 is filled with concrete 5.

That is, in the present invention, as the perforated stiffening steel plate 2, a strip steel plate 9 is provided with a large number of concrete filling holes 1.
A member having is used. The strength of the perforated stiffening steel plate 2 embedded in the concrete 5 against the slipping out of the concrete 5 is usually a steel plate, which is resisted by the frictional force between the steel plate surface and the concrete.
Its resistance is extremely small. However, in the case of a perforated steel plate having the concrete filling holes 1, in addition to the frictional force on the steel plate surface, the concrete filling holes 1 formed in the steel plate
And the interaction of the concrete 5 penetrating the concrete filling hole 1 resists the escape. According to the research conducted by the present inventors, when the force that restrains the concrete 5 from moving in the direction perpendicular to the hole acts on this resistance force, the withdrawal resistance force jumps in accordance with the constraint force. It has been experimentally confirmed to increase.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 4 and 5 are perforated stiffening steel plates 2 and shear reinforcing steel plates 10 used in the first embodiment of the present invention.
Showing a steel shell 4 having the following, inside a steel shell 4 of square cross section having four steel plates 11 joined together,
A plurality of shear reinforcing steel plates 1 having through holes 12 for passage of workers
0 is arranged, and the peripheral edge of each shear reinforcing steel plate 10 is fixed to each steel plate 11 of the steel shell 4 by welding.
In each steel plate 11 in
A plurality of perforated stiffening steel plates 2 are arranged so as to extend in the longitudinal direction of the steel shell 4, and are arranged so as to be orthogonal to the inner surface of each steel plate 11. It is fixed to the inner surface of each steel plate 11 by welding.

1 to 3 show a steel / concrete composite structure according to a first embodiment of the present invention, which is constructed by filling concrete 5 into a steel shell 4 having the perforated stiffening steel plate 2 and the shear reinforcing steel plate 10. The concrete 5 is filled in a steel shell 4 having the perforated stiffening steel plate 2 and the shear reinforcing steel plate 10, and a part 5A of the concrete 5 is a perforated stiffening steel plate 2 Is also filled in the concrete filling hole 1 in FIG.

FIGS. 6 to 8 show a steel-concrete composite structure having a perforated stiffening steel plate according to a second embodiment of the present invention, wherein a pair of front and rear wide steel plates 11A and a pair of left and right narrow steel plates are shown. The width steel plate 11B is fixed by welding,
A steel shell 4 having a rectangular cross section is configured, and a shear reinforcing steel plate 10 extending in the longitudinal direction of the steel shell 4 is fixed by welding to the central portion of the inner surface of each steel plate 11A, and the shear reinforcing steel plate 1
A plurality of perforated stiffening steel plates 2 extending in the longitudinal direction of the steel shell 4 are fixed to the inner surface of the steel plate 11A divided by 0 by welding, and the inside of the steel shell 4 is filled with concrete 5, The other structure is similar to that of the first embodiment of the present invention.

When the compressive force in the axial direction of the steel shell 4 acts on the steel plate 11 of the steel shell 4, the compressive force usually acts also on the concrete 5 inside the steel shell 4. When a compressive force acts on the concrete 5, the concrete 5 tends to spread laterally according to the Poisson's ratio. As the compressive force of the concrete 5 in the axial direction increases, the Poisson's ratio increases, so the force that tends to spread in the lateral direction increases, and as a result, the force perpendicular to the concrete filling hole 1 in the stiffened steel plate 2 with holes increases. Since the restraining force acts in different directions, the resistance force of the perforated stiffening steel plate 2 against coming out of the concrete 5 is significantly increased. As described above, the resistance of the perforated stiffening steel plate 2 having the concrete filling hole 1 to the escape from the concrete 5 suppresses the occurrence of the buckling mode as shown in FIG.
The local buckling resistance of can be greatly improved.

Next, the operation of the steel-concrete composite structure having the stiffening steel plate with holes of the present invention will be described. The resistance force of the perforated stiffening steel plate 2 embedded in the concrete 5 to the escape from the concrete 5 is resisted by the frictional force between the steel plate surface and the concrete 5 in the case of a normal steel plate, but normally the resistance force is small. However, in the case of the perforated stiffening steel plate 2, in addition to the frictional force on the surface of the steel plate, due to the interaction between the concrete filling hole 1 provided in the steel plate and the concrete 5 penetrating the concrete filling hole 1, Great resistance to getting out.

According to the research conducted by the present inventors, this resistance force is generated when a force that restrains the concrete 5 from moving in a direction perpendicular to the concrete filling hole 1 acts.
It was experimentally confirmed that the resistance to slipping out dramatically increases depending on the binding force. Considering the case where a steel plate having a large number of concrete filling holes 1 as shown in FIG. 3 is used as the perforated stiffening steel plate 2 in the present invention, the perforated stiffening steel plate 2 has a steel shell axial direction. When a compressive force acts on the concrete 5, the compressive force also acts on the concrete 5 in the concrete filling hole 1.

When a compressive force acts on the concrete 5, the concrete 5 tends to spread laterally according to the Poisson's ratio. Since the Poisson's ratio increases as the steel shell axial compressive force of the concrete 5 increases,
The force to spread laterally increases, and as a result,
Since a constraining force acts on the perforated stiffening steel plate 2 in a direction perpendicular to the concrete filling hole 1, the resistance force of the perforated stiffening steel plate 2 against coming out of the concrete 5 is significantly increased. As described above, the resistance of the perforated stiffening steel plate 2 having the concrete filling hole 1 to the escape from the concrete 5 suppresses the occurrence of the buckling mode as shown in FIG. The local buckling resistance of the steel plate 11 that constitutes the shell 4 can be significantly improved.

[0013]

According to the present invention, in a concrete-filled steel / concrete composite structure having a steel shell filled with concrete, a perforated stiffening steel plate 2 having a plurality of concrete-filled holes 1 is used as a composite structure. Steel shell 4 that composes object 3
Since the steel shell 4 is arranged and fixed so as to extend in the longitudinal direction of the steel shell and the inside of the steel shell 4 is filled with the concrete 5, the local buckling of the steel plate 11 constituting the steel shell 4 is achieved by a simple structure. Since the strength can be increased and the local buckling strength of the steel plate 11 constituting the steel shell 4 can be increased, the yield strength of the composite structure can be increased or the amount of steel material used can be reduced. Since the local buckling strength of the steel plate 11 forming the steel shell 4 is large,
The amount of perforated stiffening steel plate 2 used can be reduced, and therefore the amount of steel processed can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a steel / concrete composite structure having a stiffened steel plate with holes according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a cross-sectional plan view showing a part of FIG. 2 in an enlarged manner.

FIG. 4 is a vertical sectional side view showing a steel shell having a shear reinforcing steel plate and a perforated stiffening steel plate used in the first embodiment of the present invention.

5 is a sectional view taken along line BB of FIG.

FIG. 6 is a cross-sectional plan view showing a steel / concrete composite structure having a perforated stiffening steel plate according to the second embodiment of the present invention.

7 is a cross-sectional view taken along line CC of FIG.

FIG. 8 is a cross-sectional plan view showing a part of FIG. 6 in an enlarged manner.

FIG. 9 is a vertical sectional front view showing an example in which a vertical stiffening steel plate is fixed to a conventional base steel plate.

FIG. 10 is a cross-sectional view showing a buckling mode when the conventional stiffening cross-section member is not filled with concrete.

FIG. 11 is a cross-sectional view showing a buckling mode when the conventional stiffening cross-section member is not filled with concrete.

[Explanation of symbols]

 1 concrete filling hole 2 stiffening steel plate with holes 3 composite structure 4 steel shell 5 concrete 6 lateral stiffening steel plate 7 strip steel plate 8 strip stiffening steel plate 9 strip steel plate 10 shear reinforcing steel plate 11 steel plate 12 through hole for worker passage

Claims (1)

[Claims] 1. A concrete-filled steel-concrete composite structure in which a steel shell is filled with concrete, and a stiffening steel plate 2 having perforations having a plurality of concrete-filled holes 1 constitutes a composite structure 3. A steel-concrete composite structure having a perforated stiffening steel plate, which is arranged and fixed to the inner surface of the shell 4 so as to extend in the longitudinal direction of the steel shell, and the inside of the steel shell 4 is filled with concrete 5.