JP2003090143A - Boundary beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boundary beam capable of rationally restricting vibration in an RC structure without prohibiting space in a building. SOLUTION: In this boundary beam 1, a plurality of X-shaped bar arrangements 2 each comprising two flat bars 3 combined with each other in an X-form are disposed in parallel in a beam width direction. The X-shaped bar arrangement is disposed in such a way that an intersection of the two flat bars 3 combined in the X-form is positioned to a center point A in a cross section as the boundary beam 1 is seen in a horizontal direction. Its end part is contained in an adjacent RC core wall 7 on which the boundary beam 1 is stretched, and the X-shaped bar arrangement is rigidly coupled with the RC core wall 7. On an end part of the flat bar 3, a stud dowel 8 is preliminarily mounted to improve fixing strength to concrete 6 composing the RC core wall 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boundary beam capable of rationally suppressing vibration in a steel frame structure without obstructing the space inside the building.

[0002]

2. Description of the Related Art At present, a seismic control structure is attracting attention as a technology for reducing damage during an earthquake, and various energy absorbing devices (hereinafter referred to as seismic control dampers) have been developed, and most of high-rise buildings have been developed. Has been adopted by. However, many damping dampers are used for braces, walls, and studs that are effective for interlayer displacement, and dampers that do not obstruct space are required.

Under such circumstances, a method of incorporating a damper function into a large beam and eliminating the need for an extra vertical member has been studied. This method is intended to function as a damper by incorporating a shear-yield part conventionally used for a stud into a part of a beam and effectively absorbing energy. As an example thereof, a structure is generally adopted in which the reinforcing bars constituting the girder are laid out in an X shape, and a plurality of sets of these X type reinforced bars are arranged in parallel and filled with concrete to form a boundary beam.

[0004]

However, such an X
In the structure in which multiple sets of type reinforcements are arranged in parallel in the width direction of the boundary beam, the width of the boundary beam becomes large, and it becomes necessary to set the interval of the main bars of the column that houses the boundary beam larger than usual. Poor workability. Further, the boundary beam using the X-shaped bar is apt to be cracked in the concrete portion when an earthquake or the like occurs, and repair is difficult.

In view of the above circumstances, it is an object of the present invention to provide a boundary beam having a narrow beam width, good workability, and an X-shaped bar arrangement having a vibration damping function.

[0006]

The boundary beam according to claim 1 is a short span boundary beam having a vibration damping function, and a plurality of the boundary beams are arranged in parallel to the width direction of the boundary beam, and the ends are housed in the column. It is characterized in that it is composed of X-shaped bar arrangement by the flat bar thus formed and concrete in which the X-shaped bar is buried.

The boundary beam according to claim 2 is characterized in that the flat bar is unbonded to the concrete.

The boundary beam according to a third aspect of the present invention is characterized in that the flat bars constituting the plurality of X-shaped bar arrangements are made of different steel materials for each X-shaped bar arrangement and are combined. .

A boundary beam according to a fourth aspect of the invention is characterized in that a projecting member is attached to an end portion of the X-shaped bar arranged in the column.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A boundary beam according to the present invention will be described below with reference to FIGS.

The boundary beam 1 in the present invention is used in a building using an RC core wall 7 found in, for example, a super high-rise RC housing as shown in FIG. The boundary beam 1 is a RC span wall, a column and an RC core wall 7, or a short span beam spanned between columns.
The boundary beam 1 in the present invention can be applied between columns as long as it is a short span beam, and is not limited to a building using an RC core wall.

As shown in FIG. 1 (a), the boundary beam 1 is provided with a plurality of X-shaped bar arrangements 2 arranged so that their surfaces are oriented in a direction perpendicular to the vertical axis, and the X-shaped bar arrangements. A plurality of main reinforcements 4 are provided around the periphery of the base 2, and concrete 6 in which the main reinforcements 4 and the X-shaped reinforcement 2 are embedded.

The X-shaped rebar 2 is a combination of two rebars in an X shape, and connects adjacent RC core walls 7 and is arranged with its surface oriented in a direction perpendicular to the vertical axis.
Here, the flat bar 3 is applied instead of the reinforcing bar used for the X-shaped bar arrangement 2. The flat bar 3 is a bar-shaped steel material and has a smaller cross section than a bar steel bar having a substantially circular cross section, so that the X-shaped bar 2 does not have a width (Fig. 1 (b)). On the boundary beam 1, the intersection of the two flat bars 3 of the X-shaped bar arrangement 2 which are overlapped in the X shape is located at the center point A in the cross section of the boundary beam 1 viewed from the lateral direction. Are arranged as follows. Further, the end portion of the flat bar 3 is housed inside the adjacent RC core walls 7 on which the boundary beam 1 is bridged, and the X-shaped bar arrangement 2 is rigidly connected to the RC core wall 7. Has become. Here, a stud dowel 8 is attached in advance to the end portion of the flat bar 3 as a projecting member, and has a structure for increasing the fixing strength with the concrete 6 forming the RC core wall 7. The protrusion member is not limited to this, and any member having a function of increasing the fixing strength with the concrete 6 may be used. As shown in FIG. 3, if the pressure bearing plates 9 are attached to both surfaces of the end portion of the flat bar 3, the fixing strength can be further enhanced.

If the short-span boundary beams 1 are continuous in the lateral direction, as shown in FIG. 4 (a), the X-shaped bar arrangement 2 beams arranged on the adjacent boundary beams 1 respectively. The positions in the width direction are shifted back and forth, and the ends are arranged so as to be coaxial with each other in the beam width direction without touching each other. As shown in FIG. It may be housed in the RC core wall 7 after being sandwiched between the end portions and connected to each other.

The flat bar 3 is made of asphalt, Teflon (registered trademark), plastic, or the like by applying a paint for preventing adhesion with the concrete, except for the end portion embedded in the RC core wall 7. It is processed and has a so-called unbonded structure in which frictional resistance does not occur between the boundary beam 1 and the concrete 6 constituting the boundary beam 1.

In the embodiment of the present invention, three sets of such X-shaped bar arrangements 2 are arranged in the beam width direction of the boundary beam 1, but the number is not limited to this, and a plurality of parallel bars are arranged. You may arrange in. In addition, for example, among the three types of X-shaped bar arrangement, different types of steel materials may be arranged such that one set is ultra-soft steel, one set is ordinary steel, and one set is high-strength steel.

As shown in FIG. 2, the X-shaped bar 2 in which a plurality of these sets are arranged in parallel is covered with a main bar 4 and a stir bar 5. Main muscle 4 and stirrup muscle 5
Is made of a commonly used steel bar, and the main bars 4 are adjacent to each other in the direction of bridging the RC core walls 7 adjacent to each other, with the same spacing as the X-shaped bars 2 arranged in parallel. They are arranged so as to be located between the bar arrangements 2.

The end portion of the main bar 4 is embedded inside the RC core wall 7 like the end portion of the flat bar 3. Further, the ribs 5 are arranged vertically so as to surround the main muscles 4. These are embedded in concrete 6 to form the boundary beam 1, and the boundary beam 1 and the RC core wall 7 are rigidly fastened by the concrete 6.

According to the above-mentioned structure, since the X-shaped bar 2 is formed by using the flat bar 3, the beam width is reduced because the X-shaped bar 2 itself does not have a width. Is possible. As a result, also for the RC core wall 7 provided with the boundary beam 1 to which the X-shaped bar arrangement 2 is applied,
There is no need to take measures such as taking a large gap between the main bars.

The material of the flat bar 3 used for the X-shaped bar 2 may be steel, and a plurality of sets of X-shaped bar 2 made of different kinds of steel may be combined to form the boundary beam 1.
Since the reinforcement may be arranged inside, the performance of the damper required for the boundary beam 1 can be controlled according to the situation by these combinations.

[0021]

According to the boundary beam of the first aspect of the present invention, in a short span boundary beam having a vibration damping function, a plurality of boundary beams are arranged in parallel to the width direction of the boundary beam, and the ends are housed in the column. The beam width of the boundary beam can be reduced because the X-shaped bar itself does not have a width because it is composed of the X-shaped bar by the flat bar and the concrete in which the X-shaped bar is embedded. It will be possible. As a result, it is not necessary to take a large distance between the main bars even for the column provided with the boundary beam to which the X-shaped bar is applied.

According to the boundary beam of the second aspect, since the flat bar is unbonded with respect to the concrete, it is possible to improve the performance of the boundary beam as a damper during a large earthquake. At the same time, it is possible to obtain a high quality boundary beam in which the amount of cracks that are likely to occur in the boundary beam is small.

According to the boundary beam of the third aspect, since the X-shaped reinforcing bar is a combination of flat bars made of different steel materials, the boundary beam using the X-shaped reinforcing bar excellent in energy absorption capacity at the time of earthquake is It becomes possible to do.

According to the boundary beam of claim 4, the X
Since the stud dowel is attached to the end portion of the type reinforcement arranged in the column, it becomes possible to enhance the anchoring strength between the X type reinforcement and the concrete constituting the column, and eventually the boundary. It is possible to increase the bonding strength between the beam and the column.

[Brief description of drawings]

FIG. 1 is a diagram showing details of a boundary beam according to the present invention.

FIG. 2 is a diagram showing a perspective view of a boundary beam according to the present invention.

FIG. 3 is a diagram showing an example of an end portion of an X-shaped bar arrangement of a boundary beam according to the present invention.

FIG. 4 is a diagram showing an example of an end portion of an X-shaped bar arrangement of a boundary beam according to the present invention.

FIG. 5 is a diagram showing an example of installation positions of boundary beams according to the present invention.

[Explanation of symbols]

1 boundary beam 2 X type bar arrangement 3 flat bar 4 main lines 5 stirrups 6 concrete 7 RC core wall 8 Stud Gibel 9 bearing plate

Front page continued (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16F 15/02 F16F 15/02 L

Claims (4)

[Claims] 1. A short span boundary beam having a vibration damping function, wherein a plurality of boundary beams are arranged parallel to the width direction of the boundary beam.
A boundary beam comprising an X-shaped bar arrangement having a flat bar whose end is housed in a column, and concrete burying the X-shaped bar. 2. The boundary beam according to claim 1, wherein the flat bar is unbonded to the concrete. 3. The boundary beam according to claim 1, wherein a plurality of the flat bars constituting the X-shaped bar arrangement are arranged,
A boundary beam made of different steel materials for each X-shaped bar and combining these. 4. The boundary beam according to claim 1, wherein the X
A boundary beam, wherein a projecting member is attached to an end portion of the type reinforcement arranged in the column.