JP3185681B2 - Boundary beam structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a boundary beam sandwiched between multi-story shear walls in a reinforced concrete building, and more particularly to a technology for giving the boundary beam a function of effectively absorbing large seismic energy. .

[0002]

2. Description of the Related Art In designing a reinforced concrete building, as shown in FIG. 1, by adopting a multi-story earthquake-resistant wall 1, the shear force borne by other members is reduced, and the span is increased. There is a method of making the thickness narrower. In this case, two adjacent multi-story shear walls 1 are connected by some boundary beams 2, and the characteristics of the boundary beams 2 greatly affect the seismic performance of the entire building.

[0003]

SUMMARY OF THE INVENTION A multi-story shear wall 1 of this kind
In a high-rise or super-high-rise building in which the boundary beam 2 and the boundary beam 2 are used as seismic elements, as shown in FIG. 1, the bending deformation of the boundary beam 2 becomes extremely large during a large earthquake. It is theoretically possible to utilize this characteristic positively and to absorb seismic energy by yielding the boundary beam 2 prior to other members during a large earthquake, thereby preventing damage to other members. .

However, hitherto, a structure of a boundary beam capable of appropriately absorbing large seismic energy has not been developed, and a large earthquake has often been unable to absorb seismic energy, resulting in insufficient strength.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a structure in which a boundary beam sandwiched between multi-story shear walls has a large seismic energy absorbing ability. .

[0006]

Therefore, according to the present invention, a plurality of independent beams are arranged in close contact with each other as a boundary beam sandwiched between multi-story shear walls, and the collection of these independent beams is performed .
The characteristics of coalescing are changed from strength type shearing type to toughness type bending type.
Due to the increase in shear deformation, the binding force is lost
It was restrained integrally with restraint means to be.

As the restraining means, a metal plate is applied to the side surface of the aggregate of the independent beams, and the metal plate is fixedly fastened to each of the independent beams with bolts or the like. The aggregate of the independent beams is impregnated with plastic. Tied with the high-strength fiber thus formed, covering the aggregate with an FRP jacket, providing a cotter on the joint surface between the independent beams, and bonding the independent beams via an adhesive layer, as appropriate. . Here, or can be implemented in appropriate combination.

[0008]

FIG. 2 shows a first embodiment of the present invention. One unit of boundary beam 2 connecting two adjacent multi-story shear walls 1 is composed of three independent beams 2a
b · 2c. Each independent beam 2a ・ 2b ・ 2c
Are arranged above and below, and their upper and lower surfaces are in contact with each other. The independent beams 2a, 2b, 2c are made of a reinforced concrete structure, a steel reinforced concrete structure, or a filled steel pipe concrete structure.

An iron plate 3 is applied to both side surfaces (vertical surfaces) of a set of three independent beams 2a, 2b, 2c, and
The iron plate 3 is fastened to the beam assembly by fastening with bolts 4 provided in the through-hole type or embedded type in 2b and 2c. As shown in FIG. 2, in the central independent beam 2b, the iron plate 3 is fastened by six bolts 4 arranged in the central part. The upper and lower independent beams 2a and 2c are provided with six bolts 4 at both ends thereof to fasten the iron plate 3.

Thus, the three independent beams 2a, 2b, 2
Since c is integrally joined by the iron plate 3 bolted to both sides, this assembly becomes one short span aggregate beam. The short span aggregate beam undergoes shear deformation due to the seismic force, but the same amount of deformation occurs in the iron plate 3 as the deformation, so that the plastic deformation of the iron plate 3 absorbs the seismic force. And
When the plastic deformation of the iron plate 3 proceeds to some extent, the three independent beams 2a, 2b, and 2c cannot be restrained as an integral body by the iron plate 3, so that each of the independent beams 2a, 2b, and 2c bends independently. Slip occurs at the joint surface of each independent beam). In this state, seismic force is absorbed by the bending deformation of each of the independent beams 2a, 2b, 2c. Since the individual independent beams 2a, 2b, and 2c only partially generate the shear cracks generated when they are integrated, they function as bent beams without being subjected to shear failure due to the presence of shear reinforcing bars and the like. Will do.
In other words, as shown in the graph of FIG. 3, the characteristics of the boundary beam of this structure naturally shift from the strength type shearing type to the toughness type bending type, and absorb seismic energy during that time.

FIG. 4 shows a second embodiment of the present invention. Three independent beams 2a, 2b, 2c in which one unit of boundary beam 2 connecting two adjacent multi-story shear walls 1 is in close contact with each other
Is the same as that of the embodiment shown in FIG. In this embodiment, as the restraining means for integrating the assembly of the independent beams 2a, 2b, 2c with an appropriate restraining force, the beam assembly is made of carbon fiber or aramid fiber impregnated with plastic,
The aggregate is covered with an FRP jacket 5 by binding with high-strength fiber such as Kevlar fiber. The FRP jacket 5 functions in the same manner as the iron plate 3 of the embodiment. In other words, the independent beams 2a, 2b, and 2c function as one short span aggregate beam while the integrated restraining force by the FRP jacket 5 is acting, and when the shear deformation increases, the FRP jacket 5 peels or the reinforcing fibers are removed. Break and each independent beam 2a
・ 2b and 2c are bent independently.

FIG. 5 shows a third embodiment of the present invention. Here, a cotter 6 is provided on the joint surface between the independent beams as a restraining means for integrating the aggregate of the independent beams 2a, 2b, 2c with an appropriate restraining force. Before the cotter 6 breaks, each independent beam 2a, 2b, 2c functions as one short span aggregate beam, and when the shear deformation increases, the cotter 6 breaks, and each independent beam 2a, 2b, 2c becomes independent. Bending deformation occurs.

FIG. 6 shows a third embodiment of the present invention. Here, the independent beams are connected via a mortar adhesive layer 7 as a restraining means for integrating the aggregate of the independent beams 2a, 2b, 2c with an appropriate restraining force. Before the mortar adhesive layer 7 breaks, each of the independent beams 2a, 2b, and 2c functions as one short span collecting beam. When the shear deformation increases, the mortar adhesive layer 7 breaks, and each of the independent beams 2a, 2b.
2c is independently bent and deformed.

[0014]

According to the present invention, while the restraining force of the restraining means is acting normally, the aggregate of the plurality of independent beams functions as one short span beam, and the shear deformation increases to increase the restraining means. When the restraining force is lost , each independent beam bends independently. Therefore, the boundary beam of this structure naturally shifts from the strength type shearing type to the tough type bending type, and absorbs seismic energy during that time, and the seismic energy absorbing ability becomes extremely large.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a building having a multi-story earthquake-resistant wall and a boundary beam as earthquake-resistant elements.

FIG. 2 is a configuration diagram of a boundary beam according to the first embodiment of the present invention.

FIG. 3 is a graph showing seismic energy absorption characteristics of a boundary beam according to the structure of the present invention.

FIG. 4 is a configuration diagram of a boundary beam according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram of a boundary beam according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram of a boundary beam according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-layer earthquake-resistant wall 2 Boundary beam 2a ・ 2b ・ 2c Independent beam 3 Iron plate 4 Bolt 5 FRP jacket 6 Cotter 7 Adhesive layer

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuzuru Kobayashi 4-640, Shimoseito, Kiyose-shi, Tokyo Inside the Obayashi Corporation Technical Research Institute (72) Inventor Koichiro Kurisu 4-640, Shimoseito, Kiyose-shi, Tokyo Ltd. Inside the Technical Research Institute (72) Inventor Yoshikazu Utsumi 4-640 Shimoseito, Kiyose-shi, Tokyo Inside Obayashi Corporation Technical Research Institute (56) References JP-A-57-40074 (JP, A) JP-A-5-2955851 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E04H 9/02-9/02 351 F16F 7/12

Claims (5)

(57) [Claims] 1. As a boundary beam sandwiched between multi-story shear walls, a plurality of independent beams are arranged in close contact with each other,
The assembly of these independent beams is changed from the strength type shear type to the tough type
To increase the shear deformation to transfer the characteristics to
The structure of the boundary beam, wherein the structure is integrally restrained by a restraining means whose binding force is lost . 2. The boundary according to claim 1, wherein a metal plate is applied to a side surface of the aggregate of the independent beams, and the metal plate is fastened and fastened to each independent beam by a bolt or the like. Beam structure. 3. The boundary beam as claimed in claim 1, wherein the aggregate of the independent beams is bound with high-strength fibers impregnated with plastic, and the aggregate is covered with an FRP jacket. Construction. 4. The structure of a boundary beam according to claim 1, wherein a cotter is provided on a joint surface between the independent beams as the restraining means. 5. The structure of a boundary beam according to claim 1, wherein said independent beams are connected via an adhesive layer as said restraining means.