JPH02144435A - Vibration-resistant reinforcing construction for opening of reinforced concrete structure - Google Patents

Abstract

PURPOSE:To improve vibration resistivity by providing a bracing member to a frame member constructed closely fitting to the inner peripheral surface of an opening of reinforced concrete structure, and by cutting a part of column's main reinforcements at least at one end of the columns, making the cut-out part left without being filled up. CONSTITUTION:To the inner peripheral surface of an opening 3, surrounded by reinforced concrete columns 1 and beams 2, a frame member 5 is constructed closely fitting to the surrounding members. Webs of the upper and lower horizontal frames of the frame member 5 are reinforced respectively at its center (for the upper frame) and at the opposite ends (for the lower frame) with stiffeners 6. The upper horizontal frame of the frame member 5 is further equipped with a shearing panel 7, which is fixed to and hung down from the center of the frame. Then braces 8, erected up in the diagonal directions from each of the opposite ends of the lower horizontal frame, are connected and fixed to the hung-down lower end of the panel 7. Notches are then made at the outer side of upper and lower ends of each of the columns at its upper and lower ends, and the notches are left open without making filling-ups thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an earthquake-resistant reinforced structure that improves the earthquake-resistant performance of an opening in a reinforced concrete (RC) building frame.

(Conventional technology) When constructing a building with reinforced concrete, the cross-sectional area of columns and beams was increased in order to improve seismic performance. Also, earthquake-resistant walls were installed. However, increasing the cross-sectional area of columns and beams reduces the living space and increases the weight. On the other hand, since shear walls do not have high toughness, the weight increases due to the need to increase their strength.While particular attention was paid to reinforcing the openings in the shear walls, a reinforcement method with high toughness was expected. In addition, in the case of earthquake-resistant walls, the openings are blocked by the earthquake-resistant walls, making it difficult to use due to the lack of openings. This is because providing an opening in a seismic wall reduces reinforcement efficiency.

Therefore, recently, for example, a rectangular steel frame member that abuts and engages with the inner circumferential surface of a column/beam frontage, and a roughly central portion of the other side that is opposite both ends of any one side of the rectangular steel frame member. A toughness resistance type seismic reinforcement structure consisting of a protruding steel bundle or a steel brace extending diagonally to the end of a steel pole has been proposed.

In other words, the brace and shear panel constitute a Y-shaped toughness resistance type brace within the square frame, and the square frame members distribute stress to reduce damage to the RC frame and the joint between the frame member and the RC frame. In addition, by increasing the strength and rigidity of the braces sufficiently, damage will be concentrated on the shear panels when subjected to excessive seismic force.

Shear panels can have adequate strength and high toughness to buckle before frame members and braces, so shear panels can absorb a large amount of energy during an earthquake, reduce the building's response deformation, and improve the structure of the building. It functions as a damper to reduce damage, so it has a vibration damping effect.

(Problem to be solved by the invention) However, the advantage of this type of seismic reinforcement structure, such as the toughness resistance type seismic reinforcement structure as described above, that is, the toughness resistance type steel brace as exemplified in the prior art, is that the toughness performance is Due to their height, the existing RC columns were required to have high toughness in order to utilize their advantages to the maximum efficiency.

The present invention has been made in view of the above circumstances, and its purpose is to enable a column to follow the deformation of a toughness resistance type seismic reinforcement structure applied to an opening while maintaining axial force,
An object of the present invention is to provide an earthquake-resistant reinforced structure for an opening in an RC building that can make maximum use of the high toughness of the reinforced structure.

(Means for Solving the Problems) In order to achieve the above object, the seismic reinforcement structure of an RC opening according to the present invention provides a frame portion that is configured in close contact with the inner peripheral surface of an existing RCC closed opening surrounded by columns and beams. A brace has been set up within the company;
In a structure in which the frame member and the brace constitute a toughness-resistant seismic reinforcement structure, a part of the main column reinforcement of the column is cut off at least at one end of the column, and the cut portion is left as a void without being filled. It is. In addition, when using the column without damage, a brace is provided inside the frame that is configured in close contact with the inner circumferential surface of the existing RCC closed opening surrounded by the column and beam, and the frame member and the brace are used to form a tough resistance type. In those that constitute an earthquake-resistant reinforcement structure, steel plates or reinforcing fibers such as carbon fibers and aramid fibers are wound around the outer periphery of the columns, or they are tightly attached to the inner peripheral surface of existing RCC closed openings surrounded by columns and beams. In the case where a brace is provided inside the frame, and the frame member and the brace constitute a toughness resistance type seismic reinforcement structure, the single vertical frame member attached to the column among the frame members is Use something that has an axial force that can bear the axial force that the column originally bears.

(Function) With the above configuration, in any case, the ability of the column at the opening to follow the behavior of the toughness-resistant earthquake-resistant structure is improved, and the toughness of the H-resistant structure can be efficiently utilized.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Note that the same reference numerals in FIGS. 1 to 3 refer to the same items or members.

FIG. 1 shows a case where a toughness-resistant steel frame seismic structure 4 is applied to a rectangular opening 3 surrounded by reinforced concrete (RC) columns 1 and beams 2.

A frame member 5 as a stress transmitting material is constructed by assembling H-shaped steel into a similar shape smaller than the opening 3. The central part web of the upper horizontal frame located on the upper side of the frame member 5 and the both end part webs of the lower horizontal frame located on the lower side are reinforced with stiffeners 6. Furthermore, a shearing panel 7 is hung down and fixed to the center of the lower horizontal frame of the frame member 5, and braces 8, which stand up diagonally upward from both ends of the lower horizontal frame, are connected and fixed to the hanging ends of the shearing panel 7. There is.

In the steel-frame seismic structure 4 having the above configuration, the braces 8 are not directly connected in a "V" shape within the frame member 5, but are formed in a reverse rYJ shape through bundled shear panels 7. Improves toughness with elasticity. Note that when installing this steel-frame earthquake-resistant structure 4 into the opening 3, the pillar 1. After driving an anchor into the thread 2 and attaching a stud to the outer peripheral surface of the frame member 5, the frame member 5 is placed in the opening 3, and the anchor in the opening 3 and the frame member 5 are attached.
Non-shrinkage mortar, etc. is placed between the studs on the outer periphery to complete the installation.

Cutouts 9 are provided outside the upper and lower ends of the pillar 1-1. The position of this notch 9 may be on the inside or the entire surrounding area, but it must be within the range that takes into consideration the axial strength of the column, and the position of the notch 9
is formed when cutting the main column reinforcement 10 recently. That is, the notch 9 cuts the recent column main reinforcement 10, and the notch created at that time is left as a gap without being backfilled.

Deformation of the column 1 is allowed at the notch 9, and the column main reinforcement 1
Since 0 is cut, the stress in the column 1 is reduced and the deformation of the steel earthquake-resistant structure 4 is fully followed.

In the embodiment shown in FIG. 2, the frame member 5 is fixed using the thread 2 of the opening 3 in which the steel-based earthquake-resistant structure 4 is housed.

Column 1-1 is made of carbon fiber 11 to reinforce its toughness.
are wound around each other, and in this relationship, the upper and lower horizontal frames of the frame member 5 are fixedly attached to the beams 2-2, respectively.

Therefore, if the beam 2 has sufficient strength, the column 1 will not be damaged, and even if the column 1 is forced to undergo a considerable deformation, sufficient axial force can be maintained by the restraining force of the carbon fibers 11. Therefore, together with the action of the frame member 5, the column 1 of the opening 3. The beam 2 is able to sufficiently follow the deformation of the steel-based earthquake-resistant structure 4.

FIG. 3 shows still another embodiment, in which when the beam 2-2 does not have sufficient strength and it is impossible to damage the column 1-1 as shown in FIG. The frame 12-12 is set as follows.

That is, the vertical frame 12 is strong enough to bear all the axial force borne by the columns.

As a result, since the vertical frames 12-12 are strong, the pillars 1 are difficult to break, and even if they are destroyed, the vertical frames 12 can bear the axial force, so the building will not collapse.

(Effects) As explained in detail above, in the seismic reinforcement structure of an opening in an RC building according to the present invention, the toughness of the column facing the opening can be improved by reinforcing carbon fiber or the vertical frame of the frame member, etc. Therefore, it is possible to integrate the behavior of the toughness resistance type seismic reinforcement structure, and it is possible to fully utilize the performance of this type of earthquake resistance reinforcement structure.

[Brief explanation of the drawing]

FIG. 1 is a front view illustrating an earthquake-resistant reinforcement structure for openings in RC construction according to the present invention, FIG. 2 is a front view illustrating another earthquake-resistant reinforcement structure, and FIG. 3 is a front view illustrating yet another earthquake-resistant reinforcement structure. It is a front view. 9...Notch 11...Carbon fiber 10...Column main reinforcement 12...Vertical frame

Claims (3)

[Claims] (1) A brace is provided in a frame member that is closely attached to the inner circumferential surface of an existing RC opening surrounded by columns and beams, and the frame member and the brace constitute a toughness-resistant seismic reinforcement structure. An earthquake-resistant reinforcing structure for an opening in an RC building, characterized in that a part of the main column reinforcement of the column is cut off at least at one end of the column, and the cut portion is left as a void without being filled. (2) A brace is provided in a frame member that is closely attached to the inner circumferential surface of an existing RC opening surrounded by columns and beams, and the frame member and the brace constitute a toughness-resistant seismic reinforcement structure. An earthquake-resistant reinforcement structure for an opening in an RC building, characterized in that a steel plate or reinforcing fibers such as carbon fibers and aramid fibers are wound around the outer periphery of the pillar. (3) A brace is provided within a frame member that is closely attached to the inner circumferential surface of an existing RC opening surrounded by columns and beams, and the frame member and the brace constitute a toughness-resistant seismic reinforcement structure. , an RC opening characterized in that a single vertical frame member attached to the column among the frame members has an axial force strength capable of bearing the axial force originally borne by the column. seismic reinforcement structure.