JP5419522B2 - Seismic reinforcement structure for openings in existing RC rigid frame structures - Google Patents

Description

  The present invention relates to seismic reinforcement technology for existing RC rigid frame structures. In particular, the present invention relates to a seismic reinforcement structure for openings such as doorways and windows in the existing RC rigid frame structure.

  As an anti-seismic reinforcement technique for this type of existing RC rigid frame structure, there is widely known an anti-seismic reinforcing method in which a steel frame using a shaped steel brace is attached to a window of an existing RC rigid frame structure to reinforce an opening. However, in the case of this conventional seismic reinforcement method, there is a drawback that the opening is blocked by the braces of the shape steel. Therefore, seismic reinforcement technology has been developed in which H-shaped steel frames are attached to existing columns and existing beams located on the outer wall surface, and braces are not provided in the frame formed by that. Reference 1). However, in the case of this prior art, a large amount of steel material is required, and there is a troublesome problem that the material cost increases and the amount of construction work increases.

  Furthermore, as a seismic reinforcement technology for openings such as doorways and windows, a technology for seismic reinforcement by attaching vibration-proof reinforcement hardware with deformed parts at the joints between the pillars and beams at the four corners of the openings has been developed. (Patent Document 2). 5 and 6 are a partially enlarged view and a cross-sectional view taken along the line A-A showing the vibration-damping reinforcement hardware when the deformed portion disclosed in Patent Document 2 is bent and formed in a bellows shape. As shown in FIG. 6, the conventional vibration-damping reinforcement hardware 101 bent in a bellows shape is applied to the joint between the column 102 and the beam 103. As shown in FIG. A bending shape is employed in which the length H is constant over the entire length of the bending line L, and the bending angle θ gradually increases from the side closer to the inner corner C of the joint toward the outside.

  However, the bent shape in which the height H of the bent portion is constant and the bent angle θ gradually increases outward as in the vibration-damping reinforcement metal fitting 101 is not easy to process the bent shape itself. There was a big difficulty. Further, in the case of this conventional vibration-damping reinforcement hardware 101, on the one hand, the bending angle θ gradually increases from the side close to the corner C of the joint portion toward the outside, and on the other hand, the in-plane direction generated by an external force such as an earthquake. Since the amount of deformation increases gradually from the side closer to the corner C toward the outside, the difference in the bending angle θ between the corner C side and the outer side increases further, so that the deformation based on the external force is increased. The properties related to the process greatly fluctuate between the side close to the corner C and the outside, and there is a problem in that it affects uniform bending deformation in the bending line direction, and also affects smooth and efficient energy absorption.

JP 2004-169504 A JP 2002-235457 A

  The present invention solves the above-mentioned problems of the prior art, and provides an anti-seismic reinforcement technology for openings in existing RC rigid frame structures that is effective in reducing the amount of steel used and, in turn, reducing material costs and construction work. The purpose is to do. It is another object of the present invention to provide a seismic reinforcement technology capable of realizing a more uniform deformation at a deformed portion with respect to an external force such as an earthquake and obtaining smoother and more efficient energy absorption.

In order to solve the above-mentioned problems, the present invention provides a deformed part by bending the middle part into a bellows-like shape at the four corners of a rectangular frame-shaped steel frame that can be installed in an opening part of an existing RC rigid frame structure. The vibration-damping reinforcement hardware is attached through the attachment parts on both sides, and the opening is reinforced with anti-vibration reinforcement by the vibration-damping reinforcement hardware provided at the four corners of the rectangular steel frame. Further, the deformed portion of the intermediate portion of the vibration-damping reinforcement hardware is alternately bent along a plurality of bending lines extending radially from the inner corner of the steel frame to form a bellows shape. The bend angle at each bend is approximately constant over the entire length of the bend line, and the height of each bend gradually increases from the side closer to the corner toward the outside. that having a characteristic in that was realized seismic reinforcement structure capable of efficient energy absorption.

According to the present invention, the following effects can be obtained.
(1) Since it was constructed so as to be seismically reinforced using a rectangular frame-shaped steel frame provided with damping reinforcement hardware at the four corners, the seismic reinforcement of the opening can be performed without blocking with braces.
(2) The rectangular frame-shaped steel frame can be efficiently reinforced with anti-seismic reinforcement by means of vibration-damping reinforcement hardware provided at the four corners. It is possible to reduce material costs and construction work volume by reducing.
(3) By making the bending angle at each bending portion of the vibration-damping reinforcement hardware substantially constant over the entire length of the bending line, the shape is simplified and the manufacture is facilitated.
(4) Further, by constructing the height of the bent portion so as to gradually increase from the side closer to the inner corner of the joint portion toward the outside, the amount of deformation in the in-plane direction caused by an external force such as an earthquake is reduced. Since the influence on the bending angle derived from gradually increasing from the side closer to the corner to the outside is mitigated and the fluctuation of the bending angle with respect to the bending line direction is suppressed, a more uniform bending deformation becomes possible and smoother. Efficient energy absorption is obtained.

It is principal part explanatory drawing which showed 1st Example of this invention. It is the expansion perspective view which showed the steel frame. It is the expansion perspective view which showed the vibration suppression reinforcement metal fitting. It is principal part explanatory drawing which showed 2nd Example of this invention. It is the elements on larger scale which showed the conventional vibration suppression reinforcement metal fitting. It is AA sectional drawing of FIG.

  The seismic reinforcement structure according to the present invention can be widely applied as a seismic reinforcement means for openings in existing RC rigid frame structures. The steel frame used in this seismic reinforcement structure may be in a form that fits into a space in an opening of an existing RC rigid frame structure, or may be in a form that is attached outside the opening. In addition, the vibration-damping reinforcement hardware installed at the four corners of the steel frame is made of steel and has a bellows-like deformed portion in the middle, and the overall planar shape is suitably a fan shape as in the following examples. However, rectangular and square shapes are also possible. The deformed portion of the intermediate portion formed in a bellows shape is formed by alternately bending along a plurality of bending lines extending radially from the corners of the steel frame. In that case, the number of times of alternate bending is an appropriate design matter, and the height and bending angle of the bent portion can also be set appropriately according to the use conditions.

  1 to 3 show a first embodiment of the present invention. In the figure, 1 is an existing RC rigid frame structure, 2 is an opening of the existing RC rigid frame structure 1, and 3 is a steel frame. As shown in FIG. 1, the steel frame 3 in the present embodiment shows a case in which the steel frame 3 is fitted into the opening 2 of the existing RC rigid frame structure 1.

  As shown in FIG. 2, at the four corners of the steel frame 3, vibration suppression reinforcement hardware 4 that provides a vibration suppression function and a reinforcement function against an external force such as an earthquake is installed. In the present embodiment, a case where two vibration suppression reinforcements 4a and 4b are installed facing each other on the front and back surfaces of each corner of the steel frame 3 is shown.

  FIG. 3 is a perspective view showing the vibration damping reinforcement hardware 4. As shown in the drawing, the vibration damping reinforcement hardware 4 in the present embodiment has a fan-like overall planar shape, and is formed with attachment portions 5 and 6 for fixing to the steel frame 3 on both sides. A deformed portion 7 is formed by bending an intermediate portion between the attachment portions 5 and 6 into a bellows shape. Thus, the vibration-damping reinforcement hardware 4 is fixed to each corner of the steel frame 3 by appropriate fixing means through the mounting holes 8 and 9 formed in the mounting portions 5 and 6, and the deformation portion 7 of the intermediate portion is fixed. The deformation absorbs energy such as earthquakes.

  Next, a specific shape of the deforming portion 7 formed in the middle portion of the vibration damping reinforcement hardware 4 will be described. As illustrated in FIG. 3, the deformed portion 7 of the intermediate portion of the vibration-damping reinforcement hardware 4 includes a plurality of bending lines La˜ that extend substantially radially around a corner C (see FIG. 2) inside the steel frame 3. It is formed in a bellows shape by alternately bending along Lc. The bending angle θ at each of the bent portions is a substantially constant angle over the entire length of the bent lines La to Lc so that the height H of each bent portion gradually increases from the side closer to the corner C toward the outside. It is formed. And the bending angle (theta) in each former bending part was made into the substantially constant angle in the full length of bending line La-Lc, and the shape of the damping reinforcement metal fitting 4 is simplified and manufacture becomes easier. In addition, since the height H of each of the latter bent portions is formed so as to gradually increase from the side close to the corner C toward the outside, the amount of deformation in the in-plane direction caused by an external force such as an earthquake is reduced. Since the influence on the bending angle θ of each bent portion derived from gradually increasing from near to the outer side is alleviated, more uniform bending deformation in the directions of the bending lines La to Lc becomes possible. As a result, the vibration-reinforcing reinforcement hardware 4 capable of absorbing energy more easily and smoothly and efficiently can be obtained together.

  FIG. 4 shows a second embodiment of the present invention. The second embodiment shows a form in which a steel frame 10 is attached to the outside of the opening 2 of the existing RC rigid frame structure 1. As shown in the figure, at the four corners of the steel frame 10, as in the case of the first embodiment, vibration suppression reinforcement hardware 11 is installed, and has a vibration suppression function and a reinforcement function against external forces such as earthquakes. become. And in the case of a present Example, since the construction inside a building is unnecessary, there exists an advantage that it can construct while using a building. Incidentally, the steel frame 10 and the existing RC rigid frame structure 1 are generally joined by using post-installed anchors or studs, but depending on the damping function and the reinforcing function of the damping reinforcement hardware 11. Since the proof stress of the steel frame 10 can be small, the number of post-installation anchors and studs can be reduced.

  1: Existing RC frame structure, 2: Opening portion, 3: Steel frame, 4: Damping reinforcement hardware, 5, 6: Mounting portion, 7: Deformation portion, 8, 9: Mounting hole, 10: Steel frame, 11 : Damping reinforcement hardware, C: Corner, La to Lc: Bending line, θ: Bending angle, H: Bending height

Claims (1)

At the four corners of the rectangular frame-shaped steel frame that can be installed in the opening of the existing RC frame structure, the vibration-damping reinforcement hardware that is bent at both sides and bent into a bellows at the middle is deformed. The opening is an anti-seismic reinforcement structure in an existing RC rigid frame structure that is configured to be anti-seismic reinforced by vibration-damping reinforcement hardware provided at the four corners of the rectangular frame-shaped steel frame. The deformed portion of the middle portion of the vibration-reinforcing hardware is formed in a bellows shape by alternately bending along a plurality of bending lines extending radially about the inner corner of the steel frame, and each of the bent portions. existing RC rigid frame structure that the bending angle is substantially a constant angle in the entire length of the bent wire, wherein the height of each bent portion is configured to gradually increase toward the outside from the side closer to the corner of the Seismic reinforcement structure of the opening in the.

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