JP3807497B2

JP3807497B2 - Seismic isolation damper

Info

Publication number: JP3807497B2
Application number: JP2002162678A
Authority: JP
Inventors: 栄介柏木; 直之山口
Original assignee: Sumitomo Metal Mining Co Ltd
Current assignee: Sumitomo Metal Mining Co Ltd
Priority date: 2002-06-04
Filing date: 2002-06-04
Publication date: 2006-08-09
Anticipated expiration: 2022-06-04
Also published as: JP2004011167A

Description

【０００１】
【発明の属する技術分野】
本発明は、地震発生時に上部構造物の振動を減衰させ、地震エネルギーを吸収させる免震ダンパに関するものである。
【０００２】
【従来の技術】
従来、地震発生時に建築物を保護するために、建築物等の上部構造体と基礎側の下部構造体との間に、免震アイソレータと免震ダンパとからなる免震装置を介在させて建築物に伝播される地震エネルギーを減少させることは知られている。上記の免震アイソレータとしては、一般にゴム等の弾性板と、鋼板等の剛性板とを上下方向に交互に順次積層したものが用いられている。また免震用ダンパとしては、一般に鉛等の金属を利用したものが多く用いられ、例えば特開平２−１９４２３３号公報においてはダンパ本体を鉛等の金属により断面Ｕ字状に形成したものが提案されている。
【０００３】
しかしながら、上記のような免震ダンパは、断面Ｕ字状に形成したダンパ本体の両端部を上下方向に配置して、それぞれ上部構造体と下部構造体とに取付け、地震発生時に生じる上部構造体と下部構造体とのずれによってダンパ本体が変形しながら地震エネルギーを吸収するもので、その際、変形による応力が上記Ｕ字形ダンパ本体の屈曲部もしくはその近傍に局部的に集中しやすく、変形を繰り返すうちに上記屈曲部もしくはその近傍の肉厚が低下して振動吸収性能が次第に低下する不具合がある。
【０００４】
その性能低下の原因等を調べるために、図１１に示すような断面Ｕ字形のダンパ本体１を有する免震ダンパについて、上記ダンパ本体１の板厚ｔ、幅Ｄ、長さＬをパラメータとする確認試験を行った。その試験方法としては、図１２に示すようにダンパ本体１の両端部１１・１１を、それぞれ水平方向に進退動可能な上下一対の可動体ａ・ｂに取付板２やボルト３等を介して取付け、上記可動体ａ・ｂを図１１に示すようにダンパ本体１の長手方向（図１１においてダンパ本体両端部１１・１１の中心線Ｘ−Ｘと平行な方向）と図１４に示すようにダンパの幅方向（上記の中心線Ｘ−Ｘと直角方向）にそれぞれ所定の振幅で振動（相対移動）させて上記試験体が破断するまでの定振幅試験を行った。
【０００５】
その結果、上記試験体は、特にダンパ本体１の長手方向に振動させたとき、変形による応力が上記Ｕ字形屈曲部１２およびその近傍に集中して、その部分の板厚ｔが急激にやせてきて被断することが分かった。また図１５は上記の定振幅試験によって得られた加振回数と振動１サイクルでのエネルギー吸収量との関係を示すグラフであり、ダンパ本体１の長手方向（Ｘ−Ｘ方向）に振動させたときの変化曲線Ｅｘと、ダンパ本体１の幅方向（Ｘ−Ｘと直角方向）に振動させたときの変化曲線Ｅｙとを比較すると、幅方向よりも長手方向に振動させた方が、エネルギー吸収量（振動吸収性能）が急激に低下することが分かる。
【０００６】
また上記の実験の結果からダンパ本体１の板厚をｔ、幅をＤ、長さをＬとすると、ダンパの耐力Ｑは、
Ｑ∝（ｔ^２×Ｄ）／Ｌ^ｎ ‥‥‥（１）
の関係が成り立つことが分かった。なお上記（１）式中のｎは、係数である。
【０００７】
さらに上記Ｌ^ｎ項は、他の２つパラメータに比べ耐力に与える影響が小さいため、無視できることが分かった。よって、上記の耐力Ｑは、
Ｑ∝ｔ^２×Ｄ ‥‥‥（２）
の関係が成り立つ。
【０００８】
上記（２）式からも明らかなように、ダンパの体力Ｑは、ダンパ本体１の板厚ｔと幅Ｄの大きさ左右され、特に板厚ｔは耐力Ｑに対して２乗で影響するので、ダンパの板厚ｔが小さくなることが、ダンパの耐力を急激に劣化させる大きな要因であることが分かる。
【０００９】
そこで、ダンパ本体１の板厚ｔを厚くすることが考えられるが、板厚ｔを厚くするとダンパの耐力は増大できるが、振動吸収性能が低下する場合があり、またダンパが大型化する等の不具合もある。また板厚ｔの減少は、応力の集中、特にＵ字形ダンパ本体１の屈曲部もしくはその近傍への局部的な応力集中による変形が原因なので、その応力を分散させるために上記の屈曲部を大きく形成することが考えられるが、免震ダンパの高さ寸法が必然的に大きくなり、往々にして免震アイソレータよりも高くなって前記の上部構造体と下部構造体との間隔を大きく確保しなければならない。又その際、免震アイソレータと上記構造体との間に間隔調整部材等を介在させなければならない等の問題がある。
【００１０】
【発明が解決しようとする課題】
本発明は上記の問題点に鑑みて提案されたもので、ダンパ本体の高さ寸法を必ずしも大きくしなくても、振動吸収性能がよく、しかも振動の繰返しによる性能劣化の少ない耐久性のよい免震ダンパを提供することを目的とする。
【００１１】
【課題を解決するための手段】
上記の目的を達成するために本発明による免震ダンパは以下の構成としたものである。即ち、免震アイソレータと併用して地震発生時に建築構造物に伝わる地震エネルギーを減少させる免震ダンパであって、金属により略Ｕ字状に屈曲形成したダンパ本体の両端部を上下に配置して、それぞれ建築物等の上部構造体と基礎側の下部構造体とに取付けると共に、上記ダンパ本体の平面形状を湾曲形成して該ダンパ本体の両端部とＵ字形屈曲部との間に湾曲部を設けたことを特徴とする。
【００１２】
上記のようにダンパ本体の平面形状を湾曲形成して該ダンパ本体の両端部とＵ字形屈曲部との間に湾曲部を設けたことにより、地震発生時にはダンパ本体が全体でねじれ変形して応力を広く分散させることが可能となり、振動の繰り返しによる性能の劣化を低減することができる。また湾曲の組合せ方法次第では加力方向による性能の差を少なくすることも可能である。
【００１３】
【発明の実施の形態】
以下、本発明による免震ダンパを、図に示す実施形態に基づいて具体的に説明する。
【００１４】
図１および図２は本発明による免震ダンパの一実施形態を示すもので、図１（ａ）はダンパ本体の平面図、同図（ｂ）はその正面図、同図（ｃ）はその側面図、図２（ａ）は上記免震ダンパの使用状態を示す正面図、同図（ｂ）はその側面図である。
【００１５】
本実施形態は、ダンパ本体１を鉛等の金属により図１（ｂ）のように断面略Ｕ字形に屈曲形成すると共に、そのダンパ本体１の平面形状を同図（ａ）のように略Ｌ字形に湾曲形成したもので、そのダンパ本体１の両端部１１・１１とＵ字形屈曲部１２との間の対向辺１３・１４には湾曲部１３ａ・１４ａが設けられ、上記両端部１１・１１の幅方向の中心線Ｘ−Ｘと、上記Ｕ字形屈曲部１２の幅方向の中心線Ｙ−Ｙとが略直角になるように形成されている。
【００１６】
上記ダンパ本体１の両端部１１・１１は、やや肉厚に形成され、その両端部１１・１１を、図２に示すように建築物等の上部構造体Ａと基礎側の下部構造体Ｂとに、それぞれ直接もしくは鋼板等の取付板２を介して取付けるもので、図の場合は鉛製のダンパ本体１と一体に形成した鉛合金製の両端部１１・１１内にそれぞれ上記取付板２の一部を埋設して一体化し、その各取付板２を上部構造体Ａおよび下部構造体Ｂにそれぞれボルト３で取付けた構成である。
【００１７】
なお上記両端部１１・１１の材質は適宜であり、またダンパ本体１と別体に形成してダンパ本体１および上記取付板２と抵抗溶接やホモゲン溶着等で一体的に固着することもできる。また上記取付板２の構造体ＡおよびＢに対する取付手段は上記のようなボルトに限らずその他適宜である。
【００１８】
上記のようにして上下の構造体Ａ・Ｂにダンパ本体１を取付けた状態で、地震により例えば前記図２（ａ）で左右方向に振動したとき、上記構造体Ａ・Ｂおよびダンパ本体１の両端部１１・１１には、図３（ａ）および（ｂ）のように互いに反対方向にずれるような力が作用するが、ダンパ本体１は上記のように平面略Ｌ字形に湾曲形成されているので、ダンパ本体１は単に左右方向にずれるだけでなく、図３（ａ）および（ｂ）のようにダンパ本体１の両端部１１・１１を除くダンパ本体１のほぼ全体がねじれ変形しながら地震エネルギーを吸収する。
【００１９】
それによって、上記の振動による応力が、ダンパ本体１のＵ字形屈曲部１２もしくはその近傍にのみ集中することなく、両端部１１・１１を除くダンパ本体１のほぼ全体に応力が分散されるので、繰り返し振動してもダンパ本体１の板厚が急激に低下するのが防止され、性能劣化の進行速度を可及的に低減することができる。
【００２０】
また地震により例えば前記図２（ｂ）で左右方向に振動したときは、上記構造体Ａ・Ｂおよびダンパ本体１の両端部１１・１１には、図４（ａ）および（ｂ）のように互いに反対方向にずれるような力が作用するが、その場合にも同図（ａ）および（ｂ）のようにダンパ本体１の両端部１１・１１を除くダンパ本体１のほぼ全体がねじれ変形しながら地震エネルギーを吸収することができるもので、上記以外の他の水平方向および上下方向の振動についてもほぼ同様である。さらに上記ダンパ本体１の厚さや幅を適宜調整することで、水平方向のいずれの振動方向に対しても振動吸収性能をほぼ同等にすることも可能である。
【００２１】
なお、上記実施形態はダンパ本体１を平面略Ｌ字形、特に図の場合は両端部１１・１１の前記中心線Ｘ−Ｘと、Ｕ字形屈曲部１２の前記中心線Ｙ−Ｙとが略直角になるように形成したが、その角度は適宜であり、例えば図５に示すように両端部１１・１１とＵ字形屈曲部１２とが略４５度の角度で湾曲した平面略Ｊ字形に形成してもよい。また図の場合は上記両端部１１・１１とＵ字形屈曲部１２との間の対向辺１３・１４の湾曲部１３ａ・１４ａを円弧状に形状したが、鋭角に角張った形状としてもよい。
【００２２】
さらに上記湾曲部１３ａ・１４ａやＵ字形屈曲部１２の断面積が漸次変化する変断面構造としてもよく、図６はＵ字形屈曲部１２の断面積が該屈曲部１２の中央部に行くに従って漸次小さくなるようにした例、図７はＵ字形屈曲部１２の中央部に行くに従って漸次大きくなるようにした例である。
【００２３】
またダンパ本体１の平面形状は上記のようなＬ字形やＪ字形に限らず、例えば図８のような平面略Ｓ字形、もしくは図９のような平面略波形に形成してもよく、特に上記図８および図９の場合は、ダンパ本体１の両端部１１・１１とＵ字形屈曲部１２との間の対向辺１３・１４に、それぞれ湾曲部１３ａ・１４ａが互いに反対方向になるように設けられている。また上記以外にもダンパ本体１の平面形状は適宜変更可能であり、少なくとも平面もしくは底面側から見た状態において１つ以上の湾曲部を有する構成とすれば、前記と同様の効果が得られる。
【００２４】
【実施例】
前記図１に示す形状の免震ダンパを試験体として前記と同様の定振幅試験を行ったところ、本発明による上記試験体は、図１０に示すようにダンパ本体１の長手方向（図１でＸ−Ｘと直角方向）の変化曲線Ｅｙは、前記従来の試験体と殆ど変わらないが、ダンパ本体１の幅方向（図１でＸ−Ｘと平行な方向）の変化曲線Ｅｘ’は、前記従来の変化曲線Ｅｘに比べて大幅に改善され、従来のようなエネルギー吸収量の急激な低下がなくなり、被断までの振動回数も大幅に増大させることができた。また上記以外の方向についてもエネルギー吸収量の急激な低下が生じないことが確認できた。
【００２５】
【発明の効果】
以上のように本発明による免震ダンパは、上記のようにダンパ本体の平面形状を湾曲形成したことにより、地震発生時に水平方向のいずれの方向に振動してもダンパ本体が全体でねじれ変形して応力を広く分散させることが可能となり、繰返し振動することによるＵ字形屈曲部およびその近傍の肉厚が局部的に低下したり、それによって振動吸収性能の低下もしくは劣化を低減することができる。また本発明によれば、ダンパ本体の高さ寸法を大きくすることなく振動吸収性能や耐久性を向上させることが可能となり、免震用アイソレータの周囲に該アイソレータの高さ寸法を大きく変更したり、間隔調整部材等を用いることなく配置することが可能となる。しかもアイソレータの周囲にダンパを配置することで、免震層の部材設置箇所の減少による設置手間の省力化が可能となる。さらに免震建築物設計時においてはダンパの配置バリエーションや設計の自由度も増大させることが可能となる等の効果がある。
【図面の簡単な説明】
【図１】（ａ）は本発明免震ダンパに用いるダンパ本体の一例を示す平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図２】（ａ）は上記免震ダンパの使用状態を示す正面図。
（ｂ）はその側面図。
【図３】（ａ）および（ｂ）は上記ダンパを長手方向に振動させた状態の正面図。
【図４】（ａ）および（ｂ）は上記ダンパを幅方向に振動させた状態の正面図。
【図５】（ａ）はダンパ本体の他の例を示す平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図６】（ａ）はダンパ本体の更に他の例を示す平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図７】（ａ）はダンパ本体の更に他の例を示す平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図８】（ａ）はダンパ本体の更に他の例を示す平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図９】（ａ）はダンパ本体の更に他の例を示す平面図。
（ｂ）はその正面図。
【図１０】本発明免震ダンパによる加振回数とエネルギー吸収量との関係を示すグラフ。
【図１１】（ａ）は従来の免震ダンパにおけるダンパ本体の平面図。
（ｂ）はその正面図。
（ｃ）はその側面図。
【図１２】（ａ）は上記免震ダンパの使用状態を示す正面図。
（ｂ）はその側面図。
【図１３】（ａ）および（ｂ）は上記ダンパを長手方向に振動させた状態の正面図。
【図１４】（ａ）および（ｂ）は上記ダンパを幅方向に振動させた状態の正面図。
【図１５】従来の免震ダンパによる加振回数とエネルギー吸収量との関係を示すグラフ。
【符号の説明】
１ダンパ本体
１１両端部
１２Ｕ字形屈曲部
１３、１４対向辺
１３ａ、１４ａ湾曲部
２取付板
３ボルト[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a seismic isolation damper that attenuates vibration of an upper structure and absorbs seismic energy when an earthquake occurs.
[0002]
[Prior art]
Conventionally, in order to protect buildings in the event of an earthquake, the building is constructed by interposing an isolation device consisting of an isolation isolator and an isolation damper between the upper structure of the building and the lower structure on the foundation side. It is known to reduce seismic energy transmitted to objects. As the seismic isolation isolator, generally, an elastic plate made of rubber or the like and a rigid plate such as a steel plate are alternately laminated in the vertical direction. In general, as a damper for seismic isolation, a material using a metal such as lead is generally used. For example, Japanese Patent Laid-Open No. 2-194233 proposes a damper body formed of a metal such as lead in a U-shaped cross section. Has been.
[0003]
However, the seismic isolation damper as described above has an upper structure that is generated when an earthquake occurs by disposing both ends of the damper main body formed in a U-shaped section in the vertical direction and attaching them to the upper structure and the lower structure, respectively. The seismic energy is absorbed while the damper body is deformed due to the displacement of the U-shaped damper and the lower structure. At that time, the stress due to the deformation tends to concentrate locally at or near the bent part of the U-shaped damper body. There is a problem in that the vibration absorption performance gradually decreases due to a decrease in the thickness of the bent portion or the vicinity thereof over time.
[0004]
In order to investigate the cause of the performance degradation, the thickness t, width D, and length L of the damper main body 1 are used as parameters for the seismic isolation damper having the U-shaped damper main body 1 as shown in FIG. A confirmation test was conducted. As the test method, as shown in FIG. 12, both end portions 11 and 11 of the damper main body 1 are respectively connected to a pair of upper and lower movable bodies a and b that can be moved back and forth in the horizontal direction via mounting plates 2 and bolts 3 and the like. As shown in FIG. 14, the movable bodies a and b are mounted in the longitudinal direction of the damper main body 1 as shown in FIG. 11 (the direction parallel to the center line XX of the both ends 11 and 11 of the damper main body in FIG. 11). A constant amplitude test was performed until the specimen was broken by vibrating (relatively moving) with a predetermined amplitude in the width direction of the damper (a direction perpendicular to the center line XX).
[0005]
As a result, particularly when the test body is vibrated in the longitudinal direction of the damper main body 1, stress due to deformation concentrates on the U-shaped bent portion 12 and its vicinity, and the thickness t of that portion suddenly decreases. It turned out to be refused. FIG. 15 is a graph showing the relationship between the number of excitations obtained by the above-described constant amplitude test and the amount of energy absorbed in one cycle of vibration. The damper body 1 is vibrated in the longitudinal direction (XX direction). And the change curve Ey when the damper body 1 is vibrated in the width direction (the direction perpendicular to XX) of the damper body 1 are compared, the energy absorption is greater when the vibration is caused in the longitudinal direction than in the width direction. It can be seen that the amount (vibration absorption performance) decreases rapidly.
[0006]
Further, from the result of the above experiment, when the thickness of the damper body 1 is t, the width is D, and the length is L, the proof stress Q of the damper is
Q∝ (t ² × D) / L ⁿ (1)
The relationship was established. Note that n in the above equation (1) is a coefficient.
[0007]
Furthermore, it was found that the above L ⁿ term is negligible because it has less influence on the proof stress than the other two parameters. Therefore, the yield strength Q is
Q∝t ² × D (2)
The relationship holds.
[0008]
As is clear from the above equation (2), the physical strength Q of the damper depends on the thickness t and the width D of the damper body 1, and in particular, the thickness t influences the proof strength Q by a square. It can be seen that a reduction in the thickness t of the damper is a major factor that rapidly deteriorates the proof stress of the damper.
[0009]
Therefore, it is conceivable to increase the plate thickness t of the damper main body 1. However, if the plate thickness t is increased, the proof stress of the damper can be increased, but the vibration absorption performance may be reduced, and the damper may be enlarged. There are also defects. Further, the decrease in the plate thickness t is caused by stress concentration, in particular, deformation due to local stress concentration on the bent portion of the U-shaped damper body 1 or in the vicinity thereof. However, the height of the seismic isolation damper is inevitably large, and is often higher than that of the seismic isolation isolator, so that the space between the upper structure and the lower structure must be kept large. I must. At that time, there is a problem that an interval adjusting member or the like must be interposed between the seismic isolation isolator and the structure.
[0010]
[Problems to be solved by the invention]
The present invention has been proposed in view of the above-described problems, and the vibration absorption performance is good and the durability is excellent with little performance deterioration due to repeated vibrations, without necessarily increasing the height of the damper body. The purpose is to provide seismic dampers.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the seismic isolation damper according to the present invention has the following configuration. In other words, it is a seismic isolation damper that is used in combination with a seismic isolation isolator to reduce the seismic energy transmitted to the building structure when an earthquake occurs , with both ends of the damper body bent in a substantially U shape made of metal arranged vertically In addition, each is attached to an upper structure such as a building and a lower structure on the foundation side, and the planar shape of the damper main body is curved to form a curved portion between both ends of the damper main body and the U-shaped bent portion. It is provided .
[0012]
As described above, the damper main body is curved and the curved portions are provided between the both ends of the damper main body and the U-shaped bent portion. Can be widely dispersed, and performance degradation due to repeated vibrations can be reduced. Also, depending on the method of combining the curves, it is possible to reduce the difference in performance depending on the direction of the applied force.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the seismic isolation damper by this invention is demonstrated concretely based on embodiment shown in a figure.
[0014]
1 and 2 show an embodiment of a seismic isolation damper according to the present invention. FIG. 1 (a) is a plan view of a damper body, FIG. 1 (b) is a front view thereof, and FIG. FIG. 2A is a side view, FIG. 2A is a front view showing a use state of the seismic isolation damper, and FIG. 2B is a side view thereof.
[0015]
In this embodiment, the damper main body 1 is bent and formed with a metal such as lead in a substantially U-shaped cross section as shown in FIG. 1B, and the planar shape of the damper main body 1 is substantially L as shown in FIG. Curved portions 13a and 14a are provided on opposite sides 13 and 14 between both end portions 11 and 11 of the damper main body 1 and the U-shaped bent portion 12, and the both end portions 11 and 11 are formed. The width direction center line XX and the width direction center line Y-Y of the U-shaped bent portion 12 are formed to be substantially perpendicular.
[0016]
Both ends 11 and 11 of the damper main body 1 are formed to be slightly thick, and the both ends 11 and 11 are formed with an upper structure A such as a building and a lower structure B on the foundation side as shown in FIG. In addition, in the case shown in the figure, the mounting plate 2 is mounted in both ends 11 and 11 made of lead alloy integrally with the lead damper body 1. A part is embedded and integrated, and each mounting plate 2 is attached to the upper structure A and the lower structure B with bolts 3 respectively.
[0017]
The material of the both end portions 11 and 11 may be appropriate, and may be formed separately from the damper main body 1 and integrally fixed to the damper main body 1 and the mounting plate 2 by resistance welding, homogen welding or the like. Moreover, the attachment means with respect to the structures A and B of the said mounting plate 2 is not restricted to the above volt | bolts, but is other appropriate.
[0018]
When the damper main body 1 is attached to the upper and lower structures A and B as described above, when the vibration is caused in the left-right direction in FIG. 2A due to an earthquake, the structures A and B and the damper main body 1 Forces that are shifted in opposite directions as shown in FIGS. 3 (a) and 3 (b) are applied to both end portions 11 and 11, but the damper main body 1 is curved and formed in a substantially L-shape as described above. Therefore, the damper body 1 is not only displaced in the left-right direction, but the entire damper body 1 excluding both ends 11 and 11 of the damper body 1 is twisted and deformed as shown in FIGS. 3 (a) and 3 (b). Absorbs seismic energy.
[0019]
Thereby, the stress due to the vibration is not concentrated on the U-shaped bent portion 12 of the damper main body 1 or the vicinity thereof, but the stress is distributed over almost the entire damper main body 1 excluding the end portions 11 and 11. Even if it vibrates repeatedly, the plate thickness of the damper main body 1 is prevented from rapidly decreasing, and the progress speed of performance deterioration can be reduced as much as possible.
[0020]
Further, when the vibration is caused in the left-right direction in FIG. 2B due to an earthquake, the structures A and B and the both end portions 11 and 11 of the damper main body 1 are as shown in FIGS. 4A and 4B. Forces that deviate in opposite directions act on each other, but in this case as well, almost the entire damper body 1 except for the end portions 11 and 11 of the damper body 1 is twisted and deformed as shown in FIGS. However, it can absorb seismic energy, and the same applies to other horizontal and vertical vibrations other than those described above. Furthermore, by appropriately adjusting the thickness and width of the damper main body 1, the vibration absorbing performance can be made substantially equal in any vibration direction in the horizontal direction.
[0021]
In the above-described embodiment, the damper main body 1 has a substantially L-shaped plane. In particular, in the case of the figure, the center line XX of both end portions 11 and 11 and the center line YY of the U-shaped bent portion 12 are substantially perpendicular. However, the angle is appropriate. For example, as shown in FIG. 5, both end portions 11 and 11 and the U-shaped bent portion 12 are formed in a plane substantially J-shape curved at an angle of approximately 45 degrees. May be. In the case of the figure, the curved portions 13a and 14a of the opposing sides 13 and 14 between the both end portions 11 and 11 and the U-shaped bent portion 12 are formed in an arc shape, but may be formed in an acute angle.
[0022]
Further, a variable cross-sectional structure in which the cross-sectional areas of the curved portions 13a and 14a and the U-shaped bent portion 12 gradually change may be employed. FIG. FIG. 7 shows an example in which the size of the U-shaped bent portion 12 is gradually increased.
[0023]
Further, the planar shape of the damper main body 1 is not limited to the L-shape or J-shape as described above, and may be formed in, for example, a substantially planar S shape as shown in FIG. 8 or a substantially planar waveform as shown in FIG. 8 and 9, the curved portions 13a and 14a are provided on opposite sides 13 and 14 between the end portions 11 and 11 of the damper body 1 and the U-shaped bent portion 12, respectively, in opposite directions. It has been. In addition to the above, the planar shape of the damper main body 1 can be changed as appropriate, and the same effect as described above can be obtained if the structure has one or more curved portions at least when viewed from the plane or bottom side.
[0024]
【Example】
When a constant amplitude test similar to that described above was performed using the seismic isolation damper having the shape shown in FIG. 1 as a test specimen, the test specimen according to the present invention was, as shown in FIG. The change curve Ey in the direction perpendicular to XX is almost the same as that of the conventional specimen, but the change curve Ex ′ in the width direction of the damper body 1 (the direction parallel to XX in FIG. 1) is Compared with the conventional change curve Ex, the energy absorption amount is not drastically reduced as in the conventional case, and the number of vibrations to be cut off can be greatly increased. It was also confirmed that there was no sudden decrease in the amount of energy absorption in directions other than the above.
[0025]
【The invention's effect】
As described above, the seismic isolation damper according to the present invention is formed by bending the planar shape of the damper body as described above, so that the damper body as a whole is twisted and deformed even if it vibrates in any horizontal direction when an earthquake occurs. Thus, the stress can be widely dispersed, and the thickness of the U-shaped bent portion and the vicinity thereof due to repeated vibration can be locally reduced, thereby reducing the deterioration or deterioration of the vibration absorption performance. Further, according to the present invention, it is possible to improve the vibration absorption performance and durability without increasing the height of the damper body, and the height of the isolator can be greatly changed around the seismic isolation isolator. It becomes possible to arrange without using an interval adjusting member or the like. In addition, by arranging a damper around the isolator, it is possible to save labor by reducing the number of places where the seismic isolation layer is installed. In addition, when designing a base-isolated building, there are effects such as the possibility of increasing damper layout variations and design freedom.
[Brief description of the drawings]
FIG. 1A is a plan view showing an example of a damper body used in a seismic isolation damper according to the present invention.
(B) is the front view.
(C) is the side view.
FIG. 2A is a front view showing a usage state of the seismic isolation damper.
(B) is the side view.
FIGS. 3A and 3B are front views showing a state in which the damper is vibrated in the longitudinal direction. FIGS.
4A and 4B are front views showing a state in which the damper is vibrated in the width direction. FIG.
FIG. 5A is a plan view showing another example of the damper main body.
(B) is the front view.
(C) is the side view.
FIG. 6A is a plan view showing still another example of the damper main body.
(B) is the front view.
(C) is the side view.
FIG. 7A is a plan view showing still another example of the damper main body.
(B) is the front view.
(C) is the side view.
FIG. 8A is a plan view showing still another example of the damper main body.
(B) is the front view.
(C) is the side view.
FIG. 9A is a plan view showing still another example of the damper main body.
(B) is the front view.
FIG. 10 is a graph showing the relationship between the number of vibrations and the amount of energy absorbed by the seismic isolation damper of the present invention.
FIG. 11A is a plan view of a damper body in a conventional seismic isolation damper.
(B) is the front view.
(C) is the side view.
FIG. 12A is a front view showing a usage state of the seismic isolation damper.
(B) is the side view.
FIGS. 13A and 13B are front views showing a state in which the damper is vibrated in the longitudinal direction.
FIGS. 14A and 14B are front views showing a state in which the damper is vibrated in the width direction.
FIG. 15 is a graph showing the relationship between the number of vibrations and the amount of energy absorbed by a conventional seismic isolation damper.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Damper main body 11 Both ends 12 U-shaped bending part 13, 14 Opposite side 13a, 14a Bending part 2 Mounting plate 3 Bolt

Claims

It is a seismic isolation damper that is used in combination with a seismic isolation isolator to reduce the seismic energy transmitted to the building structure when an earthquake occurs, and arranges both ends of the damper body bent in a substantially U shape with metal vertically, Attached to an upper structure such as a building and a lower structure on the foundation side, the planar shape of the damper body is curved, and a curved portion is provided between both ends of the damper body and the U-shaped bent portion . This is a seismic isolation damper.

The planar shape of the damper body is curved into a substantially L shape, a substantially J shape, a substantially S shape, or a substantially corrugated shape, and one or a plurality of curved portions are provided between both ends of the damper body and the U-shaped bent portion. provided comprising claim 1 seismic isolation damper according.