JP2004100308A

JP2004100308A - Vibration damper used for vibration damping seismic isolation building

Info

Publication number: JP2004100308A
Application number: JP2002264713A
Authority: JP
Inventors: Takashi Fujita; 藤田　▲隆▼史; Nobuyasu Kawai; 川井　伸泰; Yuji Funayama; 舟山　勇司; Masaki Mochimaru; 持丸　昌己; Shinji Sato; 佐藤　新治
Original assignee: Oiles Industry Co Ltd; Okumura Corp
Current assignee: Oiles Industry Co Ltd; Okumura Corp
Priority date: 2002-09-10
Filing date: 2002-09-10
Publication date: 2004-04-02
Anticipated expiration: 2022-09-10
Also published as: JP3849624B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration damper proper for a seismic isolation building, in which an upper structure is borne on a lower structure through a seismic isolator with an isolator base-isolation operated to vibrations by an earthquake and an elasto-plastic system or friction system vibration damper damping vibrations, capable of effectively damping even micro-vibrations by wind or the like at an early stage and capable of imparting a vibration-control effect in the case of strong wind to the seismic isolation building. <P>SOLUTION: This vibration damping seismic isolation building 1 has a foundation 2 made of concrete fixed and installed on a ground by piles or the like, the seismic isolator 5 composed of the isolator 4 embedded with a lead support 3, the upper structure 6 supported to the foundation 2 through the seismic isolator 5 and the vibration damper 7 arranged between the foundation 2 and the upper structure 6. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、免震装置で免震化された事務所ビル、集合住宅又は戸建住宅等の上部構造物の風等による微小振動を効果的に減衰させて強風時の制振効果を得るようにした制振型免震建物に用いるための振動減衰装置に関する。
【０００２】
【従来の技術】
従来から、地震を対象にした免震建物は、建物の基部を地震による振動に対して免震作動するアイソレータと振動を減衰させるダンパーとからなる免震装置により基礎上に支承されている。斯かる免震建物では、元来、地震の他に小変位の交通振動や風による揺れについては考慮されないのが普通であり、例えば、ロック機構により所定の水平荷重を越える地震が作用するまでは免震装置を不作動にし、それより大きな水平荷重が発生すると、ロック機構を解除して免震装置を作動させるようにしたものが一般的である。
【０００３】
ところで、都市に建設される高層建物では、地震の他に小変位の交通振動や風の揺れを減衰させて居住性を改良することが要求されるようになっているが、単に、ロック機構を省いて、小変位の交通振動や風による揺れをも免震装置のダンパーにより減衰させようとしても、斯かる免震装置に用いられるダンパーの多くは弾塑性ダンパー（例えば、特許文献１参照）又は摩擦ダンパー（例えば、特許文献２参照）であって、これらは、その特性上、小変位における振動エネルギの吸収効率が低いために、交通振動や風による揺れを効果的に早期に減衰させることが困難である。
【０００４】
【特許文献１】
特公平６−８６７７６号公報
【特許文献２】
特開平１１−３２４４０１号公報
【０００５】
【発明が解決しようとする課題】
本発明は、前記諸点に鑑みてなされたものであって、その目的とするところは、地震による振動に対して免震作動するアイソレータと振動を減衰させる弾塑性系又は摩擦系の振動減衰装置とを具備した免震装置を介して上部構造物を下部構造物上で支承してなる免震建物に用いて好適であって、風等による微小振動をも効果的に早期に減衰できて強風時の制振効果を免震建物に与えることができる振動減衰装置を提供することにある。
【０００６】
【課題を解決するための手段】
地震による振動に対して免震作動するアイソレータと振動を減衰させる弾塑性系又は摩擦系の振動減衰装置とを具備した免震装置を介して上部構造物を下部構造物上で支承してなる免震建物に用いるための本発明の第一の態様の粘性系の振動減衰装置は、上部構造物及び下部構造物のうちの一方に固着されるようになっており、上部構造物及び下部構造物のうちの他方に粘性抵抗力により連結されるようになっている粘性ダンパーと、下部構造物に対して上部構造物が相対的に所定の水平変位を越えると、該粘性抵抗力による連結を解除する解除機構とを具備しており、上部構造物に対する振動減衰に関して、所定の水平変位を越えない小さな振動に対しては粘性抵抗力による連結を維持して免震装置と共に粘性ダンパーを作動させ、所定の水平変位を越える大きな振動に対しては粘性抵抗力による連結を解除して免震装置のみを作動させるようになっている。
【０００７】
第一の態様の振動減衰装置によれば、粘性ダンパーが上部構造物に対する振動減衰に関して、小さな振動に対しては免震装置と共に作動するようになっているために、風等による上部構造物の微小振動を効果的に早期に減衰できて強風時の制振効果を免震建物に与えることができ、しかも、所定の水平変位を越える地震による大きな振動に対しては解除機構により免震装置のみを作動させることができるために、風や交通振動等の小さな振動から地震による大きな振動まで効果的に制振することができる。
【０００８】
斯かる本発明の振動減衰装置において、その第二の態様のように、粘性ダンパーは、固定板と、固定板に対して隙間をもって水平方向に可動に粘性体内に配されている可動板と、固定板と可動板との間の隙間に配された粘性体と、可動板を囲繞する囲繞体とを有しており、解除機構は、上下方向に移動自在であって上部構造物の水平方向の振動と共に水平方向に振動するように、上部構造物に連結されるようになっていると共に、可動板との間に微小隙間をもって可動板に対面した粘性抵抗部材と、微小隙間に配された粘性体と、可動板に設けられていると共に、可動板に対する粘性抵抗部材の水平方向の移動で可動板から粘性抵抗部材を離反させる離反体とを具備しており、粘性抵抗部材は、可動板の囲繞体への当接で、可動板に対して水平方向に移動されるようになっていてもよく、斯かる第二の態様の振動減衰装置において、解除機構は、好ましくは、第三の態様のそれのように、可動板と粘性抵抗部材との間の微小隙間に粘性体が残存する程度に、粘性抵抗部材を可動板に向かって弾性的に付勢する弾性部材を更に具備しており、粘性抵抗部材は、第四の態様のそれのように、微小隙間への粘性体の流入を許容する貫通孔を有しており、また、離反体は、第五の態様のそれのように、粘性抵抗部材の外縁の周りに配されている。
【０００９】
本発明において、免震装置は、好ましくは、剛性層及び弾性層が交互に積層された積層ゴムからなるアイソレータと、この積層ゴムに埋設された鉛支柱からなる振動減衰装置とを具備しており、また上部構造物は、好ましくは、事務所ビル、集合住宅又は戸建住宅であるが、本発明はこれに限定されず、その他の上部構造物であってもよい。
【００１０】
次に本発明及びその実施の形態を制振型免震建物に用いた例について、図を参照して更に詳細に説明する。なお、本発明はこれら実施の形態に何等限定されないのである。
【００１１】
【発明の実施の形態】
図１から図３において、本例の制振型免震建物１は、地盤に杭等により固定されて設置されたコンクリート製の基礎２と、鉛支柱３入りのアイソレータ４からなる免震装置５と、免震装置５を介して基礎２に支持された上部構造物６と、基礎２と上部構造物６との間に配された振動減衰装置７とを具備している。
【００１２】
下部構造物としての基礎２と上部構造物６との間に介在されて、上部構造物６の上下方向（鉛直方向）Ｖの荷重を支持すると共に、地震による水平方向Ｈの振動に対して上部構造物６に関して免震作動と弾塑性系の振動減衰作動とを行う免震装置５は、鋼板等からなる複数の剛性層１１及びゴム等からなる複数の弾性層１２が上下方向Ｖに交互に積層されている積層ゴムからなると共に免震作動を行うアイソレータ４と、アイソレータ４に埋設されていると共に弾塑性系の振動減衰作動を行う鉛支柱３と、アイソレータ４を挟持していると共に基礎２と上部構造物６の事務所ビル１５との夫々にアンカーボルト等を介して固着された上下取り付け鋼板１３及び１４とを具備している。斯かる免震装置５は、上部構造物６の荷重を受けるべく、基礎２上に適当に分散されて複数個配されている。
【００１３】
上部構造物６は、本例では、高層の事務所ビル１５と、事務所ビル１５の下面１６にボルト等により固着されている取り付け板部１２８及び取り付け板部１２８に溶接等により固着された円柱部１２９を有した係合部材１２７とを具備している。
【００１４】
免震装置５を介して基礎２に対して水平方向Ｈの振動に関して基礎２上で免震支持された上部構造物６の当該水平方向Ｈの振動を減衰させる粘性系の振動減衰装置７は、上部構造物６に粘性抵抗力により連結されていると共に、基礎２に対する上部構造物６の所定の水平変位、例えば略１００ｍｍ以下の強風等による微小の水平変位では、粘性抵抗力による上部構造物６への連結を維持されて、上部構造物６に対する振動減衰に関して鉛支柱３と共に作動し、上部構造物６の水平方向Ｈの振動を減衰させる粘性ダンパー１３１と、地震に起因して基礎２に対して上部構造物６が相対的に所定の水平変位、例えば略１００ｍｍを越えると、該粘性抵抗力による連結を解除する解除機構１３２とを具備している。
【００１５】
粘性ダンパー１３１は、厚肉部１３５及び薄肉部１３６を有する円板状の可動板１３７と、可動板１３７を囲繞する囲繞体としての円筒部１３８を有した容器１３９と、円筒部１３８内に配されて容器１３９内に収容された粘性体１４０と、可動板１３７を偏倚した位置から元の位置（図２及び図３に示す位置）に戻す戻し機構１４１とを具備している。
【００１６】
容器１３９は、固定板としてのその底板部１４５でアンカーボルト等を介して基礎２に固着されている。
【００１７】
水平方向に可動に粘性体１４０内に配された可動板１３７は、隙間１４６をもって容器１３９の底板部１４５と対面しており、可動板１３７と容器１３９の底板部１４５との間には、底板部１４５に固着されていると共に可動板１３７が摺動自在に接触した複数個のスペーサ１４７が設けられており、スペーサ１４７により隙間１４６が保持されている。
【００１８】
可動板１３７は、その水平方向Ｈの移動により隙間１４６に配された粘性体１４０に粘性剪断変形を生じさせ、斯かる粘性体１４０の粘性剪断変形でその水平方向Ｈの移動に抗する抵抗力を発生し、而して、その水平方向Ｈの移動を減衰させるようになっている。
【００１９】
粘性ダンパー１３１は、可動板１３７の水平方向Ｈの移動で、可動板１３７と底板部１４５との間の隙間１４６に配された粘性体１４０に粘性剪断変形を生じさせて減衰力を発生し、而して、可動板１３７の水平方向Ｈの移動を減衰させ、延いては上部構造物６の水平方向Ｈの移動を減衰させる。
【００２０】
解除機構１３２は、上下方向Ｖに移動自在であって上部構造物６の水平方向Ｈの振動と共に水平方向Ｈに振動するように、上部構造物６の係合部材１２７の円柱部１２９を上下方向Ｖに移動自在に受容して当該円柱部１２９に係合して上部構造物６に連結されている円筒部１５１に加えて、当該円筒部１５１が固着されていると共に、可動板１３７の厚肉部１３５の上面１５４との間に微小隙間をもって可動板１３７に対面した粘性抵抗発生板部１５２を有する粘性抵抗部材１５３と、可動板１３７と粘性抵抗発生板部１５２との間の微小隙間に配された粘性体１４０と、上部構造物６の円柱部１２９と粘性抵抗部材１５３の粘性抵抗発生板部１５２との間に介在されていると共に、粘性抵抗部材１５３の粘性抵抗発生板部１５２を可動板１３７の厚肉部１３５の上面１５４に向かって、当該上面１５４と粘性抵抗発生板部１５２との間の微小隙間に粘性体１４０が残存する程度の弱い弾性力をもって付勢する弾性部材１５５と、粘性抵抗部材１５３の粘性抵抗発生板部１５２が対面する厚肉部１３５の上面１５４に設けられていると共に、可動板１３７に対する粘性抵抗部材１５３の所定量以上の水平方向Ｈの移動で可動板１３７の厚肉部１３５から粘性抵抗部材１５３を図６に示すように離反させる離反体１５６とを具備している。
【００２１】
粘性抵抗発生板部１５２は、その外周側の下面にテーパ面からなる環状の案内面１６０と、その上面側と下面側とを連通して、上面１５４と粘性抵抗発生板部１５２との間の微小隙間への粘性体１４０の流入を許容する複数の貫通孔１６１とを有しており、案内面１６０は、図６に示すような粘性抵抗発生板部１５２の離反体１５６への乗り上げを容易にし、粘性抵抗発生板部１５２の上下面を連通している貫通孔１６１は、粘性抵抗発生板部１５２の離反体１５６への乗り上げに際して、上面１５４と粘性抵抗発生板部１５２との間の微小隙間に粘性体１４０を供給して、可動板１３７の厚肉部１３５の上面１５４からの粘性抵抗部材１５３の上方への離反を容易にする。
【００２２】
本例では板ばねからなる弾性部材１５５は、その弾性的な圧縮により可動板１３７からの粘性抵抗部材１５３の離反を可能にしている。なお、斯かる弾性部材１５５を省いて、粘性抵抗部材１５３の自重でもって、粘性体１４０が残存する微小隙間が粘性抵抗発生板部１５２と上面１５４との間に生じるようにしてもよい。
【００２３】
離反体１５６は、厚肉部１３５の上面１５４に一体的に形成されていると共に、粘性抵抗発生板部１５２の外縁の周りに配されている環状の断面半円形の突起からなる。
【００２４】
粘性抵抗発生板部１５２と上面１５４との間の微小隙間に残存する粘性体１４０は、粘性抵抗発生板部１５２の水平方向Ｈの移動において粘性剪断変形されて斯かる水平方向Ｈの移動に抗する粘性抵抗力であって、上部構造物６の水平方向Ｈの所定振幅以下の振動に起因して可動板１３７により発生される抵抗力よりも大きな粘性抵抗力を粘性抵抗発生板部１５２に与えて、斯かる粘性抵抗力により上部構造物６に粘性ダンパー１３１を連結するようになっており、而して、粘性体１４０を間にして可動板１３７と対面して配されている粘性抵抗部材１５３の粘性抵抗発生板部１５２は、上部構造物６の水平方向Ｈの所定振幅以下の振動に起因して可動板１３７により発生される抵抗力では、水平方向Ｈの移動と共に可動板１３７を水平方向Ｈに移動させることができる一方、上部構造物６の水平方向Ｈの所定振幅を超える振動に起因して可動板１３７の円筒部１３８への当接により発生される抵抗力では、可動板１３７に対して独立に水平方向Ｈに移動できるようになっていると共に、この移動で離反体１５６へ乗り上げて粘性体１４０から受ける粘性抵抗力を減少させて上部構造物６と粘性ダンパー１３１との粘性抵抗力による連結を解除するようになっている。
【００２５】
戻し機構１４１は、一端が可動板１３７の厚肉部１３５に、他端が円筒部１３８に球面継手等を介して夫々連結された複数のコイルばね１７１を具備しており、図２及び図３に示す位置から偏倚した位置に移動した可動板１３７をコイルばね１７１の弾性力により図２及び図３に示す元の位置に戻すようになっている。
【００２６】
以上の上部構造物６を有すると共に免震装置５でもって上部構造物６が免震支持されてなる制振型免震建物１に用いられている振動減衰装置７では、通常時、図２及び図３に示すように、初期状態では、可動板１３７は、水平方向Ｈに関して容器１３９の中央部に配されており、粘性抵抗部材１５３は、同じく水平方向Ｈに関して可動板１３７の中央部に配されている。この状態で、強風が生じて免震装置５の弾性層１２の剪断変形により基礎２に対して上部構造物６が水平方向Ｈに振動される場合であって、その振動が強風等による上部構造物６の水平方向Ｈの所定振幅以下の小さな振動の場合は、粘性ダンパー１３１が可動板１３７と粘性抵抗発生板部１５２との間の粘性抵抗力を介して上部構造物６に連結されている結果、上部構造物６の水平方向Ｈの移動が粘性抵抗発生板部１５２と可動板１３７の上面との間に介在する薄膜状の粘性体１４０を介して可動板１３７に伝達され、これにより可動板１３７も上部構造物６の水平方向Ｈの移動と共に水平方向Ｈに移動されて、可動板１３７の水平方向Ｈの移動により可動板１３７と底板部１４５との間の隙間１４６の粘性体１４０が粘性剪断変形され、粘性ダンパー１３１におけるこの粘性剪断変形に起因する抵抗力は、可動板１３７の水平方向Ｈの振動を減衰させ、而して、上部構造物６の水平方向Ｈの振動を減衰させる。強風が収まると、免震装置５の弾性層１２による原点復帰機能により制振型免震建物１は、図１に示す状態に戻されると共に、可動板１３７及び粘性抵抗部材１５３の夫々もまた、水平方向Ｈに関して容器１３９及び可動板１３７の夫々の中央部に戻される。
【００２７】
地震が生じて免震装置５の弾性層１２の剪断変形により基礎２に対して上部構造物６が水平方向Ｈに振動される場合であって、その振動が所定振幅を越える場合には、解除機構１３２が可動板１３７を所定振幅まで水平方向Ｈに移動させた後に、図４に示すように、可動板１３７の薄肉部１３６が円筒部１３８へ当接して可動板１３７が水平方向Ｈに移動できなくなる結果、粘性ダンパー１３１は、上部構造物６の水平方向Ｈの振動に対する減衰動作を行い得ないようになる一方、粘性抵抗発生板部１５２は、当該粘性抵抗発生板部１５２と可動板１３７との間の微小隙間に存在する粘性体１４０の粘性剪断変形に起因する粘性抵抗力に打ち勝って、可動板１３７に対して独立に水平方向Ｈに移動されて、図５に示すように、離反体１５６に当接した後に、図６に示すように、弾性部材１５５の弱い弾性力に抗して離反体１５６に乗り上げて可動板１３７から離反して、可動板１３７との間に大きな隙間を形成して、この隙間に介在する粘性体１４０で生じる粘性剪断変形に起因する粘性抵抗力を減少し、これにより上部構造物６の水平方向Ｈの振動が粘性ダンパー１３１からの粘性剪断変形に起因する抵抗力及び粘性抵抗発生板部１５２と可動板１３７の上面１５４との間に存在する粘性体１４０に起因する抵抗力を受けることなしに許容されるようになり、而して、更なる上部構造物６の水平方向Ｈの移動では、鉛支柱３が十分に変形されるために、鉛支柱３のこの変形でもって上部構造物６の水平方向Ｈの大きな移動が好ましく早期に減衰されることになる。
【００２８】
水平方向Ｈに所定振幅を越えて最大まで変位した上部構造物６が水平方向Ｈにおいて前記と逆方向に移動すると、粘性抵抗発生板部１５２は、粘性抵抗発生板部１５２と可動板１３７との間に存在する粘性体１４０の粘性により、離反体１５６に乗り上げた状態での離間が可動板１３７の上面１５４との間で維持されて、換言すれば可動板１３７の上面１５４から大きく離間された状態をもって、上部構造物６と共に水平方向Ｈにおいて前記と逆方向に移動される。以下、上記の動作が繰り返されて、地震が収まると、免震装置５の弾性層１２による原点復帰機能により上部構造物６は、図１に示す状態に戻されると共に、粘性抵抗発生板部１５２もまた、その自重と弾性部材１５５の弾性力により粘性体１４０の粘性に抗して徐々にゆっくりと下降されて、上面１５４との間に薄膜状の粘性体１４０が介在する程度の微小隙間を残して図２及び図３に示す状態に戻される。また、可動板１３７は、粘性抵抗発生板部１５２がその自重と弾性部材１５５の弾性力により粘性体１４０の粘性に抗して徐々に下降される間に、戻し機構１４１の弾性力でもって図４から図６に示す偏倚した位置から図２及び図３に示す状態に戻される。
【００２９】
図２及び図３に示す振動減衰装置７は、上部構造物６には解除機構１３２を介して解除自在に粘性抵抗力により連結され、基礎２には容器１３９及びアンカーボルト等を介して連結されていると共に、基礎２に対して上部構造物６が相対的に所定の水平変位を越えると上部構造物６に対する連結を解除する解除機構１３２を備えており、上部構造物６に対する振動減衰に関して、所定の水平変位を越えない地震や風、交通振動等による小さな振動に対しては鉛支柱３と粘性ダンパー１３１とを共に作動させ、所定の水平変位を越える地震による大きな振動に対しては鉛支柱３のみを作動させるようになっており、粘性系の解除機構１３２は、上部構造物６が所定の水平変位を越えると、粘性抵抗発生板部１５２と可動板１３７との間の微小隙間に存在する粘性体１４０の粘性剪断変形に起因する粘性抵抗力に打ち勝って粘性抵抗発生板部１５２が可動板１３７に対して独立に水平方向Ｈに移動可能となって、上部構造物６と粘性ダンパー１３１との間を連結していた粘性抵抗力を減少させて、而して、解除機構１３２を介する上部構造物６と振動減衰装置７との連結を解除するようになっている。
【００３０】
ところで、一般に、減衰率（ｈ）が零の場合（ｈ＝０）の高層の免震建物は、風による上部構造物の応答加速度（ｃｍ／ｓｅｃ^２）と層（階数）との関係の一例を示す図７において曲線ａで示すように、上部構造物と基礎とを剛に結合した場合（非免震であって図７において曲線ｂで示す）よりも風により大きく揺れるのであるが、振動減衰装置７を具備した本例の制振型免震建物１によれば、曲線ｃで示すように風による揺れを極めて小さくできる。
【００３１】
即ち、振動減衰装置７によれば、粘性ダンパー１３１が上部構造物６に対する振動減衰に関して、小さな振動変位に対しては鉛支柱３と共に作動させるようになっているために、上部構造物６の風等による微小振動を効果的に早期に減衰できて強風時の制振効果を制振型免震建物１に与えることができ、しかも、所定の水平変位を越える地震による大きな振動に対しては解除機構１３２により鉛支柱３のみを作動させるようにしているために、風や交通振動等の小さな振動から地震による大きな振動まで効果的に制振することができる上に、大きな振動変位に対しても作動することができるように水平方向Ｈのストロークを長大にする必要もなく、したがって、小型に構成できて上部構造物６と基礎２との間に小さなスペースをもって設置できる。
【００３２】
なお、鉛支柱３を用いる代わりに、摩擦系の振動減衰作動を行うものを用いた免震装置を介して支承された免震建物に本発明の振動減衰装置を適用してもよく、また、基礎２に対して上部構造物６が相対的に所定の水平変位を越える場合に、上部構造物６との連結を解除する代わりに、基礎２との連結を解除するように振動減衰装置７を構成してもよい。
【００３３】
【発明の効果】
本発明によれば、地震による振動に対して免震作動するアイソレータと振動を減衰させる弾塑性系又は摩擦系の振動減衰装置とを具備した免震装置を介して上部構造物を下部構造物上で支承してなる免震建物に用いて好適であって、斯かる免震建物の風等による微小振動を効果的に早期に減衰できて強風時の制振効果を免震建物に与えることができ、しかも、解除機構により所定の水平変位を越える地震による大きな振動に対しては上部構造物に対する振動減衰に関して免震装置のみを作動させることができるために、風や交通振動等の小さな振動から地震による大きな振動まで効果的に制振することができる振動減衰装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の実施態様の好ましい例を制振型免震建物に適用した正面説明図である。
【図２】図１に示す例の正面説明図である。
【図３】図２に示すＩＩＩ−ＩＩＩ線矢視説明図である。
【図４】図２に示す例の動作説明図である。
【図５】図２に示す例の動作説明図である。
【図６】図２に示す例の動作説明図である。
【図７】図１に示す制振型免震建物の作用説明図である。
【符号の説明】
１　制振型免震建物
２　基礎
３　鉛支柱
４　アイソレータ
５　免震装置
６　上部構造物
７　振動減衰装置
１３１　粘性ダンパー
１３２　解除機構[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention effectively attenuates minute vibrations caused by wind or the like of an upper structure such as an office building, an apartment house or a detached house seismically isolated by a seismic isolation device, and obtains a vibration damping effect in a strong wind. The present invention relates to a vibration damping device for use in a vibration-damping type seismic isolation building.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a base-isolated building for an earthquake is supported on a foundation by a base-isolation device including an isolator that operates to isolate the base of the building against the vibration caused by the earthquake and a damper that attenuates the vibration. In such a base-isolated building, originally, it is normal that the vibration due to traffic and wind of small displacement is not considered in addition to the earthquake.For example, until an earthquake exceeding a predetermined horizontal load is applied by a lock mechanism. Generally, when the seismic isolation device is deactivated and a horizontal load greater than that is generated, the locking mechanism is released to activate the seismic isolation device.
[0003]
By the way, in high-rise buildings constructed in cities, it is required to improve the livability by attenuating traffic vibration of small displacement and wind sway in addition to earthquakes, but it is only necessary to use a lock mechanism. Even if it is omitted and the vibration of small displacement and the vibration due to the wind are also attenuated by the damper of the seismic isolation device, most of the dampers used in the seismic isolation device are elasto-plastic dampers (for example, see Patent Document 1) or Friction dampers (for example, refer to Patent Document 2), which have a low efficiency of absorbing vibration energy at a small displacement due to their characteristics, so that they can effectively attenuate traffic vibrations and wind-induced shaking effectively and early. Have difficulty.
[0004]
[Patent Document 1]
Japanese Patent Publication No. 6-86776 [Patent Document 2]
JP-A-11-324401
[Problems to be solved by the invention]
The present invention has been made in view of the above-described points, and an object thereof is to provide an isolator that operates to be isolated from vibration due to an earthquake and an elasto-plastic or friction-based vibration damping device that dampens the vibration. It is suitable for use in seismic isolation buildings where the upper structure is supported on the lower structure via seismic isolation devices equipped with An object of the present invention is to provide a vibration damping device capable of giving a vibration-damping effect to a base-isolated building.
[0006]
[Means for Solving the Problems]
A seismic isolation system in which an upper structure is supported on a lower structure through a seismic isolator equipped with an isolator that operates to be isolated from vibrations caused by an earthquake and an elasto-plastic or frictional vibration damping device that attenuates the vibration The viscous vibration damping device according to the first aspect of the present invention for use in a seismic building is fixed to one of an upper structure and a lower structure, and the upper structure and the lower structure The viscous damper, which is connected to the other of them by viscous resistance, and the connection by viscous resistance is released when the upper structure relative to the lower structure exceeds a predetermined horizontal displacement. With respect to vibration damping to the upper structure, for a small vibration that does not exceed a predetermined horizontal displacement, maintain the connection by viscous resistance force and operate the viscous damper together with the seismic isolation device, Predetermined For large vibrations exceeding the flat displacement and is adapted to operate only isolator to release the connection by the viscous resistance force.
[0007]
According to the vibration damping device of the first aspect, regarding the vibration damping of the upper structure, the viscous damper operates together with the seismic isolation device for small vibrations. It can effectively attenuate small vibrations early and give a vibration-damping effect to a seismic isolated building in the case of strong wind.In addition, for large vibration caused by an earthquake exceeding a predetermined horizontal displacement, only a seismic isolation device is provided by a release mechanism. Can be effectively controlled from small vibrations such as wind and traffic vibrations to large vibrations due to earthquakes.
[0008]
In such a vibration damping device of the present invention, as in the second aspect, the viscous damper includes a fixed plate, and a movable plate disposed in the viscous body so as to be movable in a horizontal direction with a gap with respect to the fixed plate, It has a viscous body disposed in a gap between the fixed plate and the movable plate, and a surrounding body surrounding the movable plate, and the release mechanism is movable in the vertical direction, and the release mechanism is movable in the horizontal direction of the upper structure. The viscous resistance member facing the movable plate with a small gap between the movable plate and the viscous resistance member, and is arranged in the small gap so as to vibrate in the horizontal direction together with the vibration of the movable plate. A viscous body, and a separating member provided on the movable plate and separating the viscous resistance member from the movable plate by moving the viscous resistance member relative to the movable plate in a horizontal direction. Contact with the surrounding body, In the vibration damping device of the second aspect, the release mechanism is preferably provided between the movable plate and the viscous resistance member, as in the third aspect. An elastic member for elastically biasing the viscous resistance member toward the movable plate to such an extent that the viscous body remains in the minute gap between them is further provided, and the viscous resistance member is similar to that of the fourth embodiment. In addition, a through hole that allows the viscous body to flow into the minute gap is provided, and the separating body is arranged around the outer edge of the viscous resistance member as in the fifth embodiment.
[0009]
In the present invention, the seismic isolation device preferably includes an isolator made of laminated rubber in which rigid layers and elastic layers are alternately laminated, and a vibration damping device composed of a lead post embedded in the laminated rubber. The superstructure is preferably an office building, an apartment house or a detached house, but the present invention is not limited to this, and may be another superstructure.
[0010]
Next, an example in which the present invention and its embodiments are used in a vibration-damping type seismic isolation building will be described in more detail with reference to the drawings. It should be noted that the present invention is not limited to these embodiments.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
1 to 3, a vibration-damping type seismic isolation building 1 of the present example is a seismic isolation device 5 including a concrete foundation 2 fixed and installed on a ground with a pile or the like and an isolator 4 containing a lead support 3. And an upper structure 6 supported on the foundation 2 via the seismic isolation device 5, and a vibration damping device 7 disposed between the foundation 2 and the upper structure 6.
[0012]
It is interposed between the foundation 2 as a lower structure and the upper structure 6 to support a load in the vertical direction (vertical direction) V of the upper structure 6 and to be capable of supporting the upper part against horizontal vibration H caused by an earthquake. The seismic isolation device 5 that performs the seismic isolation operation and the elasto-plastic vibration damping operation with respect to the structure 6 includes a plurality of rigid layers 11 made of a steel plate or the like and a plurality of elastic layers 12 made of a rubber or the like alternately in the vertical direction V. An isolator 4 made of laminated rubber and performing a seismic isolation operation, a lead column 3 embedded in the isolator 4 and performing an elasto-plastic vibration damping operation, and a base 2 holding and holding the isolator 4 And upper and lower mounting steel plates 13 and 14 secured to the upper structure 6 and the office building 15 via anchor bolts and the like, respectively. A plurality of such seismic isolation devices 5 are appropriately dispersed on the foundation 2 to receive the load of the upper structure 6.
[0013]
In this example, the upper structure 6 is a high-rise office building 15, a mounting plate 128 fixed to the lower surface 16 of the office building 15 with bolts or the like, and a column fixed to the mounting plate 128 by welding or the like. And an engagement member 127 having a portion 129.
[0014]
The viscous vibration damping device 7 for damping the vibration in the horizontal direction H of the upper structure 6 supported on the foundation 2 with respect to the vibration in the horizontal direction H with respect to the foundation 2 via the seismic isolation device 5 includes: In addition to being connected to the upper structure 6 by viscous resistance, a predetermined horizontal displacement of the upper structure 6 with respect to the foundation 2, for example, a minute horizontal displacement due to a strong wind of about 100 mm or less, causes the upper structure 6 to be viscous resistance. And a viscous damper 131 that works with the lead struts 3 for vibration damping to the superstructure 6 to dampen horizontal H vibrations of the superstructure 6 and to the foundation 2 due to the earthquake. When the upper structure 6 relatively exceeds a predetermined horizontal displacement, for example, approximately 100 mm, a release mechanism 132 is provided to release the connection due to the viscous resistance.
[0015]
The viscous damper 131 is disposed in a circular plate-shaped movable plate 137 having a thick portion 135 and a thin portion 136, a container 139 having a cylindrical portion 138 as a surrounding body surrounding the movable plate 137, and a cylindrical member 138. The viscous body 140 is accommodated in the container 139 and a return mechanism 141 for returning the movable plate 137 from the biased position to the original position (the position shown in FIGS. 2 and 3).
[0016]
The container 139 is fixed to the foundation 2 at its bottom plate portion 145 as a fixing plate via an anchor bolt or the like.
[0017]
A movable plate 137 movably disposed in the viscous body 140 in the horizontal direction faces the bottom plate 145 of the container 139 with a gap 146, and a bottom plate is provided between the movable plate 137 and the bottom plate 145 of the container 139. A plurality of spacers 147 fixed to the portion 145 and slidably in contact with the movable plate 137 are provided, and the spacers 147 hold gaps 146.
[0018]
The movable plate 137 causes the viscous body 140 disposed in the gap 146 to undergo viscous shearing deformation by the movement in the horizontal direction H, and resists the viscous shearing deformation of the viscous body 140 against the movement in the horizontal direction H. Is generated, and the movement in the horizontal direction H is attenuated.
[0019]
The viscous damper 131 causes the viscous shearing deformation of the viscous body 140 disposed in the gap 146 between the movable plate 137 and the bottom plate 145 by the movement of the movable plate 137 in the horizontal direction H to generate a damping force. Thus, the movement of the movable plate 137 in the horizontal direction H is attenuated, and thus the movement of the upper structure 6 in the horizontal direction H is attenuated.
[0020]
The release mechanism 132 moves the column 129 of the engaging member 127 of the upper structure 6 in the vertical direction so that the release mechanism 132 is movable in the vertical direction V and vibrates in the horizontal direction H together with the vibration of the upper structure 6 in the horizontal direction H. In addition to the cylindrical portion 151 movably received by the V and engaged with the cylindrical portion 129 and connected to the upper structure 6, the cylindrical portion 151 is fixed and the movable plate 137 has a thick wall. A viscous resistance member 153 having a viscous resistance generating plate portion 152 facing the movable plate 137 with a minute gap between the upper surface 154 of the portion 135 and a minute gap between the movable plate 137 and the viscous resistance generating plate portion 152. The viscous body 140, the viscous resistance generating plate 152 of the viscous resistance member 153, and the viscous resistance generating plate 152 of the viscous resistance member 153 are movable. Board 1 7, an elastic member 155 urged toward the upper surface 154 of the thick portion 135 with a weak elastic force such that the viscous body 140 remains in a minute gap between the upper surface 154 and the viscous resistance generating plate portion 152; The viscous resistance generating plate portion 152 of the viscous resistance member 153 is provided on the upper surface 154 of the thick portion 135 facing thereto, and the movable plate 137 is moved by a predetermined amount or more of the viscous resistance member 153 relative to the movable plate 137 in the horizontal direction H. And a separating body 156 for separating the viscous resistance member 153 from the thick portion 135 of FIG.
[0021]
The viscous resistance generating plate portion 152 communicates with the annular guide surface 160 formed of a tapered surface on the lower surface on the outer peripheral side thereof, and communicates between the upper surface side and the lower surface side. It has a plurality of through holes 161 that allow the viscous body 140 to flow into the minute gap, and the guide surface 160 makes it easy for the viscous resistance generating plate portion 152 to climb onto the separating body 156 as shown in FIG. The through-hole 161 communicating the upper and lower surfaces of the viscous resistance generating plate 152 has a small size between the upper surface 154 and the viscous resistance generating plate 152 when the viscous resistance generating plate 152 rides on the separating body 156. The viscous body 140 is supplied to the gap to facilitate the upward separation of the viscous resistance member 153 from the upper surface 154 of the thick portion 135 of the movable plate 137.
[0022]
In this example, the elastic member 155 made of a leaf spring enables the viscous resistance member 153 to separate from the movable plate 137 by its elastic compression. The elastic member 155 may be omitted, and a minute gap in which the viscous body 140 remains may be generated between the viscous resistance generating plate portion 152 and the upper surface 154 by the weight of the viscous resistance member 153.
[0023]
The separating body 156 is formed integrally with the upper surface 154 of the thick portion 135 and is formed of an annular semicircular projection disposed around the outer edge of the viscous resistance generating plate portion 152.
[0024]
The viscous body 140 remaining in the minute gap between the viscous resistance generating plate portion 152 and the upper surface 154 undergoes viscous shear deformation when the viscous resistance generating plate portion 152 moves in the horizontal direction H, and resists the movement in the horizontal direction H. The viscous resistance generated by the movable plate 137 due to the vibration of the upper structure 6 having a predetermined amplitude or less in the horizontal direction H is applied to the viscous resistance generating plate 152. Thus, the viscous damper 131 is connected to the upper structure 6 by the viscous resistance force. Therefore, the viscous resistance member disposed facing the movable plate 137 with the viscous body 140 interposed therebetween. The viscous resistance generating plate portion 153 moves the movable plate 137 horizontally with the movement in the horizontal direction H by the resistance force generated by the movable plate 137 due to the vibration of the upper structure 6 having a predetermined amplitude or less in the horizontal direction H. direction On the other hand, the resistance generated by the contact of the movable plate 137 with the cylindrical portion 138 due to the vibration of the upper structure 6 exceeding the predetermined amplitude in the horizontal direction H causes the movable plate 137 The viscous drag between the upper structure 6 and the viscous damper 131 can be reduced by reducing the viscous drag force received from the viscous member 140 by riding on the separating body 156 by this movement. To release the connection.
[0025]
The return mechanism 141 includes a plurality of coil springs 171 each having one end connected to the thick portion 135 of the movable plate 137 and the other end connected to the cylindrical portion 138 via a spherical joint or the like. The movable plate 137 moved to a position deviated from the position shown in FIG. 2 is returned to the original position shown in FIGS. 2 and 3 by the elastic force of the coil spring 171.
[0026]
The vibration damping device 7 used in the vibration-damping type seismic isolation building 1 having the above upper structure 6 and having the upper structure 6 supported by the seismic isolation device 5 is normally used in FIGS. As shown in FIG. 3, in the initial state, the movable plate 137 is disposed at the center of the container 139 in the horizontal direction H, and the viscous resistance member 153 is also disposed at the center of the movable plate 137 in the horizontal direction H. Have been. In this state, a strong wind is generated and the upper structure 6 is vibrated in the horizontal direction H with respect to the foundation 2 due to the shear deformation of the elastic layer 12 of the seismic isolation device 5, and the vibration is caused by the strong wind or the like. In the case of a small vibration of the object 6 in the horizontal direction H having a predetermined amplitude or less, the viscous damper 131 is connected to the upper structure 6 via a viscous resistance force between the movable plate 137 and the viscous resistance generating plate portion 152. As a result, the movement of the upper structure 6 in the horizontal direction H is transmitted to the movable plate 137 via the thin film-like viscous body 140 interposed between the viscous resistance generating plate portion 152 and the upper surface of the movable plate 137, thereby moving the upper structure 6. The plate 137 is also moved in the horizontal direction H together with the movement of the upper structure 6 in the horizontal direction H, and the movement of the movable plate 137 in the horizontal direction H causes the viscous body 140 in the gap 146 between the movable plate 137 and the bottom plate portion 145 to move. Viscous shear deformation Resistance caused by the viscosity shear deformation in the damper 131 attenuates the vibration in the horizontal direction H of the movable plate 137, and Thus, damping vibrations in the horizontal direction H of the upper structure 6. When the strong wind stops, the vibration-damping type seismic isolation building 1 is returned to the state shown in FIG. 1 by the return-to-origin function by the elastic layer 12 of the seismic isolation device 5, and the movable plate 137 and the viscous resistance member 153 also The container 139 and the movable plate 137 are returned to the respective center portions in the horizontal direction H.
[0027]
If the upper structure 6 is vibrated in the horizontal direction H with respect to the foundation 2 due to the shear deformation of the elastic layer 12 of the seismic isolation device 5 due to the occurrence of an earthquake, and the vibration exceeds a predetermined amplitude, the release is performed. After the mechanism 132 moves the movable plate 137 to the predetermined amplitude in the horizontal direction H, as shown in FIG. 4, the thin portion 136 of the movable plate 137 contacts the cylindrical portion 138 and the movable plate 137 moves in the horizontal direction H. As a result, the viscous damper 131 cannot perform the damping operation with respect to the vibration of the upper structure 6 in the horizontal direction H, while the viscous resistance generating plate portion 152 is connected to the viscous resistance generating plate portion 152 and the movable plate 137. 5, the viscous body 140 overcomes the viscous resistance caused by the viscous shear deformation of the viscous body 140 existing in the minute gap between the movable plate 137 and the movable plate 137. To body 156 After the contact, as shown in FIG. 6, the movable member 156 rides on the separating body 156 against the weak elastic force of the elastic member 155, separates from the movable plate 137, and forms a large gap with the movable plate 137. The viscous resistance caused by the viscous shear deformation generated by the viscous body 140 interposed in the gap is reduced, so that the vibration of the upper structure 6 in the horizontal direction H is reduced by the resistance force caused by the viscous shear deformation from the viscous damper 131 and The viscous-resistance generating plate portion 152 and the upper surface 154 of the movable plate 137 are allowed to be received without receiving a resistance force caused by the viscous body 140, so that the further upper structure 6 In the movement in the horizontal direction H, since the lead column 3 is sufficiently deformed, a large movement of the upper structure 6 in the horizontal direction H is preferably attenuated early by this deformation of the lead column 3.
[0028]
When the upper structure 6 displaced to the maximum beyond the predetermined amplitude in the horizontal direction H moves in the opposite direction in the horizontal direction H, the viscous resistance generating plate 152 Due to the viscosity of the viscous body 140 present between the movable plate 137 and the upper surface 154 of the movable plate 137, the distance between the movable plate 137 and the upper surface 154 of the movable plate 137 is largely separated from the upper surface 154 of the movable plate 137. With the state, the upper structure 6 is moved in the horizontal direction H in the opposite direction to the above. Thereafter, when the above operation is repeated and the earthquake subsides, the upper structure 6 is returned to the state shown in FIG. 1 by the return-to-origin function by the elastic layer 12 of the seismic isolation device 5, and the viscous resistance generating plate portion 152 Also, by virtue of its own weight and the elastic force of the elastic member 155, it is gradually and slowly descended against the viscosity of the viscous body 140, and a minute gap is formed between the upper surface 154 and the thin film-like viscous body 140. The state is returned to the state shown in FIGS. Further, the movable plate 137 is moved by the elastic force of the return mechanism 141 while the viscous resistance generating plate portion 152 is gradually lowered against its own weight and the elastic force of the elastic member 155 against the viscosity of the viscous body 140. 4 is returned from the deviated position shown in FIG. 6 to the state shown in FIGS.
[0029]
The vibration damping device 7 shown in FIGS. 2 and 3 is releasably connected to the upper structure 6 via a release mechanism 132 by viscous resistance, and connected to the base 2 via a container 139 and anchor bolts. And a release mechanism 132 that releases the connection to the upper structure 6 when the upper structure 6 exceeds a predetermined horizontal displacement relative to the foundation 2. The lead column 3 and the viscous damper 131 are operated together for a small vibration caused by an earthquake, wind, traffic vibration or the like which does not exceed a predetermined horizontal displacement, and a lead column is used for a large vibration caused by an earthquake exceeding a predetermined horizontal displacement. 3 is activated, and the viscous release mechanism 132 provides a small gap between the viscous resistance generating plate 152 and the movable plate 137 when the upper structure 6 exceeds a predetermined horizontal displacement. The viscous resistance generating plate portion 152 can move in the horizontal direction H independently of the movable plate 137 by overcoming the viscous resistance force caused by the viscous shear deformation of the viscous body 140 existing in the upper structure 6, and the viscous resistance generating plate portion 152 becomes viscous with the upper structure 6. The viscous resistance force connected to the damper 131 is reduced, so that the connection between the upper structure 6 and the vibration damping device 7 via the release mechanism 132 is released.
[0030]
By the way, in general, a high-rise base-isolated building with a damping rate (h) of zero (h = 0) is an example of the relationship between the response acceleration (cm / sec ² ) of the upper structure due to the wind and the story (floor number). As shown by a curve a in FIG. 7 which shows that the upper structure and the foundation are rigidly coupled (the base structure is not seismically isolated and is greatly shaken by the wind than in the case of a curve b in FIG. 7). According to the vibration-damping type seismic isolation building 1 of this example provided with the damping device 7, the sway caused by the wind can be extremely reduced as shown by the curve c.
[0031]
That is, according to the vibration damping device 7, the viscous damper 131 operates with the lead column 3 for a small vibration displacement with respect to the vibration damping of the upper structure 6. Can effectively attenuate small vibrations at an early stage, giving a vibration-damping effect in strong winds to the vibration-isolated building 1 and canceling large vibrations caused by an earthquake exceeding a predetermined horizontal displacement. Since only the lead post 3 is operated by the mechanism 132, it is possible to effectively control vibrations from small vibrations such as wind and traffic vibrations to large vibrations due to earthquakes, and also to a large vibration displacement. It is not necessary to lengthen the stroke in the horizontal direction H to be able to operate, and therefore, it can be configured to be small and can be installed with a small space between the superstructure 6 and the foundation 2. That.
[0032]
Instead of using the lead pillar 3, the vibration damping device of the present invention may be applied to a seismic isolation building supported through a seismic isolation device that uses a vibration damping operation of a friction system. When the upper structure 6 relatively exceeds a predetermined horizontal displacement with respect to the foundation 2, instead of disconnecting the upper structure 6, the vibration damping device 7 is disconnected so as to release the connection with the foundation 2. You may comprise.
[0033]
【The invention's effect】
According to the present invention, the upper structure is placed on the lower structure through the seismic isolation device including the isolator that operates to isolate the vibration from the earthquake and the elasto-plastic or frictional vibration damping device that dampens the vibration. It is suitable for use in seismic isolation buildings supported by the above, and it is possible to effectively attenuate minute vibrations due to the wind or the like of such seismic isolation buildings at an early stage and to provide the seismic isolation building with a strong wind in a strong wind. It is possible to operate only the seismic isolation device with respect to the vibration damping to the upper structure against the large vibration due to the earthquake exceeding the predetermined horizontal displacement by the release mechanism. It is possible to provide a vibration damping device capable of effectively damping even large vibrations caused by an earthquake.
[Brief description of the drawings]
FIG. 1 is an explanatory front view of a preferred example of an embodiment of the present invention applied to a vibration-damping type seismic isolation building.
FIG. 2 is an explanatory front view of the example shown in FIG. 1;
FIG. 3 is an explanatory view taken along line III-III shown in FIG. 2;
FIG. 4 is an operation explanatory diagram of the example shown in FIG. 2;
FIG. 5 is an operation explanatory diagram of the example shown in FIG. 2;
FIG. 6 is an operation explanatory diagram of the example shown in FIG. 2;
FIG. 7 is an operation explanatory view of the vibration-damping type seismic isolation building shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Damping type seismic isolation building 2 Foundation 3 Lead support 4 Isolator 5 Isolation device 6 Upper structure 7 Vibration damping device 131 Viscous damper 132 Release mechanism

Claims

A seismic isolation system in which an upper structure is supported on a lower structure through a seismic isolator equipped with an isolator that operates to be isolated from vibrations caused by an earthquake and an elasto-plastic or frictional vibration damping device that attenuates the vibration A viscous vibration damping device for use in a seismic building, which is fixed to one of an upper structure and a lower structure, and a viscous vibration damper is attached to the other of the upper structure and the lower structure. A viscous damper adapted to be connected by resistance, and a release mechanism for releasing the connection by viscous resistance when the upper structure exceeds a predetermined horizontal displacement relative to the lower structure. Regarding vibration damping to the upper structure, for small vibrations that do not exceed the predetermined horizontal displacement, maintain the connection by viscous resistance and operate the viscous damper together with the seismic isolation device to exceed the predetermined horizontal displacement. Vibration damping device adapted to actuate only the seismic isolation device to release the connection by viscous drag forces against large vibrations.

The viscous damper includes a fixed plate, a movable plate disposed in the viscous body movably in the horizontal direction with a gap with respect to the fixed plate, a viscous body disposed in a gap between the fixed plate and the movable plate, And a surrounding body surrounding the plate, wherein the release mechanism is connected to the upper structure so as to be movable in the vertical direction and vibrate in the horizontal direction together with the horizontal vibration of the upper structure. And a viscous resistance member facing the movable plate with a minute gap between the movable plate, a viscous body disposed in the minute gap, and a viscous resistance member provided on the movable plate and for the movable plate. A separating member that separates the viscous resistance member from the movable plate by horizontal movement of the movable plate, and the viscous resistance member is moved in the horizontal direction with respect to the movable plate by abutment of the movable plate on the surrounding body. The vibration damping device according to claim 1, wherein .

The release mechanism further includes an elastic member that elastically urges the viscous resistance member toward the movable plate to such an extent that the viscous body remains in the minute gap between the movable plate and the viscous resistance member. 3. The vibration damping device according to 2.

The vibration damping device according to claim 2, wherein the viscous resistance member has a through hole that allows the viscous body to flow into the minute gap.

The vibration damping device according to any one of claims 2 to 4, wherein the separating body is disposed around an outer edge of the viscous resistance member.