BASE-ISOLATION DAMPER

To provide a base-isolation damper which can prevent its buckling while securing a stroke length enough to cope with long-period earthquake vibration, generate stable damping force while preventing the breakage of the base-isolation damper and surrounding members of the base-isolation damper, and suppress residual displacement in a base-isolation layer after earthquake.SOLUTION: A base-isolation damper D1 includes a hydraulic damper OD, a structure side mounting device SB for mounting the hydraulic damper OD on a structure S in a horizontally rotatable manner, and a ground side mounting device GB for mounting the hydraulic damper OD on a ground G in a horizontally rotatable manner, the ground side mounting device GB having a hydraulic buffer FD which can expand/contract in one direction while exerting damping force to prevent the expansion/contraction when expanding/contracting, a damper side bracket 18 connecting one end of the hydraulic buffer FD to the hydraulic damper OD, and a guide member 19 for guiding the movement of the damper side bracket 18 in association with the expansion/contraction of the hydraulic buffer FD.SELECTED DRAWING: Figure 1 【課題】長周期地震動にも対応できるストローク長を確保しつつ、座屈を防止でき、免震用ダンパおよび免震用ダンパの周辺部材の破損を防止しつつ安定した減衰力を発生できるとともに地震終息後の免震層における残留変位を抑制できる免震用ダンパの提供である。【解決手段】本発明の免震用ダンパＤ１は、油圧ダンパＯＤと、油圧ダンパＯＤを水平方向回転可能に構造物Ｓへ取り付ける構造物側取付装置ＳＢと、油圧ダンパＯＤを水平方向回転可能に地盤Ｇへ取り付ける地盤側取付装置ＧＢとを備え、地盤側取付装置ＧＢは、一方向に伸縮可能であって伸縮時に伸縮を妨げる減衰力を発揮する油圧バッファＦＤと、油圧バッファＦＤの一端を油圧ダンパＯＤに連結するダンパ側ブラケット１８と、油圧バッファＦＤの伸縮に伴うダンパ側ブラケット１８の移動を案内するガイド部材１９とを備えている。【選択図】図１