| 摘要 |
PROBLEM TO BE SOLVED: To provide a base isolation bearing device which prevents excessive displacement of a bridge at the time of an earthquake that is likely to occur several times in its entire service life, thereby ensuring a bridge function, and exerts a base isolation function to prevent damage of the bridge at the time of a very strong earthquake. SOLUTION: The base isolation bearing device 1 for the bridge is fixed to a bridge girder 3 via its upper surface 2 and to a pier 5 via its lower surface 4, respectively, and formed of a base isolation bearer 6 and a buckling mechanism 7. The base isolation bearer functions to bear the load of the bridge girder 3 in the vertical direction V and to seismically isolate the bridge girder 3 by displacement of the upper surface 2 with respect to the lower surface 4 in the horizontal direction H at the time of occurrence of vibrational displacement of the bridge girder 3 with respect to the pier 5 in the horizontal direction H. The buckling mechanism is arranged between the bridge girder 3 and the pier 5 so as to inhibit displacement of the upper surface 2 of the base isolation bearer 6 with respect to the lower surface 4 in a direction H1 orthogonal to a bridge axis when an external force F applied to the base isolation bearer 6 is at a predetermined value or below, and to buckle and allow the displacement of the upper surface 2 of the base isolation bearer 6 with respect to the lower surface 4 in the direction H1 orthogonal to the bridge axis when the external force F applied to the base isolation bearer 6 is in excess of the predetermined value. COPYRIGHT: (C)2005,JPO&NCIPI |
