| 摘要 |
PURPOSE:To make it possible to correct easily shearing deformation of a seismic isolation bearing by moving a lower plate slidingly by the shrinkage of an expansion device and obtaining driving reaction from a bride girder by way of upper racks to be installed to the lower part of the bridge girder. CONSTITUTION:An engagement rack 18, an upper rack 19 and an expansion jack 20 are installed to a seismic isolation bearing 12 during correction work or preliminarily. Then, if the seismic isolation bearing 12 is subjected to shearing deformation produced by the movement of a bridge girder 31 resultant from dry shrinkage or cracks of the bridge girder 31, an expansion jack 20 is operated so as to correct the shearing deformation. In this case, an engagement claw 17 of an engagement rack 18 comes into contact with a lateral end face of a lower plate 15, thereby drawing the lower rack 15 near. Then, the lower plate 15 is slidingly moved to the lower part of an upper plate 14, thereby removing the shearing deformation of the seismic isolation bearing 12 where the lower plate 15 is surface-treated so that it may be slippery and corrosion resistant just like an anchor plate 11, thereby making smooth the sliding of the anchor plate 11 and the lower plate 15. |
