BASE ISOLATION BRIDGE ABUTMENT SYSTEM

PROBLEM TO BE SOLVED: To improve function by providing a space corresponding to a large displacement between an abutment and a girder in a recessed part of the upper side of the abutment, and installing an approach panel on the upper surface of the end of the girder. SOLUTION: An abutment 1 where a recessed part having a U-shaped section is formed is provided on the side of the upper part, the end of a girder 5 is supported through a base isolation device 6 in the recessed part, the maximum displacement SG possible within the design level is provided in the recessed part to secure a large space, thereby preventing breakage due to a collision of a structure at the time of an earthquake. A stepped part having an inclined surface formed at the inner part, which has a length corresponding to the maximum displacement SG, is provided on the upper surface of the end of the girder 5, an approach panel 4 is disposed in the stepped part to enable running, and the abutment 1 and the panel 4 are connected to each other by a link 3. At the time of an earthquake, when the girder 5 is moved to the abutment 1 side, the panel 4 is turned upward on the link 3 and displaced along the inclined surface of the stepped part to avoid a collision between the panel 4 and the girder 5. Thus, breakage of the abutment or the like in the case of the greatest earthquake can be prevented without any obstacle to running of the vehicle.