| 摘要 |
PROBLEM TO BE SOLVED: To reduce occurrence of local distortion, and diminish damage and rupture due to the local distortion, by forming the side end part of a hard plate into a shape which is swelled out to an outer side in a circular arc cross sectional shape or a circular arc analogous shape, and coating the outer surface of a laminated structural body with a coating rubber having weatherability. SOLUTION: In a base isolation rubber 20, flanges 4, 5 are arranged on the upper and lower surfaces of a laminated structural body 13 in which soft plates 11 such as rubber and hard plates 12 are alternately laminated. Parts brought into contact with the flanges 4, 5 are so formed that their cross sectional dimension are gradually increased toward the flanges 4, 5 and their outer surfaces are formed into curved surfaces which are curved in a circular arc cross sectional shape or a circular arc analogous shape to an inner side. The side end surfaces of the hard plates 12 are formed into the circular arc cross sectional shape or the circular arc analogous shape which is expanded to an outer side, and also the peripheral parts thereof are covered with a rubber excellent in weatherability, and the hard plates 12 are embedded in the inside of an outer layer. The edge parts of the hard plates 12 are smoothened, thereby, reducing stress or distortion generated in the parts of the soft plates 11 to a large extent. |
