抄録
In surveys on the damage of buildings caused by the 2011 Tohoku-Pacific Ocean earthquake, it was reported that damages such as cracks were detected in a number of lead dampers used in seismically isolated buildings. After investigations of the damaged dampers in detail, it was confirmed that these cracks were generated by accumulation of small-amplitude loading like middle-small earthquakes or winds rather than by large-amplitude loading like large earthquakes or strong winds. From this background, fatigue characteristics of a lead rubber bearing (LRB) under repeated small-amplitude were evaluated by cyclic loading tests of scaled models. The shear-strain amplitudes of the testing were 1%, 10%, 20%, and the maximum number of the cycles for each level of amplitude was 4000000, 59000, and 17000, respectively.
