The knock-off type steel side block, proposed by the authors, provides a displacement restraint against a small earthquake but has some technical problems to be solved for a wider application of it. In this study, an improved design equation on breaking load of the side block is proposed by referring to its failure mechanism. Also dynamic behavior of isolation bearings having the side block are grasped through shaking table test and seismic responses of viaduct with the bearings having the side blocks in the transverse direction of the bridge axis are investigated through seismic response analyses.
