Abstract
Rubber bearings show large changes in their performances due to the heat oxidation deterioration. Their performance changes in any construction site have not been clarified. Therefore, the long-term deterioration of rubber bearings is not considered in the current design method. In this research, performance changes of natural rubber bearings at any site could be estimated. It was clarified how the performance changes of natural rubber bearings depended on the time, the temperature and the size of the rubber bearings. Then, the design formula was proposed, which could estimate the horizontal stiffness of deteriorated rubber bearings in any construction site.