Performance study of an 8-story steel building equipped with oil damper damaged during the 2011 great east Japan earthquake part 2: Novel retrofit strategy

Abstract

In this paper, the full rehabilitation process of a damaged passively controlled building is reported. A hybrid retrofit plan that uses tin-rubber bearings to replace the damaged oil dampers is proposed and tested within the size requirement and cost budget. Structural Identification and nonlinear dynamic analyses have been conducted to verify the effectiveness of the hybrid retrofit plan. After the rehabilitation was completed, the retrofitted building with tin-rubber isolators is proved by a recent earthquake to have a better seismic performance than the original building with oil dampers. Finally, the performance of the damping system will be discussed in this paper based on the performance-based design concepts. The performance level of the energy dissipation devices should be set accordingly based on the building performance level for the seismic rehabilitation design. The safety issues of the structural frame and retrofit procedure after the failure or degradation of the damping devices should be investigated in the future.