Risk-Target-Based Design of Base-Isolated Buildings

Seismic isolation is widely used both for the design of new buildings and for the retrofit of existing ones. So far, however, little attention has been paid to the collapse performance and risk analysis of base-isolated buildings, mostly because this requires advanced numerical models and considerable computational efforts. This chapter deals with the seismic risk analysis of base-isolated buildings, providing an in-depth insight into failure modes and collapse conditions of base-isolated buildings. Advanced numerical models and analytical tools for the seismic assessment of reinforced concrete (RC) buildings with seismic isolation are first presented. Next, a risk-target based design (RTBD) approach for base-isolated buildings is proposed, considering different sources of uncertainty (including record-to-record variability, modeling assumptions, and limit state definition). The proposed approach is then applied to a residential RC building equipped with a rubber-based isolation system. Based on the outcomes of this study, some preliminary practice-oriented conclusions are drawn.