The quest for resilience: The Chilean practice of seismic design for reinforced concrete buildings

The satisfactory structural behavior observed during large earthquakes and the high seismicity of the country has conditioned the Chilean society to expect immediate occupancy performance level for their buildings under these extreme events, although the seismic design code in Chile mandates only a scope of life safety performance level. Based on observational and statistical evidence from recent strong earthquakes in Chile, it is concluded that the observed seismic resilience of buildings is a consequence of limiting damage, considering that operational performance and life safety are different challenges that require different approaches; furthermore, to provide society with resilient and safe buildings, both challenges must be met simultaneously and not alternatively. The present article describes the concepts, strategies, and future challenges in the context of the Chilean practice, and the authors describe several lessons learned from the design of thousands of concrete buildings that have experienced earthquakes with a magnitude of 8.0 and higher with limited damage; these lessons have proven to be effective in ensuring resilient structural performance under extreme seismic events.