New Concept on Fail-Safe Design of Foundation Structure Systems Insensitive to Extreme Motions

Owing to systematic and dense seismic observation networks, extreme ground motions have been recorded in recent major earthquakes with high velocity or high acceleration far exceeding the conventional design code level. At the same time, most of reinforced concrete (RC) building structures in Japan survived these severe motions, probably because of higher capacity than design requirements or of input loss at the base. The authors have conducted shake table tests on full-scale RC buildings with flexible foundation at E-Defense to verify the input loss at the base. The test results are outlined in this paper, where the obvious reduction of damage to the building structure was observed owing to the slip behavior at the base. The results show that it is feasible to and apply in practice a fail-safe system against possible and yet unseen future extreme motions, by incorporating the slip behaviour positively to control damage or ensure safety.