Displacement capacity of ancient structures through non-linear kinematic and dynamic analyses
In seismic prone areas, the topic of ensuring the buildings an adequate safety level is difficult to cope with. The public use related to several monumental buildings (churches, palaces, castles, etc.) sharpens the seismic risk, increasing the exposure factor. On this topic, in Italy, the recent seismic decrees (OPCM 3274/2003 and OPCM 3431/2005) have strongly modified the safety concept both for new-designed constructions and existing buildings. This code introduces the idea of design and verification through displacement-based analysis. Recent works propose an approach based on the Equilibrium Limit Analysis (kinematic theorem), which reliability needs to be verify through systematic numerical checks. For this purpose, nonlinear dynamic analyses on the equivalent SDOF systems have been performed (Resemini et al. 2006). In this paper, the seismic performance of various church façades (Umbria region, Tuscany region) is evaluated using both non-linear kinematic and dynamic analyses. The estimated displacement capacity of the case studies is then compared to the surveyed damage pattern after the earthquakes in the ‘90s.