Seismic Vulnerability Assessment of Reinforced Concrete Frame Structure by Finite Element Analysis

Performance of structures depends on the vulnerability of the structure and the seismic hazard of the region. As part of the Mediterranean-Transasian belt, the Croatian territory is located in an earthquake prone area. Implementation of earthquake-resistant building design rules is essential in order to mitigate the damages of earthquakes affecting settlement areas. Performance-based evaluation of buildings may be conducted through fragility curves developed for different levels of performance. In this paper, a reinforced concrete frame structure was designed as a moderately ductile building according to EN 1998-1:2004. Incremental dynamic analysis of the nonlinear numerical reinforced concrete model is implemented in the software package SeismoStruct, wherein the frame elements (column, beam) were defined as finite elements. The seismic risk of the model is estimated by probabilistic analysis that takes the randomness of seismic excitation into account and evaluates the probability of exceeding a certain critical condition. Seven real time histories selected from European Strong-motion Database were used. The structural behaviour is observed based on maximum interstorey drifts through the entire height of the building for each seismic excitation. The results obtained by incremental dynamic analysis of the nonlinear numerical model are also compared with an empirical seismic vulnerability method - macroseismic method.