ABSTRACT
In seismic risk mitigation policies, fragility functions of existing
buildings play a fundamental role. In this paper, a procedure to develop
analytical fragility curves for Moment Resisting Frame Reinforced Concrete
buildings is presented. The design of the selected building typologies was performed
according to the codes at the time of construction using force-based methods
and the state of the practice at the time of construction. A total of 216
building classes were defined, considering different ages, number of storeys,
infill panels, plan dimensions, beam stiffness, and concrete strength. The
investigated buildings can be considered low-engineered buildings, using no
seismic codes or old seismic codes. The seismic capacity of the selected models
representing the existing RC buildings has been evaluated through non-linear
dynamic simulations. Seismic response has been analyzed, considering various
peak and integral intensity measures and various response parameters, such as
ductility demands and Interstorey Drift Ratio (IDR). A new relationship among
structural performance, damage levels and interstorey drift ratios for each
studied type is introduced, which is calibrated using the damage levels
described in EMS98. It is important to highlight that in this study, different
thresholds of IDR have been associated with different typologies, considering
their different ductility member levels after their different structural
responses. Fragility Curves (FCs) for the studied structural types are set up,
developed and discussed.