Reliability-Targeted Behaviour Factor Evaluation for Code Compliant RC Italian Frames

The evaluation of structural safety, by means of the so-called reliability analysis, plays currently a key role in earthquake civil engineering. In particular, some recent studies focused on the quantification of seismic performance of code-conforming buildings. In fact, it is of interest to evaluate if the implicit performance approach adopted by current codes is capable of guaranteeing a uniform safety levels for new-designed buildings. In other terms, if it is necessary to redefine code formulation in order to directly state the desired performance levels at the beginning of the design workflow. For these reasons, the present study evaluates extensively the seismic behavior of code compliant Italian RC frames. To this aim, it has been developed a framework to parametrically design code-conforming buildings and then to estimate their vulnerability through nonlinear dynamic analyses. In this way, the quantification of seismic failure rates exhibits a strict link between them and seismic hazard of sites. To overcome this issue, the so-called risk-targeted design approach has been adopted, in order to reformulate the actual force-based approach. The new reduction factor, i.e. behavior factor, depends not only by inherent structural characteristic but also by the pre-defined desired safety level. This task has been achieved by means of a hands-on method applied to frames with different elevation configuration (3-, 6-, -9 floors) for both ductility class and considering both bare and infilled archetypes.