1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Nowadays, many Codes develop a force-based design approach, which accounts for the inelastic capacity of structures by means of a reduction coefficient, i.e. behaviour factor. At the same time, in earthquake engineering there is an ever-increasing interest on the evaluation of structural safety, through the so-called reliability analysis. Consequently, some studies analysed failure probability of some code-conforming buildings and they pointed out that actual code’s provisions lead to a non-uniform structural safety level. For this reason, the first main objective of this study is to investigate extensively the failure rates of Italian code-conforming frame RC buildings, in order to establish how the rate of failure varies along the Italian territory. For this purpose, buildings with different number of floors, i.e. 3-6-9, with both levels of ductility (DCM-DCH) and in bare or infilled configuration have been studied, carrying on parametrically both the design and non-linear dynamic analyses in order to define frames vulnerability. Next generation of Eurocodes will explicit define the target reliability level that must be ensured by code’s provisions. For this reason, has been developed a framework to obtain a risk-targeted spectral acceleration for the design of uniform reliability frames, which is one of the main aims of a risk-oriented earthquake engineering. In particular, this acceleration has been related to the code’s workflow by the formulation of an alternative behaviour factor, that depends not only on structural features but also on the target failure’s rate. This task is achieved by means of a hands-on approach, in fact the proportional relationship between elastic and targeted spectral acceleration is exploited.