On the definition of seismic recovery interventions in r.c. buildings by non-linear static and incremental dynamic analyses

Incremental Dynamic Analysis (IDA) is a parametric analysis method that allows evaluating the structural performance under seismic loads more accurately than traditional static and dynamic analyses. With respect to a single non-linear analysis, the incremental dynamic analysis has the advantage to evaluate the structural performance under different levels of intensity, scaling proper ground motion records, until the structure collapses or until a fixed level of deformation is reached. In this study the potentialities of incremental dynamic analysis have been investigated in identifying the damaged elements in existing irregular r.c. buildings and a comparison with the results of static Pushover Analyses has been performed. In particular a strongly irregular building has been considered, representative of a particular manufacture and of an historical period of economic growth and speculation; it has not structural problems but suffers from abandonment and weathering effects. An interpretation of IDA procedure has been proposed, with the set of a mean IDA capacity curve, then bi-linearized in order to close the pushover procedure according to the extended N2 method. The aim is to underline in a specific case study how the choice of a methodology can affect the definition of recovery interventions, especially in the case of historical buildings, where the criterion of minimum intervention should be followed in order to preserve the original features.