Simplified assessment of seismic performance for RC building classes towards preliminary applications of SISMABONUS incentive at the community scale

This paper applies a simplified approach for the attribution of seismic risk classes SRC to infilled reinforced concrete RC archetype buildings representative of existing gravity load designed GLD building typologies in Italy and investigates on the effect of possible local retrofit interventions to reduce SRC. The evaluation is based on simplified modeling of lateral seismic behavior and on the estimate of the peak ground acceleration PGA corresponding to attainment of building capacity at increasing damage limit states. The SRC is attributed as the minimum between two classes, depending on safety level (percentage of new building standard %NBS) and on expected annual loss EAL. It is shown that, due to brittle failures induced by local infill-frame interaction and consequent low seismic capacity at life safety limit state, the lower (worst) SRC is generally attained for the considered building typologies, independently from the seismic hazard at the site. The application of local retrofit interventions allows ameliorating the SRC and it is found that the most probable SRC for retrofitted building typology depends on the seismic hazard at the site; lower SRC are obtained for zones of higher hazard. Application to RC building typologies in the town of Pompei, near Naples, and cost benefit analysis CBA is performed to investigate on the convenience of alternative retrofit strategies towards risk reduction at the community level. The Sismabonus incentive mechanism, in Italy, regulates the possibility to benefit of tax deductions after seismic strengthening interventions on buildings. Polese et al. (2018) presented a simplified approach for evaluating the effects of implementation of the Sismabonus policy at the territorial scale, evaluating SRC for RC (bare) building typologies identified in the interested area; a speed method for calculating the SRC was introduced and applied for the town of Portici, in Campania region. The evaluation is based on simplified modeling of lateral seismic behavior and on the estimate of the PGA corresponding to attainment of building capacity (PGAc) for relevant limit states, namely damage limitation (SLD) and life safety limit state