DAMAGE ASSESSMENT FOR RAPID RESPONSE: THE CENTRAL ITALY 2016 M6 EVENT

In case of a seismic event, building damage is one of the causes of casualties. For this reason, the rapid estimation of expected structural damage in near-real time is of greatest importance to improve and support rapid response life-saving actions of emergency managers. Within this framework, we have developed the Damage Assessment for Rapid Response method that allows us to estimate the expected damage by using earthquake recordings in real or near-real time, and the knowledge of the fundamental frequency and the damping of the building. We simulate the linear dynamic behavior of buildings in a first order approximation as single-degree-of-freedom oscillators. We are not interested in a precise reconstruction of the dynamic behavior including the non-linear one, but in the exceeding of the relative displacement of predefined damage thresholds. The relative displacement at the top of the buildings is compared with damage thresholds defined in literature for different building typologies to assess the expected damage. The method can be applied to single buildings or building typologies in target areas using earthquake recordings of sensors installed at the basement or on the soil. In this study, we show the estimation of the expected damage for the dominant building typologies (low to mid-rise unreinforced masonry and low to high-rise reinforced concrete buildings) for four selected target areas (Amatrice, Norcia, Sulmona and Visso) for the M6 August 24 event of the Central Italy 2016-2017 seismic sequence. The considered towns are located at diverse epicentral distances and are characterized by different building typologies for which varying damage patterns have been observed. The fundamental frequencies are estimated using specific building-soil period-height relationships obtained from empirical measurements. The expected damage is compared with the observed one for the dominant building typologies and is in accordance with it for most of the considered building typologies in the four target areas.