A seismological and engineering perspective on the 2016 Central Italy earthquakes

Abstract

Abstract:The strong earthquake (M 6.0-6.2) that hit the central Apennines on August 24, 2016, occurred in one of the most seismically active areas in Italy. Field surveys indicated severe damage in the epicentral area where, in addition to the loss of human life, widespread destruction of cultural heritage and of critical buildings occurred. Using the neo-deterministic seismic hazard assessment (NDSHA), we apply the maximum deterministic seismic input (MDSI) procedure at two of the most relevant sites in the epicentral area, comparing the results with the current Italian building code. After performing an expeditious engineering analysis, we interpret as a possible cause of the reported damages the high seismic vulnerability of the built environment, combined with the source and site effects characterising the seismic input. Therefore, it is important to design and retrofit with appropriate spectral acceleration levels compatible with the possible future scenarios, like the ones provided by MDSI.

Physics-Based Ground Motion Simulations for the Prediction of the Seismic Vulnerability of Masonry Building Compounds in Mirandola (Italy)

“…Regarding the physical definition of the MCSI response spectrum, it is described in [29,42] where, for each seismogenic source, n-scenarios (in terms of magnitude, epicentre distance and focal mechanism of the earthquake) have been considered, the obtained n-spectral acceleration values (SA) have been compared, and the maximum median has been selected, as depicted in Figure 6. Figure 6.…”

“…With this intent, according to [29,42], the MCSI response spectrum, taking into account the stochastic nature of the algorithm implemented by the XeRIS tool [35], is evaluated at the 95th percentile, based on the number of realizations of the fault rupture process considered. Therefore, by defining the maximum credible seismic input, the maximum contribution in terms of seismic hazard is offered by the Mirandola source (MIR, see Table 4) due to a reduced site-source distance.…”

“…Afterwards, having fixed the reference scenario and a specific rupture process, the spatial variability (site-to-site) of the intensity measure depends mainly on the propagation of the seismic wave through different soil layers. Overall, it is clear that the spatial variability of seismic motion is a fundamental component for the seismic risk analysis of both urban and infrastructural systems for the quantification of expected losses [27][28][29].…”