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The seismic events which hit Central Italy on 24 August, October 26 and October 30 2016 have caused casualties and major damage mostly to buildings and architectural heritage of the Italian Regions of Abruzzo, Lazio, Marche and Umbria; the most deadly events occurred on August 24, 2016 and caused a total of 298 victims and about 4.600 people evacuated. The mainshock occurred at 3:36 am with epicenter close to Accumoli (Rieti province) and a magnitude Mw 6.0; the aftershock occurred at 4.33 am with epicenter close to Norcia (Perugia province) and a magnitude Mw 5.3. Most of the victims were in the areas of Amatrice (Ri), Accumoli (Ri) and Arquata del Tronto (AP). The earthquakes of October 30 didn't cause any victim but only some injured thanks to the fact that people was already evacuated and also because the Civil Protection was already present on the territory. Nevertheless, the impact of this seismic event was destructive; many small towns and villages, which have survived to the first earthquake, were heavily damaged. In the days following the earthquake of august 24 the Department of Civil Protection and RELUIS started the usability surveys by using the Aedes form (Italian acronym for "accessibility and damage during seismic emergency" [1]) which guides the inspector to rapidly assess the usability of a structure, including the description of damage and all the details of the building.

The inelastic torsional response of an asymmetric-plan hospital building is studied. The response of the structure in the time domain was recorded by highly sensitive sensor network, integrated by a data acquisition system. The identification was performed using techniques of modal extraction in the frequency domain (frequency domain decomposition). A calibration process was applied in order to identify a reliable structural model to be used for the seismic vulnerability assessment of the hospital building. In particular, a nonlinear static procedure accounting for mass distribution, higher modes contribution and mode-shapes correlation was proposed for the estimation of the seismic response of irregular buildings. Finally, the influence of lateral force distribution, node control during pushover and accidental eccentricity is investigated.

The paper addresses two case studies of structural monitoring and seismic assessment of medieval masonry towers in Italy: the bell tower of Aversa and the bell tower of Capua. These monuments in the Campania region were monitored by means of full-scale environmental vibration testing. Measured responses were then used for modal identification. The procedure is based on a typical finite element model updating technique based on vibration test results. Parameters optimization is carried out by minimizing a weighted error criterion relative to the building’s modal properties. A satisfactory improvement on modal parameters is thus obtained, resulting in a close agreement between the modal properties observed in dynamic tests and those calculated from numerical model. Seismic assessment is carried out with nonlinear static analysis of the tower under multimodal distributions of lateral loads. Nonlinear analysis indicates the potential collapse mechanisms and evidences dangerous structural weakness which may play a role in the seismic vulnerability of the towers.

The seismic safety of two medieval masonry bell towers in Italy is investigated. At first, compressive tests, flat jacket tests and environmental vibration measurement are used for structural identification. In particular, a vibration-based procedure is used to investigate the dynamic features of monuments dealing with the uncertainties due to the mechanical characteristic of the material. The procedure is based on a typical finite element (FE) model updating technique using environmental vibration test results. The updated FE model of the towers is defined from a set of parameters minimizing an error criterion relative to modal properties. A satisfactory improvement on modal parameters which is in close agreement with the experimental results is found. The seismic assessment is carried out with nonlinear static analysis of the tower under multimodal distributions of lateral loads. Nonlinear analysis shows the potential collapse mechanisms and evidences the dangerous characteristics which may play a role in seismic vulnerability of the towers. A displacement-based version of the capacity spectrum method based on the inelastic demand spectra is finally used to evaluate the seismic performance of the towers at the different limit states.

Due to their historical value the old structures of the iron railway bridges can be still considered to be studied for architectural and static interests. Despite their age, of at least a century and much more, old iron bridges are still been used in many secondary lines all over Europe, presenting unique safety assessment problems to the responsible agencies. These concerns stimulated investigations on some railroad iron bridges in South Italy. The paper presents a study involving evaluations of material properties, connections and external restraints, and the actual loads. Some dynamic tests with service train as well as with a mechanical excitation were performed. The results gave dynamic and static information on the structure, which were used to tune and improve the numerical finite element model. Finally, the “real” dynamic amplification coefficient was evaluated for different speed of the train, and compared with that one suggested by the Italian code.

The structural identification from environmental vibration testing of a hospital building in Avezzano (Abruzzo - Italy) was presented. The comparison of the results enables to verify and calibrate numerical pre-dictions on the base of data obtained from modal testing. The response of the structure in the time domain was recorded by highly sensitive sensor network, integrated by a data acquisition system. The identification was performed using techniques of modal extraction in the frequency domain (frequency domain de-composition). During the calibration process of the numerical model the values initially adopted were successively corrected in order to identify a reliable structural model to be used to have an accurate seismic vulnerability assessment of the hospital building.