Issue 51

C. Ferrero et alii, Frattura ed Integrità Strutturale, 51 (2020) 92-114; DOI: 10.3221/IGF-ESIS.51.08

the significant deterioration of the building conditions produced by the earthquakes of October 26 th , 2016. Large and extensive cracks occurred in most of the walls, especially in the Y direction. Furthermore, an out-of-plane mechanism was activated in one corner. As shown in Figure 5c, the damage state did not change significantly after the shake of October 30 th as compared with October 26 th .

After August 24 th , 2016

After October 26 th , 2016

After October 30 th , 2016

a) c) Figure 5: Damage observed in “Pietro Capuzi” school after the earthquakes that occurred on: a) August 24 th , 2016, b) October 26 th , 2016, and c) October 30 th , 2016 [11, 12]. Permanent Monitoring by the Seismic Observatory of Structures As part of the OSS, “Pietro Capuzi” school was permanently monitored by a system of accelerometers located in different parts of the building (Figure 6): one tri-axial accelerometer was located in the basement to measure the seismic input, and ten bi-axial accelerometers were placed at the first and second levels, at the intrados of the slabs, to record the accelerations experienced by the structure. b)

a) c) Figure 6: Location of the accelerometers: a) basement, b) raised ground floor, c) first floor [10]. b)

This monitoring system was used to identify the dynamic behavior of “Pietro Capuzi” school within the framework of the experimental campaign performed in 2010-2011 on behalf of the OSS. As described in [9], dynamic identification tests were carried out by CESI S.p.A to determine the natural frequencies and mode shapes of the first three modes of vibration of

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