PSI - Issue 44

Gianluca Standoli et al. / Procedia Structural Integrity 44 (2023) 2066–2073 G. Standoli et al. / Structural Integrity Procedia 00 (2022) 000 – 000

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the image the 2021 trend, after environmental effects removal, is reported in black, while the total trend in red. Numerous voids can be found in the graphs of Fig. 5. This occurrence is more likely linked to the low level of Signal to Noise Ratio (SNR), being the Cathedral located in a not accessible area of the city which reflects in a lack of external sources of excitation, and consequentially in a failure in modal parameters extraction. 4. Conclusions The paper shows an application of continuous structural monitoring by a particular type of accelerometric sensors, i.e. MEMS. Through a Matlab© script it was possible to identify the dynamic characteristics associated to the first four modes of the two twin towers of Santissima Maria Annunziata Cathedral in Camerino, a historical building strongly damaged by the seismic events of 2016- ‘17, and then subdued to temporary reinforcement interventions. The procedure produced interesting results, allowing to understand the differences in the dynamic behavior of the two towers, despite their symmetry, and evaluating its evolution during years. Moreover, it was possible to prove the efficiency of MEMS sensors for continuous monitoring activity. Future developments expect to extend this study towards damage identification and localization. References Clementi, F., Ferrante, A., Giordano, E., Dubois, F., Lenci, S., 2020. Damage assessment of ancient masonry churches stroked by the Central Italy earthquakes of 2016 by the non-smooth contact dynamics method. Bulletin of Earthquake Engineering 18, 455 – 486. https://doi.org/10.1007/s10518-019-00613-4. Deraemaeker, A., Reynders, E., De Roeck, G., Kullaa, J., 2008. Vibration-based structural health monitoring using output-only measurements under changing environment. Mechanical Systems and Signal Processing 22, 34 – 56. https://doi.org/10.1016/j.ymssp.2007.07.004. Ferrante, A., Clementi, F., Milani, G., 2019. Dynamic Behavior of an Inclined Existing Masonry Tower in Italy. Frontiers in Built Environment, Vol. 5. https://doi.org/10.3389/fbuil.2019.00033. Garcia-Macias, E., Ubertini, F., 2020. MOVA/MOSS: Two integrated software solutions for comprehensive Structural Health Monitoring of structures. Mechanical Systems and Signal Processing 143, p. 106830. https://doi.org/10.1016/j.ymssp.2020.106830. Gentile, C., Guidobaldi, M., Saisi, A., 2016. One-year dynamic monitoring of a historic tower: damage detection under changing environment. Meccanica 51, 2873-2889. https://doi.org/10.1007/s11012-016-0482-3. Giordano, P.F., Ubertini, F., Cavalagli, N., Kita, A., Masciotta, M.G., 2020. Four years of structural health monitoring of the San Pietro bell tower in Perugia, Italy: two years before the earthquake versus two years after. International Journal of Masonry Research and Innovation Vol. 5, No 4, 445-467. DOI: 10.1504/IJMRI.2020.111797. Jacobsen, N.J., Andersen, P., Brinker, R., Kullaa, J., 2006. Using Enhanced Frequency Domain Decomposition as a Robust Technique to Harmonic Excitation in Operational Modal Analysis. Proceedings of ISMA2006: International Conference on Noise & Vibration Engineering Katholieke Universiteit. Magalhães, F., Cunha, A., Caetano, E., 2012. Vibration based structural health monitoring of an arch bridge: From automated OMA to damage detection. Mechanical Systems and Signal Processing 28, 212-228. https://doi.org/10.1016/j.ymssp.2011.06.011. Masciotta, M.G., Roque, J.C.A., Ramos, L.F., Lourenco, P.B., 2016. A multidisciplinary approach to assess the health state of heritage structures: The case study of the Church of Monastery of Jerónimos in Lisbon. Construction and Building Materials 116, 169 – 187. https://doi.org/10.1016/j.conbuildmat.2016.04.146. Pastor, M., Binda, M., Harčarik , T., 2012. Modal Assurance Criterion. Procedia Engineering 48, 543 – 548. https://doi.org/10.1016/j.proeng.2012.09.551. Peeters, B., De Roeck, G., 1999. Reference-Based Stochastic Subspace Identification for Output-Only Modal Analysis. Mechanical Systems and Signal Processing 13, 855 – 878. https://doi.org/10.1006/mssp.1999.1249. Pierdicca, A., Clementi, F., Fortunati, A., Lenci, S., 2019. Tracking modal parameters evolution of a sch ool building during retrofitting works,” Bulletin of Earthquake Engineering 17(2), 1029-1052, https://doi.org/10.1007/s10518-018-0483-9. Ramos, L.F., De Roeck, G., Lourenco, P.B., Compos-Costa, A., 2010. Damage identification on arched masonry structures using ambient and random impact vibrations. Engineering Structures 32, 146 – 162. https://doi.org/10.1016/j.engstruct.2009.09.002. Reynders, E., Houbrechts, J., De Roeck, G., 2012. Fully automated (operational) modal analysis. Mechanical Systems and Signal Processing 29, 228 – 250. https://doi.org/10.1016/j.ymssp.2012.01.007. Saisi, A., Gentile, C., Guidobaldi, M., 2015. Post-earthquake continuous dynamic monitoring of the Gabbia Tower in Mantua, Italy. Construction and Building Materials 81, 101-112. https://doi.org/10.1016/j.conbuildmat.2015.02.010. Ceravolo, R. Coletta, G., Miraglia, G., Palma, F., 2021. Statistical correlation between environmental time series and data from long-term monitoring of buildings. Mechanical Systems and Signal Processing 152. https://doi.org/10.1016/j.ymssp.2020.107460.