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The application of 3D motion capture systems to shaking table testing provides a unique tool for recording relative displacements of a large number of measurement points of the tested structure. The analysis of 3D relative displacements during dynamic tests allows us to evaluate the structure deformations and to monitor the cracks formation and evolution. The present paper focuses on the processing and analysis of 3D motion capture data to extract accurate displacements between markers positioned on a full-scale model of a masonry cross vault representing a vault of the mosque of Dey, Algiers, tested at the ENEA Casaccia Research Centre. The management and processing of the data acquired through 67 markers located on the vault are described, showing the potentialities of the methodology. Moreover, the possible formulation of damage indices based on the structure deformations and cracks aperture detected from markers relative displacements (MRDs) was explored. In particular, cracks could be counted and classified as a function of the detected apertures, following damage thresholds indicated in the Italian regulations. Moreover, the failure mechanism could be easily visualized and analysed by monitoring the cumulative MRDs. In addition, in-plane and out-of-plane deformations of walls could be monitored during each seismic test, providing accurate information on the torsional and bending effects.
3D motion capture, crack, deformations, masonry structures, shaking table tests
[1] D’Ayala, D. & Speranza, E., Definition of collapse mechanisms and seismic vulnerability of historic masonry buildings. Earthq Spectra, 19(3), pp. 479–509, 2003. https://doi.org/10.1193/1.1599896
[2] lagomarsino, S. & Podesta, S., Seismic vulnerability of ancient churches: I. Damage assessment and emergency planning. Earthquake Spectra, 20(2), pp. 377–394, 2004. https://doi.org/10.1193/1.1737735
[3] Carpinteri, A., Invernizzi, S. & lacidogna, G., In siti damage assessment and nonlinear modelling of a historical masonry tower. Engineering Structure, 27(3), pp. 387–395, 2005. https://doi.org/10.1016/j.engstruct.2004.11.001
[4] Polimeno, M.R., Roselli, I., luprano, V., Mongelli, M., Tatì, A. & De Canio, G., A non-destructive testing methodology for damage assessment of reinforced concrete buildings after seismic events. Engineering Structures, 163, pp. 122–136, 2018. https://doi.org/10.1016/j.engstruct.2018.02.053
[5] Grünthal, G., European Macroseismic Scale 1998 (EMS-98). Cahiers du Centre Européen de Géodynamique et de Séismologie, Helfent-Betrange (luxembourg) 15, 1998.
[6] OPCM Regulation n. 28, June 9, 2017. Modifiche all’ordinanza n. 19, 7 aprile 2017, recante ‘Misure per il ripristino con miglioramento sismico e la ricostruzione di immobili ad uso abitativo gravemente danneggiati o distrutti dagli eventi sismici verificatisi a far data dal 24 agosto 2016’. Gazzetta Ufficiale, (in Italian), Italian standard, 143, June 22, 2017.
[7] Park, y.J., Ang, A.H.S. & Wen, y.k., Seismic damage analysis and damage-limiting design of RC buildings. Structural Research Series, 516, University of Illinois: Urbana, USA. 1984.
[8] Park, y.J., Ang, A.H.S. & Wen, y.k., Damage-limiting aseismic design of buildings. Earthquake Spectra, 3(1), pp. 1–26, 1987. https://doi.org/10.1193/1.1585416
[9] Roufaiel, M.S.l. & Meyer C., Analytical modelling of hysteretic behavior of R/C frames. Journal of Structural Engineering, 113(3), pp. 429–444, 1987. https://doi. org/10.1061/(ASCE)0733-9445(1987)113:3(429)
[10] Roselli, I., Fioriti, V., Mongelli, M., Colucci, A. & De Canio, G., Machine Vision-Based Application to Structural Analysis in Seismic Testing by Shaking Table. Optoelectronics in Machine Vision-Based Theories and Applications, IGI Global ed., 2018. https:// doi.org/10.4018/978-1-5225-5751-7.ch010
[11] De Canio, G., Mongelli, M. & Roselli, I., 3D Motion capture application to seismic tests at ENEA Casaccia Research Center: 3DVision system and DySCo virtual lab. WIT Transactions on The Built Environment, 134, pp. 803–814, 2013. https://doi. org/10.2495/SAFE13071
[12] Roselli, I., Mongelli, M., Tatì, A., & De Canio, G., Analysis of 3D motion data from shaking table tests on a scaled model of Hagia Irene, Istanbul. Key Engineering Materials, 624, pp. 66–73, 2015. https://doi.org/10.4028/www.scientific.net/ kEM.624.66
[13] Calderini, C., lagomarsino, S., Rossi, M., De Canio, G., Mongelli, M. & Roselli, I., Shaking table tests of an arch-pillars system and design of strengthening interventions by the use of tie-rods. Bulletin of Earthquake Engineering, 13(1), pp. 279–297, 2015. https://doi.org/10.1007/s10518-014-9678-x
[14] De Canio, G., de Felice, G., De Santis, S., Giocoli, A., Mongelli, M., Paolacci, F. & Roselli, I., Passive 3D motion optical data in shaking table tests of a SRG-reinforced masonry wall. Earthquakes and Structures, 40(1), pp. 53–71, 2016. https://doi. org/10.12989/eas.2016.10.1.053
[15] Vicon documentation, https://docs.vicon.com/display/CamDocs. (accessed January 23, 2019).
[16] Mongelli, M., Roselli, I., De Canio, G. & Ambrosino, F., Quasi real-time FEM calibration by 3D displacement measurements of large shaking table tests using HPC resources. Advances in Engineering Software, 120, pp. 14–25, 2018. https://doi.org/10.1016/j. advengsoft.2016.07.005
[17] Williams, M.S. & Sexsmith, R.G., Seismic damage indices for concrete structures: A state-of-the-art review. Earthquake Spectra, 11(2), pp. 319–349, 1995. https://doi.org/10.1193/1.1585817
[18] DiPasquale, E., Ju, J.W., Askar, A. & Çakmak, A.S., Relation between Global Damage Indices and local Stiffness Degradation. Journal of Structural Engineering, 116(5), pp. 1440–1456, 1990. https://doi.org/10.1061/(ASCE)0733- 9445(1990)116:5(1440)
[19] Roselli, I., Fioriti, V., Mongelli, M., Bellagamba, I. & De Canio, G., Mutual vali- dation between different modal analysis techniques for dynamic identification of the so-called Temple of Minerva Medica, Rome. IOP Conference Series: Materials Science and Engineering, 364, p. 012004, 2018. https://doi.org/10.1088/1757- 899X/364/1/012004
[20] Abdessemed-Foufa, A., Visual screening for a potential evaluation of seismic vulnerability of historical building: Palace of the Dey (Citadel of Algiers). WIT Transactions on The Built Environment, ed. WIT Press, 123, pp. 119–123, 2012. https://doi.org/10.2495/ DSHF120101
[21] Abdessemed Foufa, A., Terki, y. & Benouar, D., Case study: local seismic culture in vernacular architecture in Algeria. In Seismic Retrofitting: Learning from Vernacular Archi- tecture, eds. Correia M.R, lourenco P.B & Varum H. CRC Press, pp. 101–102, 2015. https://doi.org/10.1201/b18856
[22] khellafi, A.M., Harichane, Z., Afra, H. & Sadouki, A., A Case Study of Accelerometric Records Analysis of May 21st, 2003, Boumerdes (Algeria) Earthquake. International Journal of Geotechnical Earthquake Engineering (IJGEE), 4(2), pp. 34–52, 2013. https://doi.org/10.4018/ijgee.2013070103