GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 2.3 527 useful for the development of the exposure model and for the design of laboratory tests. Quasi-static cyclic tests on structural members and assemblies, performed by EUCENTRE and TU Delft, represented an essential source of information allowing an accurate investigation of several aspects related to their seismic response. They also constituted a valuable basis for the development of specific capacity models, strength criteria and limit state thresholds. Out-of-plane static and dynamic tests were also performed on cavity wall systems in one-way and two-way bending conditions. These pioneering tests represented an important benchmark for the analysis of the response of local mechanisms in existing URM buildings. The experimental information collected during the tests constituted a basis for the development and calibration of numerical models and analytical tools used for predicting the behaviour of example buildings belonging to the most common building types in the region, i.e. URM terraced buildings, typically with cavity walls and different diaphragm solutions depending on the construction period, and pre-1940 detached houses, with solid brick walls and timber diaphragms. These analyses where then used to feed vulnerability models and derive the fragility curves used in the risk analysis process. Six full-scale shaking table tests on building (additional ones are scheduled for 2019 and 2020) were performed in the EUCENTRE and LNEC laboratories on entire building specimens or representative portions. Such tests, never performed on similar structures subjected to induced seismicity records, resulted to be fundamental for assessing the modelling capabilities on complete building systems and directly allowed the study of their complex dynamic behaviour, specific energy dissipation characteristics, especially in the highly nonlinear range, and peculiar collapse modes. The shaking table tests on building specimens also allowed for a direct comparison of the seismic vulnerability of specimens representing two of the most common building typologies. The solid-walls detached houses showed a lower seismic vulnerability. The near-collapse conditions were attained for values of peak ground acceleration ranging from 0.6g to 0.7g for detached houses and from 0.3g to 0.4g for terraced houses. A novel timber retrofit technique was also tested demonstrating its capability. All the reports, the majority of the videos and the data recorded by EUCENTRE and LNEC during the tests are available for interested researchers and stakeholders (they can be requested online at www.eucentre.it/nam-project) . Acknowledgments. This work is part of the EUCENTRE project “Study of the vulnerability of masonry buildings in Groningen”, within the research program framework on hazard and risk of induced seismicity in the Groningen region, sponsored by the Nederlandse Aardolie Maatschappij BV (NAM). The authors would like to thank all parties involved in this project: the DICAr Laboratory of the University of Pavia and the EUCENTRE Laboratory, which performed the tests; and partners NAM, Arup, TU Delft and TU Eindhoven for their insight and contributions related to the test program. Thanks also go to J. Uilenreef, A. Campos Costa, A.A. Correia, H. Crowley, F. Dacarro, A. Fragomeli, S. Girello, G. Guerrini, L. Grottoli, S. Kallioras, M. Mandirola, B. Marchesi, S. Peloso, A. Rossi, S. Sharma, G. Sinopoli and U. Tomassetti for the practical support. References Avanes C., Fusco C., Asghari Mooneghi M., Huang Y., Palmieri M. and Sturt R.; 2018: LS-DYNA Numerical Simulation of Full Scale Masonry Cavity Wall Terraced House Tested Dynamically . In: Proc. of the 16th Europ. Conf. on Earthq. Eng., 16ECEE, 18-21/6, Thessaloniki, GR. Fig. 3 - Different numerical modelling of unreinforced brick-masonry buildings using: (a) equivalent-frame macroelements (TREMURI; Kallioras et al. 2019); (b) finite elements (LS-DYNA; Avanes et al. 2018); (c) discrete elements (Extreme Loading Software; Malomo et al. 2019).