GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 2.3 525 effective connections, flexible diaphragms, very large openings) which did not even allow a complete and satisfactory reference to studies available in literature; • the effect on these buildings of low-magnitude short-duration induced earthquake signals, including magnitudes smaller than 4 usually not considered in engineering design, on buildings which were designed and constructed without any provision for lateral resistance against seismic; • the need for estimating the “Local Personal Risk” of buildings, defined as the annual probability of fatality for a hypothetical person continuously present inside or within 5 meters of a building (Crowley et al. 2017, van Elk et al. 2019), which requires a robust estimate of the probability of collapse of structural and non-structural elements within a building which implied consideration of uncertainties higher than those associated with other damage states and the challenging design of experimental tests allowing for the execution and interpretation of collapse shake-table tests on structural components and building prototypes. Description of the testing program. The testing campaign was specifically designed to support the development of the risk engine used in the framework of a project aimed at assessing the induced seismicity risk for the Groningen gas field. Crowley et al. (2017) well stated the needs of a risk analysis for the assessment of the “Local Personal Risk”, including fragility models robustly estimating the probability of collapse of structural and non-structural elements within a building, for the estimation of casualties for a scenario earthquake, and consequence models requiring estimates of the amount of collapsed debris to provide the probability of injury or death to people hit by this debris. The experimental campaign was specifically designed to provide the information needed to define numerical models capable of predicting the response of structures up to collapse conditions, to be used in the calibration of the vulnerability models embedded in the engine used to compute the seismic risk. The experimental program performed by EUCENTRE - Pavia, LNEC - Lisbon and Delft University of Technology (TUD) included in-situ mechanical characterization tests and laboratory tests, such as: (i) characterization tests on bricks, mortar and small masonry assemblies; (ii) in-plane cyclic shear-compression tests (e.g. Messali and Rots 2018, see Fig.1) Fig. 1 - Pictures of different staic and dynamic tests on structural and nonstructural compoments. and dynamic out-of-plane tests on full-scale masonry piers in one- and two-way bending (e.g. Graziotti et al. 2016, see Fig.1); and (iii) full-scale unidirectional and bidirectional shake table tests on different URM building typologies (e.g. Kallioras et al. 2018, see Fig.2). An overview of the experimental campaign on URM structures is reported in Graziotti et al. (2019). It is noted that, within the framework of the seismic risk assessment for Groningen, a parallel experimental campaign, similar in scope but smaller in extent, was deployed also for those