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Damage data on low-to-mid-rise Reinforced Concrete (RC) buildings, collected during the UK Earthquake Engineering Field Investigation Team post-earthquake reconnaissance mission on the August 24 Central Italy earthquake, are employed to derive empirical fragility relationships. Given the small dataset, the new data distributions are used for the Bayesian update of fragility functions derived for the L’Aquila earthquake (same seismic region and similar construction typologies). Other properties such as number of storeys, age of construction and shape in plan of the buildings are also analyzed. This information is employed to assess the ability of the FAST method to predict damage states in non-regular infilled RC buildings for the municipalities of Amatrice, Accumoli, Arquata del Tronto and Norcia, all severely affected by the 2016 Central Italy sequence. FAST is a spectral-based method to derive capacity curves and peak ground acceleration damage state thresholds for buildings. It is a dedicated methodology for regular RC frame buildings with masonry infills, first calibrated on damage data from the 2009 L’Aquila earthquake and applied to the 2011 Lorca (Spain), the 2012 Emilia (Italy) events for damage back-analyses. The new data from the August 2016 Central Italy earthquake provide a test-bed for FAST further employments in case of less homogenous building samples. The application of FAST presented here accounts for different shake-maps produced by both the United States Geological Survey and the Italian National Institute of Geophysics and Volcanology which are significantly different and representative of different refinements of the demand scenario. For the area of Amatrice, where the two shake-maps provide similar estimates and the buildings considered match reasonably well the typology for which FAST is calibrated, the comparison between damage level observed and as provided by FAST is very satisfactory. For other structural typologies like RC industrial structures and dwellings with non-hollow-clay-bricks as infills, FAST needs further calibration. [ABSTRACT FROM AUTHOR]

• New closed-form solution for the calculation of the out-of-plane force-displacement response of masonry walls is presented. • Analytical model is validated with respect to 17 experimental tests available in the literature. • Out-of-plane assessment of a case-study Nepalese school building is carried out with the Capacity Spectrum Method (CSM). • Asymptote of the hysteretic damping in CSM is calibrated with shaking table tests. • PGAs of different damage states are compared with median values from empirical fragilities. Traditional unreinforced masonry (URM) constructions still represent an important part of the school building stock in several low-income countries including Nepal. Unfortunately, their intrinsic vulnerability impacts negatively on the resilience of cities and local communities. Observations after major seismic events have shown that the predominant mode of failure is the out-of-plane (OOP) of the weak and loosely connected perimeter masonry walls which typically leads to partial or global collapse. Starting from this evidence, a closed-form analytical approach is presented aimed at deriving the OOP force-displacement response of URM walls for different boundary conditions and vertical loads. The novel analytical solution is successfully validated with the results of seventeen OOP experimental tests on URM walls available in the literature. Then, referring to a case-study Nepalese school building, capacity curves of the constituting walls are derived and adopted for the vulnerability assessment of the structure through the Capacity Spectrum Method (CSM) where equivalent hysteretic damping is calibrated with available OOP shaking table test results. Lastly, PGA capacities for different damage states are successfully compared with median values from observational fragility curves. [ABSTRACT FROM AUTHOR]

The main features of the Reinforced Concrete (RC) building stock that was struck by the Emilia 2012 earthquake and damage observed after the event are analyzed. Building stock characteristics and historical seismic classification are employed for the definition of two benchmark structures, representative of the whole building stock. Seismic capacity of the two structures, at different damage states, is assessed through static push-over analyses, within the N2 spectral assessment framework. Infill panels׳ contribution in terms of strength and stiffness is explicitly taken into account in the analytical model. Damage States are defined according to a mechanical interpretation of EMS-98 scale. Fragility functions at each Damage State are obtained through the application of a Response Surface Method. Finally large-scale damage scenarios are obtained crossing the geo-referenced census data regarding the characteristics of the Emilia RC building stock and starting from the seismic input provided by the shake map of the event. The scenarios seem to be in reasonable agreement with the observed damage. [ABSTRACT FROM AUTHOR]