Seismic assessment of churches through integration of digital survey, texture recognition and distinct element modelling

The paper proposes an integrated methodology for the seismic assessment of masonry churches, which exploits the recent progresses of digital survey tools, image-processing algorithms for automatic texture identification, and non-linear seismic analysis. Starting with the digital survey of structural macro-elements, which provides accurate information on geometry, defects and blocks arrangement, discrete element models are generated. Then, a pushover analysis is carried out, which allows to detect local collapse mechanisms and follow their development up to failure. The capacity curve of the macro-element is therefore obtained, including both ascending and descending branches. The effect of retrofitting measures is directly considered within the model and their efficacy evaluated in terms of variation in acceleration and displacement capacity. The proposed methodology is described step-by-step through the application to the case study of the Romanesque church of Santa Maria Maggiore in Tuscania, Italy.