The domus of Arianna in Pompeii archaeological site. Risk assessment on the colonnades through historical analysis and digitization techniques.

The archaeological site of Pompeii presents several areas that are precluded to visitors, due to the risks connected to colonnades forming the characteristic courtyards of the Roman houses. The columns were reassembled after the exca-vation of the site, following anastylosis principles, but they are not linked to any entablature or roofing system and can be subjected to failure effects in case of ex-ceptional actions like seismic events. As part of a research project coordinated by the University of Naples Federico II (prof. Renata Picone) and Politecnico di Mi-lano (prof. Daniela Oreni), the authors investigated the mechanical response of the colonnades in the House of Arianna, a domus sited in the 9th regio district of the town, composed by two courtyards. The north colonnade presents severe damage on the columns, constituted by stone blocks and coated by a thick painted plaster. The second colonnade is formed by stone drums, appears more complete than the first one, with less damage. The two typologies of the columns were studied through advanced survey acquisitions, historical analysis, materials and decays mapping, and structural evaluation. According to a base literature review on this topic, the first typology of colonnade, made by masonry stone blocks, is rarely investigated from the point of view of mechanical behavior under seismic and other actions. Thus, the authors developed an HBIM based geometrical mod-el, set for collecting multilayered analyses obtained from the on-field investiga-tions, for the risk evaluation referred to free standing columns, realized with dif-ferent building technologies, without reliable constraints at the top.