Role of repeated seismic events on the collapse of two Calidaria in Rome dating back to the imperial age

The seismic assessment of two vaulted monuments made of Roman concrete is here presented. Both their structural forms and constituent materials are here explored, whose combination enabled to build such largescale structures, and whose knowledge is essential for assessing and maintaining the safety of the portions of such structures that still exist. Specifically, two different monuments dating back to the Imperial age are analyzed: the Calidarium of the Baths of Caracalla and the Calidarium of the Diocletian's Baths. The two structures were built at a distance of less than one century one each other and both were erected with the same construction technique. Nowadays both Calidarium structures no longer exist: the first one still presents two not collapsed monumental pillars, whilst the ruins of the second were demolished in the Sixteenth Century. Therefore, the present work aims at investigating the causes behind their collapse and how their collapse occurred by performing advanced numerical simulations.