The effects of the Phlaegrean Bradyseism on building systems: Field research applied in Pozzuoli

The contribution presents the results of field research aimed at assessing the effects of the Phlaegrean Bradyseism phenomena on a building system located in the historic centre of Pozzuoli (Italy). The study falls within the scope of building façade vulnerability analyses conducted by the authors to support the Public Administration in managing bradyseismic emergencies. Considering that the seismic-deformation phenomena connected to Bradyseism affect the performance and integrity of façade components, the research focused on studying its impact on the technical elements within the Technological Unit Classes of “Load-bearing Structure”, “Enclosure”, and “External Partition”, which directly project onto the external environment and collectively constitute the Building Envelope. The methodology for impact assessment was developed by correlating data acquired from a monitoring system installed on the façade of a surveyed building with characteristic parameters related to seismic events and soil deformations in a specific reference period. The analyses conducted excluded any significant impact of these seismic-deformation forcings on the building's Load-bearing Structure, both in terms of displacements and damage. On the other hand, significant impacts were found on the technical elements of the building envelope, which, due to their lower resistance and ductility, represent a constant hazard for the exposed urban system’s safety, configuring a Building Risk scenario.