Dynamic identification of a strategic building of the sixties with a mixed structure

The present paper shows and discusses the results of the identification procedure applied to the building of the Municipality of Castellaneta, Taranto (Puglia, Italy). The case study has been chosen for its structural complexity; indeed, the building has been built in two successive phases, block A built between 1955 and 1957, and block B, for completion, presumably built between the years 1960 and 1961. Block A constitutes the main building and represents the original nucleus. The structure was subsequently subject to structural interventions to replace some load-bearing walls with steel beams. The building constituting block B, joined to the original body of the building, has a structure in load-bearing masonry, while the floors, more recently built, are also in brick-concrete, but with pre-cast prestressed joists. The dynamic response of the building was assessed through OMA (Operational Modal Analysis) identification technique which allows you to determine the properties of the structure in real operating conditions, without the need to interrupt the activities inside the structure itself. The structural excitement, therefore, is due only to the environmental condition. A 3D model was defined in PRO_SAP; the results obtained from the finite element model were subsequently compared with those obtained from the experimental model.