Limit state analysis for the Catania fire-station (Italy)

Strategic buildings, such as fire-stations, need to be extremely accurately designed against ultimate limit state (ULS) and damage limitation state (DLS). In this context, dynamic soil-structure analysis appears a crucial design phase. The present paper deals with the seismic behavior of the fire-station located in Catania (Italy). Three different FEM models are considered: in the first one the structure rests on a significant soil volume; in the second one the structure is fixed at the base; in the third one the structure rests on stiffnesses, simulating the soil deformability. Artificial accelerograms related to elastic response spectrum for rock are considered. The results show that the fixed base structure model, which is very often utilized in routine design, leads to bending moment and shear forces on the structure significantly different from those of the more realistic model, in which the structure rests on soil. The third model, involving soil impedances, leads to results similar to those of the first model; thus, it could represent a useful schematization, which allows us to easily take soil deformability into account.