In Portugal, at the end of the World War II, a new generation of architects emerged, influenced by the Modern Movement
Architecture. In the fifties, it was built a large number of Modern housing buildings in Lisbon, with particular structural
characteristics that, in certain conditions, can induce weaknesses in structural behaviour, especially under earthquake
loading. For example, the concept of buildings lifted in "pilotis", present in this architectural style, can strongly facilitate
the occurrence of soft-storey mechanisms, which makes these structures very vulnerable to earthquake actions. To
investigate the vulnerability of this type of construction, one building, representative of the Modern Architecture, in
Lisbon, was studied with a non-linear dynamic analysis program, PORANL, which allows the safety evaluation according
to recently proposed assessment procedures. Additionally, it was proposed and analyzed a retrofitting solution, to improve
the seismic performance, based on a bracing system with a damping device associated
