Integrated solution-base isolation and repositioning-for the seismic rehabilitation of a preserved strategic building

This paper deals with the design of the seismic rehabilitation of a case-study building located in Florence, Italy. The particular reinforced concrete building hosts an important operational center of the main company that manages the Italian highway network. It is composed of the juxtaposition of three reinforced concrete edifices standing out from a common basement. The design of the interventions for the seismic rehabilitation of this case study posed different challenges, some even in contrast with each other. The main design challenge was to reach the seismic retrofitting, due to the strategic role of the activities hosted herein, safeguarding as much as possible the peculiarity of the architectural elements. Moreover, the design was made harder by the presence of existing thermal joints between adjacent edifices which were inadequate to prevent the latter from pounding upon each other during an earthquake. This outcome yielded the need to intervene by enlarging the gap between the adjacent buildings. This latter intervention was in stark contrast with the explicit request of the client to bring the least possible disturbance to the strategic activities carried out within it; in fact, the joints are crossed by optical fibers and other technological systems which can be damaged easily. The need to fulfill all these design constraints brought the development of an original design strategy based on the employment of base-isolation in a rather unusual configuration. The details of the design procedure, along with the innovative aspects and the designed devices, are presented. With the objective to refine the adopted strategy in view of its possible repeatability by colleague engineers, the paper also presents a fair discussion of every aspect with regards to both the design and the realization phases. Possible ideas for new research and developments are also highlighted.