RE-CENTERING AND DISSIPATIVE CONNECTIONS FOR PINNED-FRAME PRECAST STRUCTURES.

The response of buildings not specifically designed to resist seismic actions can be generally improved by imposing the dissipation of an appropriate amount of energy. The use of passive devices to improve the seismic performance of precast structures is investigated. These devices can be successfully applied at the beam-column connections of pinned-frame structures, typical of international precast industry, in order to increase the connection degree of fixity and the dissipated energy during a seismic event. The peculiarity and efficiency of passive dissipation devices based on rotational friction with the addition of a re-centering device is analyzed. Both devices may be used in the case of one-story or multi-story existing buildings and new designed structures. Moreover, they are able to mitigate the inter-story drift demand, which often governs the seismic design of typical commercial and industrial precast buildings. The investigated devices are applied to a selected case study, a single-story precast reinforced concrete hinged-frame building. Nonlinear time history analyses are carried out to outline the improved structural performance under seismic actions. The difference between the application of such devices to existing or new buildings is also addressed.