Seismic response of a RC structure with new self-centering metallic dampers under biaxial near-field ground motions: Shake table tests

Resumen

A new metallic energy dissipation device (EDD) with self-centering capability is proposed, and its effectiveness in controlling the seismic response of buildings subjected to near-fault earthquakes is investigated experimentally in combination with an inherently very flexible structural system: the RC waffle-flat plate structure. The new EDD combines the high energy dissipation capacity of stainless steel with the super-elastic properties of shape memory alloys. EDDs are installed in a 2/5 scale portion of a prototype RC waffle-flat plate structure designed only for gravity loads and tested on a shake table. The specimen is subjected to two horizontal components of a ground motion scaled in amplitude to represent different levels of seismic hazard at the building site. The RC structure with EDDs performed basically elastic under frequent earthquakes, remained “operational” under the design-level earthquake, and performed within the limits of “operational” and “life safety” under maximum credible earthquakes. The new EDD substantially reduced the maximum residual inter-story drifts —up to 1/10 of those of a conventional metallic EDD without self-centering capability. The response was also compared with a counterpart conventional RC structure without EDDs. The importance of providing the metallic EDDs with self-centering capability is highlighted.