Seismic performance and damage evaluation of a waffle-flat plate structure with hysteretic dampers through shake-table tests

摘要

Reinforced concrete waffle-flat plate (WFP) structures present 2 important drawbacks for use as a main seismic resisting system: low lateral stiffness and limited ductility. Yet the former can serve a positive purpose when, in parallel, the flexible WFP structure is combined with a stiff system lending high-energy dissipation capacity, to form a flexible-stiff mixed structure. This paper experimentally investigates the seismic performance of WFP structures (flexible system) equipped with hysteretic dampers (stiff system) through shake-table tests conducted on a 2/5-scale test specimen. The WFP structure was designed only for gravitational loads. The lateral strength and stiffness provided by the dampers at each story were, respectively, about 3 and 7times greater than those of the bare WFP structure. The mixed system was subjected to a sequence of seismic simulations representing frequent to very rare ground motions. Under the seismic simulations associated with earthquakes having return periods ranging from 93 to 1894years, the WFP structure performed in the level of immediate occupancy, with maximum interstory drifts up to about 1%. The dampers dissipated most (75%) of the energy input by the earthquake.