Experimental testing of a two-storey 5875 square meters steel braced-frame building structure on a reinforced concrete slab isolated from the foundations through a hybrid system (28 high-damping rubber bearings and 36 low-friction sliding bearings) is presented. The base-isolated building incorporates a push-and-release device that allows to evaluate its actual global dynamic response up to displacement amplitudes induced by extreme seismic events. The push-and-release tests can be performed and repeated during the service life without damaging the building and the isolation system. The set up designed to test the building, whose cost represents a small increment of its construction cost if planned in the early stages of the design process, is presented. Afterwards, the experimental campaign, consisting of quasi-static push tests (slow loading and unloading) and push-and-release dynamic tests (slow loading and subsequent sudden release), is described. Although other experimental activities of this type were carried out and documented in the past, the tests presented in this paper have peculiarities related to the building (structural typology and size, foundation geometry on a steep slope, presence of the push-and-release device for future test repetitions), the magnitude of the maximum horizontal displacement achieved (284.6 mm), the global and local monitored parameters (accelerations, strains, horizontal and vertical displacements, in addition to environmental conditions) providing a comprehensive insight into the behaviour of the hybrid isolation system and superstructure.

Keywords: base-isolation, dynamic tests, experimental testing, full-scale tests, push-and-release tests.