Preliminary results from push-and-release tests of a base-isolated building in Camerino, Italy

Abstract

Experimental testing of a two-storey steel braced-frame building structure on a reinforced concrete slab isolated from the foundations resting on a steep slope through a hybrid system (high-damping rubber bearings and low-friction sliding bearings) is presented. The base-isolated building incorporates a permanent push-and-release device capable of displacement amplitudes as those induced by extreme seismic events and allowing the push-and-release tests to be repeated in the future. The tested building as well as its testing set up, whose cost represents a small increment of its construction cost if planned in the early stages of the design process, are presented. Afterwards, preliminary results from quasi-static push tests (slow loading and unloading) and push-and-release dynamic tests (slow loading and subsequent sudden release) are briefly described. Compared to push-and-release tests documented in the past, the activities presented in this article have peculiarities related to the building (typology, size, and foundation geometry), the magnitude of the maximum horizontal displacement achieved (284.6 mm), the possibility to repeat the same tests in the future, producing comprehensive sets of data for the analysis of the behaviour of the hybrid isolation system and superstructure.