Experimental Hybrid Simulation of Severe Aftershocks Chains on Buildings Equipped with Curved Surface Slider Devices

Abstract

In this research work the outcomes of a hybrid experimental campaign are analyzed, in order to evaluate the influence of aftershock events on the frictional response of sliding-based isolation devices for buildings. To achieve this, a hybrid testing framework was accordingly defined, by considering a numerical substructure, in terms of a simplified analytical model of a case study structure, and a physical substructure, as a full-scale Curved Surface Slider device, tested within the Bearing Tester System of the EUCENTRE Foundation Laboratory in Pavia (Italy). The tested isolator was equipped with a special sliding material, made up of a Poly-Tetra-Fluoro-Ethylene-based compound (PTFE), filled with carbon fibers and with a solid lubrication. The hybrid tests were performed, in terms of earthquake simulations, and the response of the base-isolated structural system was computed, by applying single-events, rather than aftershock chains. Results lead to a better understanding of the behavior of sliding-based seismic isolation systems, characterized by medium-to-high tribological properties, in terms of peak and residual displacements for both the single-event and the mean responses. Specifically, this work provides hybrid experimental evidence of the influence of an initial displacement offset on the overall behavior of the considered structural system.

The Generation of the Target Aftershock Spectrum Based on the Conditional Mean Spectrum of Aftershocks

“…However, this method could be improved if the correlation and randomness of the main shock and aftershocks for the source mechanism, spectral shape, etc., are also considered. The same limitation was also observed in other studies [14]. Wei et al [15] pointed out that the concrete-filled steel tubular composite columns with ultra-high performance concrete plates demonstrated good seismic performances with MS-AS sequences.…”