201. SEISMIC RESPONSE CONTROL SYSTEMS AT STRATEGIC ELEVATION OF BUILDINGS: ANALYTICAL INVESTIGATION AND SIMULATED EXPERIMENTAL TESTS
Name: Gloria Faraone
Grad Year: 2020
The majority of the medium-tall buildings are not seismically isolated, as they present a relatively elongated Fundamental Period with respect to the low-rise and usually isolated buildings. Thus, base isolation may not seem necessary. However during a seismic event the higher storeys withstand large interstorey displacements and accelerations that produce considerable damages. Thus, in order to avoid the collapse of the upper floors of medium, high and tall buildings, the classical seismic isolation is supposed to be used at different locations from the base of the building. In this work, we will investigate the effective benefits that can derive from a typical isolation system located at different elevations, through the height of the building. In the first part of the project, analytical results obtained with computer simulations will be compared to the data provided by experimental tests on reduced scale models. In the second part of the project, a new way to validate the analysis is presented: the disruptive technology of the 3D printer will be used to quickly assemble multi-storey building models with an easy and low-cost process of realization. As the first step to assess the feasibility of testing with small-scale printed models is to match the first natural frequency of the studied structure, impact tests are conducted on the scaled structures. The obtained analytical results show significant reductions in terms of interstorey drift and relative accelerations as long as the seismic isolation system is located up to the first half of the height of the building. From the second part of the project it is shown that it is potentially feasible to use little-scale plastic models to test the behavior of real structures under seismic events. Further research is required to understand better the printed model's behavior in order to develop easy way to properly scale the models and predict the dynamic response of real structures. Similitude relationships and scaling factors may be determined once the accelerations and the displacements are recorded and the material damping properties are analyzed.