1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Following the destruction and panic caused by the earthquakes that rocked Croatia during the past year (all of which happening during a global pandemic), this work provides a brief description over the effectiveness of seismic isolation techniques in the region. To achieve that, we design, detail and analyse a six-story RC residential building, making use of the traditional capacity design approach and the seismic isolation approach, considering the local settings of seismic hazard and site characterization in the region of the capital city of Croatia, Zagreb. Furthermore, through Fast Nonlinear Analysis, the performance of seismically isolated building and the isolation system is verified with artificial Time Histories generated to match the spectrum of the design earthquake in the region. The shift in frequency of vibration and dissipation ability of the isolation system reduced the shear force induced in the superstructure in the case of the isolated building, allowing for a reduction in the cross-section and rebar area of the structural members which compensate for a part of the cost of isolation system. Moreover, the notably low interstory drifts in the case of seismically isolated building, ensure that no structural or non-structural member of the building sustain any damages at all, while the reduction of the floor acceleration enables a remarkable reduction in human perception of the seismic event, avoiding this way the panic or uncertainties that are common in the case of traditional design approach. Overall, given the country’s relatively high seismic hazard, the structural analysis revealed a significant enhancement in structural performance, indicating that seismic isolation is very relevant in the region.