1st Croatian Conference on Earthquake Engineering 1CroCEE 2021

Every man-made structure induce more or less seismic energy through it’s foundations, but the most of the human casualties happens in residential buildings. Unfortunately, although most of the old houses and buildings are seismically vulnerable by default, many of the new design structures also represent threat during seismic event to their residents. Conventional aseismic standards imply the concept of increasing resistance capacity for all structural members, with fixed support to the foundation. Modern, but not yet widely accepted aseismic approach is to apply systems for base isolation, which can be active or passive. Both types can be used in residential buildings, but the cheaper investment and easier maintenance provides initial advantages to passive base isolation.
This paper presents the results of nonlinear response of a multi-storey reinforced concrete building imposed to seismic actions, which is modelled using ETABS software. Comparative behaviour analysis has been established onto two separate models: one with the fixed supports and the other with base isolation system incorporated into foundations. This system consists of rubber isolators and energy dissipaters, and experimental data for their nonlinear stiffness and yield strength are inputted into time-history analysis. The behaviour of structural elements in plastic range is defined through performance-based seismic design. Comparative diagrams of vibration modes, required reinforcement, frame displacement and inter-story drifts are given as results of behaviour analysis. Also, obtained results are compared with EC8 criteria, focusing on limit drifts in both models and their role in preventing and limiting structural damage depending on desired structural performance.