EXPLORING THE EXPECTED INCREASE OF COSTS AND LOSS REDUCTION BY RAISING THE BAR IN SEISMIC DESIGN: COMPARISON OF ALTERNATIVE DESIGN METHODOLOGIES AND EARTHQUAKE-RESISTANT TECHNOLOGIES

The severe socio-economic impact of recent earthquakes has further highlighted the existing mismatch between societal expectations and reality of seismic performance of modern buildings. Targeting the traditional Life-Safety level is not enough when dealing with new building design, thus the seismic scientific community is currently aiming to raise the bar in terms of seismic/structural safety. To achieve this goal, different strategies might be adopted, as implementing more advanced design methodologies, increasing the seismic demand (design) level and/or switching from a traditional/monolithic building system to an innovative high performance low-damage structure, capable to withstand high levels of shaking without being (significantly) damaged. Based on this motivation, the paper aims at comparing – through a parametric study – the cost/performance of Reinforced Concrete case-study buildings designed for increasing level of seismic intensity (low-to-high) according to: a) alternative design approaches (force-based vs displacement-based) and b) different earthquake-resisting technologies (monolithic vs low-damage). Thirty-seven parametric configurations are investigated. Analytical/numerical investigations are carried out to determine the building capacity curves and loss assessment investigations are performed to compute the Expected Annual Losses (EAL). Results highlight the convenience of a displacement-based design approach, allowing for a better control of the building performance in the plastic domain, as well as of the adoption of a low-damage technology, leading to a very high performance and significantly reduced economic losses for a small increase of the initial investment costs.