A slama-based analytical procedure for the cost/performance-based evaluation of buildings

The decision-making process for seismic risk is affected by the assessment/design procedure adopted and rigorous methodologies have been developed to estimate performance metrics relevant to stakeholders to take informed decisions. Input data for loss estimations of buildings are typically floor accelerations and inter-storey drift ratios, generally obtained from: 1) simplified evaluations, based on linear models and static analysis, 2) more accurate non-linear static analyses, or 3) more complex and time-consuming non-linear history analyses. Considering that non-linear static analyses are arguably the best compromise between accuracy and simplicity, this paper proposes the application of an analytical non-linear static procedure, based on the Simplified Lateral Mechanism Analysis (SLaMA) of the NZSEE 2017 Guidelines, for the cost/performance-based evaluation of Reinforced Concrete structures. In order to validate the accuracy of the method, multi-storey case-study buildings are analyzed using different structural analysis methods (the proposed SLaMA-based approach vs. numerical Pushover vs. Time-History) and through sophisticated or simplified loss assessment methodologies (FEMA P-58, 2012; D.M. n.65, 2017). The results in terms of Expected Annual Losses from the SLaMA-based approach are quite satisfactory - increase of 7-18% or 3-7% compared to numerical Pushover results from probabilistic or simplified loss estimations, increase of 20-40% compared to numerical Time-History results - and, in general, more accurate than static analyses results, even though no numerical modelling is needed. Therefore, the SLaMA-based method can be a promising tool for a daily use of practicing engineers for a rapid evaluation of economic losses for both the seismic assessment of existing buildings and the initial feasibility studies of new structures.