Comparative Assessment of Empirical and Analytical Methods for Seismic Risk of Old Structures

Abstract

This study assesses the seismic vulnerability of traditional masonry and pre-1985 reinforced concrete buildings in Cyprus, addressing the critical challenge of evaluating older structures in regions with aging building stocks. A comparative framework evaluates three methodologies: an empirical methodology based on EMS-98, the European Seismic Risk Model 2020 (ESRM20), and an integrated multi-degree-of-freedom (MDOF) framework termed the Xekalakis approach. The Xekalakis method integrates detailed field surveys with three-dimensional (3D) finite-element modeling and derives fragility curves via nonlinear time-history analysis. Validation demonstrates close alignment between the Xekalakis and empirical PLINIVS results, with a damage probability variance of less than 3%. In contrast, the ESRM20 approach tends to underestimate masonry vulnerability. To enable direct comparison, the study introduces a harmonized damage state classification. These findings underscore the value of combining empirical data with advanced numerical simulation for robust regional risk assessment. The proposed framework provides a practical and scalable tool for disaster risk reduction planning in regions with vulnerable, aging building stocks.