Urban-Scale Risk Assessment: (How) Does It Change If We Include SSI and Site Amplification Effects?

Abstract

AbstractWe introduce, develop, compare and apply two holistic, modular methods to include site amplification (SA) and soil-structure interaction (SSI) effects in urban scale earthquake risk assessment. We propose two methods, including a detailed and a simplified structural modeling approach. SSI and SA effects are explicitly considered in both approaches’ fragility and vulnerability calculation. The detailed method is accompanied by a significant time and effort cost, while it more elaborately captures the structural response. The simplified modeling approach facilitates the analyses procedures; however, it neglects certain aspects of the more complex nonlinear dynamic structural behavior. We applied the two approaches to the risk assessment of a block of buildings in Thessaloniki, Greece, and demonstrated each method’s advantages and disadvantages. Our main results suggest that SA effects increase fragility more than SSI. Using a detailed modeling approach may lead to a more reliable estimate of the expected losses, compromised, however, by the significantly higher modeling and computational effort.KeywordsFragilityVulnerabilityUrban-scaleSoil-structure interactionSite amplification