Search

Regional, multi-country seismic hazard models provide a comparison basis for national seismic hazard models that are generally used to underpin the seismic design prescriptions of national building codes. Our study presents an attempt to formalize a framework for performing such a comparison. This comparison consists of sequential steps for identifying and understanding similarities of the key elements informing the seismic hazard models and the code design ground motions in addition to their numerical comparison. The challenge may arise, on one hand, from the lack of transparency of some national seismic codes and, on the other hand, from the intrinsic difficulties in comparing seismic hazard models. In this study, as an example we compare the seismic design spectrum of the Iranian national design code with the uniform hazard spectra from the recent, fully-harmonized, cross-borders Earthquake Hazard Model for the Middle East region (EMME). This comparison focuses on the two 10% in 50-year exceedance probability maps for PGA and on the pairs of design spectra for four cities with different seismicity levels. While, in general, the two reference maps for PGA on rock seem similar, the comparison of the uniform hazard spectra and design spectra for the four selected cities for different soil conditions show large differences. We offer some plausible causes for these differences as well as generic recommendations for overcoming them. [ABSTRACT FROM AUTHOR]

A risk-consistent approach is proposed for the evaluation of behaviour factors that are compatible with Eurocode 8, using nonlinear static and dynamic analysis. It comprises seven discrete steps, involving hazard assessment and record selection at multiple sites, designing and modelling multiple archetype buildings and assessing their performance vis-à-vis target safety objectives. In all cases, uncertainty is incorporated and propagated to the final results whereby a flexible verification procedure is offered to account for the confidence of the investigator on the data available. An example application is offered on steel concentrically braced frames, highlighting the need for selecting appropriate performance targets for Europe. The overall added value goes beyond the current state of art, offering a consistent risk basis for the seismic design of different systems that is compatible with current uniform hazard design spectra and can benefit from future risk-targeted hazard maps. • A risk-consistent approach is proposed for deriving EN1998 compatible behaviour factors. • Hazard assessment, record selection and incorporation of uncertainty are important aspects of the approach. • Setting appropriate performance targets is required to achieve consistency with current EN1998 implied safety. • An example is shown for steel concentrically braced frames. [ABSTRACT FROM AUTHOR]