TY - JOUR A1 - Orcesi, André A1 - Diamantidis, Dimitris A1 - O’Connor, Alan A1 - Palmisano, Fabrizio A1 - Sýkora, Miroslav A1 - Boros, Vazul A1 - Caspeele, Robby A1 - Chateauneuf, Alaa A1 - Mandić Ivanković, Ana A1 - Lenner, Roman A1 - Kušter Marić, Marija A1 - Nadolski, Vitali A1 - Schmidt, Franziska A1 - Skokandić, Dominik A1 - van der Spuy, Pierre T1 - Investigating Partial Factors for the Assessment of Existing Reinforced Concrete Bridges JF - Structural Engineering International N2 - There is great interest in developing an adequate partial factor format for the assessment of existing structures, and in particular bridges, that should be able to take various aspects into account linked to the fact that the structure already exists. As the structure is existing, additional information related to material parameters, loading conditions, local structural defects, etc. can be accounted for. In addition, the degree of conservatism needs to be well balanced to avoid unnecessary investment of resources in replacement or retrofitting. This contribution considers the experience gained in recent years in parallel with some ongoing standardisation work in relation to Eurocodes and the next edition of the fib Model Code for new and existing concrete structures. The current state of the art of partial factors for the assessment of existing structures is explored and the differences are assessed based on a comparison between (i) the use of recommended fixed partial factors as provided in many national and international codes, (ii) adjusted (flexible) partial factors derived for the individual case under consideration, and (ii) reliability-based verification. In order to assess the adequacy of proposals and identify some differences, the available partial factor formats are applied to two case studies of reinforced concrete bridges and they are critically assessed. Y1 - 2023 U6 - https://doi.org/10.1080/10168664.2023.2204115 SP - 1 EP - 16 PB - Taylor & Francis ER - TY - CHAP A1 - Sykora, Miroslav A1 - Nadolski, Vitali A1 - Novak, Lukáš A1 - Novak, Drahomír A1 - Diamantidis, Dimitris T1 - Pilot comparison of semi-probabilistic methods applied to RC structures with multiple failure modes T2 - Concrete Innovation for Sustainability, 6th fib International Congress in Oslo, Norway (2022), proceedings, 12-16 June 2022, Oslo, Norway Y1 - 2022 SP - 1890 EP - 1899 PB - fib ER - TY - CHAP A1 - Orcesi, Andre A1 - Bastidas-Arteaga, Emilio A1 - Markogiannaki, Olga A1 - Li, Yue A1 - Schoefs, Franck A1 - Ballester, Jorge A1 - O'Connor, Alan A1 - Sýkora, Miroslav A1 - Imam, Boulent A1 - Pregnolato, Maria A1 - Stewart, Mark A1 - Ryan, Paraic A1 - Diamantidis, Dimitris A1 - Wu, Teng A1 - Schmidt, Franziska A1 - Kreislová, Kateřina A1 - Salman, Abdullahi M. T1 - Investigating the effects of climate change on structural resistance and actions T2 - IABSE Congress, Ghent 2021, Structural Engineering for Future Societal Needs: 22.02.2021 - 24.02.2021, Ghent, Belgium N2 - One major issue when considering the effects of climate change is to understand, qualify and quantify how natural hazards and the changing climate will likely impact infrastructure assets and services as it strongly depends on current and future climate variability, location, asset design life, function and condition. So far, there is no well-defined and agreed performance indicator that isolates the effects of climate change for structures. Rather, one can mention some key considerations on how climate change may produce changes of vulnerability due to physical and chemical actions affecting structural durability or changes of the exposure in terms of intensity/frequency of extreme events. This paper considers these two aspects and associated challenges, considering some recent activities of members of the IABSE TG6.1. KW - adaptation KW - climate change KW - Durability KW - extreme events KW - vulnerability Y1 - 2021 U6 - https://doi.org/10.2749/ghent.2021.0974 SP - 974 EP - 985 PB - International Association for Bridge and Structural Engineering (IABSE) CY - Zürich ER - TY - JOUR A1 - Pandey, Mahesh A1 - Viljoen, Celeste A1 - Way, Andrew A1 - Katharina Fischer, Katharina A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Steenbergen, Raphaël D.J.M. A1 - Lind, Niels A1 - Frangopol, Dan M. A1 - Yang, David Y. A1 - Retief, Johan Verster A1 - André, João A1 - Nathwani, Jatin A1 - Lenner, Roman T1 - Life safety in the Reliability-Based design and assessment of structures JF - Structural Safety N2 - We review the developments in life safety and the incorporation thereof in the design and assessment of structures over the last 50 years. Various measures of life safety are presented that have been developed according to the marginal life saving cost principle based on individual, societal and economic considerations. Target probabilities of failure, or target reliabilities, are central to modern structural design and assessment. These are derived either through back-calibration to existing practice or through life cycle cost minimisation, both of which yield comparable safety levels, and are underpinned by lower bounds from life safety. Life cycle cost minimisation is reviewed here, which considers all direct and indirect costs of failure including loss of life and limb, as well as the costs and efficiency of increasing reliability. We discuss the incorporation of life safety into reliability-based design and assessment through the concept of the Life Quality Index, which uses key societal indicators, namely, the GDP and life expectancy, and health economics as a basis for specifying minimum reliabilities for both new and existing structures. The current state of advancement of reliability- and risk-informed design, and recommendations for future developments in life safety are considered. KW - Life safety KW - Structural assessment KW - Standardization KW - Reliability-based design KW - Risk-informed design Y1 - 2024 U6 - https://doi.org/10.1016/j.strusafe.2024.102453 PB - Elsevier ER - TY - JOUR A1 - Diamantidis, Dimitris A1 - Tanner, Peter A1 - Holicky, Milan A1 - Madsen, Henrik O. A1 - Sykora, Miroslav T1 - On reliability assessment of existing structures JF - Structural Safety N2 - This contribution discusses the reliability assessment of existing structures emphasizing on developments within or initiated by the JCSS. After a bibliographical review, the principles of reliability updating, i.e. Bayesian updating of random variables and updating of event probabilities are summarized. Developments in standards and established verification formats—partial factor or load and resistance factor, reliability-based, and risk-informed—are briefly presented and discussed. The impact of JCSS work in recent standards such as ISO 13822, the draft Eurocode prEN1990-2, and the fib Model Code 2020 as well as in national standards is highlighted. Criteria for defining target reliabilities for existing structures including human safety and optimization are critically reviewed. Obstacles for a wider implementation of reliability-based and risk-informed methods in practice are identified and conclusions for future developments are drawn. Finally, Annex A illustrates updating procedures for resistance variables and Annex B presents a case study. KW - Existing structures KW - Uncertainties KW - Updating KW - Target reliability KW - Reliability verification Y1 - 2024 U6 - https://doi.org/10.1016/j.strusafe.2024.102452 SN - 0167-4730 PB - Elsevier ER -