@inproceedings{HolickyDiamantidisSykora, author = {Holicky, Milan and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Economically optimum structural design}, series = {High Performance and Optimum Design of Structures and Materials III (HPSM/OPTI 2018) ; Ljubljana, Slovenia 11.07.2018 - 13.07.2018}, booktitle = {High Performance and Optimum Design of Structures and Materials III (HPSM/OPTI 2018) ; Ljubljana, Slovenia 11.07.2018 - 13.07.2018}, editor = {de Wilde, W. P. and Hern{\´a}ndez, S. and Kravanja, S.}, publisher = {WIT}, doi = {10.2495/hpsm180151}, pages = {143 -- 153}, abstract = {Codes of practice aim to assure structures have acceptable risks to the public and the minimum total costs over the working life of a design. However, current codified criteria for structural design correspond to a broad range of reliability levels, specified for dissimilar reference periods even though their recalculation for different periods is uncertain due to unknown dependence of failure events in time. In this contribution, target reliability levels are specified on the basis of probabilistic risk optimization considering the objective function as a sum of various costs including effects of time to failure and discounting. A case study presents probabilistic optimization of the roof of a stadium for 4,000 spectators and illustrates the effect of the considered input parameters. Failure consequences and relative cost of safety measure are shown to be major factors affecting the optimum reliability level. Less important factors are the discount rate and working life. Large uncertainty in failure cost estimates seems to have only a marginal effect on derived optimum reliability levels.}, language = {en} } @inproceedings{CroceDiamantidisSykora, author = {Croce, Valeria and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Seismic Damage Evaluation and Decisions on Interventions Supported by UAV-Based Surveys}, series = {Protection of Historical Constructions: Proceedings of PROHITECH 2021}, volume = {209}, booktitle = {Protection of Historical Constructions: Proceedings of PROHITECH 2021}, editor = {Vayas, Ioannis and Mazzolani, Federico M.}, publisher = {Springer International Publishing}, address = {Cham}, isbn = {978-3-030-90787-7}, doi = {10.1007/978-3-030-90788-4_20}, pages = {206 -- 221}, abstract = {The contribution demonstrates the benefits of Unmanned Aerial Vehicles (UAV)-based surveys for building damage evaluation and decisions on interventions after an earthquake. The case study focuses on the historic village of Castelluccio di Norcia (Italy), heavily damaged by the 2016 earthquake. By constructing a 3D model based on UAV flights, the damage levels are estimated for buildings in the village and an optimal set of intervention measures is proposed. For the decision analysis, a pre-posterior Bayesian technique is utilized. The efficiency of the UAV-based survey is highlighted through a cost-benefit analysis and by considering parameters such as the time constraints, the quality of obtained data and the risk of inspecting persons. The proposed method seems to be efficient in organizing rescuing activities, managing emergency measures and specifying interventions, following the occurrence of an accidental situation.}, language = {en} } @inproceedings{CroceDiamantidisSykora, author = {Croce, Valeria and Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Planning post earthquake surveys: assessments and reconstruction of small historical centres}, series = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, booktitle = {1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings}, editor = {Bien, Jan}, publisher = {Curran Associates Inc}, address = {Red Hook, NY}, isbn = {978-1-7138-2387-2}, pages = {332 -- 339}, abstract = {The contribution presents a methodological procedure for the management and planning of interventions after earthquake events in small historic centres. Reference is made to the case study of Castelluccio di Norcia, a village in the Apennine Mountains affected by the seismic sequence that hit Central Italy in 2016. The earthquake risk of the area and the damaging events of 2016 are critically reviewed. The implementation of cognitive analysis and the application of advanced survey techniques involving the use of nmanned Aerial Vehicles (UAVs) for the purposes of emergency management and monitoring of damaged areas are analysed. The outcomes, combined with the direct involvement of the local population, represent a complete and integrated approach allowing the definition of a) possible intervention strategies, b) related decision criteria and c) practical recommendations for the reconstruction and regeneration of Castelluccio, and, in general, of small historic centres damaged by catastrophic events.}, language = {en} } @inproceedings{DiamantidisSykora, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Reliability Differentiation and Uniform Risk in Standards}, series = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, booktitle = {Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029}, doi = {10.5592/CO/FTCE.2019.11}, pages = {241 -- 260}, abstract = {Reliability of structures and infrastructures is a major issue in structural engineering. Structural standards have traditionally been mainly concerned with public safety preventing loss of life or injury; this view has been shifting in recent years towards minimisation of economic loss. This contribution discusses the reliability differentiation principle in modern standards. Its aim is to achieve uniform risk levels for the various classes of structures. Codified criteria for reliability differentiation and risk informed decisions inherent in standards and especially in the Eurocodes are critically reviewed. It is shown that the classification of structures based on consequences of failure is an approach that has not been widely implemented in everyday design. Practical rules for the classification and implementation in design are needed and related proposals are presented.}, language = {en} } @article{SykoraDiamantidisMuelleretal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Mueller, Dominik and Sousa, Helder}, title = {A practical guide on the quantification of value of information gained by structural health monitoring and application to historic masonry structures}, series = {Structure and Infrastructure Engineering}, volume = {18}, journal = {Structure and Infrastructure Engineering}, number = {4}, publisher = {Taylor\&Francis}, doi = {10.1080/15732479.2020.1857793}, pages = {441 -- 455}, abstract = {Structural health monitoring (SHM) projects are mostly based on semi-empirical decisions, emphasising the importance of the structure and lacking a rational comparison of the benefits and costs. The present work offers guidance to overcome this, based on an objective framework using the quantification of the value of SHM in an engineering context. Firstly, procedures for practising engineers are outlined on the basis of the COST guidelines. Secondly, a case study, focused on the reliability of a historic masonry structure, demonstrates the optimisation of surveys based on non-destructive tests calibrated by destructive tests. Both the outlined procedures and case study are carefully prepared and in tune, so the reader can easily understand the feasibility of the framework. Decisions on the utilisation of SHM in practical applications can be effectively achieved based on the highest expected utility gained by SHM. For this, two scenarios are needed: (i) a scenario with at least one SHM strategy and (ii) a scenario without any SHM.}, language = {en} } @article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Markov{\´a}, Jana and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {Assessment of compressive strength of historic masonry using non-destructive and destructive techniques}, series = {Construction and Building Materials}, volume = {193}, journal = {Construction and Building Materials}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.conbuildmat.2018.10.180}, pages = {196 -- 210}, abstract = {Masonry structures were built by various techniques using different materials, the properties of which exhibit a considerable scatter dependent on periods of construction and region-specific conditions. For historic structures with a heritage value, various non- or minor-destructive tests (NDTs) are commonly applied, while the application of destructive tests (DTs) is minimized. The contribution is based on investigations of 15 historic stone and clay brick masonry structures, for which NDT strengths of masonry units are verified by DTs. The proposed operational approach makes it possible to account for statistical uncertainty due to a limited number of DTs used to calibrate NDTs.}, language = {en} } @inproceedings{DiamantidisSykora, author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav}, title = {Implementing Snow Load Monitoring to control Reliability of a Stadium Roof}, series = {Transactions of VSB}, volume = {19}, booktitle = {Transactions of VSB}, number = {1}, publisher = {TECHNICAL UNIVERSITY OF OSTRAVA}, doi = {10.35181/tces-2019-0006}, pages = {35 -- 40}, abstract = {This contribution shows how monitoring can be used to control reliability of a structure not complying with the requirements of Eurocodes. A general methodology to obtain cost-optimal decisions using limit state design, probabilistic reliability analysis and cost estimates is utilised in a full-scale case study dealing with the roof of a stadium located in Northern Italy. The results demonstrate the potential of monitoring systems and probabilistic reliability analysis to support decisions regarding safety measures such as snow removal, or temporary closure of the stadium.}, language = {en} } @article{SykoraDiamantidisHolickyetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holicky, Milan and Jung, Karel}, title = {Target reliability for existing structures considering economic and societal aspects}, series = {Structure and infrastructure engineering}, volume = {13}, journal = {Structure and infrastructure engineering}, number = {1}, publisher = {Taylor\&Francis}, doi = {10.1080/15732479.2016.1198394}, pages = {181 -- 194}, abstract = {Specification of target reliability levels is one of the key issues of the assessment of existing structures. ISO 13822:2010 and ISO 2394:2015 indicate procedures for specification of target reliability levels by optimisation of the total cost related to an assumed remaining working life of a structure. These approaches are critically compared with human safety criteria, with target levels based on a marginal life-saving costs principle, and with recommendations of present standards. Optimal target reliability levels are then derived in the representative case study for an existing structural member. It appears that the requirement to reach the same target reliability levels for existing and new structures is uneconomical. Decisions made in the assessment can result in the acceptance of the actual state or in the upgrade of an existing structure. Two reliability levels are thus needed - the minimum level below which the structure is unreliable and should be upgraded, and the target level indicating an optimum upgrade strategy. It is recommended that these levels be established using economic optimisation and the marginal life-saving costs principle, as both the approaches take into account the costs of safety measures and the failure consequences.}, language = {en} } @article{SykoraHolickyDiamantidis, author = {S{\´y}kora, Miroslav and Holick{\´y}, Milan and Diamantidis, Dimitris}, title = {Probabilistic updating in the reliability assessment of industrial heritage structures}, series = {Heron}, volume = {59}, journal = {Heron}, number = {2/3}, publisher = {Stevin-Laboratorium, TU Delft}, address = {Delft}, issn = {0046-7316}, abstract = {Assessment of existing structures should be based on the actual as-built conditions concerning geometry, material properties, loading and environmental conditions. A crucial step of the assessment consists in updating of prior information by newly obtained measurements which may be conducted by Bayesian approach. Updating of probabilistic distributions of basic variables or direct updating of failure probability can be effectively used. Application of theoretical principles is illustrated by a case study of a historic factory built in 1900s. The paper is a tribute to Ton Vrouwenvelder for his essential contributions to developments of theory and promotion of practical applications of probabilistic assessment of existing structures.}, language = {en} } @article{SteenbergenSykoraDiamantidisetal., author = {Steenbergen, R.D.J.M. and S{\´y}kora, Miroslav and Diamantidis, Dimitris and Holick{\´y}, Milan and Vrouwenvelder, A.C.W.M.}, title = {Economic and human safety reliability levels for existing structures}, series = {Structural Concrete. JOurnal of the fib}, volume = {16}, journal = {Structural Concrete. JOurnal of the fib}, publisher = {Wiley}, doi = {10.1002/suco.201500022}, pages = {323 -- 332}, abstract = {Specifying the target reliability levels is one of the key issues in the assessment of existing structures. For a majority of existing buildings and infrastructures, the design life has been reached or will be reached in the near future. These structures need to be reassessed in order to verify their safety. Eurocodes provide a general basis primarily intended for the design of new structures, but the basic principles can be used for assessing existing buildings, too. Reliability levels are generally based on both economic optimization and criteria for human safety. In this study, both methods are elaborated for existing structures. It appears that the requirement for the same target reliability for existing and new structures is uneconomical. Further, cost optimization seems to yield rather low reliability levels and human safety criteria often become the critical factor. The study concludes with practical guidelines for establishing reliability indices for existing structures linked to Eurocode principles.}, language = {en} } @book{TannerdeDiegoLaraSaracheetal., author = {Tanner, Peter and de Diego, Ana and Lara Sarache, Carlos and Prieto, Miguel and Hingorani, Ram{\´o}n and Holick{\´y}, Milan and S{\´y}kora, Miroslav and Diamantidis, Dimitris and Men{\´e}ndez Ondina, Antonio and Croce, Pietro and Bartelletti, Raffaello and Beconcini, Maria Luisa and Formichi, Paolo and Marsili, Francesca and Muzzi, Martina and Rosso, Elisa and Toprak, Selcuk and Inel, Mehmet and Koc, Cem and Nacaroglu, Engin and Senel, Sevket Murat}, title = {Operational methods for the assessment and management of aging infrastructure}, publisher = {Tipograf{\´i}a editrice Pisana}, address = {Pisa, Italia}, isbn = {9788882501471}, pages = {186}, abstract = {The Leonardo da Vinci Project, "Innovation Transfer in Risk Assessment and Management of Aging Infrastructures", CZ/13/LLP-LdV/TOI/134014, addresses the urgent need to train students, young engineers and professionals in the assessment of existing infrastructures. The future of the construction industry lies in moving from new constructions towards the maintenance, repair and rehabilitation of existing structures, particularly of aging infrastructures. Risk management consisting of risk assessment and risk control of existing structure therefore plays thereby an important role. The assessment of existing infrastructures is an imperative issue of great economic significance in most countries around the world, as more than 50 \% of all construction activities concerns existing buildings, bridges and other civil engineering works. At present, the Eurocodes which will be used in all CEN Member countries are primarily focused on the design of new structures. Additional operational rules for existing structures are still missing. The international standard ISO 13822 provides only general principles for the assessment of existing structures which should be further developed for their effective operational use in practice. The overall procedure of risk management of aging infrastructures is therefore an urgent issue of great economic significance in most countries around the world. This is primarily caused due to the fact that many infrastructures are affected by action effects, fatigue and environmental influences, and inevitably deteriorate. Moreover, available resources for the maintenance, repair or possible replacement of infrastructures are always limited. Typical questions and problems which must be solved in this context can be summarized as follows: • What is the current state of a particular infrastructure? • What is an acceptable level of the relevant risk? • Which aspects are critical to sustainable performance? • What is the optimum life-cycle cost? • What is the best long-term funding strategy? The proposed project highlights the above problems and focusses also on vocational training in risk management and assessment of aging infrastructure in the partner countries (CZ, DE, ES, IT and TR). The current project addresses the urgent need for practical implementation of principles of the management and risk assessment of existing infrastructures in all the partner countries. The project is supported by the Czech Chamber of Chartered Engineers (ČKAIT). The project consortium, under the leadership of the Klokner Institute of the Czech Technical University in Prague (KI CTU), consists of five other partners, including research institutions and universities from three EU Member States (DE, ES, IT) as well as one associated country (TR), and also the Secondary Technical School of Civil Engineering in Ceske Budejovice (CZ). All researchers within the partnership are involved in research projects dealing with reliability assessment of existing structures. They participate in the national and international standardization activities within the international organizations CEN (European Committee for Standardisation) and ISO (International Standardization Organisation). The project outcomes consist of vocational training materials based on international research and relevant standard committee's activities, and on the significant experience gained from case studies, and on selected results obtained from the previous projects of the Leonardo da Vinci programme. In particular, the experience gained by the partners of the present consortium from the completed project on vocational training related to assessment of existing structures is utilized. Available innovations are transferred to undergraduate and graduate students, practising engineers and local government representatives. The developed training materials are of practical use in offering illustrative examples and several case studies. All the project outcomes are based on documents of the international research organization, Joint Committee on Structural Safety JCSS and international research projects, selected outcomes of the previous project of the Leonardo da Vinci programme (developed by five partners of the present consortium in 2013-2015) and also on background documents to the new European and international standards. Particular outcomes of the proposed project include practical handbooks, software tools, web-sites, e-learning, courses and seminars organized in the partners´ home countries. The project outcomes will also be offered to other European countries through code committees work, lectures and the project web-sites. It is foreseen that the outcomes being used by engineers, designers, technicians, and representatives of public authorities involved in planning and management will have an impact on the risk-based management of infrastructures. One of the important project outcomes is the present Handbook 2 "Operational Methods for the Assessment and Management of Aging Infrastructure", which is focussed on operational techniques for the assessment of aging infrastructures supplemented by illustrative case studies developed according to ISO 13822 and Eurocodes for different structures and materials. From the mentioned project also result Handbook 1, where general procedures of risk-management and assessment of aging infrastructures are presented, and Handbook 3, where operational techniques for the assessment of aging infrastructures supplemented by illustrative case studies are presented with a more basic approach. Handbook 2 consists of eleven chapters. Chapter 1 gives a brief introduction. Chapter 2 summarizes current applicable standards and codes for existing structures. Chapter 3 reviews survey methods. The remaining chapters are devoted to the illustration of relevant case studies, referring to the assessment of different existing infrastructures. In particular, chapter 4 refers to a commercial building, chapter 5 to a r.c. building damaged by corrosion, chapter 6 to silos, chapter 7 to pipelines and water supply systems, chapter 8 to tanks, chapter 9 to historical aqueducts, chapter 10 to bridges and chapter 11 to dams and flood protection systems. In each case studies the entire procedure of the assessment is illustrated step by step emphasizing references to relevant Codes and in particular to ISO 13822. It is believed that the material of this handbook is presented in an understandable way, referring to several case studies. A number of references mentioned in each chapter provide additional background materials, further guidance and information useful to widen the significance and the field of application of the assessment methods illustrated for each case study. Pisa and Prague, 2015}, language = {en} } @inproceedings{DiamantidisHolickySykora, author = {Diamantidis, Dimitris and Holick{\´y}, Milan and S{\´y}kora, Miroslav}, title = {Risk and reliability acceptance criteria for civil engineering structures}, series = {Structural Reliability and Modelling in Mechanics Conference, Ostrava, Czech Republic, May 2016}, booktitle = {Structural Reliability and Modelling in Mechanics Conference, Ostrava, Czech Republic, May 2016}, pages = {1 -- 10}, abstract = {The specification of risk and reliability acceptance criteria is a key issue of structural design and verification of existing structures. Current target reliability levels in standards appear to have considerable scatter. Critical review of risk acceptance approaches to societal, economic and environmental risk indicates that an optimal design strategy is mostly dominated by economic aspects while human safety aspects need to be verified only in special cases. It is recommended to specify the target levels considering economic optimisation and the marginal life-saving costs principle, as both these approaches take into account the failure consequences and costs of safety measures.}, language = {en} } @inproceedings{DiamantidisSykoraBarnardoViljoenetal., author = {Diamantidis, Dimitris and S{\´y}kora, Miroslav and Barnardo-Viljoen, Celeste and Retief, Johan Verster and R{\´o}zs{\´a}s, {\´A}rp{\´a}d}, title = {On Risk-Based Design of Structures Exposed to Changing Climatic Actions}, series = {Life-Cycle of Engineering Systems : Emphasis on Sustainable Civil Infrastructure ; The Fifth International Symposium on Life-Cycle Civil Engineering (IALCCE 2016) 16-20 October 2016, Delft, The Netherlands}, booktitle = {Life-Cycle of Engineering Systems : Emphasis on Sustainable Civil Infrastructure ; The Fifth International Symposium on Life-Cycle Civil Engineering (IALCCE 2016) 16-20 October 2016, Delft, The Netherlands}, editor = {Bakker, Jaap and Frangopol, Dan M. and Van Breugel, Klaas}, publisher = {Taylor \& Francis}, address = {London ; Boca Raton}, isbn = {978-1-138-02847-0}, language = {en} } @incollection{SykoraHolickyJungetal., author = {S{\´y}kora, Miroslav and Holick{\´y}, Milan and Jung, Karel and Diamantidis, Dimitris}, title = {Target reliability levels for assessment of existing structures considering economic and societal aspects}, series = {Life-Cycle of Structural Systems}, booktitle = {Life-Cycle of Structural Systems}, editor = {Akiyama, Mitsuyoshi and Furuta, Hitoshi and Frangopol, Dan M.}, publisher = {CRC Press}, address = {London}, isbn = {9780429227196}, doi = {10.1201/b17618-121}, pages = {838 -- 845}, abstract = {Specification of the target reliability levels is one of the key issues of the assessment of existing structures. ISO 13822:2010 and ISO 2394:1998 indicate procedures for deriving the target reliability levels by optimisation of the total cost related to an assumed remaining working life of a structure. In the submitted study this approach is applied to estimate the target reliability levels of an existing structural member in conjunction with the human safety criteria. Obtained results are critically compared with the recommendations given in present standards. It appears that the requirement on the same target reliability levels for existing structures as for new structures is uneconomical. Further, the cost optimisation seems to yield rather low reliability levels and human safety criteria become commonly decisive for specification of the target reliabilities of existing structures.}, language = {en} } @inproceedings{SykoraDiamantidisMarkovaetal., author = {S{\´y}kora, Miroslav and Diamantidis, Dimitris and Markov{\´a}, Jana and Masciotta, Maria Giovanna}, title = {Optimizing in-situ testing for historic masonry structures: a case study}, series = {International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) : Durability, Monitoring and Repair of Structures, 20-22 March 2019, Rovinj, Croatia}, booktitle = {International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) : Durability, Monitoring and Repair of Structures, 20-22 March 2019, Rovinj, Croatia}, editor = {Baričević, Ana and Jelčić Rukavina, Marija and Damjanović, Domagoi and Guadagnini, Maurizio}, publisher = {RILEM Publications}, isbn = {978-1-5108-9296-5}, pages = {684 -- 691}, language = {en} } @article{OrcesiO'ConnorDiamantidisetal., author = {Orcesi, Andr{\´e} and O'Connor, Alan and Diamantidis, Dimitris and S{\´y}kora, Miroslav and Wu, Teng and Akiyama, Mitsuyoshi and Alhamid, Abdul Kadir and Schmidt, Franziska and Pregnolato, Maria and Li, Yue and Salarieh, Babak and Salman, Abdullahi M. and Bastidas-Arteaga, Emilio and Markogiannaki, Olga and Schoefs, Franck}, title = {Investigating the Effects of Climate Change on Structural Actions}, series = {Structural Engineering International}, volume = {32}, journal = {Structural Engineering International}, number = {4}, publisher = {Taylor \& Francis}, doi = {10.1080/10168664.2022.2098894}, pages = {1 -- 14}, abstract = {The changing climate with resulting more extreme weather events will likely impact infrastructure assets and services. This phenomenon can present direct threats to the assets as well as significant indirect effects for those relying on the services those assets deliver. Such threats are path-dependent and place-specific, as they strongly depend on current and future climate variability, location, asset design life, function and condition. One key question is how climate change is likely to increase both the probability and magnitude of extreme weather events under different scenarios of climate change. To address this issue, this paper investigates selected effects of climate change and their consequences on structural performance, in the context of evolving loading scenarios in three different continental regions: Europe, North America, and Asia. The aim is to investigate some main place-specific changes of the exposure in terms of intensity/frequency of extreme events as well as the associated challenges, considering some recent activities of members of the IABSE TG6.1. Climate change can significantly affect built infrastructure and the society by increasing the occurrence and magnitude of extreme events and increasing potential losses. Therefore, specific relationships relating hazard levels and structural vulnerability to climate change effects should be determined.}, language = {en} } @article{OrcesiDiamantidisO’Connoretal., author = {Orcesi, Andr{\´e} and Diamantidis, Dimitris and O'Connor, Alan and Palmisano, Fabrizio and S{\´y}kora, Miroslav and Boros, Vazul and Caspeele, Robby and Chateauneuf, Alaa and Mandić Ivanković, Ana and Lenner, Roman and Kušter Marić, Marija and Nadolski, Vitali and Schmidt, Franziska and Skokandić, Dominik and van der Spuy, Pierre}, title = {Investigating Partial Factors for the Assessment of Existing Reinforced Concrete Bridges}, series = {Structural Engineering International}, journal = {Structural Engineering International}, publisher = {Taylor \& Francis}, doi = {10.1080/10168664.2023.2204115}, pages = {1 -- 16}, abstract = {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.}, language = {en} } @inproceedings{SykoraNadolskiNovaketal., author = {Sykora, Miroslav and Nadolski, Vitali and Novak, Luk{\´a}š and Novak, Drahom{\´i}r and Diamantidis, Dimitris}, title = {Pilot comparison of semi-probabilistic methods applied to RC structures with multiple failure modes}, series = {Concrete Innovation for Sustainability, 6th fib International Congress in Oslo, Norway (2022), proceedings, 12-16 June 2022, Oslo, Norway}, booktitle = {Concrete Innovation for Sustainability, 6th fib International Congress in Oslo, Norway (2022), proceedings, 12-16 June 2022, Oslo, Norway}, publisher = {fib}, pages = {1890 -- 1899}, language = {en} } @inproceedings{OrcesiBastidasArteagaMarkogiannakietal., author = {Orcesi, Andre and Bastidas-Arteaga, Emilio and Markogiannaki, Olga and Li, Yue and Schoefs, Franck and Ballester, Jorge and O'Connor, Alan and S{\´y}kora, Miroslav and Imam, Boulent and Pregnolato, Maria and Stewart, Mark and Ryan, Paraic and Diamantidis, Dimitris and Wu, Teng and Schmidt, Franziska and Kreislov{\´a}, Kateřina and Salman, Abdullahi M.}, title = {Investigating the effects of climate change on structural resistance and actions}, series = {IABSE Congress, Ghent 2021, Structural Engineering for Future Societal Needs: 22.02.2021 - 24.02.2021, Ghent, Belgium}, booktitle = {IABSE Congress, Ghent 2021, Structural Engineering for Future Societal Needs: 22.02.2021 - 24.02.2021, Ghent, Belgium}, publisher = {International Association for Bridge and Structural Engineering (IABSE)}, address = {Z{\"u}rich}, doi = {10.2749/ghent.2021.0974}, pages = {974 -- 985}, abstract = {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.}, language = {en} } @article{PandeyViljoenWayetal., author = {Pandey, Mahesh and Viljoen, Celeste and Way, Andrew and Katharina Fischer, Katharina and S{\´y}kora, Miroslav and Diamantidis, Dimitris and Steenbergen, Rapha{\"e}l D.J.M. and Lind, Niels and Frangopol, Dan M. and Yang, David Y. and Retief, Johan Verster and Andr{\´e}, Jo{\~a}o and Nathwani, Jatin and Lenner, Roman}, title = {Life safety in the Reliability-Based design and assessment of structures}, series = {Structural Safety}, journal = {Structural Safety}, publisher = {Elsevier}, doi = {10.1016/j.strusafe.2024.102453}, abstract = {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.}, language = {en} } @article{DiamantidisTannerHolickyetal., author = {Diamantidis, Dimitris and Tanner, Peter and Holicky, Milan and Madsen, Henrik O. and Sykora, Miroslav}, title = {On reliability assessment of existing structures}, series = {Structural Safety}, journal = {Structural Safety}, publisher = {Elsevier}, issn = {0167-4730}, doi = {10.1016/j.strusafe.2024.102452}, pages = {1}, abstract = {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.}, language = {en} }