TY - JOUR A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Lenzi, Daniele T1 - Optimising Monitoring: Standards, Reliability Basis and Application to Assessment of Roof Snow Load Risks JF - Structural Engineering International N2 - This paper addresses the optimisation of monitoring and decision-making criteria regarding the future use of structures. The current state of practice in standards and reliability framework are initially summarised. A general methodology for obtaining cost-optimal decisions is then presented on the basis of limit state design, probabilistic reliability analysis and cost estimates. The implementation of the risk-based approach is illustrated in a case study dealing with the roof of a stadium located in northern Italy. As the roof fails to comply with the requirements of the Eurocodes, the installation of a permanent monitoring system is recommended to allow for a real-time reliability assessment. The results demonstrate the potential of monitoring systems and probabilistic reliability analysis for supporting decisions regarding safety measures such as snow removal or temporary closure of the stadium, as well as reflecting the need to implement the discussed procedures in future standards. Y1 - 2018 U6 - https://doi.org/10.1080/10168664.2018.1462131 VL - 28 IS - 3 SP - 269 EP - 279 PB - Taylor&Francis ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Holický, Milan A1 - Rózsás, Árpád A1 - Barnardo-Viljoen, Celeste A1 - Retief, Johan Verster A1 - Diamantidis, Dimitris T1 - Risk Based Design of Infrastructures under Extreme Actions due to Environmental Change T2 - Life-cycle of engineering systems: emphasis on sustainable civil infrastructure, Symposium of the International Association for Life-Cycle Civil Engineering (IALCCE), 2016, Delft N2 - Environmental and climate change is a global issue that will and has already impacted the frequency and intensity of natural hazards in many regions throughout the world. Consequently, the actions on structures will be changing and present design practices will need to be adapted to provide for reliable structures with service lifetimes spanning over decades and centuries. A submitted review of present environmental and climate change information is focused on the distinct, but complementary climatic conditions of Central Europe and South Africa. An outline of the basis of structural design accounting for extreme wind and snow loads is presented and recommendations for future risk-based design procedures are discussed. Issues to consider include: a) use of extreme value models; b) implementation of changes in distribution parameters to obtain extremes with long return periods; c) consideration of the rate of the change. The example of a representative structure illustrates the effects of climatic actions on structural reliability. It appears that uncertainties related to the lack of observations hinder drawing strong conclusions concerning appropriate modifications of design procedures due to environmental and climate change. Uncertainties in the prediction of environmental and climate change have a direct bearing on optimal levels of reliability and the subsequent derivation of design values. Y1 - 2018 PB - Taylor & Francis ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Markova, Jana A1 - Charters Morais, Eduardo T1 - Compressive Strength of Historic Masonry based on Destructive and Non-Destructive Test Results T2 - Proceedings of the 3rd International Conference on Protection of Historical Constructions (PROHITECH'17), July 12-15, 2017, Lisbon, Portugal Y1 - 2017 UR - https://www.researchgate.net/publication/320016406_Compressive_Strength_of_Historic_Masonry_based_on_Destructive_and_Non-Destructive_Test_Results ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Markova, Jana A1 - Diamantidis, Dimitris T1 - Bayesian network application for the risk assessment of existing energy production units JF - Reliability Engineering & System Safety N2 - The assessment of existing infrastructures in the energy sector is of great economic significance worldwide. Fossil power stations are reaching their design service life and rational decisions concerning extensions of service life, maintenance and replacements of devices should be based on updated information of the actual conditions of the energy devices and their components, and on cost-benefit analysis using risk analysis and probabilistic optimisation procedures. The contribution provides an integrated framework for probabilistic reliability and risk assessment of existing energy production units considering availability and human safety criteria. An extensive case study focused on risks of an energy production unit in a fossil power station is provided to support practical applications. A Bayesian network is thereby implemented to assess the risks of the selected production unit. Special emphasis is given to the input data consisting of failure rates obtained from recorded data and expert judgements. The influence of uncertainties in the considered performance indicators on the availability of the unit is analysed. It is shown that a reasonably simplified framework can provide a valuable assessment of the influence of individual devices and their components on availability and societal risk, identifying thus the major risk contributors. (C) 2017 Elsevier Ltd. All rights reserved. KW - Availability KW - Bayesian networks KW - Decision-making KW - design KW - Failure probability KW - FRAMEWORK KW - Optimization KW - Production unit KW - Risk analysis KW - Societal risk KW - SYSTEMS KW - Uncertainties Y1 - 2018 U6 - https://doi.org/10.1016/j.ress.2017.09.006 VL - 169 IS - January SP - 312 EP - 320 PB - Elsevier ER - TY - CHAP A1 - Boccara, R. A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Optimal design of ground-mounted solar systems T2 - Safety and reliability : methodology and applications : proceedings of the European Safety and Reliability Conference, ESREL 2014, Wrocław, Poland, 14-18 September 2014 N2 - Solar energy represents a clean, natural and sustainable source of energy. Solar photovoltaic panels can be installed on roofs of structures or in the ground. This contribution focusses on ground-mounted systems, which are presently widely implemented. At present limited guidelines on the design of solar ground-mounted structures are available. Usually standards for the design of normal buildings are applied. However, the design of ground-mounted structures significantly differs from common structural design by: (1) a lower design lifetime (20-25 years) is accepted; (2) failure is not associated with the loss of human life; (3) resistance uncertainties need due attention; (4) uplift wind forces dominating structural reliability are associated with a large scatter. That is why the reliability analysis and optimal design of ground-mounted solar systems is investigated herein. The failure costs and especially their ratio to the initial costs are analyzed considering the data provided from the industry. Probabilistic reliability analyses are carried out and optimum design levels are computed for representative cost ratios. The optimal target reliability depends on the ratio between failure and initial costs; reliability index of 3.5 corresponds to a reasonable cost ratio of 10. KW - Dach KW - Montagesystem KW - Montiergerät KW - nachhaltiges Sourcing KW - Solarenergie KW - Solarmodul KW - Windkraft (Energiequelle) Y1 - 2014 SN - 978-1-138-02681-0 SP - 2175 EP - 2181 PB - CRC Press CY - Boca Raton ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Jung, Karel T1 - Target reliability for new and existing railway civil engineering structures T2 - Handbook of RAMS in Railway Systems : theory and practice N2 - The specification of target reliability levels and risk acceptance criteria is one of the key issues of design and reliability assessment of existing railway stru ctures including bridges, tunnels or secondary struc-ures like noise barriers. Target reliability levels obtained by optimisation of the total cost, related to a required working life of the structure, are critically compared with human safety criteria based on group risks, intended to avoid accidents with a large number of fatalitie s. Practical applications of the theoretical principles are demonstrated by the examples of a railway bridge, railway tunnel and road bridge over an important railway line. The examples illustrate on how probabilistic reliability analysis and risk optimisation can support decisions about alternative strategies to achieve the optimal designs complying with the requirements on human safety. The contribution reveals that target relia bility levels for civil engineering structures recommended in various normative documents are inconsistent in terms of the values and the criteria according to which the appropriate values are to be specified. The optimal target reliabilities from economic point of view primarily depend on failure consequences and costs of safety measures. Y1 - 2017 SN - 9781315269351 U6 - https://doi.org/10.1201/b21983-20 PB - CRC Press ER - TY - JOUR A1 - Diamantidis, Dimitris A1 - Holicky, Milan A1 - Sýkora, Miroslav T1 - Reliability and Risk Acceptance Criteria for Civil Engineering Structures JF - Transactions of the VSB - Technical University of Ostrava, Civil Engineering Series N2 - The specification of risk and reliability acceptance criteria is a key issue of reliability verifications of new and 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. KW - Abnahmekriterium KW - Bauingenieurwesen KW - Kosten KW - Sicherheitsmaßnahme KW - Umweltrisiko KW - Zuverlässigkeit Y1 - 2016 UR - https://www.researchgate.net/publication/312424896_Reliability_and_Risk_Acceptance_Criteria_for_Civil_Engineering_Structures VL - 16 IS - 2 SP - 1 EP - 10 PB - De Gruyter ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Masciotta, Maria Giovanna T1 - Optimising In-situ Testing for Historic Masonry Structures: a Case Study T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019): Durability, Monitoring and Repair of Structures, 20-22 March 2019, Rovinj, Croatia N2 - Masonry structures were built by means of various techniques, using materials whose properties exhibit a considerable scatter depending on the period of construction, region- specific soil resources and manufacturing procedures. Significant spatial variability within the structural system is often observed due to diverse deterioration mechanisms. Therefore, it is important to obtain case-specific information on the mechanical properties of existing masonry structures. The case study of a historic building illustrates how the number of destructive tests (DTs) used to calibrate non-destructive tests (NDTs) can be optimised for the reliability assessment. Calibrated NDTs are used to establish the probabilistic model for compressive masonry strength. The specific focus is on compressive strength of masonry units; tests of mortar strength are only briefly discussed. The preliminary assessment is based on non-calibrated NDTs. The number of DTs for calibration is then optimised by means of probabilistic cost optimisation, considering also possible subsequent actions – ‘do nothing’ or ‘strengthen the structure’. It appears that the estimates of masonry unit strength based on NDTs are associated with large dispersion and may be significantly biased. Consequently, it is often beneficial to conduct at least one DT. A practical tool is provided to determine optimum number of DTs for different outcomes of a NDT survey and different failure consequences. Y1 - 2019 UR - www.researchgate.net/publication/332447762_Optimising_In-situ_Testing_for_Historic_Masonry_Structures_a_Case_Study SN - 978-2-35158-217-6 SN - 978-2-35158-218-3 SP - 684 EP - 691 PB - RILEM Publications SARL ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Implementing Information Gained through Structural Health Monitoring – Proposal for Standards T2 - 13th International Conference on Applications of Statistics and Probability in Civil Engineering, Mai 2019, Seoul, Korea N2 - With exception of a few issues such as design by testing, current standards do not include guidelines on the use and the quantification of value of additional information gained through Structural Health Monitoring (SHM). This contribution summarizes a recently developed draft of the guideline for practicing engineers in the framework of the EU-COST project 1402 and illustrates its application in engineering decision-making. Besides continuous and periodic monitoring, visual inspection, non-destructive evaluation and proof loading are included herein as a simple form of SHM. The guideline is independent of a type of structure, construction materials, loading, and of environmental conditions. It aims at a wide field of application including design of new structures, assessment of existing structures and type specific monitoring of a population of structures. The decision process related to the use of SHM is presented first together with relevant decision objectives and variables. Performance indicators are summarized and discussed with respect to the performance objectives. The evaluation of monitoring strategies based on life cycle costs is exposed and the selection of optimal intervention actions including safety measures is shown in representative case studies. The results demonstrate the potential of the use of monitoring to support engineering decisions and reflect though the practical benefits from the application of the guideline. Y1 - 2019 UR - https://www.researchgate.net/publication/333578633_Implementing_Information_Gained_through_Structural_Health_Monitoring_-Proposal_for_Standards ER - TY - BOOK A1 - Holický, Milan A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Marková, Jana A1 - Vrouwenfelder, Ton A1 - Tanner, Peter A1 - Arteaga, Angel A1 - Lara Sarache, Carlos A1 - Croce, Pietro A1 - Toprak, Selcuk A1 - Senel, Sevket Murat A1 - Inel, Mehmet T1 - Methods for the risk assessment and risk-based management of aging infrastructure N2 - 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 1 “Methods for the Risk Assessment and Risk-Based Management of Aging Infrastructure”, which is focussed on general procedures of risk-management and assessment of aging infrastructures. The methodologies provided are independent of the type of structure and material, and are compatible with the background methodologies used in the Eurocodes. Operational techniques for the assessment of aging infrastructures supplemented by illustrative case studies are presented in Handbook 2 and Handbook 3, which also result from the mentioned project. Handbook 1 consists of ten chapters and one annex. Chapter 1 gives a brief overview of the basic concepts used in the management and risk assessment of existing structures, supplemented by the basic definitions and terminology. Chapter 2 summarizes current applicable standards, codes and recommendations related to actions and environmental influences on existing structures. Chapter 3 reviews the most important degradation models due to environmental influences. Fatigue effects are treated separately in Chapter 4. The following Chapters, 5, 6, 7 and 8, are devoted step by step to the entire procedure of risk management, including probabilistic reliability analysis, consequence analysis, risk evaluation and risk assessment based on risk acceptance criteria, and consequently provide important information supporting decisions concerning the safety of the structure. The last two Chapters, 9 and 10, illustrate instructive case studies concerning risk management and risk assessment of road tunnels. Annex A presents basic statistical methods and techniques used in the evaluation and updating of available data required for probability and consequence analysis. It is believed that the material of this handbook is presented in an understandable way, illustrated by several realistic examples. A number of references mentioned in each chapter provide additional background materials, further guidance and information useful for particular practical applications. Prague and Regensburg, 2014 Y1 - 2014 SN - 978-80-01-05611-0 PB - Czech Technical University in Prague, Klokner Institute CY - Prague ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Botte, Wouter A1 - Caspeele, Robby A1 - Diamantidis, Dimitris A1 - Muttoni, Aurelio A1 - Steenbergen, Raphaël D.J.M. T1 - Probabilistic models for resistance variables in fib Model Code 2020 for design and assessment T2 - Acta Polytechnica CTU Proceedings N2 - The fib Model Code offers pre-normative guidance based on the synthesis of international research, industry and engineering expertise. Its new edition (draft MC 2020) will bring together coherent knowledge and experience for both the design of new concrete structures and the assessment of existing concrete structures. This contribution presents an overview of the main developments related to the partial factors for materials. In the draft MC2020, the partial factors are presented in tables for clusters of cases depending on consequence classes and variability of basic variables. Furthermore, formulas and background information are provided to facilitate updating of the partial factors. This contribution discusses the different assumptions adopted in MC 2020 for design and assessment. Main changes with respect to the previous version are related to description of the difference between in-situ concrete strength and the material strength measured on control specimens, and to modelling of geometrical variables. The presented comparison of the requirements imposed by Eurocodes and MC 2020 for design reveals insignificant differences. The assessment requirements may be decreased by about 25% when the conditions specified in MC 2020 are satisfied. Hence, the revised MC 2020 will provide designers and code makers with wider possibilities to utilise actual data and long-term experience in assessments of existing structures. KW - assessment of existing concrete structures KW - fib Model Code 2020 KW - partial factors KW - probabilistic models Y1 - 2022 UR - https://ojs.cvut.cz/ojs/index.php/APP/article/view/8407 U6 - https://doi.org/10.14311/APP.2022.36.0206 VL - 36 SP - 206 EP - 215 PB - Czech Technical University in Prague ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Holicky, Milan A1 - Jung, Karel A1 - Diamantidis, Dimitris T1 - Human safety criteria for risk-based structural design JF - International Journal of Safety and Security Engineering N2 - Risk and reliability criteria are well established in many industrial sectors such as the offshore, chemi- cal or nuclear industries. Comparative risk thresholds have been specified to allow a responsible organization or regulator to identify activities, which impose an acceptable level of risk concerning the participating individuals, or society as a whole. The scope of this contribution is to present target reliability criteria based on acceptable human safety levels. Application of theoretical principles is illustrated by examples of railway engineering structures. Initially it is shown how civil engineering structures for which human safety criteria play a role are classified according to Eurocodes. Examples include bridges, tunnels or station buildings. The general concepts for risk acceptance are then briefly reviewed, particularly in their relation to the target reliability criteria. The distinction between the two types of criteria is made: group risk and the acceptance criterion based on the Life Quality Index LQI approach introduced by ISO 2394:2015. The differences between the criteria for new and existing structures are discussed. The application is illustrated by an example of a bridge crossing an important railway line. It appears that while benefits and costs of a private stakeholder or public authority are reflected by economic optimisation, the society should define the limits for human safety to achieve uniform risks for various daily-life activities and across different industrial sectors. Keywords: group risk, human safety, individual risk, Life Quality Index, railway, risk acceptance, structure, target reliability KW - individual risk KW - group risk KW - human safety KW - Life Quality Index KW - railway KW - risk acceptance KW - structure KW - target reliability Y1 - 2018 U6 - https://doi.org/10.2495/SAFE-V8-N2-287-298 VL - 8 IS - 2 SP - 287 EP - 298 PB - WIT Press ER - TY - JOUR A1 - Holicky, Milan A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris T1 - Reliability levels related to different reference periods and consequence classes JF - Beton- und Stahlbetonbau N2 - The target reliability levels recommended in various national and international documents for new and existing structures are quite different and vaguely related to types of structures and consequences of failure. The optimum reliability levels can be obtained by considering the total expected cost of the structure over the design working life. Indicative values of reliability indexes are given in EN 1990 (2002) for two reference periods, 1 year and 50 years. The annual target reliability levels βt1 are presently indicated in the recent draft of EN 1990 (2017) without any explicit link to different reference period or design working life. When determining the target reliability index for the reference period of n years that generally differs from the design working life, correlation of failure events in subsequent years should be taken into account. Considering the annual reliability index β1 an approximate formula is proposed for the reliability index βnk related to the reference period of n years and independence interval of k years. The independence interval k ≤ n corresponds to the mean time period in years for which the failures in subsequent periods of k years are assumed to be mutually independent. The operational use of the proposed formula is clarified by practical tools. The reliability differentiation reflected in consequence classes is also discussed in this contribution. Y1 - 2018 U6 - https://doi.org/10.1002/best.201800039 VL - 113 IS - S2, Supplement: 16th International Probabilistic Workshop SP - 22 EP - 26 PB - Ernst & Sohn, a Wiley Brand ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Bertacca, Elena T1 - Obsolescence Rate: Framework, Analysis and Influence on Risk Acceptance Criteria T2 - 6th International Symposium on Life-Cycle Civil Engineering (IALCCE), Ghent, Belgium N2 - Buildings are major long lasting assets of the society and business enterprises and form a significant part of infrastructure management. They require continual maintenance and in many cases they can become inap-propriate for their original purpose due to obsolescence and are demolished. The present contribution ex-plores the obsolescence of buildings and in particular the definitions of obsolescence, the related influenc-ing factors and the associated uncertainties. Thereby definitions of the obsolescence rate based on the physi-cal and useful (service) life are clarified. The experienced useful life of buildings in Finland, Germany and North America is statistically analysed, utilizing available databases, and comparisons with the design (minimum) working life specified in standards are made. The probability of not exceeding the required min-imum service life is evaluated and discussed. Whereas many factors affecting the obsolescence rate are be-yond the control of civil engineers, particular attention needs to be paid to cases where the service life of the structure is determined by physical aspects related to deterioration. These cases are identified and recom-mendations to improve structural design are offered. The service life and the related renewal rate is influ-encing the risk acceptance criteria as given in ISO 2394. Such criteria are derived on the basis of economic optimization and the LQI marginal safety costs principle. A statistical model for the renewal rate is obtained and its influence on the target reliability is investigated for a representative failure limit state. The influence of the obsolescence rate is quantified and critically disputed. Y1 - 2018 UR - https://www.researchgate.net/publication/328578867_Obsolescence_Rate_Framework_Analysis_and_Influence_on_Risk_Acceptance_Criteria ER - TY - JOUR A1 - Steenbergen, Raphael D. J. M., A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holicky, Milan A1 - Vrouwenvelder, Ton T1 - Economic and human safety reliability levels for existing structures JF - Structural concrete N2 - 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. KW - existing structures KW - reliability KW - safety Y1 - 2015 U6 - https://doi.org/10.1002/suco.201500022 VL - 16 IS - 3 SP - 323 EP - 332 PB - Ernst & Sohn, a Wiley brand ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Lenzi, Daniele A1 - Sýkora, Miroslav T1 - Optimal decisions based on monitoring – case study of steel roof T2 - Proceedings of the Joint COST TU1402-TU1406 - IABSE WC1 Workshop, Zagreb 2-3 March 2017 N2 - Monitoring of structures and related decisions based on cost optimization are discussed in this contribution. Many research publications and experimental data are currently available on inspection and on monitoring and they represent the outcome of the remarkable work done. Not all the topics of interest are widely debated and implemented in standards. The current state-of-practice in standards is summarized and aspects to be included in future recommendations are proposed. The implementation of risk-based decisions is illustrated in a case study dealing with a stadium roof in Northern Italy. Snow actions are important especially in northern and mountainous regions where heavy snowfalls and related accumulation result to considerable loads. As the roof structure fails to comply with the requirements of Eurocodes, a permanent monitoring system has been installed to allow for real time evaluation of the reliability level of the structure. The system supplies the necessary information supporting immediate decisions on closure of the stadium in case of an extraordinary snow load. Cost-optimal decisions regarding the closure of the stadium are analysed based on a limit state function, on probabilistic models for the influencing parameters including measurement uncertainty, economic losses related to closure and failure consequences. The results demonstrate the potential of the use of the monitoring systems and probabilistic reliability analysis in order to support decisions and highlight the need for their implementation in future standards. KW - probabilistic methods KW - reliability analysis KW - reliability level KW - risk analysis KW - SHM KW - snow load KW - monitoring Y1 - 2017 U6 - https://doi.org/10.5592/CO/BSHM2017.4.7 SP - 4.7-1 EP - 4.7-7 ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Optimizing Monitoring - Implementation of Draft Guideline and Case Study of Roof Exposed to Snow Loads T2 - Proceedings of 40th IABSE Symposium : Tomorrow's Megastructures, Nantes, France, 19-21 September 2018 N2 - This contribution addresses the optimisation of monitoring and decision-making criteria regarding the future use of structures and the related implementation in modern guidelines. A summary of the state-of-practice reveals deficiencies that are addressed by prospective guidance for the anticipated updates of standards, providing a general methodology to obtain cost-optimal decisions using limit state design, probabilistic reliability analysis and cost estimates. The implementation of a draft guideline and the corresponding risk-based approach are illustrated in a full-scale case study dealing with the roof of a stadium located in Northern Italy. The results demonstrate the potential of using monitoring systems and probabilistic reliability analysis in order to support decisions regarding safety measures such as snow removal, or temporary closure of the stadium. KW - cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof KW - standard Y1 - 2018 SN - 978-3-85748-161-1 U6 - https://doi.org/10.2749/nantes.2018.s27-27 PB - Curran Associates Inc CY - Red Hook, NY ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Sýkora, Miroslav T1 - Target Reliability Levels Based on Societal, Economic and Environmental Consequences of Structural Failure T2 - Proceedings of the 12th International Conference on Structural Safety & Reliability (ICOSSAR 2017), 6-10 August 2017, Vienna, Austria N2 - Target reliability levels are derived by optimizing initial structural costs and considering three major types of potential consequences of structural failure: a) direct and indirect economic losses, b) societal consequences resulting from fatalities and injuries, and c) environmental impacts. The guidance on how to e stimate and combine these consequences is provided; societal consequences are expressed using the Life Quality Index (LQI) concept. The case study focused on a generic load-bearing member reveals that target reliability levels for structural design are commonly dominated by economic criteria. Y1 - 2017 UR - https://www.researchgate.net/publication/319123444_Target_Reliability_Levels_Based_on_Societal_Economic_and_Environmental_Consequences_of_Structural_Failure ER - TY - CHAP A1 - Holický, Milan A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Effects of Quality Control on Reliability of Reinforced Concrete Structures according to Eurocodes T2 - fib Symposium 2016 : Performance-Based Approaches for Concrete Structures, 14, 2016, Cape town N2 - The effect of quality control on structural reliability represents an increasingly important concern of designers and thus is investigated in this contribution, focusing on reinforced concrete structures. Recent European documents for structural design – Eurocodes, fib Model Code 2010 and ISO 2394:2015 for general principles on structural reliability indicate that the partial factors may be adjusted to available information on the quality control of structures. In particular, the partial factors for concrete and steel strength may be significantly reduced taking into account actual execution quality and related available data. Using probabilistic methods of structural reliability, effects for execution quality are investigated in this contribution considering two fundamental reinforced concrete members: a beam (or slab) exposed to bending and a short column exposed to compression. It is shown that the reliability of reinforced concrete members may vary with the load ratio of variable and permanent actions. It appears also that the structural members of a basic quality, designed using unreduced partial factors, have a greater reliability level than the members of an increased quality, designed using the partial factors reduced according to EN 1992 1 1. This provides the basis for recommendations for further code developments. KW - Eurocodes KW - partial factors KW - quality control KW - reliability Y1 - 2016 UR - https://www.researchgate.net/publication/310616676_Effects_of_quality_control_on_reliability_of_reinforced_concrete_structures_according_to_Eurocodes ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris T1 - Snow Load Monitoring - Measure to Control Reliability of the Roof of a Stadium T2 - International Conference Structural Reliability & Modelling in Mechanics, 24.-25.05.2018, Ostrava, Czech Republic N2 - 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. KW - Cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof KW - standard Y1 - 2018 UR - www.researchgate.net/publication/325569518_Snow_Load_Monitoring_-_Measure_to_Control_Reliability_of_the_Roof_of_a_Stadium ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Holicky, Milan A1 - Diamantidis, Dimitris T1 - Target Reliability for Existing Civil Engineering Systems T2 - 2016 Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management (SMRLO), 15-18 Feb. 2016, Beer Sheva, Israel N2 - Specification of the target reliability levels is one of the key issues of the assessment of existing systems. ISO 2394:2015 indicate procedures for specification of the target reliability levels by optimisation of the total cost related to an assumed remaining working life of a structural system. These approaches are critically compared with human safety criteria and with recommendations of present standards. It appears that the requirement on the same target reliability levels for existing civil engineering systems as for newly designed is uneconomical. Decisions in the assessment can result in the acceptance of the actual state or in upgrade of the 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. When reliability of a system or its key component is verified (as compared to design of a common component), the target reliability index should be increased by about 0.5. KW - cost optimization KW - Economics KW - existing structural systems KW - human safety KW - ISO Standards KW - Optimization KW - Reliability engineering KW - safety KW - target reliability Y1 - 2016 U6 - https://doi.org/10.1109/SMRLO.2016.28 SP - 109 EP - 114 PB - IEEE ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Markova, Jana A1 - Diamantidis, Dimitris T1 - Bayesian Network Application for the Risk Assessment of Existing Energy Production Units T2 - 2016 Second International Symposium on Stochastic Models in Reliability Engineering, Life Science and Operations Management (SMRLO), 15-18 Feb. 2016, Beer Sheva, Israel N2 - A Bayesian network is applied in this contribution in order to assess the risks of a selected production unit in a fossil power station. A general framework for the risk assessment of production units of a power station is presented first by implementing statistical methods and Bayesian networks. Special emphasis is given to the input data consisting of failure rates which are obtained on the basis of recorded data and expert judgements. The consequences of failure are divided into economical and human (societal): economic consequences include outages of key technological devices, societal consequences cover potential injuries and fatalities. Probabilistic risk assessment methods are applied to the selected production unit of a power station. The influence of the uncertainties in the considered technical parameters on the availability of the unit is assessed and the acceptance of the calculated availability represented through the mean value and the standard deviation is discussed. Societal risks given in terms of weighted injuries and fatalities are obtained and respective risk acceptance criteria are presented. Uncertainties affecting the risks are discussed. It appears that the proposed framework provides a valuable assessment of the influence individual devices and their components on availability and societal risk. For that purpose the used methodology, intentionally simplified for operational applications, includes important factors affecting risks of production units. It is concluded that Bayesian networks are a transparent method for the probabilistic risk assessment of complex technological systems. The results of the performed analyses can be easily updated when additional information becomes available as illustrated in characteristic examples. KW - Availability KW - Bayes methods KW - Bayesian networks KW - Economics KW - Power generation KW - Probabilistic logic KW - Production KW - Production unit KW - Risk analysis KW - Societal risk KW - Uncertainties KW - uncertainty Y1 - 2016 U6 - https://doi.org/10.1109/SMRLO.2016.116 SP - 656 EP - 664 PB - IEEE ER - TY - CHAP A1 - Holicky, Milan A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav ED - de Wilde, W. P. ED - Hernández, S. ED - Kravanja, S. T1 - Economically optimum structural design BT - methodology and case study T2 - High Performance and Optimum Design of Structures and Materials III (HPSM/OPTI 2018) ; Ljubljana, Slovenia 11.07.2018 - 13.07.2018 N2 - 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. KW - failure consequences KW - risk acceptance KW - probabilistic optimization KW - target reliability, KW - stadium KW - total cost KW - working life Y1 - 2018 U6 - https://doi.org/10.2495/hpsm180151 SP - 143 EP - 153 PB - WIT ER - TY - CHAP A1 - Croce, Valeria A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav ED - Vayas, Ioannis ED - Mazzolani, Federico M. T1 - Seismic Damage Evaluation and Decisions on Interventions Supported by UAV-Based Surveys T2 - Protection of Historical Constructions: Proceedings of PROHITECH 2021 N2 - 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. KW - Decision analysis KW - Natural hazards KW - Post-seismic areas KW - UAV survey Y1 - 2022 SN - 978-3-030-90787-7 U6 - https://doi.org/10.1007/978-3-030-90788-4_20 VL - 209 SP - 206 EP - 221 PB - Springer International Publishing CY - Cham ER - TY - CHAP A1 - Croce, Valeria A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav ED - Bien, Jan T1 - Planning post earthquake surveys: assessments and reconstruction of small historical centres T2 - 1st IABSE Online Symposium 2020, Synergy of culture and civil engineering - history and challenges: Wrocław, Poland, 7-9 October 2020, Proceedings N2 - 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. Y1 - 2021 UR - http://toc.proceedings.com/57946webtoc.pdf SN - 978-1-7138-2387-2 SP - 332 EP - 339 PB - Curran Associates Inc CY - Red Hook, NY ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Reliability Differentiation and Uniform Risk in Standards BT - a Critical Review and a Practical Appraisal: kriticki pregled i prakticna ocjena T2 - Scientific Symposium Future Trends in Civil Engineering, Zagreb,Croatia, 17 October 2029 N2 - 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. T2 - Razlikovanje pouzdanosti i ujednacenost rizika u propisima Y1 - 2020 U6 - https://doi.org/10.5592/CO/FTCE.2019.11 SP - 241 EP - 260 ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Mueller, Dominik A1 - Sousa, Helder T1 - A practical guide on the quantification of value of information gained by structural health monitoring and application to historic masonry structures JF - Structure and Infrastructure Engineering N2 - 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. KW - Decision-making KW - guidelines KW - historic masonry KW - optimisation KW - STRENGTH KW - structural health monitoring KW - tests KW - uncertainty KW - value of information Y1 - 2020 U6 - https://doi.org/10.1080/15732479.2020.1857793 VL - 18 IS - 4 SP - 441 EP - 455 PB - Taylor&Francis ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Marková, Jana A1 - Rózsás, Árpád T1 - Assessment of compressive strength of historic masonry using non-destructive and destructive techniques JF - Construction and Building Materials N2 - 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. KW - Calibration KW - Clay bricks KW - Compressive strength KW - Mortar KW - Non-destructive test KW - Statistical analysis KW - Stone masonry KW - Uncertainty Y1 - 2018 U6 - https://doi.org/10.1016/j.conbuildmat.2018.10.180 VL - 193 IS - December SP - 196 EP - 210 PB - Elsevier ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav T1 - Implementing Snow Load Monitoring to control Reliability of a Stadium Roof T2 - Transactions of VSB N2 - 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. KW - Cost optimisation KW - decision making criteria KW - Eurocodes KW - monitoring KW - reliability analysis KW - snow load KW - stadium roof, standard Y1 - 2019 U6 - https://doi.org/10.35181/tces-2019-0006 VL - 19 IS - 1 SP - 35 EP - 40 PB - TECHNICAL UNIVERSITY OF OSTRAVA ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holicky, Milan A1 - Jung, Karel T1 - Target reliability for existing structures considering economic and societal aspects JF - Structure and infrastructure engineering N2 - 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. KW - design KW - Economic optimisation KW - existing structures KW - human safety KW - Life Quality Index KW - Optimization KW - target reliability, *GuI Y1 - 2017 U6 - https://doi.org/10.1080/15732479.2016.1198394 VL - 13 IS - 1 SP - 181 EP - 194 PB - Taylor&Francis ER - TY - JOUR A1 - Sýkora, Miroslav A1 - Holický, Milan A1 - Diamantidis, Dimitris T1 - Probabilistic updating in the reliability assessment of industrial heritage structures JF - Heron N2 - 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. Y1 - 2016 UR - http://www.heronjournal.nl/59-23/1.pdf SN - 0046-7316 VL - 59 IS - 2/3 PB - Stevin-Laboratorium, TU Delft CY - Delft ER - TY - JOUR A1 - Steenbergen, R.D.J.M. A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Vrouwenvelder, A.C.W.M. T1 - Economic and human safety reliability levels for existing structures JF - Structural Concrete. JOurnal of the fib N2 - 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. Y1 - 2015 U6 - https://doi.org/10.1002/suco.201500022 VL - 16 SP - 323 EP - 332 PB - Wiley ER - TY - BOOK A1 - Tanner, Peter A1 - de Diego, Ana A1 - Lara Sarache, Carlos A1 - Prieto, Miguel A1 - Hingorani, Ramón A1 - Holický, Milan A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Menéndez Ondina, Antonio A1 - Croce, Pietro A1 - Bartelletti, Raffaello A1 - Beconcini, Maria Luisa A1 - Formichi, Paolo A1 - Marsili, Francesca A1 - Muzzi, Martina A1 - Rosso, Elisa A1 - Toprak, Selcuk A1 - Inel, Mehmet A1 - Koc, Cem A1 - Nacaroglu, Engin A1 - Senel, Sevket Murat T1 - Operational methods for the assessment and management of aging infrastructure N2 - 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 Y1 - 2015 SN - 9788882501471 PB - Tipografía editrice Pisana CY - Pisa, Italia ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Holický, Milan A1 - Sýkora, Miroslav T1 - Risk and reliability acceptance criteria for civil engineering structures T2 - Structural Reliability and Modelling in Mechanics Conference, Ostrava, Czech Republic, May 2016 N2 - 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. Y1 - 2016 SP - 1 EP - 10 ER - TY - CHAP A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Barnardo-Viljoen, Celeste A1 - Retief, Johan Verster A1 - Rózsás, Árpád ED - Bakker, Jaap ED - Frangopol, Dan M. ED - Van Breugel, Klaas T1 - On Risk-Based Design of Structures Exposed to Changing Climatic Actions T2 - 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 Y1 - 2016 SN - 978-1-138-02847-0 SN - 978-1-315-37517-5 PB - Taylor & Francis CY - London ; Boca Raton ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Holický, Milan A1 - Jung, Karel A1 - Diamantidis, Dimitris ED - Akiyama, Mitsuyoshi ED - Furuta, Hitoshi ED - Frangopol, Dan M. T1 - Target reliability levels for assessment of existing structures considering economic and societal aspects T2 - Life-Cycle of Structural Systems N2 - 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. Y1 - 2014 SN - 9780429227196 U6 - https://doi.org/10.1201/b17618-121 SP - 838 EP - 845 PB - CRC Press CY - London ER - TY - CHAP A1 - Sýkora, Miroslav A1 - Diamantidis, Dimitris A1 - Marková, Jana A1 - Masciotta, Maria Giovanna ED - Baričević, Ana ED - Jelčić Rukavina, Marija ED - Damjanović, Domagoi ED - Guadagnini, Maurizio T1 - Optimizing in-situ testing for historic masonry structures: a case study BT - a case study T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) : Durability, Monitoring and Repair of Structures, 20-22 March 2019, Rovinj, Croatia Y1 - 2019 UR - http://toc.proceedings.com/50441webtoc.pdf SN - 978-1-5108-9296-5 SP - 684 EP - 691 PB - RILEM Publications ER - TY - JOUR A1 - Orcesi, André A1 - O'Connor, Alan A1 - Diamantidis, Dimitris A1 - Sýkora, Miroslav A1 - Wu, Teng A1 - Akiyama, Mitsuyoshi A1 - Alhamid, Abdul Kadir A1 - Schmidt, Franziska A1 - Pregnolato, Maria A1 - Li, Yue A1 - Salarieh, Babak A1 - Salman, Abdullahi M. A1 - Bastidas-Arteaga, Emilio A1 - Markogiannaki, Olga A1 - Schoefs, Franck T1 - Investigating the Effects of Climate Change on Structural Actions JF - Structural Engineering International N2 - 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. KW - climate change KW - extreme weather events KW - flooding KW - hurricanes KW - scour KW - sea-level rise KW - tsunami Y1 - 2022 U6 - https://doi.org/10.1080/10168664.2022.2098894 VL - 32 IS - 4 SP - 1 EP - 14 PB - Taylor & Francis ER - 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 -