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 - Bazzurro, Paolo A1 - Cornell, C. A1 - Diamantidis, Dimitris A1 - Manfredini, Gian T1 - Seismic damage hazard analysis for requalification of nuclear power plant structures: methodology and application JF - Nuclear Engineering and Design N2 - A methodology for the evaluation of the annual probability of occurrence of post-elastic seismic damage in realistic structures is presented. The seismic damage hazard analysis (SDHA) is carried out here by coupling conventional seismic hazard analysis (SHA) for the site and the structural response to earthquakes of different intensities. The structural performance is statistically investigated by conducting appropriate non-linear dynamic analyses for a limited set of real ground-motion records that might potentially pose a threat to the structure at the site. The merging of these two approaches permits calculation of the seismic hazard faced by the structure in direct damage terms. The methodology is presented in this paper with the aid of a simple illustrative case study where the annual probability of damage and, eventually, failure of a power house steel structure is computed. This methodology can find practical applications in seismic retrofit of nuclear power plant structures and in the evaluation of seismic damage hazards in new structure designs. Y1 - 1996 U6 - https://doi.org/10.1016/0029-5493(95)01111-0 VL - 160 IS - 3 SP - 321 EP - 332 PB - Elsevier 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 - JOUR A1 - Diamantidis, Dimitris T1 - A Critical View on Environmental and Human Risk Acceptance Criteria JF - International Journal of Environmental Science and Development N2 - Natural and technological hazards have a major impact on environmental and human safety. Risk assessment plays an essential role in the risk management of the effects of such hazards. This contribution summarizes first the general formulation of risk depending on two parameters: hazard probability and associated consequences. Problems faced in industrial applications based on the experience of the author are discussed. Risk acceptance criteria for the contributors to risk i.e. human, economic and environment are critically reviewed. Resilience based criteria are also included and conclusions for future developments are provided. KW - Environmental risk KW - human risk KW - Risk acceptance KW - Risk analysis KW - safety measures Y1 - 2017 U6 - https://doi.org/10.18178/ijesd.2017.8.1.921 N1 - Corresponding author: Dimitris Diamantidis VL - 8 IS - 1 SP - 62 EP - 66 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 - Gerard Canisius, T. D. A1 - Diamantidis, Dimitris A1 - Kumar, Suresh ED - Stewart, Mark G. ED - Rosowsky, David V. T1 - Fire Safety in Road Tunnels T2 - Engineering for Extremes N2 - Modern industrial societies need efficient and safe transportation systems for their existence and progress. Tunnels form an important component of road transportation systems in many countries. However, significant fire incidents within them have highlighted human safety as a major concern, resulting in considerable changes to the safety requirements to be satisfied during the design and assessment of new and existing tunnels, respectively. This chapter discusses state-of-practice related to the implementation of risk analysis methods in road tunnel projects. It reviews relevant safety criteria in standards and describes basic aspects on risk acceptance and decision-making with respect to the choice of the safety measures to be implemented. This contribution presents the determination of human safety consequences for use in risk analysis by considering design fires, the development and spread of effects of such fires and emergency evacuation of people. The methodology is illustrated via a case study that deals with the re-qualification of an existing road tunnel in Wales. Y1 - 2022 SN - 978-3-030-85017-3 U6 - https://doi.org/10.1007/978-3-030-85018-0_14 SP - 293 EP - 311 PB - Springer Nature CY - Cham 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 -