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Cabrero, J. M., Honfi, D., Jockwer, R. & Yurrita, M. (2019). A probabilistic study of brittle failure in dowel-type timber connections with steel plates loaded parallel to the grain. Wood Material Science and Engineering
Open this publication in new window or tab >>A probabilistic study of brittle failure in dowel-type timber connections with steel plates loaded parallel to the grain
2019 (English)In: Wood Material Science and EngineeringArticle in journal (Refereed) Epub ahead of print
Abstract [en]

Dowel-type connections in timber structures should be typically designed in a way that, if the load bearing capacity is exceeded, desirable ductile failure should likely occur, i.e. yielding of the metal dowel or embedment of the timber. However, the probability of brittle failures cannot be completely avoided in many cases. If the connection is loaded parallel to the grain direction, splitting, row-shear, plug/block shear and tensile failure are examples of such brittle failure modes. To ensure a beneficial structural performance locally and sufficient structural robustness globally, the probability of such brittle failures should be kept at a sufficiently low level. However, in the current version of EN1995, the probability of such failure is not considered explicitly. The final aim of the presented research study is to develop a rational approach for the consideration of brittle failure in timber connections with dowel-type fasteners and steel plates loaded parallel to the grain, consistently with the partial factor method. As a first step, a probabilistic model has been used to study the susceptibility to brittle failure and provide a rational basis for the calibration of a “brittle overstrength factor”. The results of this study are reported in the current contribution.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2019
Keywords
Dowel-type connections, brittle failure, structural reliability
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39704 (URN)10.1080/17480272.2019.1645206 (DOI)
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Nasr, A., Björnsson, I., Ivanov, O. L., Johansson, J., Honfi, D. & Kjellström, E. (2019). A qualitative prioritization of the risks imposed on bridges due to climate change. In: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report. Paper presented at IABSE Symposium 2019 Guimaraes: Towards a Resilient Built Environment - Risk and Asset Management, 27 March 2019 through 29 March 2019 (pp. 80-87). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>A qualitative prioritization of the risks imposed on bridges due to climate change
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2019 (English)In: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report, International Association for Bridge and Structural Engineering (IABSE) , 2019, p. 80-87Conference paper, Published paper (Refereed)
Abstract [en]

Climate change and its impacts on infrastructures may seriously affect the functionality of societies. Despite the alarming potential consequences climate change pose, not enough effort has been directed towards averting these impacts or managing them in some other way (e.g. mitigation, reduction, etc.). Well-functioning infrastructure networks play a key role in societies’ resilience and their ability to cope with climate-induced hazards. Therefore, ensuring the efficient performance of infrastructure networks, even during climate related emergencies, is central to the resilience of societies in the face of climate change. At the heart of a resilient transportation infrastructure network lays robust bridge structures. This paper builds on previous work where the potential risks from climate change on bridges were surveyed. Here, a qualitative risk prioritization scheme for bridges to rank these risks is presented. The aim of this work is hence to provide a tool for determining which of these risks are more worthy of closer investigation. The suggested framework is based on the basic elements of risk; i.e. hazard, exposure, vulnerability, and consequences. Several indices reflecting these four components and their different characteristics are introduced. Subsequently, a method for ranking the different risks based on these indices is presented. This framework can be used to optimize investments in adapting bridges to climate change.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2019
Keywords
Bridge, Climate change, Infrastructure, Risk prioritization, Transportation
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38912 (URN)2-s2.0-85065248204 (Scopus ID)9783857481635 (ISBN)
Conference
IABSE Symposium 2019 Guimaraes: Towards a Resilient Built Environment - Risk and Asset Management, 27 March 2019 through 29 March 2019
Note

Funding text 1: Innovation Agency ?Vinnova ?? the Swedish transport infrastructureadaptationRobust prioritizationframeworkfor Research Council ?Formas ? ? and the Swedish investments under uncertainty of climate Energy Agency 縀Energimyndigheten缃堀 Any change ? ASCE ?ASME J ? Risk Uncertainty Eng ?

Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-08-13Bibliographically approved
Nasr, A., Björnsson, I., Honfi, D., Larsson Ivanov, O., Johansson, J. & Kjellström, E. (2019). A review of the potential impacts of climate change on the safety and performance of bridges. Sustainable and Resilient Infrastructure
Open this publication in new window or tab >>A review of the potential impacts of climate change on the safety and performance of bridges
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2019 (English)In: Sustainable and Resilient Infrastructure, ISSN 2378-9689Article in journal (Refereed) Epub ahead of print
Abstract [en]

ABSTRACTAn overabundance of evidence, both observational and from model projections, indicate that changes to the climate system are taking place at unprecedented rates. Although the magnitudes of these changes involve large uncertainties, the fact that our climate is changing is unequivocal. To ensure an unimpaired functionality of our societies,it is therefore of crucial importance to study the potential climate change impacts on infrastructure. Taking into account that bridges have a considerably long service life, it is of direct relevance to ascertain their reliable performance against climate change risks. This paper synthesizes the findings of over 190 research articles to identify the potential risks climate change may pose on bridges. Over 30 potential risks, supported by pertinent previous bridge damage (or failure) cases, are identified, categorized, and linked to the projected future climate changes. The identified risks can be used as a basis for future risk prioritization by bridge managers.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38669 (URN)10.1080/23789689.2019.1593003 (DOI)
Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2019-08-12Bibliographically approved
Nogal, M. & Honfi, D. (2019). Assessment of road traffic resilience assuming stochastic user behaviour. Reliability Engineering & System Safety, 185, 72-83
Open this publication in new window or tab >>Assessment of road traffic resilience assuming stochastic user behaviour
2019 (English)In: Reliability Engineering & System Safety, ISSN 0951-8320, E-ISSN 1879-0836, Vol. 185, p. 72-83Article in journal (Refereed) Published
Abstract [en]

When assessing the resilience of road transport networks, users’ response should be considered as they represent the main capability of the system to adapt to changes when any disruptive event occurs and to recover afterwards. Given the variability in users’ response, it seems deterministic approaches might not be adequate to represent the real system performance, thus, a stochastic perspective is required. This paper presents a new approach to assess the resilience of a traffic network when suffering from a disruptive event, considering the stochastic behaviour of the users, where their decisions will be biased by their perception of the traffic conditions rather than by the actual conditions. This approach provides more realistic patterns than the deterministic approach, mainly in terms of recovery times. The real traffic network Luxembourg-Metz has been used to illustrate the approach.

Keywords
Dynamic traffic networks, Policy making, Resilience, Road safety, Stochastic user behaviour, Stress level, Behavioral research, Motor transportation, Roads and streets, Uncertainty analysis, Dynamic traffic, Stress levels, User behaviour, Stochastic systems
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37343 (URN)10.1016/j.ress.2018.12.013 (DOI)2-s2.0-85058707087 (Scopus ID)
Note

 Funding details: 653390; Funding text 1: IMPROVER has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 653390.

Available from: 2019-01-22 Created: 2019-01-22 Last updated: 2019-08-12Bibliographically approved
Stepinac, M., Rajčić, V. & Honfi, D. (2019). Condition assessment of timber structures - Quantifying the value of information. In: IABSE Symposium, Nantes 2018: Tomorrow's Megastructures. Paper presented at 40th IABSE Symposium in Nantes 2018: Tomorrow's Megastructures, 19 September 2018 through 21 September 2018 (pp. S27-9-S27-18).
Open this publication in new window or tab >>Condition assessment of timber structures - Quantifying the value of information
2019 (English)In: IABSE Symposium, Nantes 2018: Tomorrow's Megastructures, 2019, p. S27-9-S27-18Conference paper, Published paper (Refereed)
Abstract [en]

Advanced inspection techniques, non-destructive (NDT) and semi-destructive (SDT) testing methods and structural health monitoring (SHM) are increasingly important for the preservation of both old and new timber structures. However, e.g. the application of SHM within the context of timber structures is not adequately represented in strategic documents. COST Action TU1402 is trying enhance the benefit of SHM by novel utilization of applied decision analysis on how to assess the value of SHM - even before it is implemented. The present paper illustrates how pre-posterior decision analysis can help quantifying the Value of Information (VoI) obtained by the condition assessment of timber structures and thus help select appropriate assessment procedures and subsequent maintenance actions. As a case study a timber exhibition hall in Zagreb, Croatia is investigated in the context of VoI analysis.

Keywords
Assessment, Heritage, NDT, SHM, Timber structures, Value of information, Cost benefit analysis, Decision making, Exhibition buildings, Nondestructive examination, Timber, Assessment procedure, Condition assessments, Inspection technique, Structural health monitoring (SHM), Structural health monitoring
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37016 (URN)2-s2.0-85059399610 (Scopus ID)9783857481611 (ISBN)
Conference
40th IABSE Symposium in Nantes 2018: Tomorrow's Megastructures, 19 September 2018 through 21 September 2018
Available from: 2019-01-21 Created: 2019-01-21 Last updated: 2019-08-12Bibliographically approved
Larsson Ivanov, O., Honfi, D., Santandrea, F. & Stripple, H. (2019). Consideration of uncertainties in LCA for infrastructure using probabilistic methods. Structure and Infrastructure Engineering, 15(6), 711-724
Open this publication in new window or tab >>Consideration of uncertainties in LCA for infrastructure using probabilistic methods
2019 (English)In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 15, no 6, p. 711-724Article in journal (Refereed) Published
Abstract [en]

The construction and usage of transport infrastructure are major causes of greenhouse gas emissions and energy consumption. The effects of resource consumption and pollutant emissions are often quantified through Life Cycle Assessment (LCA) models. All decisions made in infrastructure projects during the whole life cycle are afflicted by uncertainty, e.g. physical properties of materials or amount of pollutants emitted by certain processes. The pervasive role of uncertainty is reflected in LCA models, which therefore should consider uncertainty from various sources and provide a sound quantification of their effects. The aim of the work presented in this paper is to give an overview of different sources of uncertainty in LCA of infrastructure projects and to describe systematic methods to evaluate their influence on the results. The possibility of including uncertainty in a LCA-tool for infrastructure is presented, studying the sensitivity of the model output to the input parameters and two alternative approaches for propagation of uncertainty using two case studies. It is shown that, besides the influence of uncertainty in emission factors, other inputs such as material amounts and service life could contribute significantly to the variability of model output and has to be considered if reliable results are sought. © 2019, © 2019 The Author(s).

Keywords
bridges, Life cycle assessment, Monte Carlo simulations, tunnels, uncertainty, variation mode and effect analysis, Energy utilization, Gas emissions, Greenhouse gases, Intelligent systems, Monte Carlo methods, Pollution, Uncertainty analysis, Effect analysis, Infrastructure project, Life Cycle Assessment (LCA), Life cycle assessment model, Physical properties of materials, Propagation of uncertainties, Transport infrastructure, Life cycle
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38227 (URN)10.1080/15732479.2019.1572200 (DOI)2-s2.0-85062357537 (Scopus ID)
Available from: 2019-03-27 Created: 2019-03-27 Last updated: 2019-08-12Bibliographically approved
Stepinac, M., Rajcic, V. & Honfi, D. (2019). Decision analysis and scenarios for the assessment of existing timber structures. In: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report. Paper presented at IABSE Symposium 2019 Guimaraes: Towards a Resilient Built Environment - Risk and Asset Management, 27 March 2019 through 29 March 2019 (pp. 479-486). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>Decision analysis and scenarios for the assessment of existing timber structures
2019 (English)In: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report, International Association for Bridge and Structural Engineering (IABSE) , 2019, p. 479-486Conference paper, Published paper (Refereed)
Abstract [en]

Condition assessment of existing timber structures is typically followed by a decision about intervention options, and consequently comparing various possible scenarios. These decisions are based on the updated knowledge obtained through the assessment. Condition assessments, however, can be done in multiple ways, e.g. basic visual assessment of a structure, assessment with various destructive, non-destructive and semi-destructive testing methods, interpretation of a data from structural health monitoring, various levels of structural modelling and safety verification formats. The present paper discusses how pre-posterior decision analysis can guide decisions concerning the condition assessment of timber structures by selecting appropriate assessment procedures and subsequent maintenance actions.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2019
Keywords
Condition assessment, Heritage, NDT, SDT, Timber structures, Value of information
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-38907 (URN)2-s2.0-85065250247 (Scopus ID)9783857481635 (ISBN)
Conference
IABSE Symposium 2019 Guimaraes: Towards a Resilient Built Environment - Risk and Asset Management, 27 March 2019 through 29 March 2019
Note

Conference code: 147396; Export Date: 28 May 2019; Conference Paper; Correspondence Address: Stepinac, M.; University of ZagrebCroatia; email: mstepinac@grad.hr

Available from: 2019-06-10 Created: 2019-06-10 Last updated: 2019-08-12Bibliographically approved
Björnsson, I., Larsson Ivanov, O., Honfi, D. & Leander, J. (2019). Decision support framework for bridge condition assessments. Structural Safety, 81, Article ID 101874.
Open this publication in new window or tab >>Decision support framework for bridge condition assessments
2019 (English)In: Structural Safety, ISSN 0167-4730, E-ISSN 1879-3355, Vol. 81, article id 101874Article in journal (Refereed) Epub ahead of print
Abstract [en]

An essential aspect in the maintenance of existing bridges is the ability to adequately and accurately assess and evaluate the condition of the structure. Condition assessments, which can be carried out in any number of ways, provide valuable information concerning the actual state of a bridge, including the severity of potential damages, and form the basis for further maintenance decisions. Any decision support concerning the management of existing structures thus requires attention towards the uncertainties associated with the assessment methods when applied in practice as well as the maintenance actions these support. These uncertainties cannot be solely described as model uncertainties but are also a result of the variation in engineering performance observed in practice. In the current paper a rational and systematic framework is presented which provides practical decision support concerning whether condition assessments are necessary, what assessment methods are recommended, if invasive actions are needed, or if some other non-invasive option may be more appropriate. The framework takes into account three main attributes of an enhanced condition assessment, namely, modelling sophistication, considerations of uncertainties and risks, and knowledge/information content. Increasing the level of one or more of these attributes may be advantageous only if the expected benefits or added value of information is considered appropriate in relation to the cost of implementation in practice. A decision making model, based on Bayesian decision theory, is adopted to evaluate this problem. Two case studies, in which the framework is applied, are provided for illustrative purposes; the first is a generic numerical example and the second a decision scenario related to the fatigue assessment of an existing railway bridge.

Keywords
Bridge operation and maintenance, Condition assessment, Decision support, Bayesian decision theory, Framework
National Category
Infrastructure Engineering
Identifiers
urn:nbn:se:ri:diva-39709 (URN)10.1016/j.strusafe.2019.101874 (DOI)
Funder
VinnovaSwedish Transport Administration
Available from: 2019-08-11 Created: 2019-08-11 Last updated: 2019-08-12Bibliographically approved
Nasr, A., Larsson Ivanov, O., Björnsson, I., Honfi, D., Johansson, J. & Kjellström, E. (2019). Klimatförändringars inverkan på broars säkerhet och prestanda : En översyn av potentiella effekter och anpassningsåtgärder.
Open this publication in new window or tab >>Klimatförändringars inverkan på broars säkerhet och prestanda : En översyn av potentiella effekter och anpassningsåtgärder
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2019 (Swedish)Report (Other academic)
Abstract [sv]

Vår infrastruktur kommer att påverkas av klimatförändringar, både nu och i framtiden.För att kunna säkerställa infrastrukturens funktion och uppfylla de säkerhetskrav somfinns kommer det därför att krävas investeringar i anpassningsåtgärder. Men åtgärder börinte tas på utifrån bristfällig kunskap, det är därför väsentligt att i förväg kartlägga vilkatyper av påverkan som kan förväntas och vilka åtgärder som är rimliga att genomföra.Denna rapport sammanfattar resultat från studier av risker med klimatförändringar ochdess potentiella effekter på broar, då dessa konstruktioner kan komma att påverkas avolika ändringar i klimatet. I studierna har 243 forskningsartiklar och rapporter från helavärlden gåtts igenom för att identifiera potentiella risker för broar på grund av ändringari klimatet. Det bör nämnas att resultaten i rapporten inte är fokuserade på Sverige utanhar ett internationellt perspektiv; de flesta av de identifierade riskerna är dock relevantaför svenska förhållanden, medan andra är mer relevanta i andra delar av världen.Totalt har 31 olika risker identifierats och kategoriserats i sju olika huvudkategorier enligtföljande:• Beständighet (riskgrupp D),• Funktion (riskgrupp S),• Geoteknik (riskgrupp G),• Ökad belastning (riskgrupp I),• Olyckslaster (riskgrupp A),• Extrema naturhändelser (riskgrupp E)• Drift (riskgrupp O).

Utöver dessa riskkategorier har även en kortare analys av samverkande händelser gjorts,dvs. händelser där två eller flera klimatfaktorer eller effekter samverkar och ger en störresammantagen effekt än om de inträffar var för sig. En avslutande del om möjligaanpassningsåtgärder har även inkluderats, där metoder funna i litteraturen för att hanterade olika riskerna som identifierats beskrivs.Den viktigaste slutsatsen i rapporten är att ett stort antal risker finns för broar.Föreliggande rapport bidrar därmed till att lyfta fram dessa risker och synliggöra desseffekter. De två klimatfaktorer som påverkar flest risker för broar är temperaturhöjningoch ökad eller minskad nederbörd, de kan individuellt eller kombinerat påverka 25 av de31 identifierade riskerna. Beroende på förutsättningarna för en specifik bro (dvs.geografiskt läge, platsegenskaper, konstruktivt system, etc.) varierar de potentiellaklimateffekterna och deras möjliga konsekvenser. En bedömning av sannolikheten för enviss risk att inträffa, eller en prioritering av de olika riskerna, tas därmed inte upp irapporten. Sådana mer detaljerade kontextspecifika studier pågår och kommer attredovisas framöver inom ramen för projektet.

Series
LUNDS Tekniska Högskola ; TVBK-3072
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39307 (URN)978-91-87993-13-8 (ISBN)
Available from: 2019-07-02 Created: 2019-07-02 Last updated: 2019-08-12Bibliographically approved
Blomfors, M., Larsson Ivanov, O., Honfi, D. & Engen, M. (2019). Partial safety factors for the anchorage capacity of corroded reinforcement bars in concrete. Engineering structures, 181, 579-588
Open this publication in new window or tab >>Partial safety factors for the anchorage capacity of corroded reinforcement bars in concrete
2019 (English)In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 181, p. 579-588Article in journal (Refereed) Published
Abstract [en]

Many reinforced concrete bridges in Europe and around the world are damaged by reinforcement corrosion and the annual maintenance costs are enormous. It is therefore important to develop reliable methods to assess the structural capacity of corroded reinforced concrete structures and avoid unnecessary maintenance costs. Although there are advanced models for determining the load carrying capacity of structures, it is not obvious how they should be used to verify the performance of existing structures. To confidently assess the bond of corroded reinforcement in concrete, for example, the calculation model must give a sufficient safety margin. When designing new structures, semi-probabilistic approaches (such as the partial safety factor method) are adopted to achieve the target reliabilities specified in structural design codes. This paper uses probabilistic methods to develop partial factors for application in an existing bond model, to assess the safety of corroded reinforced concrete structures. The response of the bond model was studied using Monte Carlo (MC) simulations for several design cases, with probability distributions fitted to the results. Partial factors were then derived, based on these distributions. Furthermore, an MC-based simulation technique called “importance sampling” was used to study the reliability of several deterministic bond assessments conducted using these partial factors. The results show that deterministic assessments which use the proposed partial factors lead to a safety level at least equal to the target value. The results presented in this paper will support the assessment of reinforced concrete structures with anchorage problems and give a reasonable approximation of the anchorage capacity with sufficient safety margin. When generalised to cover other failure modes and structural configurations, this will enable better utilisation of damaged structures and lead to major environmental and economical savings for society.

Keywords
Anchorages (foundations), Bond strength (materials), Bridges, Concrete beams and girders, Concrete buildings, Concrete construction, Concrete reinforcements, Costs, Electrochemical corrosion, Importance sampling, Maintenance, Monte Carlo methods, Probability distributions, Reinforced concrete, Safety factor, Structural design, Corroded reinforcement, Partial safety factor, Probabilistic approaches, Probabilistic methods, Reinforcement corrosion, Structural capacities, Structural configurations, Structural design codes, Failure (mechanical)
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36916 (URN)10.1016/j.engstruct.2018.12.011 (DOI)2-s2.0-85058677355 (Scopus ID)
Note

Funding details: Charles Babbage Institute, University of Minnesota; Funding details: Chalmers Tekniska Högskola;

Available from: 2018-12-28 Created: 2018-12-28 Last updated: 2019-08-12Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5879-7305

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