Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges

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Abstract

In order to design structural details of bridges for fatigue, the current version of the Eurocode for steel structures recommends partial factors for fatigue resistance based on the consequences of failure and on the maintenance method. The safe-life method is used for details where local formation of cracks could rapidly lead to failure or for details not accessible for inspection and has a relatively high partial factor. The damage tolerant method, on the other hand, is used for cases where fatigue crack initiation does not result in immediate failure so inspection and repair can be performed. In the current Eurocode, this comes with a relatively low partial factor. However, since the probability of crack detection of visual inspection by the naked eye is considerably different from more detailed inspection methods, the required partial factor to design a bridge for fatigue should be based on the way and level of inspection planned during the bridge service life. As a common practice, for most bridges, only visual inspections in short time intervals are carried out. In this paper, the added value of periodic visual inspection on the reliability status of a steel railway bridge is studied. The probability of failure after performing visual inspection is investigated by two approaches: 1) A statistical study on the main causes of bridge failure carried out by other researchers to find the relation between the safe-life design method and the design method considering visual inspection; 2) Conducting a survey to collect experts opinions on the matter and using a Bayesian algorithm to assign a probability distribution function to each opinion. A relation between reliability indices for the cases where a bridge is designed with and without considering the in-service visual inspection, is derived.
Original languageEnglish
Title of host publication5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019
Subtitle of host publicationProceedings
ISBN (Electronic)978-3-947971-07-7
Publication statusPublished - 2019
Event5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures - Potsdam, Germany
Duration: 27 Aug 201929 Aug 2019
https://www.smar2019.org/

Conference

Conference5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures
Abbreviated titleSMAR 2019
CountryGermany
CityPotsdam
Period27/08/1929/08/19
Internet address

Fingerprint

Steel bridges
Inspection
Fatigue of materials
Crack detection
Steel structures
Structural design
Crack initiation
Service life
Probability distributions
Distribution functions
Repair
Cracks

Cite this

Hashemi, S., Maljaars, J., & Snijder, B. (2019). Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges. In 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019: Proceedings
Hashemi, Seyed ; Maljaars, Johan ; Snijder, Bert. / Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges. 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019: Proceedings. 2019.
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abstract = "In order to design structural details of bridges for fatigue, the current version of the Eurocode for steel structures recommends partial factors for fatigue resistance based on the consequences of failure and on the maintenance method. The safe-life method is used for details where local formation of cracks could rapidly lead to failure or for details not accessible for inspection and has a relatively high partial factor. The damage tolerant method, on the other hand, is used for cases where fatigue crack initiation does not result in immediate failure so inspection and repair can be performed. In the current Eurocode, this comes with a relatively low partial factor. However, since the probability of crack detection of visual inspection by the naked eye is considerably different from more detailed inspection methods, the required partial factor to design a bridge for fatigue should be based on the way and level of inspection planned during the bridge service life. As a common practice, for most bridges, only visual inspections in short time intervals are carried out. In this paper, the added value of periodic visual inspection on the reliability status of a steel railway bridge is studied. The probability of failure after performing visual inspection is investigated by two approaches: 1) A statistical study on the main causes of bridge failure carried out by other researchers to find the relation between the safe-life design method and the design method considering visual inspection; 2) Conducting a survey to collect experts opinions on the matter and using a Bayesian algorithm to assign a probability distribution function to each opinion. A relation between reliability indices for the cases where a bridge is designed with and without considering the in-service visual inspection, is derived.",
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Hashemi, S, Maljaars, J & Snijder, B 2019, Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges. in 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019: Proceedings. 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures, Potsdam, Germany, 27/08/19.

Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges. / Hashemi, Seyed; Maljaars, Johan; Snijder, Bert.

5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019: Proceedings. 2019.

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

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N2 - In order to design structural details of bridges for fatigue, the current version of the Eurocode for steel structures recommends partial factors for fatigue resistance based on the consequences of failure and on the maintenance method. The safe-life method is used for details where local formation of cracks could rapidly lead to failure or for details not accessible for inspection and has a relatively high partial factor. The damage tolerant method, on the other hand, is used for cases where fatigue crack initiation does not result in immediate failure so inspection and repair can be performed. In the current Eurocode, this comes with a relatively low partial factor. However, since the probability of crack detection of visual inspection by the naked eye is considerably different from more detailed inspection methods, the required partial factor to design a bridge for fatigue should be based on the way and level of inspection planned during the bridge service life. As a common practice, for most bridges, only visual inspections in short time intervals are carried out. In this paper, the added value of periodic visual inspection on the reliability status of a steel railway bridge is studied. The probability of failure after performing visual inspection is investigated by two approaches: 1) A statistical study on the main causes of bridge failure carried out by other researchers to find the relation between the safe-life design method and the design method considering visual inspection; 2) Conducting a survey to collect experts opinions on the matter and using a Bayesian algorithm to assign a probability distribution function to each opinion. A relation between reliability indices for the cases where a bridge is designed with and without considering the in-service visual inspection, is derived.

AB - In order to design structural details of bridges for fatigue, the current version of the Eurocode for steel structures recommends partial factors for fatigue resistance based on the consequences of failure and on the maintenance method. The safe-life method is used for details where local formation of cracks could rapidly lead to failure or for details not accessible for inspection and has a relatively high partial factor. The damage tolerant method, on the other hand, is used for cases where fatigue crack initiation does not result in immediate failure so inspection and repair can be performed. In the current Eurocode, this comes with a relatively low partial factor. However, since the probability of crack detection of visual inspection by the naked eye is considerably different from more detailed inspection methods, the required partial factor to design a bridge for fatigue should be based on the way and level of inspection planned during the bridge service life. As a common practice, for most bridges, only visual inspections in short time intervals are carried out. In this paper, the added value of periodic visual inspection on the reliability status of a steel railway bridge is studied. The probability of failure after performing visual inspection is investigated by two approaches: 1) A statistical study on the main causes of bridge failure carried out by other researchers to find the relation between the safe-life design method and the design method considering visual inspection; 2) Conducting a survey to collect experts opinions on the matter and using a Bayesian algorithm to assign a probability distribution function to each opinion. A relation between reliability indices for the cases where a bridge is designed with and without considering the in-service visual inspection, is derived.

M3 - Conference contribution

BT - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019

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Hashemi S, Maljaars J, Snijder B. Added value of regular in-service visual inspection to the fatigue reliability of structural details in steel bridges. In 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures – SMAR 2019: Proceedings. 2019