Cargando…
Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling
One of the most prevalent causes of bridge failure around the world is “scour”—the gradual erosion of soil around a bridge foundation due to fast-flowing water. A reliable technique for monitoring scour would help bridge engineers take timely countermeasures to safeguard against failure. Although vi...
Autores principales: | , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2020
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7784483/ https://www.ncbi.nlm.nih.gov/pubmed/33442503 http://dx.doi.org/10.1007/s13349-020-00420-5 |
_version_ | 1783632299321982976 |
---|---|
author | Kariyawasam, Kasun D. Middleton, Campbell R. Madabhushi, Gopal Haigh, Stuart K. Talbot, James P. |
author_facet | Kariyawasam, Kasun D. Middleton, Campbell R. Madabhushi, Gopal Haigh, Stuart K. Talbot, James P. |
author_sort | Kariyawasam, Kasun D. |
collection | PubMed |
description | One of the most prevalent causes of bridge failure around the world is “scour”—the gradual erosion of soil around a bridge foundation due to fast-flowing water. A reliable technique for monitoring scour would help bridge engineers take timely countermeasures to safeguard against failure. Although vibration-based techniques for monitoring structural damage have had limited success, primarily due to insufficient sensitivity, these have tended to focus on the detection of local damage. High natural frequency sensitivity has recently been reported for scour damage. Previous experiments to investigate this have been limited as a result of the cost of full-scale testing and the fact that scaled-down soil-structure models tested outside a centrifuge do not adequately simulate full-scale behaviour. This paper describes the development of what is believed to be the first-ever centrifuge-testing programme to establish the sensitivity of bridge natural frequency to scour. A 1/60 scale model of a two-span integral bridge with 15 m spans was tested at varying levels of scour. For the fundamental mode of vibration, these tests found up to a 40% variation in natural frequency for 30% loss of embedment. Models of three other types of foundation, which represent a shallow pad foundation, a deep pile bent and a deep monopile, were also tested in the centrifuge at different scour levels. The shallow foundation model showed lower frequency sensitivity to scour than the deep foundation models. Another important finding is that the frequency sensitivity to “global scour” is slightly higher than the sensitivity to “local scour”, for all foundation types. The level of frequency sensitivity (3.1–44% per scour depth equivalent to 30% of embedment of scour) detected in this experiment demonstrates the potential for using natural frequency as an indicator of both local and global scour of bridges, particularly those with deep foundations. |
format | Online Article Text |
id | pubmed-7784483 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-77844832021-01-11 Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling Kariyawasam, Kasun D. Middleton, Campbell R. Madabhushi, Gopal Haigh, Stuart K. Talbot, James P. J Civ Struct Health Monit Original Paper One of the most prevalent causes of bridge failure around the world is “scour”—the gradual erosion of soil around a bridge foundation due to fast-flowing water. A reliable technique for monitoring scour would help bridge engineers take timely countermeasures to safeguard against failure. Although vibration-based techniques for monitoring structural damage have had limited success, primarily due to insufficient sensitivity, these have tended to focus on the detection of local damage. High natural frequency sensitivity has recently been reported for scour damage. Previous experiments to investigate this have been limited as a result of the cost of full-scale testing and the fact that scaled-down soil-structure models tested outside a centrifuge do not adequately simulate full-scale behaviour. This paper describes the development of what is believed to be the first-ever centrifuge-testing programme to establish the sensitivity of bridge natural frequency to scour. A 1/60 scale model of a two-span integral bridge with 15 m spans was tested at varying levels of scour. For the fundamental mode of vibration, these tests found up to a 40% variation in natural frequency for 30% loss of embedment. Models of three other types of foundation, which represent a shallow pad foundation, a deep pile bent and a deep monopile, were also tested in the centrifuge at different scour levels. The shallow foundation model showed lower frequency sensitivity to scour than the deep foundation models. Another important finding is that the frequency sensitivity to “global scour” is slightly higher than the sensitivity to “local scour”, for all foundation types. The level of frequency sensitivity (3.1–44% per scour depth equivalent to 30% of embedment of scour) detected in this experiment demonstrates the potential for using natural frequency as an indicator of both local and global scour of bridges, particularly those with deep foundations. Springer Berlin Heidelberg 2020-07-18 2020 /pmc/articles/PMC7784483/ /pubmed/33442503 http://dx.doi.org/10.1007/s13349-020-00420-5 Text en © The Author(s) 2020 Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Original Paper Kariyawasam, Kasun D. Middleton, Campbell R. Madabhushi, Gopal Haigh, Stuart K. Talbot, James P. Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title | Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title_full | Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title_fullStr | Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title_full_unstemmed | Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title_short | Assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
title_sort | assessment of bridge natural frequency as an indicator of scour using centrifuge modelling |
topic | Original Paper |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7784483/ https://www.ncbi.nlm.nih.gov/pubmed/33442503 http://dx.doi.org/10.1007/s13349-020-00420-5 |
work_keys_str_mv | AT kariyawasamkasund assessmentofbridgenaturalfrequencyasanindicatorofscourusingcentrifugemodelling AT middletoncampbellr assessmentofbridgenaturalfrequencyasanindicatorofscourusingcentrifugemodelling AT madabhushigopal assessmentofbridgenaturalfrequencyasanindicatorofscourusingcentrifugemodelling AT haighstuartk assessmentofbridgenaturalfrequencyasanindicatorofscourusingcentrifugemodelling AT talbotjamesp assessmentofbridgenaturalfrequencyasanindicatorofscourusingcentrifugemodelling |