Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour

Donal Ryan, Gerard Hamill, Brian Solan, Robert Ettema

Research output: Contribution to conferencePaper

Abstract

In recent years, the increased frequency of extreme rainfall events has led to many bridge failures throughout the UK and Ireland. Particularly vulnerable are short span bridges, which typically include arch structures, where abutments and piers are quickly scoured at their foundations. Several bridges have collapsed under flood conditions and, recently, such events have occurred in Northern England during the floods during the latter part of 2015. This paper is the result of an on-going experimental investigation, funded by The Royal Society, where arch bridge scale models are subjected to pressurised flow. Results demonstrate the nature of the upstream and downstream velocity distributions, and resulting scour profiles. The study provides an insight into the significance of pressurised flow on the depth and extent of scour when compared to normal open channel conditions. Measurements of velocities were taken using Acoustic Doppler Velocimeter (ADV), where significant increases in bed velocities are experienced as the flow passes under the arch. Scour depth was measured by 3D laser scanner and also verify a relationship between the shape of the resulting scour hole and the magnitude of bed velocities. The outcome of this paper is the demonstration of the severity of scour within the vicinity of an inundated arch bridge structure and demonstrates the likely risks to long term stability, identifying appropriate locations to consider in relation to protection against local scour.
LanguageEnglish
Publication statusPublished - Aug 2016
EventCERI 2016: CERI 2016 - Civil Engineering Research in Ireland - Engineering Building, NUI, Galway, Ireland
Duration: 29 Aug 201630 Aug 2016

Conference

ConferenceCERI 2016
CountryIreland
CityGalway
Period29/08/201630/08/2016

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scour
arch
pier
scanner
distribution
acoustics
laser
rainfall

Cite this

Ryan, D., Hamill, G., Solan, B., & Ettema, R. (2016). Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour. Paper presented at CERI 2016, Galway, Ireland.
Ryan, Donal ; Hamill, Gerard ; Solan, Brian ; Ettema, Robert. / Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour. Paper presented at CERI 2016, Galway, Ireland.
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title = "Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour",
abstract = "In recent years, the increased frequency of extreme rainfall events has led to many bridge failures throughout the UK and Ireland. Particularly vulnerable are short span bridges, which typically include arch structures, where abutments and piers are quickly scoured at their foundations. Several bridges have collapsed under flood conditions and, recently, such events have occurred in Northern England during the floods during the latter part of 2015. This paper is the result of an on-going experimental investigation, funded by The Royal Society, where arch bridge scale models are subjected to pressurised flow. Results demonstrate the nature of the upstream and downstream velocity distributions, and resulting scour profiles. The study provides an insight into the significance of pressurised flow on the depth and extent of scour when compared to normal open channel conditions. Measurements of velocities were taken using Acoustic Doppler Velocimeter (ADV), where significant increases in bed velocities are experienced as the flow passes under the arch. Scour depth was measured by 3D laser scanner and also verify a relationship between the shape of the resulting scour hole and the magnitude of bed velocities. The outcome of this paper is the demonstration of the severity of scour within the vicinity of an inundated arch bridge structure and demonstrates the likely risks to long term stability, identifying appropriate locations to consider in relation to protection against local scour.",
author = "Donal Ryan and Gerard Hamill and Brian Solan and Robert Ettema",
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note = "CERI 2016 : CERI 2016 - Civil Engineering Research in Ireland ; Conference date: 29-08-2016 Through 30-08-2016",

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Ryan, D, Hamill, G, Solan, B & Ettema, R 2016, 'Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour' Paper presented at CERI 2016, Galway, Ireland, 29/08/2016 - 30/08/2016, .

Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour. / Ryan, Donal; Hamill, Gerard; Solan, Brian; Ettema, Robert.

2016. Paper presented at CERI 2016, Galway, Ireland.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour

AU - Ryan, Donal

AU - Hamill, Gerard

AU - Solan, Brian

AU - Ettema, Robert

PY - 2016/8

Y1 - 2016/8

N2 - In recent years, the increased frequency of extreme rainfall events has led to many bridge failures throughout the UK and Ireland. Particularly vulnerable are short span bridges, which typically include arch structures, where abutments and piers are quickly scoured at their foundations. Several bridges have collapsed under flood conditions and, recently, such events have occurred in Northern England during the floods during the latter part of 2015. This paper is the result of an on-going experimental investigation, funded by The Royal Society, where arch bridge scale models are subjected to pressurised flow. Results demonstrate the nature of the upstream and downstream velocity distributions, and resulting scour profiles. The study provides an insight into the significance of pressurised flow on the depth and extent of scour when compared to normal open channel conditions. Measurements of velocities were taken using Acoustic Doppler Velocimeter (ADV), where significant increases in bed velocities are experienced as the flow passes under the arch. Scour depth was measured by 3D laser scanner and also verify a relationship between the shape of the resulting scour hole and the magnitude of bed velocities. The outcome of this paper is the demonstration of the severity of scour within the vicinity of an inundated arch bridge structure and demonstrates the likely risks to long term stability, identifying appropriate locations to consider in relation to protection against local scour.

AB - In recent years, the increased frequency of extreme rainfall events has led to many bridge failures throughout the UK and Ireland. Particularly vulnerable are short span bridges, which typically include arch structures, where abutments and piers are quickly scoured at their foundations. Several bridges have collapsed under flood conditions and, recently, such events have occurred in Northern England during the floods during the latter part of 2015. This paper is the result of an on-going experimental investigation, funded by The Royal Society, where arch bridge scale models are subjected to pressurised flow. Results demonstrate the nature of the upstream and downstream velocity distributions, and resulting scour profiles. The study provides an insight into the significance of pressurised flow on the depth and extent of scour when compared to normal open channel conditions. Measurements of velocities were taken using Acoustic Doppler Velocimeter (ADV), where significant increases in bed velocities are experienced as the flow passes under the arch. Scour depth was measured by 3D laser scanner and also verify a relationship between the shape of the resulting scour hole and the magnitude of bed velocities. The outcome of this paper is the demonstration of the severity of scour within the vicinity of an inundated arch bridge structure and demonstrates the likely risks to long term stability, identifying appropriate locations to consider in relation to protection against local scour.

M3 - Paper

ER -

Ryan D, Hamill G, Solan B, Ettema R. Arch Bridges under flood conditions, a study of the velocity distributions, and the resulting bed scour. 2016. Paper presented at CERI 2016, Galway, Ireland.