Reduction of local scour around bridge pier groups using collars

Heidarpour, Manouchehr; Afzalimehr, Hossein; Izadinia, Elham

doi:10.1016/s1001-6279(11)60008-5

Cited by 84 publications

(36 citation statements)

References 17 publications

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“…Heidarpour et al highlight that the addition of riprap, rock armour or collars [6] around bridge piers also helps to mitigate the effects of scour.…”

Section: Introductionmentioning

confidence: 99%

An investigation of the changes in the natural frequency of a pile affected by scour

Prendergast

Hester

Gavin

et al. 2013

Journal of Sound and Vibration

115

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Publication informationJournal of Sound and Vibration, 332 (25): 6685-6702Publisher Elsevier Item record/more information http://hdl.handle.net/10197/6581 Publisher's statementThis is the author's version of a work that was accepted for publication in Journal of Sound and Vibration. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Sound and Vibration (VOL 332, ISSUE 25, (2013) AbstractScour around bridge foundations is one of the leading causes of bridge failure. Up until recently, the monitoring of this phenomenon was primarily based around using underwater instrumentation to monitor the progression of scour holes as they develop around foundation systems. Vibration-based damage detection techniques have been used to detect damage in bridge beams. The application of these vibration based methods to the detection of scour has come to the fore in research in recent years. This paper examines the effect that scour has on the frequency response of a driven pile foundation system, similar to those used to support road and rail bridges. The effect of scour on the vibration characteristics of the pile is examined using laboratory and field testing. It is clear that there is a very clear reduction in the natural frequency of the pile as the severity of scour increases. It is shown that by combining state-of-the-art geotechnical techniques with relatively simple finite element modelling approaches, it is possible to accurately predict the natural frequency of the pile for a given scour depth. Therefore, the paper proposes a method that would allow the estimation of scour depth for a given observed pile frequency. Scour Monitoring: The accurate assessment and monitoring of existing structures to progressive scour has come to the fore of research in recent years [7,8]. A myriad of current technology aims to detect the existence and severity of scour around the foundation systems of existing bridge structures. Most of these technologies comprise underwater instrumentation that aim to monitor the evolution of scour holes over time. A brief summary of available instrumentation is given herein. The use of float-out devices [9] and Tethered Buried Switches [10] positioned in the soil near a bridge pier can provide a simple method of scour monitoring. These devices float out when the scour depth reaches their position and are programmed to send a remote signal to provide a warning. However, they require reinstallation upon floating out, which is a distinct disadvantage. Time Domain Reflectometry (TDR) aims to detect changes in the dielectric permittivity constants between materials that would occur at a water-sediment interface and thus has been used to detect scour [10 -12]. Devices using this method work very well at detecting the depth of scour i...

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“…Heidarpour et al highlight that the addition of riprap, rock armour or collars [6] around bridge piers also helps to mitigate the effects of scour.…”

Section: Introductionmentioning

confidence: 99%

An investigation of the changes in the natural frequency of a pile affected by scour

Prendergast

Hester

Gavin

et al. 2013

Journal of Sound and Vibration

115

View full text Add to dashboard Cite

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“…It has long been established that the basic mechanism causing local scour at bridge piers is the down-flow at the upstream face of the bridge pier and formation of vortices at the base. Heidarpour et al [2] and Zarrati et al [3], identified two main classifications of local scour at bridge piers, based on the mode of sediment transport by the approaching stream, namely clear-water scour and live bed scour. Live-bed scour occurs when the scour hole is continually replenished with sediment by the approach flow [4].…”

Section: Introductionmentioning

confidence: 99%

Local Scour around Group Bridge Pier with Different Shapes

2017

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This study is based on laboratory experiments for computing depth of local scour around group bridge pier, considering the effects of upstream flow conditions, size of pier, median size of bed material and spacing between bridge piers on the maximum scour depth and scour pattern around bridge piers. The study was conducted using a physical hydraulic model for bridge piers, operated under clear-water condition and using uniform cohesionless sand as bed material. Three different models of bridge piers, having different sizes were used for showing the effect of the size on the local scour.

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“…These vortices are unstable and shed disorderly from each side of the pier. They act as small tornadoes lifting the sediment from the bed to form a scour hole downstream of the pier (Akib et al, 2014;Akib et al, 2012;Heidarpour et al, 2010;Zarrati et al, 2006;). Fig.…”

Section: Introductionmentioning

confidence: 99%

Local scour around complex pier groups and combined piles at semi-integral bridge

Akib

Jahangirzadeh

Basser

2014

Journal of Hydrology and Hydromechanics

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Abstract:This research presents an experimental study on the scouring mechanism at semi-integral bridge piers. Based on laboratory experiments, this study focuses on the relationship between scour depth in complex pier groups and combined piles bridge and various parameters including the variation of inflow velocity, distance, and time. 1 200 data were collected for flow velocity and scour. The flow pattern and scour were analyzed for different flow discharges and flow depths. The results showed that the scour development with respect to time was greater for higher flow depth and bigger flow discharge at semi-integral bridges. In addition, the equilibrium scour depth increased with the approach flow depth around piers at semi-integral bridges. Velocity distribution also affected the scour development. It decreased when approaching the bridge but increased from upstream to downstream of the flume.

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Reduction of local scour around bridge pier groups using collars

Cited by 84 publications

References 17 publications

An investigation of the changes in the natural frequency of a pile affected by scour

An investigation of the changes in the natural frequency of a pile affected by scour

Local Scour around Group Bridge Pier with Different Shapes

Local scour around complex pier groups and combined piles at semi-integral bridge

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