Radar measurement of bridge scour

Forde, M. C.; McCann, D. M.; Clark, M. R.; Broughton, K. J.; Fenning, P. J.; Brown, Andrew

doi:10.1016/s0963-8695(99)00026-2

Cited by 73 publications

(49 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…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.…”

Section: Introductionmentioning

confidence: 99%

“…Devices using this method work very well at detecting the depth of scour in a particular location, but require costly underwater installations and are also susceptible to background radiation. Ground Penetrating Radar (GPR) is an effective tool for the immediate monitoring of scour-critical foundation systems [7,13]. A GPR Published in Journal of sound and vibration 332 (25), 2013 pp.…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

121

View full text Add to dashboard Cite

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...

show abstract

Section: Introductionmentioning

confidence: 99%

mentioning

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

121

View full text Add to dashboard Cite

show abstract

“…Scour erosion of bridge foundation soil is the number one cause of bridge failure in bridges located over waterways [1][2][3]. One study found that 53% of 500 bridge failures occurring between 1989 and 2000 in the United States occurred as a result of flooding and/or scour problems [4].…”

Section: Bridge Scourmentioning

confidence: 99%

“…Time-Domain Reflectometry (TDR) systems use changes in dielectric permittivity to monitor the location of the soil-water interface relative to a fixed probe [8,9]. Similarly, Ground Penetrating Radar (GPR) can be used to detect scour holes using high frequency electromagnetic waves, which are partially reflected as they pass through different media [3,10]. Sound wave devices such as Sonic Fathometers [5,9,11], Reflection Seismic Profilers [5,10] and Echo Sounders [10] emit sonic pulses to locate the soil-water interface and, hence, the scour depth, using a similar approach to the radar methods.…”

Section: Direct Monitoring Of Bridge Scour Using Depthmeasuring Instrmentioning

confidence: 99%

Isolating the location of scour-induced stiffness loss in bridges using local modal behaviour

Prendergast

Gavin

Hester

2017

J Civil Struct Health Monit

View full text Add to dashboard Cite

Detecting scour by analysing bridge vibrations is receiving an increasing amount of attention in the literature. Others have considered changes in natural frequency to indicate the presence of scour damage; however, little work has been reported on identifying the location of a scour hole based on vibration measurements. In this paper, a numerical study is carried out using a bespoke vehiclebridge-soil dynamic interaction model to examine how the first six vibration modes (Eigen frequencies) of a typical integral bridge are affected by scour at different locations. It is found that depending on the location of the scour hole, some modes are much more affected than others in terms of frequency changes. In fact, a clear pattern emerges as to which modes are affected by which scour location. Using this knowledge, the location of a scour hole can potentially be detected on a real bridge. However, recognising that it is not possible to undertake an eigenvalue analysis on an actual bridge, an analysis is performed by collecting acceleration signals from various points on the structure. The bridge is loaded by a realistic vehicle model, incorporating vehicle-bridge interaction effects, which leads to the generation of discrete acceleration signals at various 'sensor' locations on the bridge. In this paper, it is found that it is possible to detect the location of a scour hole using a relatively small number of 'sensors'. However, to achieve this, careful signal processing is necessary and advice on a number of pertinent issues is provided.

show abstract

“…To 3.3-5 overcome limitations in this assessment process, significant efforts have been made to design remote systems capable of relaying information about scour reducing the need for manual intervention. These systems can be broadly categorized as follows (Prendergast & Gavin 2014): single-use devices (NCHRP 2009;Briaud et al 2011), pulse or radar devices (Forde et al 1999;Yu 2009;Yankielun & Zabilansky 1999), buried or driven rod systems (NCHRP 2009;De Falco & Mele 2002;Zarafshan et al 2012;Fisher et al 2013), sound-wave devices (Nassif et al 2002;Fisher et al 2013;Anderson et al 2007), fiber-Bragg grating devices (Lin et al 2006;May et al 2002) and electrical conductivity devices (Anderson et al 2007). Table 1 gives an overview of the function and detection methodology of a number of types of instrument available.…”

Section: Shm For Scourmentioning

confidence: 99%

Structural Health Monitoring and Design Code compliance for performance assessment of bridges under scour and seismic hazards

Zanini¹,

Faleschini²,

Ademovic³

et al. 2017

Proceedings of the Joint COST TU1402 - COST TU1406 - IABSE WC1 Workshop: The Value of Structural Health Monitoring for the Reli

View full text Add to dashboard Cite

Abstract. When dealing with asset management of infrastructural systems, maintenance planning of bridges and other critical structures has to be thought against natural deterioration due to environmental conditions, but also taking into account potential criticalities induced by the occurrence of seismic and flood hazards. The aim of this work is to focus on potential damage scenarios, assessment methods for common bridge structures potentially subject to earthquake loading and scouring phenomena due to flooding hazards.

show abstract

Radar measurement of bridge scour

Cited by 73 publications

References 2 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

Isolating the location of scour-induced stiffness loss in bridges using local modal behaviour

Structural Health Monitoring and Design Code compliance for performance assessment of bridges under scour and seismic hazards

Contact Info

Product

Resources

About