TITLE

Composite reliability model for local scour around cylindrical bridge piers

AUTHOR(S)
Yanmaz, A Melih; Cicekdag, Ozgur
PUB. DATE
June 2001
SOURCE
Canadian Journal of Civil Engineering;Jun2001, Vol. 28 Issue 3, p520
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Bridge scour is an extremely complex phenomenon because of the random characteristics of sediment laden flow in close proximity to piers and abutments. This occurrence leads to high uncertainties and unavoidable risk in bridge pier and abutment design. In this study, a composite reliability model is developed for the reliability assessment of bridge pier scour using static resistance – loading interference. Based on the physical interpretation of the phenomenon and a statistical analysis of the available information, the relative maximum scour depth (corresponding to the minimum required relative pier footing elevation) and the linear combination of the relative approach flow depth and flow Froude number are defined as the system resistance and external loading, respectively. By examining a set of laboratory and field data, a two-parameter bivariate lognormal distribution is found to represent the joint probability density function of resistance and loading. Reliability expressions are developed in terms of resistance. Use of the model is illustrated in a practical application in which a relationship is obtained between the reliability and safety factors under various return periods. This information is of importance in decision making.Key words: reliability, bridge pier, scour, resistance, loading, safety factor, return period.L'érosion de ponts est un phénomène extrêmement complexe à cause des caractéristiques aléatoires du courant chargé de sédiments à proximité des piliers et des butées. Cet événement amène de grandes incertitudes et des risques incontournables dans la conception de piliers et de butées de ponts. En cela, un modèle de fiabilité mixte a été développé afin d'évaluer la fiabilité contre l'érosion des piliers de ponts en utilisant une résistance statique – interférence de charge. Basé sur l'interprétation physique du phénomène et une analyse statistique de l'information disponible, la profondeur d'érosion maximale relative (correspondant à l'élévation minimale requise des fondations de piliers) et la combinaison linéaire de la profondeur relative du courant suivant le nombre de Froude sont définis comme la résistance du système et la charge externe, respectivement. En examinant une série de données obtenues en laboratoire et sur le terrain, une distribution lognormale bivariée à deux paramètres a été trouvée pour représenter la fonction de densité de probabilité conjointe de la résistance et de la charge. Des expressions de fiabilité ont été développées en termes de résistance. L'utilisation du modèle est illustrée dans une application pratique où une relation est obtenue entre la fiabilité et les facteurs de sécurité pour différentes périodes de retour. Cette information est d'importance dans le processus de décision.Mots clés : fiabilité, pilier de pont, érosion, résistance, chargement, facteur de sécurité, période de retour.[Traduit par la Rédaction]
ACCESSION #
10562137

 

Related Articles

  • Reduction of Local Scour at a Bridge Pier using Collar in a 180 Degree Flume Bend. Masjedi, A.; Bejestan, M. S.; Esfandi, A. // Journal of Applied Sciences;2010, Vol. 10 Issue 2, p124 

    In this study, the use of collars for reducing the effects of local scour at a bridge pier is presented together with the time aspect of the scour development. The adoption of a collar is based on the concept that its existence will sufficiently inhibit and/or deflect the local scour mechanisms...

  • Effects of Bridge Pier Position in a 180 Degree Flume Bend on Scour Hole Depth. Masjedi, A.; Bejestan, M. S.; Kazemi, H. // Journal of Applied Sciences;2010, Vol. 10 Issue 8, p670 

    Local scouring around the bridge pier occurs because of flow separation and developing several vortexes around the bridge pier. Such scour hole can cause failure of the bridge especially during the river floods. Because of this several researches, have been conducted during the past three...

  • Application of Artificial Neural Network, Kriging, and Inverse Distance Weighting Models for Estimation of Scour Depth around Bridge Pier with Bed Sill. Rahman, Homayoon Seyed; Alireza, Keshavarzi; Reza, Gazni // Communications & Network;Nov2010, Vol. 2 Issue 4, p944 

    This paper outlines the application of the multi-layer perceptron artificial neural network (ANN), ordinary kriging (OK), and inverse distance weighting (IDW) models in the estimation of local scour depth around bridge piers. As part of this study, bridge piers were installed with bed sills at...

  • Dynamic Reliability in Bridge Pier Scouring. Yanmaz, A. Melih // Turkish Journal of Engineering & Environmental Sciences;2002, Vol. 26 Issue 4, p367 

    Studies dynamic reliability in bridge pier scouring. Information on static and dynamic reliability models for bridge pier scouring; Application of dynamic reliability model; Conclusions.

  • Pier scour and thin layered bed scour within a long contraction. Raikar, Rajkumar V.; Dey, Subhasish // Canadian Journal of Civil Engineering;Feb2006, Vol. 33 Issue 2, p140 

    The paper presents an experimental investigation of (i) scour at a pier within a long contraction and (ii) scour of a thin layered bed within a long contraction. The scour depth at piers within long contractions increases with an increase in sediment size and a decrease in channel opening ratio....

  • BRIDGE PIER SCOUR: A REVIEW OF PROCESSES, MEASUREMENTS AND ESTIMATES. Brandimarte, Luigia; Paron, Paolo; Di Baldassarre, Giuliano // Environmental Engineering & Management Journal (EEMJ);May2012, Vol. 11 Issue 5, p975 

    Scouring of piers and abutment has been recognized as the main cause of damage and failure of bridges over waterways. The scientific community has produced a number of studies addressing the complex characteristics of the scour process and has provided engineers with several techniques for the...

  • Quick Fix Reopens Outer Banks Span. Parsons, Jim // ENR: Engineering News-Record;12/30/2013, Vol. 272 Issue 15, p8 

    The article reports on the reopening of the Herbert C. Bonner Bridge on North Carolina's Outer Banks two weeks after it was closed due to the discovery of excess scour around underwater pilings. Topics addressed include the isolation of residents on Hatteras Island due to the closure, the debate...

  • EROSÕES LOCALIZADAS EM PILARES COMPLEXOS DE PONTES: DESEMPENHO DE MODELOS DE PREVISÃO EXISTENTES. Moreno, Mario Enrique; Couto, Lúcia Teixeira; Maia, Rodrigo; Cardoso, António Heleno // Recursos Hídricos;mai2014, Vol. 35 Issue 1, p5 

    The rigorous prediction of local scour depth around complex piers, used to support bridge decks, may not be guaranteed by the predictors available at present. Among the available predictors, those of Auckland, HEC-18 and FDOT are the most popular. In this article, the performance of the tree...

  • Monitoring, Evaluation and Control for Life-cycle performance of Intelligent Civil Structures. LI Hui; BAO Yuequan; LI Shunlong; CHEN Wenli; LAIMA Shujin; OU Jinping // Advances in Science & Technology;2013, Vol. 83, p105 

    This paper includes five parts. The first is the sensing technology, in which ultrasonic-based sensing technology for scour monitoring of bridge piers, electro-chemistry-based distributed concrete cracks and automobile wireless sensors are introduced. The second is the application of compressive...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics