Time evolution of the flow characteristics around bridge abutments during scouring process

Yıldız, Burhan
This study involves numerical and experimental investigation of the velocity field and the time evolution of the scour pattern forming around bridge abutments. The experimental part of the study includes velocity field recordings by using an ADV device and eroded bed bathymetry measurements by an ultrasonic ranging system. Using the ADV measurements; the velocity components, the upstream part of the primary vortex and the change of downstream recirculation region dimensions by the change in abutment length, type and closeness to the channel bed was investigated. Scour recording part of the experimental study included scour pattern recordings for various abutment lengths, types and experiment durations; and continuous measurements of scour at some predefined sections around abutments for eight hours. Maximum scour depth, scour hole dimensions and scour volume are related to scour time and abutment length. It was observed that, the contraction scour occurs together with the local scour at contraction ratios larger than 15-20% depending on the abutment type. The second part of the study includes a numerical analysis of the problem by using a commercially available CFD software. The numerical analysis consisted of simulations both for non-erodible and erodible channel bed conditions. The capability of the scour model of the software was tested.


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The performance of soft computing techniques to analyse and interpret the experimental data of local scour depth around bridge abutment, measured at different laboratory conditions and environment, is presented. The scour around bridge piers and abutments is, in the majority of cases, the main reason for bridge failures. Therefore, many experimental and theoretical studies have been conducted on this topic. This study sought to answer the following questions: Firstly, can data collected by different researc...
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Computation of temporal evolution of scour depth around bridge piers is essential for the efficient design of bridge pier footings. In this thesis, empirical scour-prediction equations and a semi-empirical model are developed to predict the temporal variation of maximum clear-water scour depth at dual cylindrical uniform piers with identical size in tandem arrangement. Experiments are conducted using different pier size, pier spacing, and flow intensities. The semi-empirical model is based on sediment conti...
Citation Formats
B. Yıldız, “Time evolution of the flow characteristics around bridge abutments during scouring process,” Ph.D. - Doctoral Program, Middle East Technical University, 2014.