scholarly journals PREDICTION OF LOCAL SCOUR AROUND WIDE BRIDGE PIERS UNDER CLEAR-WATER CONDITIONS

2017 ◽  
Author(s):  
Nordila Ahmad
Keyword(s):  
Local Scour ◽  
Bridge Piers ◽  
Clear Water ◽  
Water Conditions

Reduction of scouring depth by using inclined piers

2010 ◽  
Vol 37 (12) ◽  
pp. 1621-1630 ◽  
Author(s):  
Zafer Bozkus ◽  
Murat Çeşme
Keyword(s):  
Experimental Study ◽  
Dimensional Analysis ◽  
Local Scour ◽  
Bridge Piers ◽  
Scour Depth ◽  
Regression Analyses ◽  
Clear Water ◽  
Design Engineers ◽  
Water Conditions ◽  
Scouring Depth

The aim of this experimental study is to examine the effect of inclination of dual bridge piers on scour depth under clear-water conditions for various uniform flow depths. Duration of 4 h was used in the experiments for each run. Scour depths were measured at four different points around the piers. The depths of local scour around inclined piers were found to be substantially smaller than the scour depths around vertical piers. Dimensional and nondimensional curves were developed and presented to show the variation of scour depth with relevant parameters obtained in the dimensional analysis. Results of the study were compared to those obtained from a similar study performed with single inclined piers to see the effect of the second pier on scour depths. Useful equations for the design engineers were developed based on multiple regression analyses, to be used for predicting local scour depths around vertical and (or) inclined piers in uniform and (or) nonuniform sediments. Normalized scour depths measured around the vertical piers in the present study were compared with those computed by an equation suggested by Melville and Sutherland (1988), and also by an equation developed in the present study.

Riprap Performance at Bridge Piers Under Mobile-Bed Conditions

1998 ◽  
Vol 1647 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Carlos Toro-Escobar ◽  
Richard Voigt ◽  
Bruce Melville ◽  
Meng Chiew ◽  
Gary Parker
Keyword(s):  
Experimental Tests ◽  
Bridge Piers ◽  
Design Criteria ◽  
Research Groups ◽  
Clear Water ◽  
Pier Scour ◽  
Mobile Bed ◽  
Water Conditions ◽  
Improved Design ◽  
Flood Flow

Design criteria for riprap at bridge piers in rivers is based on the specification of a size, gradation, and cover that does not fail under an appropriately chosen flood flow. Experimental tests of riprap performance at bridge piers to date have relied on a configuration for which the ambient bed is not mobilized, that is, clear-water conditions. In the field, however, riprap is, as a rule, subjected to mobile-bed conditions during floods. Recent experiments by three cooperating research groups (University of Auckland, Nanyang University, and St. Anthony Falls Laboratory) indicate a heretofore unrecognized mechanism for riprap failure under mobile-bed conditions. When the flow is in the dune regime, the passage of successive dunes causes riprap that is never directly entrained by the flow to sink and disperse. Pier scour is realized as a consequence of these processes. In some cases, the depth of scour realized is not significantly less than that which would occur without riprap. When the riprap is fully underlain by a geotextile, edge effects can cause local removal of riprap, upturning of the geotextile, and general failure. When the riprap is underlain by a partial geotextile (i.e., one that covers an area less than the riprap), edge scour causes local sinking that anchors the geotextile. The sinking and dispersion of the rest of the riprap are greatly limited, and the riprap fails only when flow velocities are sufficient for direct entrainment. The experiments suggest improved design criteria for the installation of riprap in the field.

Temporal Evolution of Clear-Water Local Scour at Aligned and Skewed Complex Bridge Piers

2020 ◽  
Vol 146 (4) ◽  
pp. 04020026 ◽  
Author(s):  
Yifan Yang ◽  
Bruce W. Melville ◽  
Graham H. Macky ◽  
Asaad Y. Shamseldin
Keyword(s):  
Temporal Evolution ◽  
Local Scour ◽  
Bridge Piers ◽  
Clear Water

Clear-Water Local Scour at Skewed Complex Bridge Piers

2018 ◽  
Vol 144 (6) ◽  
pp. 04018019 ◽  
Author(s):  
Yifan Yang ◽  
Bruce W. Melville ◽  
D. M. Sheppard ◽  
Asaad Y. Shamseldin
Keyword(s):  
Local Scour ◽  
Bridge Piers ◽  
Clear Water

scholarly journals Study of the time-dependent clear water scour around circular bridge piers

2017 ◽  
Vol 65 (1) ◽  
pp. 26-34 ◽  
Author(s):  
Aysegul Ozgenc Aksoy ◽  
Gokcen Bombar ◽  
Tanıl Arkis ◽  
Mehmet Sukru Guney
Keyword(s):  
Empirical Relation ◽  
Local Scour ◽  
Bridge Piers ◽  
Geometric Standard Deviation ◽  
Dimensionless Time ◽  
Clear Water ◽  
Relative Water ◽  
Median Diameter ◽  
Flow Intensity ◽  
Experimental Findings

Abstract The local scour around bridge piers influences their stabilities and plays a key role in the bridge failures. The estimation of the maximum possible scour depth around bridge piers is an important step in the design of the bridge pier foundations. In this study, the temporal evolution of local scour depths as well as the equilibrium scour depths were analyzed. The experiments were carried out in a rectangular flume by using uniform sediment with median diameter of 3.5 mm and geometric standard deviation of 1.4. The diameters of the tested circular bridge piers were 40 mm, 80 mm, 150 mm and 200 mm. The flow and scour depths were determined by ultrasonic sensors. The experiments were realized in clear water conditions with various constant flow rates. The experimental findings were compared with those calculated from some empirical equations existing in the literature. A new empirical relation involving the flow intensity, the relative water depth and the dimensionless time is also introduced. The advantage of this proposed relation is that the only parameter requiring the calculation is the critical velocity, other parameters being known geometric and hydraulic parameters. The performance of this relation was tested by using experimental data available in the literature, and a satisfactory compatibility was revealed between the experimental and numerical results.

Investigation on the Local Scour Beneath Piggyback Pipelines Under Clear-Water Conditions

2021 ◽  
Vol 35 (3) ◽  
pp. 422-431
Author(s):  
Sahar Asrari ◽  
Habib Hakimzadeh ◽  
Nazila Kardan
Keyword(s):  
Local Scour ◽  
Clear Water ◽  
Water Conditions

Quantifying probability of deceedance estimates of clear water local scour around bridge piers

2021 ◽  
pp. 126177
Author(s):  
Azmayeen R. Shahriar ◽  
Brina M. Montoya ◽  
Alejandra C. Ortiz ◽  
Mohammed A. Gabr
Keyword(s):  
Local Scour ◽  
Bridge Piers ◽  
Clear Water
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