Characteristics assessment of local scour encircling twin bridge piers positioned side by side (SbS)
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In the case of multiple pier arrangements, commonly used manuals still suggest using methods for an isolated pier, irrespective of the spacing between the pier and the factors influencing the pairs of the pier. The present study is an experimental investigation for assessing maximum scour depth (MSD) characteristics around the twin piers installed in side-by-side (SbS) positioning. Twenty-seven experimental conditions were evaluated for three sets of the rate of flow. The Acoustic Doppler Velocimeter (ADV) was used to precisely measure flow intensity under the clear water condition. Center-to-center (C2C) spacing between the piers was varied from 1.5, 2, 2.5, 3, 3.5, 4, 4.5 to 5 times pier diameter (D). In the vortex region higher amount of turbulence is perceivedowing to a stronger horseshoe vortex forming between the piers. This turbulence resulted from various factors influencing the MSD, and these parameters are assessed and formulated by dimensional analysis. The findings of the study demonstrate the effect of Froud number, the effect of dimensional parameters, the effect of sediment deposition, and the effect of C2C spacing between the piers on the pattern of MSD for the two piers. During the comparison of the experimental data with the semi-empirical equations, the best value root mean square and maximum absolute percentage error was observed as 0.97 and 1.5%, respectively, for the Larsen and Toch equation. Bridge pier constitutes numbers of piers, this study will impart new light on mutual interferencebetween the two piers and its effect on the local scouring evolved in the propinquity of the pier, so that the current engineering equations can be modified for the accurate prediction of scouring.
Volume 48, 2023
Continuous Article Publishing mode
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