Numerical Investigation of Scour Reduction around the Circular Pier Using Circular and Octagonal Collars and Sacrificial Piles in a Nonuniform Sediment BedSource: Journal of Irrigation and Drainage Engineering:;2025:;Volume ( 151 ):;issue: 003::page 04025010-1DOI: 10.1061/JIDEDH.IRENG-10489Publisher: American Society of Civil Engineers
Abstract: In this study, the influence of circular, octagonal collars, and sacrificial piles on local scouring around a circular pier in a nonuniformly graded sediment bed is investigated using numerical simulations. A total of 13 simulations are performed using FLOW-3D HYDRO software to study the protection provided by the various scour countermeasures mentioned previously under clear water conditions. The simulations involve three different collar sizes with diameters of 2b, 2.5b, and 3b, where b represents the pier diameter. The sacrificial piles are arranged in two configurations: transverse and V-shaped at spacing of 2b and 3b. The study utilized the turbulence model, large eddy simulation (LES), for hydrodynamic, and Nielsen bed-load transport model for sediment transport analysis. A nested mesh consisting of 7.8045 million cells is employed to capture the scour and flow dynamics around the pier with appropriate countermeasures. The numerical model has been validated using experimental results and a good correlation of 95% is obtained between the observed and simulated value of maximum scour depth. The performance of collars and sacrificial piles in reducing scour ranges from 10% to 100% and 15% to 20%, respectively. This reduction is also expressed in terms of pier diameter (b), which ranges from 0.7b to 0b for collars and from 0.62b to 0.68b for sacrificial piles. Scour depth contours around the circular pier with different countermeasures are plotted to understand the morphology around it. From the flow structures, it is observed that when collars are placed at the bed level, the effect of downflow is observed on the upstream side of the pier and the formation of wake vortices is observed on the lateral side of the pier. In the case of sacrificial piles, the presence of piles restricts the velocity magnitude, resulting in lower velocities observed near the piles. The streamlines are visualized for the pier with collars and sacrificial piles and visualized that collars and sacrificial piles increase the number of zero-velocity streamlines near the pier, signifying a reduction in the intensity of horseshoe and wake vortices. The findings of this study provide valuable insights for engineers and practitioners involved in the design and maintenance of bridge piers. Scouring around bridge piers is a critical issue that can undermine structural stability and lead to significant maintenance costs or even failure. The research demonstrates that circular and octagonal collars can reduce scour depths by 10% to 100%, while sacrificial piles can reduce 15% to 20%. These findings are particularly relevant for nonuniform sediment beds, where scouring is often more severe. The use of these scour countermeasures can extend the lifespan of hydraulic structures, reduce the risk of failure during floods, and minimize the need for frequent repairs. This work bridges the gap between the numerical simulations and real-world applications, offering actionable strategies to enhance the safety and durability of critical infrastructure.
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contributor author | Lav Kumar Gupta | |
contributor author | T. I. Eldho | |
date accessioned | 2025-08-17T22:49:30Z | |
date available | 2025-08-17T22:49:30Z | |
date copyright | 6/1/2025 12:00:00 AM | |
date issued | 2025 | |
identifier other | JIDEDH.IRENG-10489.pdf | |
identifier uri | http://yetl.yabesh.ir/yetl1/handle/yetl/4307507 | |
description abstract | In this study, the influence of circular, octagonal collars, and sacrificial piles on local scouring around a circular pier in a nonuniformly graded sediment bed is investigated using numerical simulations. A total of 13 simulations are performed using FLOW-3D HYDRO software to study the protection provided by the various scour countermeasures mentioned previously under clear water conditions. The simulations involve three different collar sizes with diameters of 2b, 2.5b, and 3b, where b represents the pier diameter. The sacrificial piles are arranged in two configurations: transverse and V-shaped at spacing of 2b and 3b. The study utilized the turbulence model, large eddy simulation (LES), for hydrodynamic, and Nielsen bed-load transport model for sediment transport analysis. A nested mesh consisting of 7.8045 million cells is employed to capture the scour and flow dynamics around the pier with appropriate countermeasures. The numerical model has been validated using experimental results and a good correlation of 95% is obtained between the observed and simulated value of maximum scour depth. The performance of collars and sacrificial piles in reducing scour ranges from 10% to 100% and 15% to 20%, respectively. This reduction is also expressed in terms of pier diameter (b), which ranges from 0.7b to 0b for collars and from 0.62b to 0.68b for sacrificial piles. Scour depth contours around the circular pier with different countermeasures are plotted to understand the morphology around it. From the flow structures, it is observed that when collars are placed at the bed level, the effect of downflow is observed on the upstream side of the pier and the formation of wake vortices is observed on the lateral side of the pier. In the case of sacrificial piles, the presence of piles restricts the velocity magnitude, resulting in lower velocities observed near the piles. The streamlines are visualized for the pier with collars and sacrificial piles and visualized that collars and sacrificial piles increase the number of zero-velocity streamlines near the pier, signifying a reduction in the intensity of horseshoe and wake vortices. The findings of this study provide valuable insights for engineers and practitioners involved in the design and maintenance of bridge piers. Scouring around bridge piers is a critical issue that can undermine structural stability and lead to significant maintenance costs or even failure. The research demonstrates that circular and octagonal collars can reduce scour depths by 10% to 100%, while sacrificial piles can reduce 15% to 20%. These findings are particularly relevant for nonuniform sediment beds, where scouring is often more severe. The use of these scour countermeasures can extend the lifespan of hydraulic structures, reduce the risk of failure during floods, and minimize the need for frequent repairs. This work bridges the gap between the numerical simulations and real-world applications, offering actionable strategies to enhance the safety and durability of critical infrastructure. | |
publisher | American Society of Civil Engineers | |
title | Numerical Investigation of Scour Reduction around the Circular Pier Using Circular and Octagonal Collars and Sacrificial Piles in a Nonuniform Sediment Bed | |
type | Journal Article | |
journal volume | 151 | |
journal issue | 3 | |
journal title | Journal of Irrigation and Drainage Engineering | |
identifier doi | 10.1061/JIDEDH.IRENG-10489 | |
journal fristpage | 04025010-1 | |
journal lastpage | 04025010-14 | |
page | 14 | |
tree | Journal of Irrigation and Drainage Engineering:;2025:;Volume ( 151 ):;issue: 003 | |
contenttype | Fulltext |