Characterization of horseshoe vortex in a developing scour hole at a cylindrical bridge pier

2019 ◽  
Vol 34 (2) ◽  
pp. 118-124 ◽  
Author(s):  
Dawei Guan ◽  
Yee-Meng Chiew ◽  
Maoxing Wei ◽  
Shih-Chun Hsieh
Keyword(s):  
Horseshoe Vortex ◽  
Bridge Pier ◽  
Scour Hole

scholarly journals A Hooked-Collar for Bridge Piers Protection: Flow Fields and Scour

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1251 ◽  
Author(s):  
Su-Chin Chen ◽  
Samkele Tfwala ◽  
Tsung-Yuan Wu ◽  
Hsun-Chuan Chan ◽  
Hsien-Ter Chou
Keyword(s):  
Laboratory Experiments ◽  
Horseshoe Vortex ◽  
Flow Fields ◽  
Bridge Pier ◽  
The Other ◽  
Bridge Piers ◽  
Vortex Strength ◽  
Numerical Tests ◽  
Scour Hole ◽  
New Type

A new type of collar, the hooked-collar, was studied through experiments and numerical methods. Tests were conducted using a hooked collar of a width of 1.25b and a height of 0.25b, where b is the bridge-pier width. The hooked-collar efficiency was evaluated by testing different hooked-collar placements within the bridge-pier, which were compared to the bridge-pier without any collar. A double hooked-collar configuration, one placed at the bed level and the other buried 0.25b, was the most efficient at reducing the scour hole. In other cases, a hooked-collar positioned 0.25b above the bed slightly reduced the scour hole and had similar scour patterns when compared to the pier without the hooked-collar. The flow fields along the vertical symmetrical plane in the experiments are also presented. Laboratory experiments and numerical tests show that maximal downflow is highly reduced along with a corresponding decrease in horseshoe vortex strength for the experiments with the hooked-collar, compared to cases without the hooked-collar. The flow fields reveal that the maximum turbulent kinetic energy decreases with the installation of the hooked-collar.

scholarly journals Experimental Characterization of the Flow Field around Oblong Bridge Piers

Fluids ◽  
2021 ◽  
Vol 6 (11) ◽  
pp. 370
Author(s):  
Ana Margarida Bento ◽  
Teresa Viseu ◽  
João Pedro Pêgo ◽  
Lúcia Couto
Keyword(s):  
Flow Field ◽  
Large Scale ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Shear Stresses ◽  
Velocity Measurements ◽  
Bridge Foundations ◽  
Scour Hole ◽  
Movable Bed

The prediction of scour evolution at bridge foundations is of utmost importance for engineering design and infrastructures’ safety. The complexity of the scouring inherent flow field is the result of separation and generation of multiple vortices and further magnified due to the dynamic interaction between the flow and the movable bed throughout the development of a scour hole. In experimental environments, the current approaches for scour characterization rely mainly on measurements of the evolution of movable beds rather than on flow field characterization. This paper investigates the turbulent flow field around oblong bridge pier models in a well-controlled laboratory environment, for understanding the mechanisms of flow responsible for current-induced scour. This study was based on an experimental campaign planned for velocity measurements of the flow around oblong bridge pier models, of different widths, carried out in a large-scale tilting flume. Measurements of stream-wise, cross-wise and vertical velocity distributions, as well as of the Reynolds shear stresses, were performed at both the flat and eroded bed stages of scouring development with a high-resolution acoustic velocimeter. The time-averaged values of velocity and shear stress are larger in the presence of a developed scour hole than in the corresponding flat bed configuration.

Characterization of Flow Turbulence Around Bridge Pier on Rigid Bed Channel

2021 ◽  
pp. 277-287
Author(s):  
Pasupuleti Laxmi Narayana ◽  
Praful Vasharambhai Timbadiya ◽  
Prem Lal Patel
Keyword(s):  
Bridge Pier ◽  
Flow Turbulence

Experimental Study on Effect of Ogival Bridge Pier on Scour Hole Depth

2011 ◽  
Author(s):  
Alireza Masjedi ◽  
B. Zeraat ◽  
M. Hydarnejad ◽  
Jiachun Li ◽  
Song Fu
Keyword(s):  
Experimental Study ◽  
Bridge Pier ◽  
Hole Depth ◽  
Scour Hole

scholarly journals Scour around Bridge Piers: Numerical Investigations of the Longitudinal Biconcave Pier Shape

2018 ◽  
Vol 62 (4) ◽  
pp. 298-304 ◽  
Author(s):  
Bouabdellah Guemou ◽  
Abdelali Seddini ◽  
Abderrahmane Nekkache Ghenim
Keyword(s):  
Shear Stress ◽  
Flow Direction ◽  
Basic Mechanism ◽  
Horseshoe Vortex ◽  
Local Scour ◽  
Bridge Pier ◽  
Bed Shear Stress ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
The Rich

The flow pattern around a bridge pier and the scouring phenomenon are very complicated. The basic mechanism causing local scour is the down-flow at the upstream face of the pier. It is understood that the horseshoe vortex is the key mechanism that leads to the local scour around pier; existing literature revealed that the strength of the down-flow, horseshoe vortex and the wake vortex are greater in the case of square piers compared to circular piers. In this paper we have investigated a new longitudinal biconcave bridge pier shape that reduces better the bed shear stress. For that purpose, a number of numerical simulations have been carried out using a Finite Volume Method (FVM) and for the turbulence model we have chosen the Detached Eddy Simulation (DES) for its capability to capture the rich dynamics of the horseshoe vortex at the upstream junction between the pier and the bed.The present study shows that the new longitudinal biconcave bridge pier shape reduces 10 % to 12 % the bed shear stress at the junction between the pier and the bed in other hand this shape increases the bed shear stress about 20 % but at a distance of D downstream the bridge pier in the flow direction.

scholarly journals Scaling of Scour Depth at Bridge Pier Based on Characteristic Dimension of Large-Scale Vortex

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2458 ◽  
Author(s):  
Nian-Sheng Cheng ◽  
Maoxing Wei
Keyword(s):  
Large Scale ◽  
Horseshoe Vortex ◽  
Bridge Pier ◽  
Theoretical Formula ◽  
Scour Depth ◽  
Flow Depth ◽  
Flow Conditions ◽  
Hydraulic Radius ◽  
Vortex System ◽  
Large Scale Vortex

By examining the variations in the dimensions of a horseshoe vortex system in front of a pier, the present study proposes a new length scale, called pier hydraulic radius, for the scaling of the maximum scour depth at a bridge pier. It is shown that, in comparison with other length scales, the pier hydraulic radius is more effective for quantifying combined effects of pier width and flow depth on the local scour for both low and high flow conditions. A theoretical formula is finally derived, which agrees well with experimental data reported in the literature.

scholarly journals Optimal Octagonal Hooked Collar Countermeasure to Reduce Scour Around a Single Bridge Pier

2020 ◽  
Author(s):  
Rashid Farooq ◽  
Abdul Razzaq Ghumman ◽  
Muhammad Atiq Ur Rehman Tariq ◽  
Afzal Ahmed ◽  
Khan Zaib Jadoon
Keyword(s):  
Cross Section ◽  
Vital Role ◽  
Bridge Pier ◽  
Scour Depth ◽  
Clear Water ◽  
Action Current ◽  
Pier Scour ◽  
Uniform State ◽  
Scour Hole ◽  
New Equation

Pier modification countermeasures are essential as they play a vital role in protecting pier against local scour action. Current study investigates experimentally the scour around vertical pier of octagonal cross section with pier modification such as newly proposed octagonal hooked collar is explored, in steady uniform state, under clear water condition. The results of pier scour without any modification were used as a reference to compute the efficiency of hooked collar provision around octagonal pier. The results show that by increasing the hooked collar width up to 2.5 Wp reduced maximum scour depth significantly. However, the experimental investigation revealed that the best combination to be with a hooked collar width of 2.5 Wp, having sidewall height 0.45 Wp. The best combination minimized around 73.3 % of scour hole depth, compared to octagonal pier without any modification. Using experimental results, a new equation is proposed to predict the scour depth around a bridge pier fitted with hooked collar. Moreover, a relation was developed for maximum scour depth and scour hole volume. Results indicate that the scour hole volume around a bridge pier increases quadratically with maximum scour depth.

scholarly journals A Study on Interaction between Overfall Types and Scour at Bridge Piers with a Moving-Bed Experiment

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 152
Author(s):  
Wei-Lin Lee ◽  
Chih-Wei Lu ◽  
Chin-Kun Huang
Keyword(s):  
Large Scale ◽  
River Flow ◽  
Extreme Event ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Flow Conditions ◽  
Moving Bed ◽  
Directional Flow ◽  
Scour Hole ◽  
Additional Protection

River slopes can be changed due to an extreme event, e.g., a large-scale earthquake. This can uplift a riverbed greatly and thereby change the behavior of the river flow into a free or submerged overfall. Corresponding damage, including extreme erosion, on bridge piers located in the river can take place due to the aforementioned flow conditions. A reconstructed bridge pier in the same location would also experience a similar impact if the flow condition is not changed. It is important to identify these phenomena and research the mechanism in the interaction between overfall types and scour at bridge piers. Therefore, this paper is aimed at studying a mechanism of free and submerged overfall flow impacts on bridge piers with different distances by a series of moving-bed experiments. The experiment results showed clearly that bridge pier protection requires attention particularly when the pier is located in the maximum scour hole induced by the submerged overfall due to the z directional flow eddies. In many other cases, such as when the location of the bridge pier was at the upstream slope of a scour hole induced by a flow drop, a deposition mound could be observed at the back of the pier. This indicates that, while a pier is at this location, an additional protection takes place on the bridge pier.

scholarly journals Characterization of the scour cavity evolution around a complex bridge pier

2015 ◽  
Vol 4 (2) ◽  
pp. 128-137 ◽  
Author(s):  
Pedro Xavier Ramos ◽  
Ana Margarida Bento ◽  
Rodrigo Maia ◽  
João Pedro Pêgo
Keyword(s):  
Bridge Pier ◽  
Cavity Evolution
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