Experimental Study and Prediction Maximum Scour Depth Equation of Local Scour Around Bridge Pier

2018 ◽  
Author(s):  
Mohammed Tareq Shukri ◽  
M. Günal ◽  
Junaid Kameran Ahmed
Keyword(s):  
Experimental Study ◽  
Local Scour ◽  
Bridge Pier ◽  
Scour Depth

scholarly journals Impact Assessment of Pier Shape and Modifications on Scouring around Bridge Pier

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1761 ◽  
Author(s):  
Rashid Farooq ◽  
Abdul Razzaq Ghumman
Keyword(s):  
Experimental Study ◽  
Impact Assessment ◽  
Experimental Research ◽  
Vortex Formation ◽  
Local Scour ◽  
Bridge Pier ◽  
Width Ratio ◽  
Scour Depth ◽  
Length Width

Previous experimental research on utilizing pier modifications as countermeasures against local scour has focused primarily on circular pier. It is of utmost importance to further investigate the most suitable pier shape for pier modification countermeasure separately and in combination. This experimental study aims to reduce the stagnation of the flow and vortex formation in front of the bridge pier by providing a collar, a hooked collar, a cable, and openings separately and in combination around a suitable pier shape. Therefore, six different pier shapes were utilized to find out the influence of pier shape on local scouring for a length–width ratio smaller than or equal to 3. A plain octagonal shape was shown as having more satisfactory results in reducing scour compared to other pier shapes. Furthermore, the efficiency of pier modification was then evaluated by testing different combinations of collar, hooked collar, cable, and openings within the octagonal bridge pier, which was compared to an unprotected octagonal pier without any modification. The results show that by applying such modifications, the scour depth reduced significantly. The best combination was found to be a hooked collar with cable and openings around an octagonal pier. It was revealed that the best combination reduced almost 53% of scour depth, as compared to an unprotected octagonal pier.

Experimental study on local scour at complex bridge pier under combined waves and current

2020 ◽  
Vol 160 ◽  
pp. 103730
Author(s):  
Yifan Yang ◽  
Bruce W. Melville ◽  
Graham H. Macky ◽  
Asaad Y. Shamseldin
Keyword(s):  
Experimental Study ◽  
Local Scour ◽  
Bridge Pier

scholarly journals Local Scour of Bridge Pier Sited on a Multi-Layered Sedimentary Bed in Rivers

2020 ◽  
Vol 144 ◽  
pp. 01008
Author(s):  
Shaolin Yue ◽  
Huan Zhou ◽  
Wenlong Zhu ◽  
Minxi Zhang
Keyword(s):  
Local Scour ◽  
Bridge Pier ◽  
Maximum Depth ◽  
Bridge Piers ◽  
Scour Depth ◽  
Bridge Safety ◽  
Particle Sorting ◽  
River Bed ◽  
Weihe River ◽  
Sediment Particles

The riverbeds or sea beds are usually composed of multi-layers of sediments. The scour around bridge piers sited on such beds is vital to the bridge safety, but is still very difficult to be predicated as its complicated interaction between the flow and bed layers. A simple model is proposed in this study for calculating the local scour maximum depth around bridge piers sited on multi-layer of sedimentary bed, which is based on HEC-18 formula revised by Richardson and Davis (2001) and the formula of the repose angle of sediment particles proposed by Cheng (1993). This model considers the particle sorting when the scour proceeds. An application of the model into the local scour depth of Guopan bridge pier sited on the Weihe River bed in Baoji city of China preliminarily demonstrates its reliability to calculate the local scour maximum depth around bridge piers sited on multi-layer of sedimentary bed.

scholarly journals Numerical Simulation of Local Scour around Three Cylindrical Piles in a Tandem Arrangement

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3623
Author(s):  
Jyh-Haw Tang ◽  
Aisyah Dwi Puspasari
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Numerical Model ◽  
Experimental Studies ◽  
Horseshoe Vortex ◽  
Local Scour ◽  
Scour Depth ◽  
Pile Groups ◽  
Tandem Arrangement ◽  
Flow Acceleration

Scouring is one of the most common potential causes of bridge pile foundation failure, with loss of life, economic and environmental impacts. Comprehensive studies on the numerical simulation of local scour around pile groups are still limited. This paper presents a numerical simulation using Flow-3D software to calculate the maximum sediment scour depth and investigate the mechanism around the groups of three cylinders in a tandem arrangement. A validation using the experimental study was carried out to confirm the reliability of the present numerical model. By using the Van Rijn transport rate equation and RNG k-ε turbulence model, the results of time evolution of scour depth and bed elevation contour show good agreement with the experimental study. The numerical simulation of three cylinders in a tandem arrangement were conducted with pile spacing ratios, G/D of 2 and 3. The local scour is affected by the horseshoe vortex from the downflow driven by the downward pressure gradient and rotates in front of the pile and the high bed shear stress, triggered by flow acceleration. The deepest maximum local scour depth is always obtained by the front pile as a shield pile, followed by the piles behind. The trend of the maximum local scour depth in a tandem arrangement is in accordance with the experimental studies and has a better agreement than previous numerical studies with the same model setup. This means that the numerical model used to simulate pile groups is accurate and capable of calculating the depth of sediment scour.

scholarly journals Effects of Dynamical Change in Water Level on Local Scouring around Bridge Piers Based on In-Situ Experiments

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3015
Author(s):  
Takuma Kadono ◽  
Sho Kato ◽  
Shinichiro Okazaki ◽  
Toshinori Matsui ◽  
Yoshio Kajitani ◽  
...  
Keyword(s):  
Water Level ◽  
Local Scour ◽  
Bridge Pier ◽  
Angle Of Repose ◽  
Bridge Piers ◽  
Scour Depth ◽  
Water Level Change ◽  
Protection Zone ◽  
Level Change ◽  
In Situ Experiments

To evaluate the stability of bridge piers affected by the local scouring, the existing formulas for estimating the maximum local scour depth have been developed based on the results of experiments conducted under a constant water level. However, the applicability of these formulas to the cases where the water level rises and falls, such as a water level change in a real river, is not clear. In this study, water flow experiments were conducted on cylindrical and oval bridge pier models to investigate the effect of iterated water level change on the progression of local scour around piers. Results of experiments with cylindrical and oval pier showed that the local scour depth and length increased by an iterated action of the water level change; however, these values converged after the number of iterated actions reached a certain time. The local scour length at upstream of the bridge pier was approximately 1.8 times larger than the theoretical value, which was calculated through the local scour depth and angle of repose in water. The local scour length is an important parameter for defining the streambed protection zone, which is one of the measures against local scour, and we showed that the streambed protection zone needs to be defined more widely.

Empirical Formulas to Predict the Maximum Scour Depth With ‎Debris Accumulation Around A Single Cylindrical Bridge Pier: An ‎Experimental Study

2020 ◽  
Vol 38 (12A) ◽  
pp. 1790-1800
Author(s):  
Mahmoud S. Al-Khafaji ◽  
Aysar T. Al-Awadi
Keyword(s):  
Experimental Study ◽  
Woody Debris ◽  
Bridge Pier ◽  
Coefficient Of Determination ◽  
Scour Depth ◽  
Empirical Formulas ◽  
Flow Area ◽  
Debris Accumulation ◽  
Modification Factor ◽  
Length Width

The probability of debris accumulation near bridge piers during the heavy storm and river flood convert the ‎hydraulic action of flow and increase the scour depth due to the reduction of flow area and the increase in ‎velocity of flow. In this paper, the effects of debris accumulation length, width and submerged depth on ‎scour depth near bridge pier were investigated. An experimental study for three groups of woody debris ‎accumulation was conducted under clear water condition to investigate the effects on maximum scour depth. ‎The results showed that the increase of blocked area of debris ‎to 27% increases the scour depth by approximately 140%. Furthermore, two empirical exponential formulas was proposed to predict the effect of ‎debris on the maximum scour depth and the modification factor required for single pier. Well agreement ‎was obtained for both derived formulas with coefficient of determination (R2) of 0.96. ‎

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