Flow-Field Complexity and Design Estimation of Pier-Scour Depth: Sixty Years since Laursen and Toch

2017 ◽  
Vol 143 (9) ◽  
pp. 03117006 ◽  
Author(s):  
Robert Ettema ◽  
George Constantinescu ◽  
Bruce W. Melville
Keyword(s):  
Flow Field ◽  
Scour Depth ◽  
Pier Scour

Evaluation of Selected Pier-Scour Equations Using Field Data

1996 ◽  
Vol 1523 (1) ◽  
pp. 186-195 ◽  
Author(s):  
Mark N. Landers ◽  
David S. Mueller
Keyword(s):  
Field Measurements ◽  
Bridge Piers ◽  
Critical Ratio ◽  
Scour Depth ◽  
Flow Depth ◽  
Clear Water ◽  
Pier Scour ◽  
Logarithmic Space ◽  
State Highway ◽  
Federal Highway

Field measurements of channel scour at bridges are needed to improve the understanding of scour processes and the ability to accurately predict scour depths. An extensive data base of pier-scour measurements has been developed over the last several years in cooperative studies between state highway departments, the Federal Highway Administration, and the U.S. Geological Survey. Selected scour processes and scour design equations are evaluated using 139 measurements of local scour in live-bed and clear-water conditions. Pier-scour measurements were made at 44 bridges around 90 bridge piers in 12 states. The influence of pier width on scour depth is linear in logarithmic space. The maximum observed ratio of pier width to scour depth is 2.1 for piers aligned to the flow. Flow depth and scour depth were found to have a relation that is linear in logarithmic space and that is not bounded by some critical ratio of flow depth to pier width. Comparisons of computed and observed scour depths indicate that none of the selected equations accurately estimate the depth of scour for all of the measured conditions. Some of the equations performed well as conservative design equations; however, they overpredict many observed scour depths by large amounts. Some equations fit the data well for observed scour depths less than about 3 m (9.8 ft), but significantly underpredict larger observed scour depths.

scholarly journals Scour around Piers under Waves: Current Status of Research and Its Future Prospect

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2212 ◽  
Author(s):  
Ainal Hoque Gazi ◽  
Mohammad Saud Afzal ◽  
Subhasish Dey
Keyword(s):  
Process Development ◽  
Future Prospect ◽  
Review Article ◽  
Current Status ◽  
Scour Depth ◽  
Pier Scour ◽  
Scour Hole ◽  
The Future ◽  
Bridge Failure

In this review article, the current status of research on pier scour under waves is presented. This includes a summary of different bridge failure events due to scour, scour mechanism, scour depth predictors under waves, influence of pier shape on scour depth formation, shape of scour hole around piers, and many others. Further, this article describes the scour process, development of scour depth predictors, and the complexity involved in the scour related calculations. Finally, the future scope of research is delineated.

Hydrographs and Estimates of Scour Depth Excess for Pier Scour Prediction

2011 ◽  
Vol 2262 (1) ◽  
pp. 193-199
Author(s):  
Francis C. K. Ting ◽  
Ryan J. Larsen ◽  
Allen L. Jones
Keyword(s):  
Scour Depth ◽  
Pier Scour

Prediction of Scour at Bridge Pier Foundations Founded on Rock and Other Earth Materials

2000 ◽  
Vol 1696 (1) ◽  
pp. 67-70 ◽  
Author(s):  
George W. Annandale
Keyword(s):  
Laboratory Data ◽  
Bridge Pier ◽  
Scour Depth ◽  
Stream Power ◽  
Index Method ◽  
Pier Scour ◽  
Bridge Pier Scour

The erodibility index method, which can be used to predict scour thresholds for rock and other earth materials, is described. The scour threshold is defined by a relationship between the erodibility index and stream power that is based on analysis of field and laboratory data. An explanation of how the method is applied to calculate scour depth is presented, followed by a case study to calculate bridge pier scour.

Multi-lens pier scour monitoring and scour depth prediction

2014 ◽  
Vol 167 (2) ◽  
pp. 88-104 ◽  
Author(s):  
Wen-Yi Chang ◽  
Franco Lin ◽  
Jihn-Sung Lai ◽  
Lung-Cheng Lee ◽  
Whey-Fone Tsai ◽  
...  
Keyword(s):  
Scour Depth ◽  
Pier Scour ◽  
Depth Prediction ◽  
Scour Monitoring

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.

NF-GMDH-Based self-organized systems to predict bridge pier scour depth under debris flow effects

2017 ◽  
Vol 36 (5) ◽  
pp. 589-602 ◽  
Author(s):  
Mohammad Najafzadeh ◽  
Farid Saberi-Movahed ◽  
Saeed Sarkamaryan
Keyword(s):  
Debris Flow ◽  
Bridge Pier ◽  
Scour Depth ◽  
Pier Scour ◽  
Self Organized ◽  
Flow Effects ◽  
Bridge Pier Scour

scholarly journals New stochastic modeling strategy on the prediction enhancement of pier scour depth in cohesive bed materials

2020 ◽  
Vol 22 (3) ◽  
pp. 457-472 ◽  
Author(s):  
Ahmad Sharafati ◽  
Ali Tafarojnoruz ◽  
Zaher Mundher Yaseen
Keyword(s):  
Group Method ◽  
Scour Depth ◽  
Cohesive Soils ◽  
Reliable Prediction ◽  
Pier Scour ◽  
Bed Materials ◽  
Modeling Strategy ◽  
Generalized Likelihood Uncertainty Estimation ◽  
Cohesive Bed ◽  
Improvement Index

Abstract Scouring around the piers, especially in cohesive bed materials, is a fully stochastic phenomenon and a reliable prediction of scour depth is still a challenging concern for bridge designers. This study introduces a new stochastic model based on the integration of Group Method of Data Handling (GMDH) and Generalized Likelihood Uncertainty Estimation (GLUE) to predict scour depth around piers in cohesive soils. The GLUE approach is developed to estimate the related parameters whereas the GMDH model is used for the prediction target. To assess the adequacy of the GMDH-GLUE model, the conventional GMDH and genetic programming (GP) models are also developed for evaluation. Several statistical performance indicators are computed over both the training and testing phases for the prediction accuracy validation. Based on the attained numerical indicators, the proposed GMDH-GLUE model revealed better predictability performance of pier scour depth against the benchmark models as well as several gathered literature studies. To provide an informative comparison among the proposed techniques (i.e. GMDH-GLUE, GMDH, and GP models), an improvement index () is employed. Results indicated that the GMDH-GLUE model achieved = 6% and = 3%, demonstrating satisfying performance improvement in comparison with the previously proposed GMDH model.

scholarly journals ANFIS-based approach for scour depth prediction at piers in non-uniform sediments

2009 ◽  
Vol 12 (3) ◽  
pp. 303-317 ◽  
Author(s):  
M. Muzzammil ◽  
M. Ayyub
Keyword(s):  
Fuzzy Inference ◽  
Bridge Piers ◽  
Scour Depth ◽  
Fuzzy Inference Systems ◽  
Foundation Design ◽  
Pier Scour ◽  
Depth Prediction ◽  
Alternative Approach ◽  
Inference Systems ◽  
Bridge Pier Scour

An estimation of scour depth is a prerequisite for the efficient foundation design of important hydraulic structures such as bridge piers and abutments. Most of the scour depth prediction formulae available in the literature have been developed based on the analysis of the laboratory/field data using statistical methods such as the regression method (RM). Conventional statistical analysis is generally replaced in many fields of engineering by the alternative approach of artificial neural networks (ANN) and adaptive network-based fuzzy inference systems (ANFIS). These recent techniques have been reported to provide better solutions in cases where the available data is incomplete or ambiguous by nature. An attempt has been made to compare the performance of ANFIS over RM and ANN in modeling the depth of bridge pier scour in non-uniform sediments. It has been found that the ANFIS performed best amongst all these methods.

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