Temporal variation of clear water scour at cylindrical bridge piers

2006 ◽  
Vol 33 (8) ◽  
pp. 1098-1102 ◽  
Author(s):  
A Melih Yanmaz
Keyword(s):  
Temporal Variation ◽  
Semiempirical Method ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Recent Sediment ◽  
Clear Water ◽  
Design Flood ◽  
Pier Scour ◽  
Time To Peak ◽  
Bridge Pier Scour

Computation of temporal variation of clear water scour is important for the design of bridge pier footings. Previous studies indicated that very long flow duration was needed to achieve equilibrium scouring situations. However, the corresponding durations in the prototype conditions may yield considerably larger values than time-to-peak of the design flood. Therefore, there is a need to estimate the temporal variation of scour depth. This study deals with the development of a new semiempirical method for temporal variation of clear water scour at cylindrical bridge piers using the sediment continuity approach. A recent sediment pickup function proposed for sloping beds is used to formulate the rate of sediment transport out of the scour hole. Results of the proposed method agree well with experimental results. The findings of the proposed method are also compared with some recent empirical methods.Key words: bridge, pier, scour, clear water, sediment pickup.

Suction Effects on Bridge Pier Scour under Clear-Water Conditions

2013 ◽  
Vol 139 (6) ◽  
pp. 621-629 ◽  
Author(s):  
Min Qi ◽  
Yee-Meng Chiew ◽  
Jian-Hao Hong
Keyword(s):  
Bridge Pier ◽  
Clear Water ◽  
Pier Scour ◽  
Water Conditions ◽  
Bridge Pier Scour

scholarly journals Effect of Meander on Bridge Pier Scour

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mohammad Athar ◽  
M.K. Sabiree ◽  
H. Athar
Keyword(s):  
Angular Displacement ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Bend Angle ◽  
Test Bed ◽  
Pier Scour ◽  
Meandering Channel ◽  
Channel Bend ◽  
Constant Diameter ◽  
Bridge Pier Scour

Lots of work regarding the scour around bridge piers in straight channelhave been done in the past by many researchers. Many factors which affectscour around piers such as shape of piers, size, positioning and orientationetc. have been studied in detail by them. However, similar studies inmeandering channels are scanty. Very few researchers have studied theeffect of angular displacement which has considerable effects of scouraround bridge piers.In this paper an attempt has been made to carry out a detailed study ofangular displacement on scour. A constant diameter bridge pier of circularshape has been tested in a meandering channel bend with bend angle as 800 .The test bed was prepared by using uniform sand having d50 as 0.27 mmand run was taken for a discharge of 2.5 l/s.

scholarly journals Prediction of Bridge Pier Scour Depth and Field Scour Depth Monitoring

2018 ◽  
Vol 40 ◽  
pp. 03007
Author(s):  
Fong-Zuo Lee ◽  
Jihn-Sung Lai ◽  
Yuan-Bin Lin ◽  
Kuo-Chun Chang ◽  
Xiaoqin Liu ◽  
...  
Keyword(s):  
Numerical Model ◽  
Real Time ◽  
Earthquake Engineering ◽  
Model Simulation ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Scour Depth ◽  
Pier Scour ◽  
River Bed ◽  
Bridge Pier Scour

In practice, it is a major challenge in real-time simulation and prediction of bridge pier scour depth, especially using 3-D numerical model. The simulation time spend too much to use 3-D numerical model simulation and inefficiently to predict bridge pier scour depth in real-time. With heavy rainfall during flood season in Taiwan, abundant sediment with flash flood from upstream watershed is transported to downstream river reaches and transportation time is limited within one day. The flood flow tends to damage bridge structures and affect channel stabilization in fluvial rivers. In addition, the main factors affecting the erosional depth around bridge piers and river bed stabilization are hydrological and hydrographic characteristics in river basin, the scouring and silting of river bed section near the bridge piers, the bridge geometry and protection works of bridge piers. Therefore, based on the observed rainfall data provided by the Central Weather Bureau and the hydrological conditions provided by the Water Resources Agency during flood event as the boundary condition, we develop an effective simulation system for scour depth of bridge piers. The scour depth at the bridge pier is observed by the National Center for Research on Earthquake Engineering for model calibration. In this study, an innovative scour monitoring system using vibration-based Micro-Electro Mechanical Systems (MEMS) sensors was applied. This vibration-based MEMS sensor was packaged inside a stainless sphere with the proper protection of the full-filled resin, which can measure free vibration signals to detect scouring/deposition processes at the bridge pier. It has demonstrated that the measurement system for monitoring bridge scour depth evolution is quite successful in the field.

scholarly journals A New Practical Method to Simulate Flood-Induced Bridge Pier Scour—A Case Study of Mingchu Bridge Piers on the Cho-Shui River

Water ◽  
2016 ◽  
Vol 8 (6) ◽  
pp. 238 ◽  
Author(s):  
Jian-Hao Hong ◽  
Wen-Dar Guo ◽  
Yee-Meng Chiew ◽  
Cheng-Hsin Chen
Keyword(s):  
Practical Method ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Pier Scour ◽  
Bridge Pier Scour

scholarly journals Mathematical Modeling of Local Scour at Slender and Wide Bridge Piers

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Youssef I. Hafez
Keyword(s):  
Local Scour ◽  
Bridge Pier ◽  
Angle Of Repose ◽  
Bridge Piers ◽  
Bridge Scour ◽  
Pier Scour ◽  
Bed Scour ◽  
Bed Material ◽  
Bridge Pier Scour ◽  
Mitigation Methods

Most existing equations for predicting local scour at bridge piers suffer from overprediction of the scour depths which results in higher foundation costs. To tackle this problem, a mathematical model for predicting bridge pier scour is developed herein based on an energy balance theory. The present study equation was compared to commonly used bridge scour equations using scour field data in USA. The developed equation has several advantages among which we have the following: it adds to the understanding of the physics of bridge pier scour, is valid for slender and wide piers, does not suffer from overprediction of scour depths, addresses clear water and live bed scour, and includes the effects of various characteristics of the bed material such as specific gravity (or density), porosity, size, and angle of repose. In addition, the developed equation accounts for the debris effect and aids in the design of scour mitigation methods such as collars, side bars, slots, and pier protective piles.

BRIDGE PIER SCOUR: A REVIEW OF PROCESSES, MEASUREMENTS AND ESTIMATES

2012 ◽  
Vol 11 (5) ◽  
pp. 975-989 ◽  
Author(s):  
Luigia Brandimarte ◽  
Paolo Paron ◽  
Giuliano Di Baldassarre
Keyword(s):  
Bridge Pier ◽  
Pier Scour ◽  
Bridge 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.

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