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

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

Water ◽

10.3390/w11091761 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1761 ◽

Cited By ~ 6

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.

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

10.23918/iec2018.27 ◽

2018 ◽

Author(s):

Mohammed Tareq Shukri ◽

M. Günal ◽

Junaid Kameran Ahmed

Keyword(s):

Experimental Study ◽

Local Scour ◽

Bridge Pier ◽

Scour Depth

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Flume experiments on woody debris accumulation at the bridge pier during flood

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/575/1/012188 ◽

2020 ◽

Vol 575 ◽

pp. 012188

Author(s):

Muhammad Farid Maricar ◽

Farouk Maricar

Keyword(s):

Woody Debris ◽

Bridge Pier ◽

Flume Experiments ◽

Debris Accumulation

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Effects on Scour for Different Foundation Geometry of Compound Circular Bridge Piers

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b2000.078219 ◽

2019 ◽

Vol 8 (2) ◽

pp. 2439-2446

Keyword(s):

Experimental Study ◽

Rate Of Change ◽

Bridge Pier ◽

Bridge Piers ◽

Scour Depth ◽

Flowing Water ◽

Sound Design ◽

Flow Conditions ◽

The Past ◽

Bridge Failure

This experimental study examines the variation of scour depth with time of Clearwater scour condition around compound circular bridge piers for steady flow conditions. Most of the circular bridge piers are resting on the bigger diameter caissons known as the compound circular bridge piers and are widely used in India for construction of road and railways bridge across the rivers. In past studies, it has been observed that most bridge failure occurs because of scouring due to flowing water around a bridge pier across a river. Most of the past studies were done on the uniform bridge pier and a very few studies have been done so far on scouring around non-uniform bridge piers. Estimation of scour depth is required for the economical and a sound design of bridge pier foundation. In present study, an experimental investigation has been done in a tilting flume for computation of rate of change of depth of scour with time at two different models of compound circular bridge piers by varying the foundation top position with respect to level of bed, i.e., 1. The foundation top at the level of bed, and 2. The foundation top below the level of bed (viz. 10mm, 20mm, 30mm and 40mm) for uniform sediments.

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Experimental Study of Inclined Bridge Pier Scouring

Mehran University Research Journal of Engineering and Technology ◽

10.22581/muet1982.2004.18 ◽

2020 ◽

Vol 39 (4) ◽

pp. 859-870

Author(s):

Fakhar Muhammad Abbas ◽

Usman Ali Naeem ◽

Usman Ghani ◽

Amina Khan ◽

Talat Farid Ahmad

Keyword(s):

Experimental Study ◽

Inverse Relationship ◽

Bridge Pier ◽

Bridge Piers ◽

Scour Depth ◽

Clear Water ◽

Lower Strength ◽

Flow Rates ◽

Laboratory Flume ◽

Horseshoe Vortices

The bridges are one of important structures in any country. The failure of bridges occurs due to many factors including design flaws and manufacturing construction errors. Among all imperfections scouring around the pier is the most detrimental. So, the estimation of local scouring around a bridge pier is of fundamental importance for the safe design of bridges. Although numerous researches have been done on local scouring around a single bridge pier. The present study investigates the effect of angle of inclination of dual bridge pier configuration on local scouring around bridge piers. Principally rectangular shaped dual bridge piers were installed in sand bed of laboratory flume at angle of inclination of 0°,7°,12°,15° and 19° with vertical respectively. Three different flow rates 9, 14 and 18L/sec were considered during each trial. The duration of each trial was kept around 2 hours. The scour depth was measured separately around both piers with the help of point gauge under clear water condition. The value of scour depth around upstream pier was larger as compared to downstream pier because of the lower strength of horseshoe vortices around downstream pier. From the experimental results, it can be concluded that there is an inverse relationship between the angle of inclination and scour depth, an increase in the angle of inclination leads to decrease in scour depth around both piers. The value of scour depth was maximum when piers were at 0° and minimum at 19°. It was also found that scour depth increases with the increase in flow rate.

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Experimental study for determination of collar dimensions around bridge pier

The Baltic Journal of Road and Bridge Engineering ◽

10.3846/bjrbe.2015.11 ◽

2015 ◽

Vol 10 (1) ◽

pp. 89-96

Author(s):

Afshin Jahangirzadeh ◽

Shatirah Akib

Keyword(s):

Experimental Study ◽

Temporal Trend ◽

Bridge Pier ◽

Scour Depth ◽

Scour Hole ◽

Scour Countermeasure ◽

Reduction Percentage ◽

Shape And Size

The shape and size of a collar is important to maximize its effect as a scour countermeasure. Current research shows that the depth of the scour hole is decreased by using rectangular collars around circular piers. This study determined the approximate optimum dimensions for rectangular collars to minimize the temporal trend of scouring around a pier model. Effects of different sizes of rectangular collars on a model pier were investigated both at the upstream and downstream of the flume. It was observed that irrespective of the rectangular collar dimensions the upstream and the downstream were estimated to be 0.86 and 1.42, respectively. The optimum collar width was estimated to be 2.8 times the diameter of the pier. By using this optimized collar dimension, the non-dimensional depth of scour reached a min value of 0.034 at 72 h. The reduction percentage of the scour depth reached 98% at 72 h.

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