Local scour around complex pier groups and combined piles at semi-integral bridge

Akib, Shatirah; Jahangirzadeh, Afshin; Basser, Hossein

doi:10.2478/johh-2014-0015

Cited by 30 publications

(13 citation statements)

References 30 publications

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“…The reduction of the scour hole is the main purpose of scour countermeasures. Many different types of countermeasures for local scour at bridge piers are introduced in the literature (Zarrati et al 2010;Bertoldi and Kilgore 1993;Chiew 1992;Graziano et al 1990;Haque et al 2007;Jones et al 1995;Jahangirzadeh et al 2014a;Jahangirzadeh et al 2014b;Jahangirzadeh and Akib 2014). Zarrati, Chamani (Zarrati et al 2010) reviewed reduction of local scour with three methods; distinct collar, interconnected collar and interconnected collar with riprap.…”

Section: Introductionmentioning

confidence: 97%

“…The flow pattern and mechanisms of scouring are very complicated, and the complexity of flow increases with the development of the scour hole (Ghodsian and Vaghefi 2009;Akib et al 2014a). The basic mechanism causing local scour at piers is the down-flow at the upstream face of the pier and formation of the horseshoe vortex at the base of the pier.…”

Section: Introductionmentioning

confidence: 99%

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RETRACTED ARTICLE: Adaptive neuro-fuzzy estimation of the influence of slot on local scour at bridge pier groups

et al. 2014

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Scouring around bridge pier is a major cause of bridge instability. Thus, providing appropriate methods in order to reduce and control the scour depth have received much attention. Using a slot in the bridge piers is one of modern methods of reducing bridge local scouring. In the present study, the effects of a rectangular slot on local scour mitigation around bridge pier groups have been investigated with adaptive neurofuzzy (ANFIS) method. ANFIS shows very good learning and prediction capabilities, which makes it an efficient tool to deal with encountered uncertainties in any system like scouring. The results show that the scour depth increased in the first pier by reinforcing effect and it decreased in the rear piers because of sheltering effect in compare with single pier. In addition, application of the slot in pier groups leads to an increase in the impact of reinforcing effect and reduce the influence of sheltering effect.The use of slot is more influential in front bridge piers than the rear piers in pier groups with 4D distance, however, this effectiveness doesn't have significant difference among the piers with 2D distance and same as single pier. Laboratory experiments were conducted to create experimental training and checking data for ANFIS network. This intelligent estimator is implemented using Matlab/Simulink and the performances are investigated. The simulation results presented in this paper show the effectiveness of the developed method.

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Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

RETRACTED ARTICLE: Adaptive neuro-fuzzy estimation of the influence of slot on local scour at bridge pier groups

et al. 2014

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“…Das et al (2013a) employed an ADV velocimeter in an experimental study in a straight channel, and examined the flow pattern in the scour hole around a single cylindrical pier with three different diameters. Akib et al (2014) investigated scour and flow pattern around group piers. Vaghefi et al (2015) conducted an experiment in a 1-meterwide channel with a 180 degree sharp bend and a central curvature of 2 in order to investigate velocity fluctuations, and then examine distribution of turbulence kinetic energy.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study of the Effect of Displacement of Vanes Submerged at Channel Width on Distribution of Velocity and Shear Stress in a 180 Degree Bend

Chooplou

Vaghefi

2019

JAFM

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Shear stress is a parameter of high significance. Through knowledge of this parameter, assessment of scour or sedimentations at different points of bed is made viable. Therefore, this paper investigated alterations in shear stress along the bend, specifically around a bridge pier, under the influence of applying submerged vanes at the upstream side of the bridge pier. With the aim of modeling submerged vanes, vanes of Plexiglas with a thickness of 20% of the pier diameter, a length of 1.5 times the pier diameter, and submergence ratio of 75% were utilized. The vanes were installed at a distance equal to 5 times the pier diameter from the pier center at a distance of 40 to 60% of the channel width from the inner bank at the upstream side of the bridge pier. Acoustic-Doppler Velocity velocimeter device was utilized for measuring three-dimensional velocity components. The experiments were conducted in a 1-meter-wide flume with a degree of curvature of 180. The results of the study suggested that upon reaching the bend apex, the maximum flow turbulence rate occurred in a transverse direction in the case of installing submerged vanes at a distance of 40% of the channel width from the inner bank towards the inner wall; while in the case of installing submerged vanes at a distance of 60% of the channel width from the inner bank, it occurred towards the outer wall, and it could be observed that the maximum longitudinal and vertical components of turbulence rate increased by 16 and 5.5% respectively upon increase in the distance of submerged vanes from the inner bank. Furthermore, the values of uw    and uv    turbulence shear stresses at the outer bank in the case of installing the vanes at a distance of 40% of the channel width from the inner bank were smaller than those in the case of installing the submerged vanes at a distance of 60% of the channel width from the inner bank.

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“…Few studies have been done for the calculation of local scour-depth (e.g. Melville et al, 2006;Akib et al, 2014) and few for investigating the flow patterns around a complex bridge pier structure (e.g., Beheshti and Ashtiani, 2010;2016), mostly with rectangle shaped pier and pile-cap or rectangle with round ends. Beheshti and Ashtiani (2010) investigated the three-dimensional turbulent flow field around a rectangular complex bridge pier (with rectangular pilecap) placed on a fixed rough bed with the aid of experiments.…”

Section: Introductionmentioning

confidence: 99%

“…Ferraro et al (2013) performed experimental tests on scour around complex bridge piers of different arrangements for studying the influence of pile-cap thickness on the temporal development of maximum scour-depth. Akib et al (2014) presented an experi-mental study focusing on the relationship between scour depth in complex pier groups and combined piles bridge and various factors including the variation of inflow velocity, distance, and time. Moreno et al (2015) carried out experimental campaign to study three complex bridge pier models (rectangular shape of pier with round ends) under steady state, clear-water flow conditions.…”

Section: Introductionmentioning

confidence: 99%

Experimental study of scour around a complex pier with elliptical pile-cap

Gautam¹,

Eldho²,

Behera³

2016

Scour and Erosion

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A complex bridge pier is an assembly of a column and foundation such as pile foundation with a pile-cap, partially or completely exposed to the flow. Considering the interaction of various factors around the pier, the pile-cap elevation in relation to the sand bed is expected to differ with time. Therefore, it is necessary to assess scouring over various potential pile-cap elevations. In this paper, laboratory experiments were carried out to analyze scour and mean velocity profiles around complex pier under the effect of low Reynolds numbers. Three pile-cap elevation cases were studied here, viz, the sand bed depth taken above the pile-cap level; the sand bed depth taken below the pile-cap top; and the sand bed depth taken at the level of pile-cap bottom. The results showed different scour patterns in the three cases considered. It was also noted that the least scour-depth occurred in the second case and maximum in the first one.

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Local scour around complex pier groups and combined piles at semi-integral bridge

Cited by 30 publications

References 30 publications

RETRACTED ARTICLE: Adaptive neuro-fuzzy estimation of the influence of slot on local scour at bridge pier groups

RETRACTED ARTICLE: Adaptive neuro-fuzzy estimation of the influence of slot on local scour at bridge pier groups

Experimental Study of the Effect of Displacement of Vanes Submerged at Channel Width on Distribution of Velocity and Shear Stress in a 180 Degree Bend

Experimental study of scour around a complex pier with elliptical pile-cap

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