Clear water scour around a finite array of cylinders

Yağci, Oral; Yildirim, I Ilhan; Çelik, Mehmet Furkan; Kitsikoudis, Vasileios; Duran, Zaide; Kirca, V.Ş. Özgür

doi:10.1016/j.apor.2017.08.014

Cited by 62 publications

(27 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Research conducted for groups of circular cylinders represents the basis of knowledge to understand the initiation and development of local and global scour around a hydrodynamic transparent structure like a jacket. For groups of circular cylinders, several studies outlined a dependency between the distance of piles (gap ratio) and the local as well as global scour development [13][14][15]. Furthermore, it is reported that hydrodynamic interactions between individual circular piles are small if the distance between them exceeds six times the piles' diameter (see e.g.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Volume-Based Assessment of Erosion Patterns around a Hydrodynamic Transparent Offshore Structure

et al. 2019

View full text Add to dashboard Cite

The present article presents results of a laboratory study on the assessment of erosion patterns around a hydrodynamic transparent offshore foundation exposed to combined waves and currents. The model tests were conducted under irregular, long-crested waves in a scale of 1:30 in a wave-current basin. A terrestrial 3D laser scanner was used to acquire data of the sediment surface around the foundation structure. Tests have been conducted systematically varying from wave- to current-dominated conditions. Different volume analyzing methods are introduced, which can be related for any offshore or coastal structure to disclose physical processes in complex erosion patterns. Empirical formulations are proposed for the quantification of spatially eroded sediment volumes and scour depths in the near-field and vicinity of the structure. Findings from the present study agree well with in-situ data stemming from the field. Contrasting spatial erosion development between experimental and in-situ data determines a stable maximum of erosion intensity at a distance of 1.25 A, 1.25 times the structure’s footprint A, as well as a global scour extent of 2.1–2.7 A within the present study and about 2.7–2.8 A from the field. By this means, a structure-induced environmental footprint as a measure for erosion of sediment affecting marine habitat is quantified.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The literature reports that hydrodynamic interactions between groups of circular piles are small if the distance between them is larger than six times the piles' diameter [14][15][16]. In the past, this was partly interpreted as a border beyond which global scour around jacket-type foundations may not occur [10].…”

mentioning

confidence: 99%

Volume-Based Assessment of Erosion Patterns around a Hydrodynamic Transparent Offshore Structure

et al. 2019

View full text Add to dashboard Cite

show abstract

“…Qi et al [11] studied the efficiency of an end sill to attenuate the scouring of piers caused by the existence of a mining pit. Their study reported a decrease in turbulent intensity and shear stress near the pier in the presence of an end sill in a mining-affected channel Many researchers have experimentally studied the flow and scour around a group of cylinders [12,13]. The turbulent flow characteristics around cylinders in tandem arrangement depend significantly on the spacing between the two cylinders [14,15].…”

Section: Introductionmentioning

confidence: 99%

On the Morphodynamic Alterations around Bridge Piers under the Influence of Instream Mining

Lade

Deshpande

Kumar

et al. 2019

Water

View full text Add to dashboard Cite

Sand mining in an active alluvial channel can compromise the streambed stability of the hydraulic structures nearby. This experimental study is aimed at investigating the effects of rectangular mining pit on the morphodynamics around circular tandem piers in a movable bed. A rectangular pit is excavated upstream of two circular piers embedded in the sand-bed in a tandem arrangement. The results are then compared to a case having only the piers without any mining pit. Turbulent stresses and mean velocities in the near-bed region rise significantly at the upstream region of the piers in the presence of a pit. Also, stronger flow reversal and horseshoe vortices have been detected at the base of the pier front. Due to these alterations in the nature of turbulence, erosion of channel beds upstream of the piers, increased scour depths, scour volume, and lateral erosion of the scour hole have been observed. Dynamic evolution of the local scour at various time scales has been studied using a wavelet cross-correlation method. Spatial evolution of local scour is found to be faster when a pit is excavated in the channel. Thus, mining activities near the piers can lead to significant changes in the flow-field, causing excessive scour around piers.

show abstract

“…8 Researchers explored other possibilities including hydraulic-based flow alteration through modifying the pier shape, openings/slots and pier groupings. [9][10][11] The main objective of these methods are to disrupt the localised flow behaviour, subsequently reducing the intensity of downflow and hinders the complete formation of horseshoe vortex. 7,12 Apart from the hard structure-based approach, soft measures such as monitoring proved to be one of the key elements in the management of bridges.…”

Section: Introductionmentioning

confidence: 99%

“…Although these approaches are the most cost effective, the efficiency limits to nonextreme rainfall events or high discharges and eventual breakdown of the armouring layer is likely 8 . Researchers explored other possibilities including hydraulic‐based flow alteration through modifying the pier shape, openings/slots and pier groupings 9–11 . The main objective of these methods are to disrupt the localised flow behaviour, subsequently reducing the intensity of downflow and hinders the complete formation of horseshoe vortex 7,12 …”

Section: Introductionmentioning

confidence: 99%

Measuring scour level based on spatial and temporal image analyses

Mohtar

Muad

Porhemmat

et al. 2020

Struct Control Health Monit

View full text Add to dashboard Cite

Scour monitoring is an important measurement process to determine the soil erosion level at the pillar of bridge. Image-based approach is attractive because it allows monitoring process to be conducted continuously without halting the flow of the water during experiment. Scour images provide abundance of information from a single source of camera sensor. However, this information may appear in different features, orientation, size and brightness. Therefore, it is important to detect and recognise features that are related to scour monitoring and filtered out irrelevant features like image noises and artefacts. This paper presents implementation of image processing techniques to extract various information from scour images. Image inpainting technique is used to separate information of scour level and scale markers into two different images. A proposed gradient of marginal histogram technique is used to detect the horizontal scale line markers and scour level. Backpropagation neural network is used to recognise scale text markers and convert the measurement of the scour level from a pixel unit into a centimetre unit. Interpolation techniques are used to connect scour points and delineate the boundary indicating the level of the scour. Time series acquisition of scour images allows observation of the temporal variation of the scour levels. Results show that the proposed approach achieved higher accuracy than existence method. This approach allows the detection of the scour level for even and uneven sediments, contributing to the high accurate results at the spatial and temporal measurements, thus potentially offering continuous scour monitoring solution.

show abstract

Clear water scour around a finite array of cylinders

Cited by 62 publications

References 40 publications

Volume-Based Assessment of Erosion Patterns around a Hydrodynamic Transparent Offshore Structure

Volume-Based Assessment of Erosion Patterns around a Hydrodynamic Transparent Offshore Structure

On the Morphodynamic Alterations around Bridge Piers under the Influence of Instream Mining

Measuring scour level based on spatial and temporal image analyses

Contact Info

Product

Resources

About