Influence of cohesion on scour around submerged dike founded in clay–sand–gravel mixtures

Lodhi, A. S.; Jain, Rajesh Kumar; Sharma, Pramod Kumar

doi:10.1080/09715010.2015.1075916

Cited by 11 publications

(4 citation statements)

References 36 publications

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“…This process is done over a very small time interval. In the current study, scour depth was measured at different time intervals at the upstream nose of the spur dike, as this is the expected location at the equilibrium scour condition where the maximum scour depth occurs (Kothyari & Ranga Raju, 2001;Lodhi et al, 2016;Pandey et al, 2015). For the current study, all experiments refer to clear water scour conditions.…”

Section: Methodsmentioning

confidence: 99%

“…Spur dikes achieve their major function of protecting stream banks (i) directly via diverting the flowing water away from the stream banks, and (ii) indirectly by reducing the flow velocity. Spur dikes are amongst the most hydraulically and cost effective river training structures that can be built at the channels' banks (Zhang et al, 2012), to safeguard their stability, maintain a channel's navigation capacity, as well as help maintain water quality and restore aquatic habitat (Lodhi et al, 2016;Yazdi et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

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Experimental assessment and prediction of temporal scour depth around a spur dike

Pandey

Valyrakis

et al. 2021

International Journal of Sediment Research

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Spur dikes are river training structures that have been extensively used worldwide for towards enhancing flood control and the stability of embankments and riverbanks.However, scour around spur dikes can be a major problem affecting their stability and hydraulic performance. The precise computation of temporal scour depth at spur dikes is very important for the design of economical and safe spur dikes. This study focuses on experimentally assessing the temporal variation of scour depth around a vertical wall spur dike and identifying the parameters, which mostly influence spur dike performance for a channel bed surface comprised of sand-gravel mixtures. In the current study, the authors did physical experiments in a flume based study to obtain new data, aimed at deriving a new predictive model for spur dike scour and comparing its performance to others found in the literature. It was found that the dimensionless temporal scour depth variation increases with an increase in (i) the threshold velocity ratio, (ii) the densimetric Froude number of the bed surface sediment mixture, (iii) the flow shallowness (defined as the ratio of the approach flow depth, y, to the spur dike's transverse length, l), and (iv) the flow depth-particle size ratio. It is also concluded that the temporal scour depth variation in the sediment mixture is influenced by the non-uniformity of sediment and decreases with an increase in the non-uniformity of the sediment mixture. A new mathematical model is derived for the estimation of temporal scour depths in sand-gravel sediment mixtures. The proposed equation has been calibrated and validated with the experimental data, demonstrating a good predictive capacity for the estimation of temporal scour depth evolution.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental assessment and prediction of temporal scour depth around a spur dike

Pandey

Valyrakis

et al. 2021

International Journal of Sediment Research

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“…Therefore, it is unsurprising that the design and development of methods for their calculation justification are given a large place in scientific research [5][6][7][8][9], many of which are made for the conditions of lowland rivers. Many authors have focused on determining the depth of local erosion at deaf dams [10][11][12][13][14][15][16][17][18]. Meanwhile, the foothill sections of the rivers have their own peculiarities consisting both in morphology and the hydraulics of the flows.…”

Section: Introductionmentioning

confidence: 99%

Kinematic parameters of flow constrained by combined dams with through part of tetrahedra in compression region

et al. 2023

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Every major river in the world consists of mountainous, foothills, and flat areas characterized by different flow regimes. The foothill areas differ in slopes i = 0.001 ÷ 0.004, flow kinetics Fr > 0.15, and the size of sediments. The riverbed is unstable, and the banks are prone to erosion. The construction of coastal protection structures requires solving complex issues related to their design. The analysis showed that most of the studies, including ours, were carried out for the conditions of lowland rivers. This work aims to establish the flow features of the foothill sections of a combined dam with a through part of tetrahedra when the ratio of the through part ℓs to the total length of the dam ℓd is greater than or equal to 0.5, i.e., ℓs/ℓd. ≥ 0.5 The presence of a satellite flow behind the through part, a weakly perturbed core, and the presence of two zones of intense turbulent mixing was experimentally established, and the universality of the velocity distribution, which obeys the theoretical dependence of Schlichting-Abramovich, was confirmed. It is once again confirmed that the dependence is on the slope of the bottom, the Froude number, the degree of constraint, and the formation of "calm" and "critical" flow modes. The nature of the level changes along the length of the compression region in the core, and the satellite flow differ from each other, and the alignments occur in the vertical compression alignment. The problem is implemented for the "calm" mode using an integral relation characterizing the law of conservation of momentum in the flow, the equation of conservation of flow, and the differential equation of uneven motion recorded for the satellite flow behind the through part of the combined dam. The presence of a satellite flow, two zones of intense turbulent mixing, and the different nature of the leveled regime of the main and satellite flows are taken into account. A comparison of theoretical solutions with experimental ones shows their similarity.

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“…Therefore, it is not surprising that there are many theoretical and experimental studies devoted to improving structures and aimed to develop the methods of the design justification of regulatory structures [4][5][6][7][8][9][10]. The researchers paid main attention to determining the depth of local erosion near blind dams [11][12][13][14][15] and the conditions of lowland rivers.…”

Section: Introductionmentioning

confidence: 99%

Flow spreading behind a combined dam with a through part of tetrahedrons on foothill rivers

2021

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The areas of the foothill rivers are distinguished by large bottom slopes reaching 0.004, with increased kinetics of the flow of more than 0.15, and by gravel-pebble sediments of the river bed and flow. An analysis of the studies performed on the regulatory structures showed that the bulk of them was performed for the conditions of lowland rivers. In the article, a design of a combined dam with a through part of tetrahedrons is proposed. The experiments were conducted in a flume with a rigid bottom and with a variable slope of. The modeling was performed according to Froude in a self-similar area. Experimental studies revealed the presence of two flow spreading modes depending on the bottom slope: a “calm” mode at iД < iκр and a “critical” mode at iД > iκр These modes are mainly influenced by the degree of constraint and the Froude number. In the previous articles, a solution to the problem was provided for the case iД < iκр, which covers the foothill sections of rivers at a “calm” mode. At a further increase in the degree of flow constraint n > 0.3 and the Froude number Fr > 0.15, a “critical mode” is observed. Here, a solution to the problem for this case is given. The problem, in this case, differs from the previously considered one by non-uniform distribution of velocities in the weakly disturbed core, a significant reduction in the length of the vortex zone; the vertical compression of the flow continues to the end of the vortex zone. The versatility of the velocity distribution in the zones of weakly disturbed core and intense turbulent mixing is experimentally substantiated. With theoretical studies, using the basic equations of applied mechanics, a method for calculating the velocity field was developed, and the planned dimensions of the vortex zones were established. The comparison with experimental data showed satisfactory agreement.

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Influence of cohesion on scour around submerged dike founded in clay–sand–gravel mixtures

Cited by 11 publications

References 36 publications

Experimental assessment and prediction of temporal scour depth around a spur dike

Experimental assessment and prediction of temporal scour depth around a spur dike

Kinematic parameters of flow constrained by combined dams with through part of tetrahedra in compression region

Flow spreading behind a combined dam with a through part of tetrahedrons on foothill rivers

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