Searched for: subject%3A%22stone%255C+stability%22
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Winter, Theun (author)
The surge in demand for inland vessel goods transportation has necessitated the operation of larger vessels with increased drafts. These larger vessels generate significant induced loads from their more powerful bow thrusters during berthing and mooring. These loads can lead to scour, which ultimately results in instability of the quay wall. To...
master thesis 2024
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Michels, Dirk-Jan (author)
On the east coast of Romania, at Eforie, coastal erosion manifests. To strengthen the coastal area a large coastal protection project was setup involving beach nourishment combined with the construction of breakwaters. The breakwaters are designed with the well-known modified Van der Meer formulas. To ensure confidence in the breakwaters...
master thesis 2022
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NIKOLAIDOU, Lina (author)
Granular bed protections are a common measure to mitigate scour of the sand bed around hydraulic structures. In view of marching towards cost-effective solutions to tackle erosion-related problems, it is important to accurately predict the loads exerted on the bed and come up with the needed rock grading. To that end, a 3-D eddy resolving...
master thesis 2019
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Stevens, Thieu (author)
In this thesis, it is studied if the stability of a stone in a granular bed protection, can be predicted by the local output of a three-dimensional (3D) eddy resolving simulation technique.<br/><br/>In earlier studies regarding stone stability, Reynolds-Averaged Navier-Stokes (RANS) models are used to determine the loads on the bed. In the...
master thesis 2018
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Steenstra, Remco (author), Hofland, Bas (author), Paarlberg, Andries (author), Smale, Alfons (author), Huthoff, Fredrik (author), Uijttewaal, W.S.J. (author)
A stability parameter for rock in bed protections under nonuniform stationary flow is derived. The influence of the mean flow velocity, turbulence, and mean acceleration of the flow are included explicitly in the parameter. The relatively new notion of explicitly incorporating the mean acceleration of the flow significantly improves the...
journal article 2016
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Wit, E.M. (author)
A recurrent challenge in the hydraulic engineering is to establish the required stone diameter for a stone protection on mild slopes, since the stability of gravel on a mild slope is not yet sufficiently covered by existing design methods. The objective of this study is to investigate the relation between the loads and the stability of stones on...
master thesis 2015
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Steenstra, R.S. (author)
For the design of granular bed protections often a stability parameter is used. The stability parameter represents the forces that are acting on the stones and is used to predict the response of the bed to these forces. Existing parameters are often derived for a limited range of application. When the parameter is used outside this range, the...
master thesis 2014
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Hoan, N.T. (author), Stive, M.J.F. (author), Booij, R. (author), Hofland, B. (author), Verhagen, H.J. (author)
This paper presents the results of an experimental study on stone stability under nonuniform turbulent flow, in particular expanding flow. Detailed measurements of both flow and turbulence and the bed stability are described. Than various manners of quantifying the hydraulic loads exerted on the stones on a bed are extensively reviewed and...
journal article 2011
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Hoan, N.T. (author)
Despite the fact that many studies on the stability of stones in bed protections under flowing water have been conducted, our knowledge is still far from advanced and reliable. Issues like how to quantify the hydraulic loads exerted on the stones on a bed and the associated stability of the stones are still central and most challenging in stone...
doctoral thesis 2008
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Hoan, N.T. (author), Booij, R. (author), Hofland, B. (author), Stive, M.J.F. (author), Verhagen, H.J. (author)
The current research is aimed at finding a proper relation between flow forces acting on the bed and the bed response. To this end, experiments were carried out in which both the bed response (quantified by a dimensionless entrainment rate) and the flow field (velocity and turbulence intensity distributions) are measured. The three available...
conference paper 2007
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Hoan, N.T. (author), Booij, R. (author), Hofland, B. (author), Stive, M.J.F. (author), Verhagen, H.J. (author)
The current research is aimed at finding a dimensionless stability parameter for non-uniform flow in which the effect of turbulence is incorporated. To this end, experiments were carried out in which both the bed response (quantified by a dimensionless entrainment rate) and the flow field (velocity and turbulence intensity distributions) are...
conference paper 2007
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Hoan, N.T. (author)
Previous research (e.g., Jongeling et al 2003; Hofland 2005) has shown that turbulence has an important influence on stone stability and in non-uniform flow it should be modeled explicitly. The dimensionless entrainment rate should be used to describe the bed response because of its complete dependence on local hydrodynamic conditions and...
report 2007
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Hoan, N.T. (author)
This report evaluates the B009 data of the back-ward facing step experiment which was one of a series of the experiments that were designed and conducted by Hofland and Booij (2004) and De Ruijter (2004). In this experiment, the flow field and the pressure field were measured (by PIV and pressure sensors) during the displacement of a single...
report 2004
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Schokking, L.A. (author), Janssen, P.C. (author), Verhagen, H.J. (author)
The stability of stones in propeller-induced jet wash is still difficult to predict. Especially the trend of bowthrusters increasing in size and power in sea going ships (especially ferries) over the last years may be a reason for concern when dealing with the protection of slopes and beds. But also ships used in inland navigation are using...
journal article 2003
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Verhagen, H.J. (author), Van Dijk, B. (author), Nederpel, A. (author)
Medium height breakwaters are subjected to a considerable amount of overtopping. This implies the armour on the inner slope has to stable against overtopping waves. Existing equations do lack some basic understanding of the process of starting up movement of rock on the inner slopes. In case one relates the stability of the blocks on the inner...
conference paper 2003
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Van Veldhoven, V.J.C.G.L. (author)
Als een schip dat naast een kade ligt op eigen kracht wegvaart, dan maakt het gebruik van zijn boeg- en hoofdschroef. Achter een draaiende schroef ontstaat een waterstraal. Achter een boegschroef ontstaat een waterstraalloodrecht vanaf het schip gericht. Deze waterstraal zal bij de afvaartmanoeuvre de kade raken. Indien de kade uit een kademuur...
master thesis 2002
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Hofland, B. (author)
This report is structured as follows: In chapter 2 the importance of wall pressures with respect to the present research is described. The literature on wall pressures that was used, and some general features of wall pressure fluctuations are subsequently described in chapter 3. Chapter 4 deals with the pressure sensors. It begins with a brief...
report 2001
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Wijgerse, F.M. (author)
Voor de berekening van de stabiliteit van stenen moet een beschouwing worden gemaakt van de krachten welke werken op een steen in een stroming. Deze krachten zijn natuurlijk ten eerste het gewicht van de steen onder water en verder de kracht welke de stroming op de steen uitoefent. 1) De krachten door het water zijn evenredig met het kwadraat...
master thesis 2000
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De Gunst, M. (author)
Het onderwerp van deze studie is een niet-uniforme stroming waarin sprake is van een plaatselijk verhoogde aanval op het bodemmateriaal door de lokaal hogere turbulentie. In een 15 m lange stroomgoot met een breedte van 40 cm is door middel van een backward-facing step ofwel afstap een niet-uniforme stroming gecreeerd. Om de schade aan de...
master thesis 1999
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Boutovski, A. (author)
Experimental research on the stability of dumped stones for bed protections with focus on the gradation of the stones. A bottom protection has more roughness than anticipated. The Shields criterion is still applicable (psi=0.03)
master thesis 1998
Searched for: subject%3A%22stone%255C+stability%22
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