document

Scour holes in tidal rivers with heterogeneous subsoil under anthropogenic influence

Koopmans, H. (author)

Over one hundred scour holes are located in the Rhine-Meuse delta. These scour holes have relatively large depths and steep slopes and could pose a risk to the stability of river banks and hydraulic structures, especially since some scour holes are still growing. Scour holes develop at locations where either the hydrodynamics or the erodibility...

master thesis 2017

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Gravity Based Foundation: Scour and design optimisation

Van Eijk, T.F.A. (author)

Within Royal HaskoningDHV an innovative concept is thought to be feasible as a new foundation for larger wind turbines in deeper waters. In this thesis the development of this innovative offshore wind turbine foundation was aided. The research focused on two topics: - Scour at this gravity based foundations. - Possible design optimisations with...

master thesis 2016

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Predicting scour around offshore wind turbines using soft computing techniques

Centen, I. (author)

In this report a prediction method is developed for scour around monopiles. A soft computing technique called genetic programming (GP) is used to create a scour prediction formula that can compute scour in all offshore conditions, meaning current-induced, wave-induced and combined current- and wave-induced scour. The GP was trained with an...

master thesis 2015

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Modelling Scour in Front of Dune Revetments in a Surf-beat Model

Van Geer, P.F.C. (author), Van Thiel de Vries, J.S.M. (author), Boers, M. (author), Den Bieman, J.P. (author), McCall, R.T. (author)

This paper presents adaptations to the XBeach model aimed at including the relevant processes for the generation of scour holes at the toe of a revetment. Dutch assessment rules for the safety of sea defenses need to be adjusted to cope with a combination of sandy dunes and hard elements. To that end, the XBeach model is prepared to be...

conference paper 2014

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Stability of slope material affected by bow thrusters at open quay structures

Roelse, F.P. (author)

In the last decades shipping has increased significantly, resulting in larger ships with an increasing power in bow thrusters. Due to this increasing power, the hydraulic loads at bottom protection near quay structures has also increased, making a traditional bed protection more expensive. Therefore an alternative design method is suggested in...

master thesis 2014

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Scour below the toe of breakwaters: Investigation of scour formation through a geometrically open filter configuration located at the toe of a rubble mound breakwater lying upon sand

Papadopoulos, D. (author)

Scour formation at the toe of a rubble mound breakwater can lead to abrupt failure. Nowadays, counteraction of scour via geometrically closed filter rules, geotextiles or combinations is the common practice. Alternatively, in specific cases the use of geometrically open filters can save significant amount of time and decrease constructional...

master thesis 2012

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Falling aprons at circular piers under currents

De Sonneville, B. (author), Van Velzen, G. (author), Verheij, H.J. (author), Dorst, K. (author)

Traditional guidelines on rock protection at circular piers predominantly focus on preventing shear failure (by choosing a sufficiently large rock size), winnowing failure (by designing an appropriate filter) and edge failure (by selecting a sufficient extent). In particular areas (e.g. in an eroding river channel or in an area with large-scale...

conference paper 2012

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Erosion processes and bed level maintenance strategies in the tide-influenced branches of the Rhine-Meuse delta

Smits, T.C. (author)

Due to the closure of the Haringvliet in 1970 as part of the Delta works and the opening of the Beerdam in 1997, the course of the tidal flow in the Rhine-Meuse delta has changed. The tidal flow from and towards the Haringvliet is now completely taking place through the branches that connect the Haringvliet with the Nieuwe Maas and Nieuwe...

master thesis 2011

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Jet scour

Hoffmans, G. (author), Verheij, H.J. (author)

This paper discusses scour without bed protection, such as propeller scour, two-dimensional horizontal, three-dimensional horizontal scour generated by free jets downstream of gates and outlets, two-dimensional vertical and three-dimensional vertical scour. The flow velocities in two- and three-dimensional propeller and free jets are briefly...

journal article 2011

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Prefeasibility study for the Port of Itajai

Devillé, S.B. (author), Hooning, E.M. (author), De Jong, M.S. (author), Sturm, O.L.M. (author), Verhage, M.J. (author)

In southern Brazil, in the province of Santa Catarina, the port of Itajai is situated. The port is located at the mouth of the river Itajai-Acu, about 3 km inland. The Port of Itajai is very important for both the local and national economy because of its role in foreign trade, and due to this prominent role in the community many stakeholders...

student report 2010

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Scour around an offshore windturbine

Louwersheimer, W.F. (author), Verhagen, H.J. (author), Olthof, J. (author)

During the construction of the first Dutch offshore wind farm prototype measurements were performed. These measurements were aimed to monitor the behaviour of the granular filter layer of the scour protection around the mono-piles upon which the wind turbines are founded. These measurements were compared to scale model test results and...

conference paper 2007

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Uncertainties in the design of bed protections near quay walls

Roubos, A. (author), Verhagen, H.J. (author)

Design formulas for bed protections in the port of Rotterdam were investigated. Using depthsoundings, the actual level of stability of a quay wall can be compared with the design formulas. The loads on a bottom protection differ, because of diversity in shipping and tidal motion. Therefore a better comparison can be made by resembling the...

conference paper 2007

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The design and application of scour anticipated designs in river related and coastal structures in various countries and their effectiveness

Van Duivendijk, J. (author)

Keynote lecture at the ICSE2006. Various types of scour can confront the engineer, who has to design and construct a hydraulic structure in a marine environment. The engineer is interested in the magnitude of the scour to be expected and its development in time. He hopes that such information, if at all available, is accurate and that he can...

conference paper 2006

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Bowthruster-induced damage

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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Migrating Pools in Yangtze River

Li, Y. (author)

The severity and location of bank erosion and bed scour changes with the variation of water level. At low flows, the main flow thread tends to follow the concave bank. As the discharge increases, the flow tends to cut across the convex bar, to concentrate against concave bank only downstream the bend apex. This change of flow pattern is...

report 2002

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Snel zand: Een onderzoek naar een nieuwe pick-up functie voor sediment bij hoge stroomsnelheden

Feenstra, T.D.S. (author)

De laaggelegen delen van Nederland en de gebieden langs de rivieren worden tegen hoog water beschennd met een stelsel van waterkeringen, waaronder dijken. Over dijkbouw is veel bekend, maar over het bezwijken van een dijk veel minder. Dit is wel een steeds belangrijker wordend onderwerp. In de probabilistiek wordt met het mogelijk falen van een...

master thesis 1999

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Ontgrondingen rond pijpleidingen op slibhoudend zand

Van der Velden, E.T.J.M. (author)

Het transport en de erosie van mengsels van zand met 10 tot 30% slib is onderzocht. Zowel het transport in de algemene zin als de erosie rond pijpleidingen is in beschouwing genomen. De transport karakteristieken van zand waar zich slib in bevindt verschillen van die van zuiver zand. De critische bodemschuifspanning neemt toe voor een toenemend...

report 1993

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The influence of upstram turbulence on local-scour holes

Hoffmans, G.J.C.M. (author), Booij, R. (author)

Excessive local scour can progressively undermine the foundation of a structure. Because complete protection against scour is too expensive generally, the maximum scour-depth and the upstream slope of the scour hole have to be predicted to minimize the risk of failure. In 1961 a systematical research 'tY'ith respect to scour holes started in the...

conference paper 1993

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Users manual: DUCT-SUSTRA

Hoffmans, G.J.C.M. (author)

Some information is given how to use the scour model DUCT-SUSTRA (Hoffmans, 1991). The scour model predicts the morphological process in scour holes or trenches and consists of two separated sub-models: a flow model DUCT and a morphological model SUSTRA. The flow model is based on the equation of continuity and the momentum equations for...

report 1991

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Concentration and flow velocity measurements in a local scour hole

Hoffmans, G.J.C.M. (author)

Flume experiments with small Froude numbers have been carried out to study the concentration field in a local scour hole without supply of sediment load. The measuring results will be used to check the validity of the two dimensional scour model DUCT-SUSTRA. The objective of the experiments was to measure the concentrations at various locations...

report 1990