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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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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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Das Neves, L. (author), Lopes, M.L. (author), Veloso-Gomes, F. (author), Taveira-Pinto, F. (author)
Unidirectional irregular waves of varying significant wave-height and peak period but with a constant spectral shape (JONSWAP spectrum, ?=3.3) were generated over a sandy 3:20 sloped plane beach to investigate scour fronting a dune erosion control system constructed from geotextiles, slope inclined at 45º. Both passive (i.e., three dune erosion...
conference paper 2012
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Arneson, L.A. (author), Zevenbergen, L.W. (author), Lagasse, P.F. (author), Clopper, P.E. (author)
This document is the fifth edition of HEC-18. It presents the state of knowledge and practice for the design, evaluation and inspection of bridges for scour. There are two companion documents, HEC-20 entitled "Stream Stability at Highway Structures", and HEC-23 entitled "Bridge Scour and Stream Instability Countermeasures". These three documents...
report 2012
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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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Verheij, H. (Henk.Verheij@deltares.nl) (author)
Conventional ship propulsion systems and hydro jets differ in many ways. However, they are both responsible for sailing and manoeuvring of ships in a forward or reverse direction. The hydrodynamic jet is what they have in common, but the characteristics of the jets differ. For example, the outflow velocity of hydro jets is much higher than the...
conference paper 2010
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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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Gent, M.R.A. van (author), Coeveld, E.M. (author)
report 2007
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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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Zhu, Y. (author)
Numerous flood disasters occur every year worldwide, mostly resulting from failure of dikes, some with catastrophic outcomes. Examples are the dike failures along the Yangtze River in China in 1931 due to heavy rainstorms and those in the Netherlands in 1953 due to a storm surge at the North Sea. Both floods induced many deaths and enormous...
doctoral thesis 2006
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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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Verheij, H.J. (author), Mosselman, E. (author), Stolker, C. (author)
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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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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Hoffmans, G.J.C.M. (author), Den Adel, H. (author), Verheij, H.J. (author)
Scour is a natural phenomenon caused by the flow of water in rivers and streams and occurs as a part of the morphological changes caused by rivers or as a result of man-made structures. For the Dutch Delta Works hydraulic structures were often constructed on fines with loose packing. To guarantee the geotechnical stability of these structures...
report 2000
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Hoffmans, G.J.C.M. (author)
Het doel van het handboek ontgrondingen is een antwoord te geven op ontgrondingsvraagstukken zoals een ontwerper van waterbouwkundige constructies die tegenkomt. Verschillende deelstudies worden voor het afronden van dit handboek uitgevoerd. Het verifiëren van ontgrondingsformuies staat centraal in deze studies. Hier is de voorspellingskracht...
report 1995
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Hoffmans, G.J.C.M. (author)
Het doel van het handboek ontgrondingen is een antwoord te geven op ontgrondingsvraagstukken zoals een ontwerper van waterbouwkundige constructies die tegenkomt. Verschillende deelstudies worden voor het afronden van dit handboek uitgevoerd. Het verifiëren van ontgrondingsformules staat centraal in deze studies. Hier is de voorspellingskracht...
report 1995
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Hoffmans, G.J.C.M. (author)
Het handboek ontgrondingen beoogt een instrument te zijn om de grootte van lokale ontgrondingskuilen rondom brugpijlers, kribben, achter drempels met of zonder bodembescherming, uitlaatconstructies, strandmuren, strandhoofden, etc. te voorspellen. Met het handboek kunnen ontwerpers en adviseurs een eerste schatting van het ontgrondingsproces...
report 1994
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Hoffmans, G.J.C.M. (author)
Scour is a natural phenomenon caused by the flow of water in rivers and streams. Scour occurs naturally as part of the morphological changes of rivers and as result of structures man-made. Several types of scour can be distinghuished. Experience has shown that due to sand or flow slides or micro instabilities at the end of the bed protection,...
report 1993
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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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