147,262 research outputs found
Die Gestalt von natürlichen Steinen und ihr Fallverhalten in Wasser
No full textResearch at IWAWI of TU Berlin focuses on rock placement in coastal engineering and port construction. During research work it was found that objective and descriptive shape classification of rocks was needed. The introduced method utilizes three independent parameters: size referred to by volume, shape according to Zingg and roundness according to Diepenbroek or by the degree of shape deviation of the rock\u92s equivalent ellipsoid of inertia. This classification is visualized in a three dimensional parameter space. Underwater falling properties of natural rocks were object of a systematic experimental examination. These properties are associated with the parameter space. The digital visualization of the examined rocks and the experimental results on properties and motion are presented in a PC-based interactive information system RockDataBase. The user can query information on any rock by using RockDataBase as a modern form of comparison table to acquire shape properties, hydraulic properties and a visualization of its under water motion
Watertovenaars: Delftse ideeën voor nog 200 jaar Rijkswaterstaat
No full textEen bundel artikelen met inspiratie voor Rijkswaterstaat voor de ontwikkeling in de volgende 200 jaar. Watertovenaar of tovenaarsleerling? (K. d'Angremond, P. Huisman en G.I. Schiereek) De oudste deltawerken: dammen en duikers uit het begin van de jaartelling (T. de Ridder) Een erfenis uit de Bataafse periode (W.M. de Jong) Wat eerst: wonen, water, wegen of welvaart? (T.M. de Jong) Een nieuwe rol voor de waterstaatsingenieur (F.M. Sanders) De terugkeer van de stedenbouwkundige discipline (V.J. Meyer Water (P. Huisman, K. d'Angremond en G.J. Schiereek) Dynamische buffers in autosnelwegen (D. Westland en P.H.L. Bovy) Op de automatische piloot door de Randstad? (R. van der Heijden, V. Marchau, E. Molin en K. van Wees) Niet bruggen bouwen, maar zelf brug zijn (B. Enserink, M.P.M. van der Ploeg, WAH. Thissen en G.J. de Vreede) Nederland als vervoersemplacement? (M.P.C. Weijnen, W.A.H. Thissen en E.F. ten Heuvelhof) Immobilisatie van gevaarlijk afval (Ch.F.Hendriks) Dubbel verduurzamen van wegconstructies (A.A.A. Molenaar) Innovatie van de geometrische infrastructuur (P.J.G.Teunissen) Radarhoogtemetingen en de (voorname) rol van Delft (M. Naeije) Een hoog(water)standje (T. Rientjes, C. van den Akker en P. van der Veer) Naar één beslismodel voor de veiligheid (J.K. Vrijling en J. Stoop) De betrouwbaarheid van dijken (A. Verruijt) Windgolven, een fascinerend fenomeen (L.H. Holthuijsen en J.A. Battjes) Mijn droom: het railvaartuig (B. Boon) Een waterfilm in plaats van wielen (A. van Beek) Uren worden minuten (E.A.H. Vollebregt, H. Jansen en M.R.T. Roest) Een kwestie van schuiven (R.Brouwer, A.Hof en J. Schuurmans) Energie door vergisting van slib (M.S.M. letten en M.C.M. van Loosdrecht) Nóg een poldermodel: hoge-sterkte beton (J.C. Walraven) Atollen voor de Noordzeekust (J. Kristinsson) Van maker naar regisseur (H.A.J. de Ridder
Untersuchungen zum Fallverhalten würfelförmiger Einzelkörper in Wasser
No full textThe underwater fall of cubes (as reference bodies for sharp edged quarry rock material) of different sizes and densities has . been examined. The experimental study has been carried out by using a shaft (diameter: 5 m) filled with water. Due to rotary motion (Magnus' effect), the trajectories of such cubes deviate from vertical lines. The direction of such deviation cannot be predicted, because the axis of rotation changes irregularly during the fall. The cubes reach their settling velocities very fast. The observed settling velocities are in accordance with the values obtained from the general quadratic law for resistance. The drag coefficient Cw is 0,8 - independent of the size and density of the cube - referred to the maximum projection area. Since the effected projection area changes during a cube's fall, the instantaneous velocity of this object oscillates. The oscillation can sometimes be as large as 25 % of the calculated mean value
A Review on Automatic Generation of Architectural Space Layouts with Energy Performance Optimization
No full textGreen Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Climate Design and SustainabilityDesign InformaticsBuilding ServicesArchitectural Engineering +Technolog
Tuin Park Landschap: Documentatie Minor Landschapsarchitectuur 2009
No full textDit boek geeft een overzicht van analyses, ontwerpen en essays van studenten in de Minor Landschapsarchitectuur die aan de Faculteit Bouwkunde TU Delft in het najaar semester van 2009 voor de tweede keer werd gegeven onder begeleiding van de docenten Daniel Jauslin en Denise Piccinini. De minor is een nieuwe vorm van onderwijs waarin studenten uit verschillende faculteiten en universiteiten een totaal ander vak kunnen volgen buiten of binnen de grenzen van hun eigen faculteit. We hanteren voor de analyse- en ontwerpopgave drie landschaparchitectonische archetypes; tuin, park, landschap. De rivier de Rotte door Rotterdam is het verbindend landschappelijk element tussen stad en land en tussen de schalen - van klein naar groot. De driedelige thematieken, schalen en de keuze voor de Rotte als verbindend element waren de belangrijkste vernieuwingen in deze tweede lichting van de minor. De structuur tuin, park, landschap wordt daarom ook voor dit boek aangehouden met de Rotte als orientatie. Overal zijn we enthousiasme tegen gekomen voor ons vak maar ook voor het feit dat dit vak vanuit te TU Delft ontwikkeld wordt. Dit boek is daarom ook als dank aan velen bedoeld. Door de bestaande landschappen van de Faculteit Bouwkunde waait een vernieuwende wind. Wij hopen dat deze documentatie helpt om deze vernieuwing verder op te bouwen en velen ervan te overtuigen zich in de Landschapsarchitectuur te verdiepen.UrbanismArchitectur
Hydraulic performance, wave loading and response of Elastocoast revetments and their foundation - a large scale model study -
No full textELASTOCOAST revetments are highly porous structures made of crushed stones which are durably and elastically bonded by Polyurethane (PU). To improve the understanding of the physical processes involved in the wave-structure-foundation interaction and to develop prediction formulae for both hydraulic performance and wave loading more than 75 large-scale model tests using both regular and irregular waves were performed. Three ELASTOCOAST revetment alternatives with the same slope (1:3) and the same revetment thickness (0.20 m) but with different thicknesses of the underlying filter layer (0.00 m, 0.10 m and 0.20 m for Model Alternatives A, B and C, respectively) were tested. More than 85 measuring devices synchronously connected to two video cameras were used. Prediction formulae are developed for wave reflection, wave run-up and run-down as a function of the surf similarity parameter which illustrate the advantage of ELASTOCOAST revetments as compared to conventional revetments. For instance, more than 25% less wave runup may result on comparison to smooth impermeable revetments. Using a surf similarity-based wave load classification as well as a systematic parametrization in both time and space, prediction formulae are also developed for both impact loads on and just beneath the revetment. These include the peak pressure pmax, its location in relation to still water level zpmax, the spatial pressure distribution and the time related parameters (rise time and total load duration). Prediction formulae for the wave-induced pore pressure in the sand core beneath the revetment are also provided, including the maximum pressure at the upper boundary of the sand layer and its development in deeper layers. Formulae are also proposed for the flexural displacement ä of the ELASTOCOAST revetment, showing that for impact load much smaller displacements would result than for non-impact load and that ä linearly increases with peak pressure pmax for a given revetment thickness. Finally, a stability analysis of Model Alternative A is performed on basis of the results of the measurements and the simultaneously recorded videos. The results illustrate why Model Alternative failed due to local transient soil liquefaction while Model Alternative B tested synchronously under the same wave conditions did not fail.LWI098
Project Hue: Report and field study on the water related problems and solutions in and around the Cau Hai lagoon and the Tu Hien inlet, Vietnam
No full textThe Tam Giang-Cau Hai lagoon system, lying in the Thua Thien-Hue province in central Vietnam, is affected by a tropical monsoon climate. This among others is the reason the Cau Hai Lagoon area has a long history of floods and other water related problems. Inhabitants are very dependent on the lagoon, as the main sources of income of people living in the region are fishing, agri- and aquaculture. The project goal has been formulated as follows: Finding an economic as well as technical feasible solution to reduce the water related problems, specifically navigability, salt intrusion and floods, in and around the Cau Hai Lagoon and the Tu Hien inlet and thereby improving the economic development of the region. Concerning flood risk, navigability and salt intrusion the inlet stability and size are important aspects. Using an echo sounder the bathymetry of the inlet has been measured. The measured size of the inlet was one of the input parameters for the hydraulic model that has been set up. This basic model of the Cau Hai basin system was made to test some alternative solutions for the Tu Hien inlet. The different solutions were simulated for five different scenarios. These scenarios include average dry season conditions, average wet season conditions and multiple extreme events. The output of the model for the different alternatives was used to rate the alternatives for a couple of criteria in a Multi Criteria Analysis. Other criteria of the MCA are qualitatively rated. The most promising alternative proved to be the one including a jetty at the northern side of the Tu Hien inlet in combination with a bank protection at the other side. In this way a large part of the littoral drift is blocked, enlarging the equilibrium cross-section of the inlet. This in turn results in a better flood evacuation capacity, navigability and water quality in the lagoon. For both mentioned elements a preliminary technical design is made, resulting in the stone class needed for the armour layers, dimensions of the toe and characteristics of the filter.Hydraulic EngineeringCivil Engineering and Geoscience
Quantification of measurement errors, model and scale effects related to overtopping
No full textCLASH is concentrating on investigations of wave overtopping for different structures in prototype and in laboratory. The model investigations have focussed on wave overtopping and the comparison of overtopping results from small-scale model tests and prototype measurements. Possible differences in the results from small-scale tests and prototype were analysed with respect to measurement accuracy as well as model and scale effects. This report proposes a methodology to assess the aforementioned effects and to provide the uncertainties and correction factors for quantifying the various influences when performing model tests. First, the available literature on scale and model effects has been reviewed. It was found that scale effects especially for wave run-up and overtopping have been reported in the past. Manydikes up to 25% higher wave run-ups were observed. Wave overtopping for armour slopes in front of vertical walls in prototype was reported to be up to 10 times higher than in model tests but it is still not clear whether this is due solely to scale effects. Second, some theoretical considerations were performed to derive critical Weber and Reynolds numbers which should always be exceeded during model tests. It was found that for wave run-up and wave overtopping Weber numbers should not fall below Wecrit = 10 and that water depths should always be larger than 2 cm and wave periods longer than 0,35 s. This is usually the case in all models. Additionally, the overtopping related Reynolds numbers should be larger than 1·103 which is also the case for most of the model tests. Results for all field and model investigations have been plotted for the investigated sites using data from the field and two models of smaller scale. Results have shown that model tests performed for the vertical wall in Samphire Hoe and the steep Zeebrugge rubble mound breakwater do not deviate much from the prototype data points. However, for the flatter slope in Ostia differences between prototype and model have been observed in the order of up to one order of magnitude. A Monte-Carlo simulation was used to determine the variation which may occur when different measurement uncertainties and scale effects are considered. The results show a large dependency on the magnitude of the overtopping rate itself which was also evident from the observation of the model tests. Differences of a factor of about 5.0 for large overtopping rates and a factor of about 40.0 for low ones are observed. Finally, a new parameter map for scaling was proposed taking into consideration the aforementioned findings (Fig. 22). The map depends on whether or not the structure is \u91rough and sloping\u92 and eventually suggests a scaling predictor. The latter was then applied to the test cases of Zeebrugge and Ostia.Clas
Eb- en vloedschaar systemen in de Nederlandse getijwateren - Ebb and Flood channel systems in the Netherlands tidal waters
No full textThe present paper, "Eb- en vloedschaarsystemen in de Nederlandse getijwateren" (Ebb- and floodchannel systems in the Dutch tidal waters), which was published in 1950, should be considered as Van Veen's most important publication since his thesis. It summarizes the results of 20 years of intensive study of estuarine and tidal-basin morphodynamics in The Netherlands. The paper is testimony to Van Veen's keen observational and artistic skills. His approach is nearly "Da Vincian" in the sense that he is not only a fascinated but also sharp observer of nature and tries to capture the essentials ofthe dynamic behavior of complex coastal systems in apparently simple sketches. Many of the natural systems that Van Veen studied have been regulated since; thus, this paper contains a set of irreplaceable, highquality observations on the natural dynamics of tidai systems. Along with Robinson's (1960) paper on ebb-flood channel systems, it forms an excellent introduction to the study of channel dynamics in estuaries, tidal inlets, and tidal basins. Unfortunately, Van Veen's paper was published in Dutch, with only a brief summary in English. Luckily, the figure captions were given in both Dutch and English, allowing international researchers coming across the paper to read it as a kind of 'cartoon'. Understandably though, the paper has received very limited recognition in the international literature. So far, we have traced only 8 publications in which reference is made to this paper (see the reference list on page 53). The majority of these publications have Dutch-speaking (co)authors. Geyl, one of these authors, gives an extensive summary of van Veen's results in his 1976 paper, conscious of the obscurity of the original paper. Ludwick (1972) refers to an English) translation of Van Veen's paper that we have not been able to trace. Usually, reference is made to Van Veen's paper to define ebb- and flood channels in estuaries and tidal inlets. However, his paper contains much more information that should be available to the international research community. Translation of this paper has been the subject of several discussions between Graham Evans, formerly of imperial College, London, and one of us (AvdS). Until recently, a translation was not undertaken, however.Hydraulic EngineeringCivil Engineering and Geoscience
Estimation of the Maximum Physically Possible Precipitation in Saxony Using a Mesoscale Atmospheric Model
No full textA series of sensitivity studies have been performed to estimate the impact of presumed global warming on synoptic scale weather events. Within the framework of an epignostic study, mesoscale simulations of the Elbe river flood (August, 2002) employing the COSMO-DE model of the DWD have been carried out. The first set of runs was realised on a model domain size of 201 x 201 grid points with different temperature offsets at constant relative humidity. The results gave no hints on enhanced area accumulated rain sums in a warmed climate. Different temperature offsets at constant relative humidity does not result in significantly changed rain sums with respect to the reference run (climate as is). Increasing the water vapour mixing ratio so far, that the relative humidity increases, the total rain amounts increase, too. The observed rain sums originate from both thermodynamic and hydrodynamic effects (superposition of stratiform, convective and orographic rain contributions). An enhancement of the absolute water vapour mixing ratio at higher temperatures is indeed a necessary, but not a sufficient condition to enhance the rain formation. For example, a displacement of rain-promoting synoptic features might counteract rain formation, when the superposition of processes from different scale is not ensured any longer in a changed atmospheric system.Floodsit
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