Validation and Optimization of a Design Formula for Stable Geometrically Open Filter Structures

Granular filters are used for protection against scour and erosion of base material. For a proper functioning it is necessary that at the interfaces between the filter structure, the subsoil and the water flowing above the filter structure no material will be transported. Different types of granular filters can be distinguished, this paper...

Falling aprons at circular piers under currents

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...

Interface stability of granular filter structures under currents

Granular filters are used for protection of structures against scour and erosion. For a proper functioning it is necessary that the interfaces between the filter structure, the subsoil and the water flowing above the filter structure are stable. Stability means that there is no transport of subsoil material through the filter to the water above...

Erosion at transitions in landward slopes of dikes due to wave overtopping

Destructive wave overtopping tests have been performed at more than 20 dike sections in the Netherlands using the Wave Overtopping Simulator to simulate the overtopping waves. The tests show the combined behaviour of turf and substrate up to mean wave overtopping discharges of 75 ?/s per m, meaning wave volumes up to 5,500 ?/m with flow...

Jet scour

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...

Flow depths and velocities at crest and landward slope of a dike, in theory and with the wave overtopping simulator

Wave overtopping discharges at coastal structures are well described in the EurOtop Manual (2007), including the distribution of overtopping wave volumes. Each volume that overtops a dike or levee will have a certain flow velocity and depth record in time, often given by the maximum velocity and flow depth. This paper describes some further...

Staat van de scheepvaart en de binnenvaarwegen in Nederland 2009 - Tweejaarlijkse trendrapportage

Dit is de eerste uitgave van de trendrapportage met betrekking tot de Nederlandse binnenvaart en de binnenvaarwegen. Deze trendrapportage zal iedere twee jaar worden uitgegeven en is een gezamenlijke productie van Rijkswaterstaat en TU Delft, Faculteit Civiele Techniek en Geowetenschappen. In deze eerste uitgave komen onderwerpen aan de orde als...

Ten years of experience in combining ecology and navigation on Dutch waterways

In this paper we will discuss the experience gained in the Netherlands with the multifunctional management of waterways. We will especially go into how the functions of rivers and canals for navigation and nature are combined. For this we will briefly go back to the national paper for Seville 1994, "Waterways with room for nature", in which the...