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...

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

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...

Interface stability of granular filter structures: Desk study

A desk study has been carried out regarding interface stability of granular filter structures. Actually, the project focuses on two particular aspects: (1) interface stability as function of the thickness of the filter layer consisting of standard armourstone gradings, and (2) interface stability of gravel mixtures with a wide gradation The...

Open filters in breakwaters with a sand core: Study into the stability of granular geometrically open, hydraulically sand-open filters in breakwaters with a sand core

Thesis study into an alternative design for breakwaters made of granular materials like sand and quarry stone. In this design, the breakwater is constructed of a sand core and a layer of large stones directly on top of it, without the traditional filter layers in-between. The single layer of stones serves as one open filter layer that has to...

Shear stress concept in granular filters

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...

Erosie onder een geometrisch open filter

Deze notitie beschrijft de resultaten van een inleidend onderzoek naar de mechanismen van de erosie van de basislaag onder geometrisch open filters. Hierbij wordt in eerste instantie uitgegaan van de beter onderzochte erosie van de bodem van een waterloop zonder beschermende filterlaag. Op basis van metingen van Van Os (1998) in een inleidend...