Evaluation of Dutch backward erosion piping models and a future perspective: (Paper and Abstract)

The prediction of backward erosion piping is important for safety assessment of dikes in the Netherlands, where subsurface conditions are prone to this erosion mechanism. In the current assessment methodology, the adapted Sellmeijer rule is in use. In combination with the national safety philosophy and uncertainty in input parameters, this model...

Stability of stones under non-uniform flow

In the Netherlands hydraulic engineering structures are not only designed, but are also managed and maintained (M&M). In the nineteen-nineties in the United States during periods of high water scores of bridges collapsed, because American law forbids the use of bed protection around bridge piers and moreover, no maintenance plans were available....

Ontrondingen door vallende stralen

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...

Users manual: DUCT-SUSTRA

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...

Concentration and flow velocity measurements in a local scour hole

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...

Local Scour: Flow simulation by the 2-D turbulent model ODYSSEE

The general purpose of this research project is to model mathematically the local scour downstream of a structure (2-D). The model has to simulate the development of the scour as a function of the time. Basically two models are necessary namely a flow model and a morphological model. The latter model has to describe the bed and suspended load...

Local Scour: Damping of turbulence parameters in relaxation zone

The general purpose of this research project is to model mathematically the scour-hole downstream of a structure (2-D). The model has to simulate the development of the scour as a function of time. Basically two models are necessary namely a flow model and a morphological model. The latter has to describe the bed- and suspended load and the...

Local Scour: Influence of an exponential eddy viscosity distribution on the longitudial flow velocity

The general purpose of this research project is to model mathematically the local scour downstream of a structure (2-D). The model has to simulate the development of the scour as a function of the time. Basically two models are necessary namely a flow model and a morphological model. The latter model has to describe the bed and suspended load...

Local Scour: Flow model with prescribed eddy viscosity

A two dimensional mathematical model DUCT, which is based on a parabolic boundary layer technique, using finite elements, is proposed to predict the flow and turbulence field in complicated geometrical conditions, where recirculating flow may occur. Numerical results of the DUCT-model are compared with k-eps-predictions as well as laboratory...