Showing papers by "J.W. Van der Meer published in 2009"
TL;DR: In this paper, the authors describe a major program of small-scale physical model tests to establish better the influence of armour type and configuration on over-topping, which are used in the neural network prediction of over-top.
102 citations
12 Nov 2009
TL;DR: The Wave Overtopping Simulator was developed in 2006 and destructive tests have been performed in February and March of 2007, 2008 and 2009 and will probably be continued in 2010 as discussed by the authors.
Abstract: The Wave Overtopping Simulator was developed in 2006 and destructive tests have been performed in February and March of 2007, 2008 and 2009 and will probably be continued in 2010. The tests show the behaviour of various inner slopes of dikes, embankments or levees under simulation of wave overtopping, up to a mean overtopping discharge of 125 l/s per m. In 2010 a Technical Report on strength of inner slopes of dikes against wave overtopping will be written, leading to new guidelines for the required five-yearly safety assessment of flood defence assets in the Netherlands. This paper will give a mid-term review and first guidance, based on 3 years of destructive testing. Till summer 2009 15 sections of dikes at 5 different locations in the Netherlands have been tested. The paper will give guidance to practical engineers, based on observations and analysis from all the testing so far. It also discusses the possible modifications in safety assessment.
60 citations
21 Dec 2009
TL;DR: The US Wave Overtopping Simulator as discussed by the authors has been designed to simulate overtopping discharges up to 2 cfs/s/ft for wave conditions of respectively 8 ft and 3 ft with a period of 6 s. This requires a Simulator which is in size about three times larger than the existing Dutch one.
Abstract: The US Wave Overtopping Simulator has to simulate overtopping discharges up to 2 cfs/s/ft for wave conditions of respectively 8 ft with a peak period of 14 s and 3 ft with a period of 6 s. This requires a Simulator which is in size about three times larger than the existing Dutch one. This report describes the theory of waves overtopping the crest of a levee, the design of the Simulator, how to operate it and possible ways to measure hydraulics during testing. We know a lot about wave overtopping over levees, but still there are discrepancies between various formulae. First the existing theory is given about wave overtopping discharge and individual wave overtopping volumes. This leads to the distributions of wave overtopping volumes that have to be simulated by the Simulator. Then flow velocities, flow depths and flow times or durations of overtopping wave volumes at the crest of a levee have been discussed, including re-analysis of existing work and some recent research. The conclusion is that using the equations in an integration, to calculate the wave overtopping volume, the volumes are much too large, indicating that at least flow depth andflow time predictions are too large. For this reason the Simulator will mainly be based on flow velocity and the given peak periods of the waves. Good experience is available with Simulators up to a size of about 6 m3/m width. The majority of all overtopping wave volumes will be limited to this size. It is for this reason that the US Simulator has been designed with an inner Simulator, comparable to the existing sizes, and an outer Simulator, giving the maximum capacity of 16 m3/m. The outer Simulator will only be used for the very large overtopping wave volumes. The mechanical design has been described and this design has been discussed during a visit to CSU, in order to start fabrication of the Simulator. The Dutch test set-ups at various locations have been described with their improvements every consecutive year. The operation of the Simulator by a steering file and PLC has been given, first by description of the Dutch Simulator and then by possible modifications and improvements for the US Simulator. Finally, experiences to measure flow depth and front velocity of overtopping waves have been described and possible ways of improvements, which will be performed in the Netherlands and tested in February/March 2010. If successful, these kind of measurements can also be developed at CSU.