Modelling dynamic tensile failure of quasi-brittle materials using stress-enhanced nonlocal models

The development of realistic numerical tools to efficiently model the response of concrete structures subjected to close-in detonations and high velocity impacts has been one of the major quests in defense research. Under these loading conditions, quasi-brittle materials undergo a multitude of failure (damage) mechanisms. Dynamic tensile failure...

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...

Modelling dune erosion, overwash and inundation of barrier islands

Physical model experiments are performed at Deltares to investigate the morphological response of barrier islands on extreme storm events. The experiments included dune erosion, overwash and inundation regimes. Extensive measurement techniques made detailed comparison with numerical models possible. This paper describes the comparison between...

Wave overtopping resistance of grassed slopes in Viet Nam

The Simulator was applied to test the resistance against wave overtopping of grass covered dike slopes in Viet Nam. Observation and measurement during destructive tests were performed to investigate the development process of damage induced by overtopping flow. Damages were likely to be initiated at transition of either geometry or materials, at...

Wave overtopping resistance of grassed dike slopes in Vietnam

The resistance of various grassed slopes against wave overtopping has been appraised by means of the Wave Overtopping Simulator in situ for a couple of years in Viet Nam. Destructive test results show that a dike slope covered with grass could suffer a certain overtopping discharge not smaller than 20 l/s per m. During testing it was difficult...

Wave overtopping simulator tests in Vietnam

Sea dikes in Viet Nam have been built up during a long history. Every year, about 4 to 6 storms attack the coast and cause severe damages of the sea dikes. Till now, little is known about strength and stability of the inner slope covered with grass under impacts of wave overtopping during storm surges. Destructive tests have been performed with...

The influence of upstram turbulence on local-scour holes

Excessive local scour can progressively undermine the foundation of a structure. Because complete protection against scour is too expensive generally, the maximum scour-depth and the upstream slope of the scour hole have to be predicted to minimize the risk of failure. In 1961 a systematical research 'tY'ith respect to scour holes started in the...

A field experiment on beach growth in sand-dikes

The set-up and results of a field experiment on sand-dike breach erosion are described, It is found that the breaching process for the 2.2 m high sand-dike is similar to that in Visser's (1988) laboratory experiments with a 0.6 m high sand-dike. Confrontation of Visser's (1988) breach erosion model with the field data shows reasonable agreement...