Damage to Grass Covered Slopes Due to Overtopping

Many dike failures have been ignited by damage due to erosion on the landward slopes. This paper investigates how grass covered slopes perform when being attacked by overtopping flow during storm surges. Based on observations during a number of simulator tests, damage is classified into three types 'head-cut', 'roll-up' and 'collapse' depending...

Overtopping on Grass Covered Dikes: Resistance and Failure of the Inner Slopes

A large part of the Vietnamese population is living close to the coast. The sea is an essential source for supporting lives. Coastal flooding, on the other hand, threatens the people, land and infrastructures every year. Some hundreds years ago, the first sea dikes were built in Thai Binh and Nam Dinh provinces. In the north, the coastline is...

Velocity and water-layer thickness of overtopping flows on sea dikes: Report of measurements and formulas development

The study aims to establish a set of formulas estimating velocity and depth of overtopping flows at sea dikes including seaward-side slope, crest and landward-side slope. These formulas are applicable to flows which are generated by natural waves and the simulator giving associated characteristics of any arbitrary value of exceedance probability...

Effect of uncertainty in wave growth calculation on overtopping over dikes: A case study

Example calculation of a dike height incorporating the uncertainty in the wave growth formula of Young and Verhagen.

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...

Spatial distribution of overtopping

The scope of this research is to find an empirical formula to describe the distribution of wave overtopping in the region behind the crest. A physical model was set up in which irregular waves were generated. In order to find a formula which adequately describes the test observations, the influence of several parameters has been analysed. The...

Strength of the landward slopes of sea dikes in Vietnam

The landware slopes of sea dikes in the north of Vietnam are steep and solely constructed by soil covered with grass due to the budget constraints and also the out-of-date design guidelines.The resistance against erosion due to wave overtopping of several grass covered slopes were tested with the Wave Overtopping Simulator to show if a slope...

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...

Individual overtopping events at dikes

Recently, formulae have been derived for maximum flow depths and velocities on the crest and inner slope of dikes or levees at wave overtopping. Two independent physical model test programs in different wave flumes showed, however, a large difference in the results. The present paper clarifies this discrepancy and shows that the empirical...

Infiltration of overtopping water in a breakwater crest

A number of equations has been developed for calculation overtopping quantities over breakwaters, as well as equations to describe the stability of the inner slope. However, not all the water which overtops the outer boundary of the breakwater will reach the inner slope; part of the water is infiltrated in the crest. In this paper data are...

Riprap stability on the inner slopes of medium-height breakwaters

Medium height breakwaters are subjected to a considerable amount of overtopping. This implies the armour on the inner slope has to stable against overtopping waves. Existing equations do lack some basic understanding of the process of starting up movement of rock on the inner slopes. In case one relates the stability of the blocks on the inner...

Golfoploop en golfoverslag

Bij het samenstellen van het rapport "Golfoploop en golfoverslag" is er naar gestreefd: een overzicht te geven van de betreffende literatuur, de in deze literatuur voorkomende gegevens te analyseren en te interpreteren, waar mogelijk verbanden te leggen tussen de resultaten uit de verschillende literatuurbronnen, aanbevelingen te geven voor...

Wave run-up and overtopping

Overview of methods to design wave run-up and overtopping for dikes and other sloping structures for regular and irregular breaking waves. Summary of experimental data and suggestions for design formulae. English translation of: Golfoploop en golfoverslag - http://resolver.tudelft.nl/uuid:522060cb-8202-4276-bc48-ace65e137f40