Probabilistic assessment of inner slope stability in dikes: Gaining insight in the difference between the semi-probabilistic and probabilistic estimates of the reliability index for inner slope stability with overtopping

After overtopping, the most common failure mechanism in the world that leads to a dike breach is the instability of the inner slope. Two stability calculations are required for the semi-probabilistic assessment of inner slope stability. One calculation is without significant overtopping and the other calculation is with significant overtopping...

Wave overtopping and scale effects: Experimental case study New Afsluitdijk

After more than 85 years, the iconic Afsluitdijk is in need of a reinforcement. During the latest safety assessment of Rijkswaterstaat the dike did not meet the standards at two components; the amount of wave overtopping (>10 l/m/s) and armour stability. This research goes into detail about the overtopping on the Afsluitdijk. In the new...

Stability of Single Layer Cubes on Breakwater Rear Slopes

Breakwaters with single layer concrete armour are very commonly applied nowadays. Much research is available on the stability of single layer armour units on the seaward slope. However, rear slopes design methods for single layer armour units are rare. On rear side slopes usually similar sized units as on the seaward slope are applied. Limited...

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...

Wave Overtopping Resilient 'Afsluitdijk': Design Procedures for Landward Slope Erosion Stability during Large Overtopping Volume Events

The Afsluitdijk is unable to withstand the future conditions that belong to an annual probability of occurrence of 1/10 000 per year for water level and wave conditions. Solution of Rijkswaterstaat is to strengthen the dike according to the principle of the wave overtopping resilient dike (NL: Overslagbestendige dijk). Therefore the Afsluitdijk...

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...

Guidance on erosion resistance of inner slopes of dikes from 3 years of testing with the Wave Overtopping Simulator

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...

Development of Alternative Overtopping-Resistant Sea Defences: Proposal for concepts

The present proposal deals with a presentation of three potentially feasible concepts for strengthening of the sea defences as to allow for increased wave overtopping, within the framework of ComCoast. In addition, for each concept an indicative proposal is given for a further theoretical study (Phase 2) and an indicative approach is shown for...

Overtopping resistant dike, Sandy dike

An important element in the ComCoast concept is the overtopable sea defence (often a dike). In this concept the landward (inner) slope of the dike is adjusted in such a way that it can withstand higher overtopping rates. Two new concepts for covering the inner slope, sand cover and perforated mats, are discrebed in this report.

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...