Damage to grass dikes due to wave overtopping

Grass covers have been applied as an effective measure for protecting river levees and sea dikes. We conducted experiments to show how roots considerably improve the shear strength of soil on dike slopes. Roots of 1-year-old Bermuda and Carpet grass may increase the total shear strength of up to 20 kPa. Exposed to severe overtopping flow, dike...

Wave overtopping simulator tests on Vietnamese sea dikes

Little is known about the strength of the land-side slopes of the Vietnamese sea dikes under overtopping attack. Some grass-covered slopes were tested by a wave overtopping simulator. The paper describes the simulator and presents the test results. The tested grass covers could withstand overtopping rates varying from 20 l/s to 100 l/s per meter...

The application of a tandem dike system in Vietnam

In the low-lying coastal regions coastal defense structures are usually designed with a main function to protect the hinterland from highly vulnerable of sea flooding. Sea dikes are usually the most common and important elements which form the coastal flood defense system. Sea dikes are designed at a pre-defined circumstance and requirement. For...

The use of mangroves in coastal protection

Apart from many ecological advantages, mangroves in front of a coastal defence may lower the construction and maintenance costs of the defence. Although mangroves have hardly any reducing effect on water levels (and on tsunami impact) mangroves may significantly reduce wave attack on a coastal dike, and in this way reduce the cost of a revetment...

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of Vietnam are steep and solely constructed by soil covered with grass due to the budget constraints and also the out-of-date design guidelines.The resistance against erosion due to wave overtopping of several grass covered slopes were tested with the Wave Overtopping Simulator to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

Safety against inundation: The dutch approach

The most urbanized part of the Netherlands is situated below sea level and is protected by dikes. By act of parliament allowable inundation frequencies for each part of the country are fixed. In case of two dangers (river run-off and storm surge) it is a problem to determine design values for dikes. Guidelines are developed to solve these...