Low cost spillway surfaces for farm dams

With the aid of a grant from the Water Research Foundation of Australia, the Water Research Laboratory has undertaken an investigation into surface treatments for small farm dams Vegetal cover with natural gr asses and low cost soil and bitumen admixtures are under study. As a preliminary to laboratory and field testing, a survey of available...

By-wash spillways for farm dams

Model studies formed a basis for investigating the hydraulics of bywash spillways for farm darns When constructed in natural earth such spillways are trapezoidal in cross section The surface of the spillway needs protection from scour and this protection is usually in the form of grass. These tests extended to variations in spillway geometry and...

Hydraulic characteristics of low cost surfaces for farm dam bywash spillways

As part of a program of research aimed at improving the design and construction of farm dams, the Water Research Laboratory, has with the aid of a grant from the Water Research Foundation of Australia, undertaken a study of the protection afforded to spillways by various low cost surfacing techniques. These include vegetal cover by natural...

Resistance of low cost surfaces for farm dam spillways

Third report on use of grass on farm spillways; tests on slopes 1:10 to 1:2.5 (prototype scale tests). Permissible velocities suitable for design were given.

Scour resistance of farm dam spillways with grass dormant

This report is the fourth in a series dealing with the use of natural grasses and bituminous and soil admixtures for surfacing farm dam bywash spillways. When the work reported here was completed, the test channels were demolished to make way for new construction, and no further tests of this nature are contemplated. The previous report (Yong...

Stroombestendigheid van een grasmat op de dijk van Oostelijk Flevoland

A guide to the use of grass in hydraulic engineering practice

Guidance on the use of grass to stabilise surfaces subject to erosion by intermittent flow. Provides information on the erosion resistance and frictional resistance of grass. Includes recommendations on grass mixtures, etc. Extensive literature survey

Grasdijken: Analyse meetresultaten grootschalig modelonderzoek

Analyse van deltagootproeven op een grastalud: Deel 1 en 2

Er is een analyse van de waarnemingen en metingen met betrekking tot ontgronding uitgevoerd voor de 1:1 modelproef in 1992 in de Deltagoot met golven van Hs 0.75 m tot 1.35 m op een grastalud van een dijk. De gemeten ontgronding is veel geringer dan tijdens vergelijkbare proeven op klei met een bodemstructuur, maar zonder zodelaag. Pas na vele...

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...

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...

Analyses grass erosion in wave run-up and wave overtopping conditions

Within the framework of WTI, Research and Development of Flood Defence Assessment Tools (Wettelijk Toetsinstrumentarium), which is called in Dutch: WTI-2017 "Onderzoek en ontwikkeling landelijk toetsinstrumentarium", research was carried out to develop an erosion model for grass in the wave run-up zone consistent with the current model in use...

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...

Overflow Tests on Grass-Covered Embankments at the Living Lab Hedwige-Prosperpolder: An Overview

In regions with a temperate climate, a well-maintained grass sod on a clay layer is considered a reliable protection for dams and dikes. In the Living Lab Hedwige-Prosperpolder, on the left bank of the Scheldt river straddling the border between Belgium and the Netherlands, a series of 27 overflow tests with a purpose-built overflow generator...