SCOUR RESISTANCE OF FARM DAM SPILLWAYS WITH GRASS DORMANT

摘要

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.nThe previous report (Yong and Stone, 1967) dealt with the scour resistance capacity for grasses having a dense even cover, tested at the peak of their growing season. This report covers winter tests with the grass dormant. Once they have established a good root system, the grases withstand high velocities amazingly well, even when dormant, and there is no need to reduce permissible design velocities as given previously for grasses subject to winter floods.