Print Email Facebook Twitter Root characteristics of some grass species on the sea dikes in Viet Nam Title Root characteristics of some grass species on the sea dikes in Viet Nam Author Trung, L.H. Faculty Civil Engineering and Geosciences Department Hydraulic Engineering Date 2012-10-01 Abstract Between 2009 and 2011, some grass-covered sea dikes were tested with the Wave Overtopping Simulator in the north of Viet Nam. Slope specifications and grass species of sea and estuary dikes were quantitatively observed and investigated. This report is concerned with expressing main characteristics of four grass species on some dike slopes in the north of Viet Nam including root diameter, root distribution over depth, root tensile stress. Roots are classified into four levels 1, 2, 3 and 4. Level 4 roots contribute about 70 to 80 % of the total amount of roots. In general, root diameter dr can be expressed as a power function of the associated percentage Per. The distribution of number, volume and weight of roots over depth are principally identical. At an arbitrary depth, the volume and weight of roots are proportional to the number of roots despite of level and size. About 60 to 90 % of root amount (i.e., number, volume and weight) presents in the top layer of 10 cm thick. There is less than 10 % acting under 20 cm from the slope surface. To represent the distribution of roots in depth, a parameter Root Number Ratio (RNR) is proposed as the ratio of number of roots nr at a certain depth d to the number of root nr0 at a reference depth d0. Pulling tests were mainly performed with roots of levels 1 and 2 using a digital force gauge to determine root tensile stress. The inverse relationship between tensile stress and root diameter established in some earlier works is confirmed. Combination of some relevant parameters leads to the total tensile strength SUM(tr) generated by a number of roots nr at an arbitrary depth d. Subject grassrootstensile strengthvetiver grass To reference this document use: http://resolver.tudelft.nl/uuid:f95943f3-d2c6-4765-a5d9-e586af29ec2d Publisher TU Delft, Section Hydraulic Engineering ISSN 0169-6548 Source Communications on Hydraulic and Geotechnical Engineering, No. 2012-03 Part of collection Institutional Repository Document type report Rights © 2012 Lê Hai TrungTU Delft, Section Hydraulic EngineeringWater Resources University Hanoi Files PDF 12Dec14_Grass_root_charac ... istics.pdf 3.9 MB Close viewer /islandora/object/uuid:f95943f3-d2c6-4765-a5d9-e586af29ec2d/datastream/OBJ/view