Geosynthetically Reinforced Vegetation VS. Riprap: A Collection of Case Studies and Cost Analysis

摘要

"Hard armor" materials such as rock riprap were once thought to be the only suitable materials for lining channels designed to carry high velocity, high shear stress flows. Vegetative linings were simply out of the question for channels where expected velocities would exceed 2.1 meters per second (m/s) (8 feet per second (ft/s)) (Chow, 1959) or shear stresses topped the 178 pascals (pa) (3.7 pounds per square foot (lbs/ft~2)) mark (Chen and Cotton, 1988). However, modern geosynthetic turf reinforcement mattings (TRMs) have proven the ability to substantially increase the erosion resistance of natural vegetation, enabling its use in channels where high velocities and shear stresses are prevalent (Hewlett, et al., 1987) (Northcutt, 1996). This confirmation is to the delight of many designers who respect the low cost, low maintenance, low hazard and environmental benefits of "soft armor" vegetative linings. This paper will present three case studies detailing the use of geosynthetically reinforced vegetation in place of rock riprap for stabilizing high discharge channels. A cost analysis is also provided to exemplify the economic advantages of "soft armoring."