Evaluation of Geofibers and Nontraditional Liquid Additives on Erodible Slopes in Interior Alaska

Abstract Non-cohesive soils are extensively distributed in Interior Alaska and soil erosion in a newly constructed roadside embankment is of great concern. Geofibers and nontraditional additives have been used for stabilizing non-cohesive soils and controlling soil erosion. However, in cold regions where permafrost exists such as Interior Alaska, any erosion control measures in a newly constructed roadside embankment must also allow a vegetation establishment at the same time, to mitigate potential permafrost degradation caused by surface modifications. Literature review indicates that no previous research has been done to consider both effects. There is a great need to investigate if geofibers and nontraditional additives can be used in Interior Alaska for soil erosion control and permafrost degradation mitigation. This paper presents the laboratory and field test results on use of geofibers and nontraditional additives (synthetic fluid and polymer emulsion) to control soil erosion in Interior Alaska. Locally available non-cohesive soils were used as a control and compared with the same soils treated with different doses of geofibers and nontraditional additives, including: 1) 4% synthetic fluid and 0.5% geofibers, 2) 2% polymer emulsion + 0.5% geofibers, 3) 2% polymer emulsion, and 4) 0.5% geofibers only. The results on soil critical shear stresses, sediment collections, soil organic matter, and plant available nutrients were analyzed from which some conclusions were made regarding working mechanisms of the geofibers and two nontraditional additives on soil erosion control in Interior Alaska.