Revealing the Influence of Top-Soil-Cover on Slope Stability and Erosion: Insights from the ONEforest Master's Thesis

In her Master's Thesis, titled "Investigation of the impact of a Top-Soil-Cover on the erosion characteristics and the stabilisation potential on slopes and forest soils," Stefanie Radinger, a colleague from the Graz University of Technology, delved into the significance of the ONEforest project.

As part of this thesis, a novel planting technique is being developed, involving the application of a topsoil cover (TSC) as a carrier material for plant seeds on embankments and slopes. The objective of Radinger's research was to explore the potential influence of TSC on slope stability and erosion safety, which are two crucial factors in weathered exposed slopes like they are addressed in the ONEforest project.

The thesis commenced with a comprehensive literature study to establish a strong foundation in geotechnical knowledge. Subsequently, laboratory tests were conducted, including assessments of the permeability of the new material. Numerical calculations were employed to quantify the impact of TSC on slope stability. This involved distinguishing between direct influences on slope stability resulting from the strength of TSC and indirect influences stemming from its hydraulic properties. Although erosion safety was only partially addressed due to the extensive scope, it presents opportunities for future research endeavors.

The laboratory tests revealed a notably low saturated permeability of the material. Additionally, tests involving oven drying indicated the potential for cracking during periods of heat. The ongoing numerical studies suggest that the strength of the TSC material, in conjunction with its relatively thin application, has limited relevance to the overall stability of the embankment. However, the hydraulic barrier effect of TSC may contribute to minor stabilization depending on the embankment material. Notably, cracks in the TSC did not demonstrate any significant impact on slope stability.

Don't miss out on Stefanie Radinger's impressive Master's Thesis! Take a look here.