Root Characteristics of Willows on Waterway Banks

1. Home
2. Publications
3. Online Library
4. Root Characteristics of Willows on Waterway Banks

Shipping traffic on inland waterways can cause pressure fluctuations in the embankment, leading to shallow landslides. As the soil in the relevant parts of the embankment is almost completely saturated with porewater suction is not relevant. Therefore, roots stabilise banks primarily for mechanical reasons. However, stability analyses often do not consider mechanical root reinforcement. The retaining forces of roots of bushes and trees in a bank slope are rarely known due to a lack of information about the distribution and the characteristics of roots. Thus, the BAW investigated mechanical root reinforcement in field tests. During one summer period willow brush mattresses grew on a bank in a test basin with varying water levels. Then, pull out tests were carried out on 400 individual roots. After that, root excavations provided characteristic information including rooting depth and growth direction. Many commonly used models consider roots as a linear elastic fibre. The results of the pull-out-tests show rather a nonlinear force-displacement relationship of roots when pulled vertically. This agrees with soil-mechanical considerations. However, these vertical tests are not directly comparable to the more-dimensional effects during sliding failure.

3rd International Workshop on Soil-Vegetation-Atmosphere Interaction (RootS2025)

2b. Field scale characterisation of the bio-hydro-chemo-mechanical behaviour of rooted soils