Shallow slope stabilization by arbor root Systems: A physical model study

Arbor root systems are known to enhance the stability of shallow slopes. The effectiveness of this slope stabilization is closely related to the morphology and size of the roots, as well as the characteristics of the slope itself. To investigate this, the study used 3D printing technology to create different types of arbor root–soil composite models and conducted a series of physical model experiments on slopes reinforced with roots. The aim was to assess how different root morphologies and sizes influenced slope stability across various gradients. Key findings include the following. (1) Slopes supported by arbor roots exhibited increased peak and residual anti-sliding forces compared to those without root reinforcement. Additionally, there was a decrease in both displacement and sliding range, demonstrating that the presence of roots provides a protective effect on slopes. This effect typically strengthens with an increase in root volume but decreases as the slope gradient becomes steeper. Overall, Tap-like root systems offered superior protection compared to Heart-like and Plate-like root systems. (2) The impact of slope gradient on the effectiveness of arbor roots for slope protection is generally more considerable than the effects of root system morphology andvolume. The slope gradient has the greatest impact on both the peak anti-sliding force provided by the roots and the displacement associated with slope instability, while the root volume is most sensitive to the area of the slide range. (3) On gentle slopes, Tap-like and Heart-like root systems were observed to enhance stability more effectively. However, on steeper slopes, Tap-like and Heart-like systems with samll root volumes, as well as Plate-like systems with large root volumes, were less favorable for stability. These findings not only deepen the understanding of how arbor roots slopes but also offer valuable insights for designing and implementing ecological slope protection projects, particularly in terms of tree planting arrangements.