Influence of tree type to suction development and the stability of slope

Abstract

The overall aim of this research is to provide an assessment of suction development in a typical soil slope embankment. In particular, it demonstrated how different type of trees via their water-uptake demands enhances the stability of soil slope cutting, within a London clay formation. A total of 7 analyses were performed. The first analysis was performed to determine the saturated undrained Factor of Safety of the un-vegetated case study slope. A mature Oak tree was then superimposed on both the slope toe and its crest, and it was discovered that the presence of the tree at such locations increased the slope Factor of Safety by 2.15% and 2.00% respectively. A mature Horse Chestnut tree was then considered on the slope, and the tree enhanced the slope Factor of Safety by 2.01% and 1.94% on the toe and the crest respectively. The next analysis considered the effect of mature Poplar tree with a root zone deeper than both the Oak and the Chestnut; the Poplar tree increased the slope Factor of Safety by 12.65% and 2.77% at the toe and the crest respectively, indicating tree species with deeper root zone produced greater impacts than those with shallow root zone. Although 2% increase in Factor of Safety is not overlay significant but 12.7% is, therefore the findings indicate the magnitude at which trees with deep root zone enhanced the slope factor of safety albeit more on the slope toe.