Numerical study of the utility of bioengineering technique for slope stabilisation

ABSTRACT The bioengineering technique of slope stabilisation, which has been developed as a sustainable alternative to traditional civil engineering structures, requires more scientific research and a good understanding of the factors that influence its effectiveness since many a time it fails to provide the desired outcome. The present study discusses the importance of understanding the variable root distribution and root-soil-slope relationship before implementation. The probabilistic analysis was used to take into account the natural variability of root features, which includes root length, strength, branching and orientation along with heterogeneity of slope material. It was observed that the mean rooting depth plays a vital role in deciding the utility of the bioengineering technique. Though its effect in gentle slopes is negligible, in the case of moderate to steep slopes, it can significantly affect the overall stability. Improper planning can lead to aggravation of the situation leading the slope more vulnerable to failure. Furthermore, the stabilisation using vegetation is best suitable for moderate slope inclinations, and the maximum shear strength increase is obtained for slope inclining around 50°. A gradual reduction in overall stability was observed with the reduction of mean rooting depth and an increase in the spacing of the plants.