Modelling of mechanical roots on slope stability

Abstract

Root system mechanical reinforcement through root-soil cohesion on slope stability is important. However, the root cohesion of <em>Tectona grandis</em>, <em>Maesopsis eminii</em>, and shrubs (<em>Chromolaena odorata</em>) on slope stability is rarely studied and modelled. This study aimed to model the mechanical effect of vegetation through root cohesion, namely teak (<em>Tectona grandis</em>), <em>Maesopsis eminii</em>, and shrubs (<em>Chromolaena odorata</em>). The study was conducted in a simultaneous landslide on January 1, 2020, that dominantly occurred on vegetated slopes of Sukajaya District, Bogor Regency, West Java. The Wu model's root cohesion (<em>C<sub>R</sub></em>) was modelled on slope stability using a modified Bishop model. The modelling used the data from field and laboratory-measured. The study found that the presence of a root system increases slope stability's factor of safety (FOS). The root system of young <em>Maesopsiss eminii</em> produces the largest effect of FOS compared to the root system of shrubs, teak, and old <em>Maesopsis eminii</em>. The slope stability of vegetated slopes is a function of the <em>C<sub>R</sub></em> and the effective root zone depth. The highest total <em>C<sub>R</sub></em> of vegetation was teak with 0.398 kPa, followed by shrubs, young <em>Maesopsis eminii, </em>and<em> </em>old <em>Maesopsis eminii</em> with 0.202 kPa, 0.191 kPa, and 0.087 kPa, respectively. The effective root zone of teak, young <em>Maesopsis eminii</em>, and shrub were 500, 230, 140, and 66 cm, respectively.