Scaling of the reinforcement of soil slopes by living plants in a geotechnical centrifuge

• DOI: 10.1016/j.ecoleng.2017.06.067
• Publication Date: 2017-07-15T12:45:14Z
• Authors: T. Liang; A.G. Bengough; J.A. Knappett; D. MuirWood; K.W. Loades; P.D. Hallett; D. Boldrin; A.K. Leung; G.J. Meijer
• Keywords: Centrifuge; Shear Strength; Direct shear test

Understanding root-reinforcement of vegetated slopes is hindered by the cost and practicality full scale tests to explore global behaviour at slope scale, idealised nature smaller-scale testing date that has relied on model root analogues. In this study we investigated potential use living plant roots in small experiments failure would a geotechnical centrifuge achieve soil stress states comparable those field homologous points. Three species (Willow, Gorse Festulolium grass), corresponding distinct groups with different architecture ‘woodiness’ were selected cultivated for short periods (2 months Willow grass, 3 Gorse). The morphologies, tensile strength Young’s modulus these juvenile samples their effects increasing shear then measured (via direct tests) compared published results more mature grown specimens. Our test show when all three are considered, commonly used negative power law does not fit data relationship between diameter well, resulting very low R2 values (R2 < 0.14). No significant differences observed Gorse, average was 8.70 ± 0.60 MPa (Mean SE), 9.50 0.40 MPa, 21.67 1.29 Willow, grass respectively. However, strong linear plants = 0.55, 0.69, 0.50 respectively). From modelling perspective, it shown using could potentially produce prototype systems highly representative both terms mechanical properties morphology suitable growing time months) scaling factor (N 15) selected. remains challenge simultaneously simulate distribution biomass depth plant. Therefore, compromise made resolve conflicts rooting reinforcement, suggested 1:15 represent studying centrifuge.