An assessment of root reinforcement on soil slope using centrifuge and numerical modelling

Abstract

The extreme rainfall as an effect of climate change has been considered as the main problem due to landslide hazard. The rainfall can trigger slope failure through the kinetic energy of raindrop and decreasing of soil resistance due to the increasing of pore water pressure. Vegetation is considerably as low cost and environmentally friendly slope reinforcement. The root specifically provides high contribution in strengthen the soil through the root-soil interaction. However, there is a gap between slope reinforcement by root modelling and field assessment result. The gap is an impact of indirect linked between laboratory modelling and existing vegetated slope behaviour. This study used actual live-plants root and rainfall simulation to demonstrate the effect of root on slope stability under the high rainfall intensity using centrifuge test. The pore water pressure and deformation were monitored during the centrifuge test. The results were verified by numerical analysis. The rainfall simulation was analysed by using transient modelling and parented with slope stability analysis. Meanwhile the deformation was simulated by using Geo-PIV. The result showed that root significantly increasing the slope endurance against slope instability provoked by rainfall. The vegetation provided additional soil hydro-mechanical properties and root system that help soil increases slope stability. Keywords: climate change, landslide, heavy rainfall, root reinforcement, centrifuge modelling.