A New Method of Stress Analysis in Hillslopes Considering Vegetation Effects Using Poroelasticity

Abstract

This study presents a new methodology of stress analysis for a steep and vegetated hillslope. A hillslope is modelled as a poroelastic medium under influences of vegetation surcharge on the surface and root-reinforcement inside. Tree-growth allometric equations are used for quantitative modelling of transient tree surcharge and root-reinforcement. Poroelasticity is used for evaluating stress equilibrium inside the slope of any geometry under given conditions of groundwater flow and vegetation forcing. Then, Mohr-Coulomb failure theory is applied to find the unstable zones. The three parts above are numerically solved by using the finite element method. We performed case study of saturated hillslopes in different two-dimensional geometries. The results testified this method can assess the stability of vegetated hillslope in any two-dimensional geometry.