ABSTRACT
Bioengineering aspects of native vegetation are being used to improve the soil stiffness, stabilise slopes, and control erosion. Tree roots provide three major stabilising functions: reinforcement of the soil by the roots, dissipation of excess pore pressure through evapo-transpiration, and establishing a matric suction that will increase the shear strength. The main variable for estimating the transpiration rate is the root water uptake rate, which is a complex factor because of the considerable variation of the root type and geometry from one species to another. The chapter discusses the key factors, such as soil suction, root distribution, and potential transpiration rate. The geometric slope of the root zone is assumed, based on the field observation of typical root cross sections. Trench excavation is one of the appropriate methods to map the root density distribution. A two-dimensional finite element analysis was used to predict the distribution of the soil moisture content and matric suction near a selected Black Box gum tree.
