Improving finite element models of roots-soil mechanical interactions

Finite element models (fem) of roots-soil mechanical interactions have been tested taking into consideration different levels of simplifications, i.e. considering the discretization of roots with solid elements and root-soil contact behaviour, and structural beam elements embedded in the soil matrix respectively. These two modelling options have been tested and compared simulating direct shear tests of reinforced soils. The “frictional behaviour” method used with solid elements predicted shear strength of the root-soil system 4.6-6.9% higher than that predicted with “embedded beam elements”. This difference can be considered as negligible. Embedded beam elements were thus chosen to discretized digitized Maritime pine root systems and to test the effect of root failure on the mechanical response of trees to overturning.