| A better understanding of root-soil mechanical interaction is necessary for investigating the capability of structural roots to provide an efficient anchorage of trees or to participate to soil fixation against landslides and soil erosion.Based on theories and methods in elasto-plasticity mechanics, soil mechanics, soil and water conservation, methematics, the study has made finite element analysis modeling, field and lab experiments, aiming in analysing the contribution of different root elements and soil types to tree anchorage. Including to steps: (1) A 2D finite element model of root anchorage has been built and applied to twelve different herringbone-like root patterns. These root patterns have been defined varying the angle between lateral root and tap root, and removing different root parts. Bending tests has been performed in both clay and sandy soil. (2) In order to analyze the roots anchorage, the study has made both field experiments in SiChuan province ChongZhou synthetical foresty and lab experiments of shear tests. Modeling these tests using FEM software. Compare the experiment results with the modeling results.The major achievements are shown as below:(1) Roots play a significant role in anchorage, also, roots pattern and soil type are very important in root anchorage.(2) Shallow lateral roots play a critical role in root anchorage, contributing nearly 35%～40% to the root-soil strength in the whole simulations.(3) The hinge of root plate rotation axis, which can be significantly modified by root architecture and soil type, was shown during the destroy process.(4) The stress can influence the roots growth.. One side of the root which the stress is more larger grows faster than the other side, like word "I" or word "T" .(5) Take Japan ceder for example, a power regression between tensile strength and diameter wassignificant for roots. |
