Study on pull-out strength of tap-roots using cohesive elements

Researches show that the interaction between soil and root is a significant factor when stimulating and calculating the pull-out strength of root.Generally,the interaction between soil and root is assumed to be Columb-friction model.However,the simulation results obtained by solo Columb-friction model are not optimistic for pull-out strength of root and the mechanical behavior after slide begins.In this study,the model based on cohesive material of Abaqus 6.10 is applied to stimulate the relationship between soil and root.Adding a layer of cohesive material between soil and root is used to simulate colloidal soil around the root.After conducting several tap-root pull-out tests,it is confirmed that the cohesive material can diminish the drawbacks of Columb-friction model.Diameter-length matrix and volume-fixed matrix of tap-root are studied,which shows that the pullout strength of tap-root is related to the total contact area between soil and the tap-root.