Deformation characteristics test and mechanism of arbor taproot soil complex in rainforests

This study performed large-scale single shear tests on Haikou red clay and arbor taproot to explore the anti-sliding effect and deformation characteristics of rainforest arbor roots under a shallow landslide. The law of root deformation and the root-soil interaction mechanism were revealed. The results indicated the significant reinforcing effect of arbor roots on the shear strength and ductility of soil, which increased with the decrease of normal stress. The soil reinforcement mechanism of arbor roots was attributed to their friction and retaining effects through an analysis of the movement of soil particles and the deformation pattern of roots during the shear process. The root morphology of arbors under shear failure could be described using an exponential function. Consequently, an advanced Wu model which better reflected the stress state and deformation of roots was proposed based on the concept of curve segment superposition. The results are believed to a reliable experimental and theoretical basis for the in-depth study of soil consolidation and sliding resistance effects of arbor roots, and further lay a foundation for the slope protection by arbor roots.