Effects of root diameter of Pinus tabuliformis on friction characteristics for root-soil interface.

Tribological properties between plant roots and soil is an important factor for slope stability. In order to evaluate the effects of different root diameters on soil reinforcement by plant roots, the experiment of direct pulling test of single root for Pinus tabuliformis was conducted by implementing pull out load, analyzed the effects of different root diameters on friction performance between tree roots and soil system. The results showed that significant linear correlation between root diameter and root-soil friction was founded. We analyzed the friction between root and soil by the establishment of single simplified model; the results were agreed with the experimental conclusion. Meanwhile, the friction between root and soil was positive linear correlated with root burial depth by the model and experiment. In addition, we analyzed the factors affecting the initial pullout load of root, the positive correlation relationship was also founded between root diameter and root burial depth. This article examines mechanism of the effects between root diameter and root-soil composite stability,which can offer reference value for establishing the model of slope stability.