The Investigation and 3D Numerical Simulation of Herb Roots in Reinforcing Soil and Stabilizing Slope

This paper investigated and simulated the mechanical effect of root reinforcing soil and stabilizing slope. The unconfined compression test was used to investigate the reinforcement soil behavior of herb roots. This paper used the 3D finite element to quantify the mechanical effect of the herb root for slope's stability in terms of the safety factor. The soil was simulated by an elastic-plastic model, and the root was simulated by a linear elastic model. Results show that using the Root Content (RC) to estimate the additional cohesion c(r) of Setaria sphacelata and Orchardgrass was a simple and reliable method. Lateral fine roots can play a more significant role in reinforcing soils and slopes. Compared to various slope angles, the steep slope was less stable. The slope existed a slope angle threshold alpha(thr). When the slope angle alpha was smaller than alpha(thr), the herb root system can improve the stability of slope. The existed an optimal angle alpha(opt) for the root system. When alpha = alpha(opt) and alpha < alpha(thr), the herb roots can exert its maximum stabilization capacity. Moreover, we can select herb species with lateral fine roots and more roots in deeper soil layer. Results can better estimate the c(r) for the herb of lateral fine roots and select the herb and the slope's geometry in the engineering.