# Eco-engineering effects of Setaria viridis and Panicum bisulcatum Thunb roots on slope stability under controlled moisture conditions

## TL;DR

This study examines how the roots of two grass species help stabilize slopes in a coal mine area under different moisture conditions.

## Contribution

The study provides new insights into the eco-engineering effects of herbaceous plant roots on slope stability under controlled moisture.

## Key findings

- Herbaceous plant roots increased soil cohesion and shear strength while restricting lateral deformation.
- Soil cohesion and shear strength decreased with higher moisture, but internal friction angle increased slightly.
- Slope stability improved with herbaceous roots, especially when moisture content was between 9 and 13%.

## Abstract

The slope protection effect of herbaceous plants is closely related to plant species, root content in the soil, and soil moisture content. This study focuses on the roots of common herbaceous plants, such as Panicum bisulcatum Thunb and Setaria viridis, on the slopes of the Fuxin Haizhou open-pit coal mine. Field measurements were taken to determine the root content at different soil layer depths, the reinforcement effect of plant roots on soil stability was further examined through theoretical analysis of their mechanical contribution to anti-sliding performance. Laboratory tests were performed to measure the changes in shear strength of root-soil composites under different moisture content conditions. Numerical simulations were used to analyze the slope protection effect of herbaceous plant root systems under varying moisture content conditions. The results showed that the root systems of herbaceous plants increased the soil’s cohesion, restricted lateral deformation, and improved the soil’s shear strength. The cohesion and shear strength of the root-soil composite decreased with increasing moisture content, while the internal friction angle increased slightly, though not significantly. The stability factor of root-soil slopes and bare soil slopes first increased and then decreased when the slope moisture content ranged from 9 to 13%, indicating that herbaceous plants have considerable potential for enhancing shallow slope stability and can be effectively applied in ecological restoration and slope protection in mining areas.