Study on the effect of root system of grass irrigation plants on the reinforcement of iron tailing sands.

Abstract Aiming at the problems of shallow destabilization and soil erosion that are prone to occur when rainfall falls on slopes in the iron tailings mine area, research was carried out on the mechanical effects of the root systems of grass-irrigated plants (alfalfa, purple clover, and purple fringe acacia) on the reinforcement of iron tailings mine sands.It used single root tensile test and indoor straight shear test to analyze the degree of impact of each factor on the shear resistance of 2 vegetation genres on iron tailings sands.The findings of the test indicate that: (1)There was a power feature function relationship exists as between root tensile force and root diameter of the 2 plant species, and the individual root tensile strength was correlated in negative way with the root diameter.(2)The shear strength and cohesion of the root-tailings sand complex gradually increased with increasing root content.it has a relatively small variation in the angle of internal friction and an optimal root content exists.The root system improves the shear strength of tailings sands mainly in terms of increased cohesion.(3)The root-tailings sand composite has the same trend in shear strength and cohesion,it increases and then decrease with the moisture content., but the change in the angle of internal friction is not significant.In conclusion, the study of the tensile and shear resistance characteristics of the root system of irrigated grasses can provide a reference for the reinforcement of iron tailings slopes.