Multiparameter study of shear strength improvement near-surface by vegetation roots and fibers

The shear strength of soil is a significant engineering property. Recently, the utilization of nature-based elements, including roots and fibers, to enhance soil shear strength for surface applications like erosion control has received considerable attention. The experimental program outlined in this paper encompasses direct shear testing on bare soil, soil-fiber, and soil-root specimens with diverse compositions for parameters. The current study utilized four locally sourced grassroots from the Himalayan region, along with a combination of natural and synthetic fibers, to investigate the enhancement of shear strength in surface soils. A fractional factorial method of experimental design has been implemented for laboratory testing programs. Additionally, data analysis has been conducted to determine factor contributions and optimum parameter for the most favorable results. The findings demonstrate that the incorporation of plant roots and fibers significantly affects the shear strength of the soil matrix. The root area ratio serves as an equivalent for fiber content in soil-root interaction research aimed at improving shear strength at the soil surface.