Micromechanics-Based Strength Criterion for Root-Reinforced Soil

The representative volume element (RVE) of root-reinforced soil is idealized as a composite comprising a bonded element, formed by a cemented-soil matrix with root inclusions, and inclusions of frictional elements. Based on micromechanics, and with the aid of the Mori–Tanaka method, the LCC method, limit analysis theory, and macro–micro energy-equivalence principles (including both strain energy and dissipated energy), a micromechanical strength criterion for root-reinforced soil is established, revealing the failure mechanisms at the microscale. The previously used stepwise procedure for determining the stationary functional is improved, and the microscale prestress is obtained using the Mori–Tanaka method together with macro–micro strain-energy equivalence. The proposed micromechanical strength criterion reproduces well the strength variation of root-reinforced soil under freeze–thaw cycling.