Micromechanics-based analytical model for soils: review and development

Different approaches of mechanical modeling accounting for the microstructure of soils are used to develop stress-strain models for granular materials. Three typical approaches are classified: macro model with fabric tensor of microstructure, distinct element or particle flow method, and micro-plane or micro-contact analytical method. The review for the development of above approaches is first presented. Their advantages and deficiencies are discussed. It can be concluded that at the current stage, the micromechanics-based analytical modeling method can well consider the microstructure of soils and be applied in engineering practice. Therefore, this approach is presented together with the researches done during last several years by author and his related research groups for modeling the behaviors of sand and clay. Some new developments of the modeling of strain-rate dependency of clay and mechanical behaviors of coarse-fine grain mixture are finally presented.