A Constitutive Investigation of the Effects of Structure on Loess

Abstract Loess is a naturally cemented soil that can transform from a structured solid to fluidity as its meta-stable structure when experiencing wetting. The fines content of loess (i.e., sandy, silty or clayey loess) and structure affect its flow instability. A constitutive understanding is developed with clays-sands unified hardening (CSUH) model to reveal how structure and types of loess influence the shape and location of critical state lines (CSLs) of loess, and thus flow liquefaction, and to show how the location of CSLs for intact and reconstituted loess are considered in the model. The results confirm the strong effect of structure on flow liquefaction, and the model is robust in characterizing stress-strain responses of intact and reconstituted clayey (or silty) loess.