Abstract: Based on the theory of breakage mechanics，the structural loess is conceptualized as binary－medium model consisting of bonding brick and frictional band. Shear band is structural loess’ breakage, localization band sprout and development is dynamic process that bonding brick is translating into frictional band. Applying the double parameter breakage ratio binary-medium model of structural loess, the process of structural loess localization band sprouting and expanding is simulated with the numerical simulations method, the localization shear band shape, speciality and law under different disfigurement project are studied; it is found that the strain localization on a shear band of structural soil at originally is some sets discontinuous little local breakage area step by step developed, connected and formed the shape of whole destruction with the external load increased. Combining binary-medium model with general finite elements, visual reappeared the course of the local shear band germination and progress.

Key words: structural loess, binary-medium model, double parameter breakage ratio, localization shear band, finite element simulation