A new type of constitutive theory for granular soil

hypoplastic constitutive theory which was originated in recent 30 years

is introduced in detail. Comparing with the elastoplatic theory

the hypoplastic constitutive expression has automatically implied some basic concepts and factitious assumptions

e.g. decomposition of elastic strain and plastic strain

yield function

hardening law

plastic potential

flow rule and so on. The critical state of Gudehus-Bauer hypoplastic model is analyzed. Besides

the numerical simulation of triaxial test and cyclic shear test were illustrated and the results show that the model can grasp the main mechanical properties of granular soil

e.g. anelasticity

nonlinearity

dilatancy and so on.