natural structured soil with macro-pores is simulated. Based on the compressive tests of different stress paths
the initially yielding curve is confirmed according to the yielding stresses of a certain stress paths
as well as the direction of the increment of plastic strain after yielding. Furthermore the hardening law is presented in accordance with the result of the triaxial drained tests. An elastoplastic softening model which can simulate the effect of the soil structure is proposed. In addition