Abstract: The paper performs meso analysis of disturbed state concept theory(DSC) which based on hardening model. DSC permits obtaining softening response by using hardening model. In meso analysis, the comparison between softening clay and hardening clay, through antitheses of experimental results under shear loading in macro vision along with synchronous outcomes of computerized tomography real-time test in micro vision, and the relationship between clay hardening or softening and their corresponding CT value changing, explains the logical rationality of disturbed state concept theory problem analyzing and solving. The rationality lies in the correspondence of CT value changing to whether or not superpose the disturbance factor D according to hardening or softening. A new disturbance factor evolution function is put forward. In the evolution function the mean of CT value variance of each scanning stratum is the independent variable. Examples show effectiveness of the evolution function.

Key words: constitutive model, disturbed state concept theory, CT, softening, disturbance factor