Abstract: Based on the anisotropy induced by the critical stress line, the idea of transformation of stress space is presented. With reconstituted soils taken as an example, the formulas of transformation of stress space and stress increment are provided, and the influence of stress Lode’s angle is considered also. The modified Cam-Clay model is expressed again and improved in the transformed stress space; the stress-stain formulas of the improved model are presented also. Through the comparison of the computed results of four kinds of stress path by the improved model and the modified Cam-Clay model, a lot of merits of the improved model are discovered: the influence of anisotropy can be reflected better; the stress-strain characteristics of triaxial extension can be described more reasonably; the soften phenomenon of some stress path, such as , can be described.

Key words: constitutive relation, transformation of stress space, modified Cam-Clay model, anisotropy, soil