关键词: matrix theory, principal stress axes rotation, decomposition ofstress increment, stress strain relation, soils

Abstract: In the light of matrix theory, the charader of siress increment which causes the rotation of principal stress axes is analysed and the general stress increment isdecomposed into two parts: coaxial part and rolational part. Based on these, thecomplex three dimensional(3-D)problem involving the rotation of principal stress axesis simplified to the combination of the 3-D coaxial model and the theory about pureroation of principal stress axes that is only around one principal stress axes. Thedifficulty of analysis is reduced significantly. The concrete calculating method ofgeneral 3-D problem is provided and other applications are also presented.

Key words: matrix theory, principal stress axes rotation, decomposition ofstress increment, stress strain relation, soils