Abstract: The uniaxial loading tests on cement-soil are conducted by true triaxial apparatus in order to study the characteristics of cement-soil anisotropic deformation and the effect of stress on the lateral expansions. It is shown that the specimen is compressed along with the loading direction and the lateral expansions are related to the shear stress increment under uniaxial loading condition. Under the loading condition in the direction of maximum principal stress, the value of the shear stress increment is greater than zero, and the lateral expansions in two directions of intermediate principal stress and minor principal stress are shown; under the loading condition in the direction of intermediate principal stress, the lateral expansions in the directions of minor principal stress are shown when the value of the shear stress increment is greater than zero only; under the loading condition in the direction of minor principal stress, lateral expansions are not produced due to the value of the shear stress increment is less than zero; both the lateral expansions and compressive strain decrease with the increasing of consolidation stress for the same stress increment. It can be seen that the lateral expansions have a negative correlation with the constraining force at a certain direction according to the energy analysis.

Key words: cement-soil, uniaxial loading, anisotropy, true triaxial apparatus, deformation