Abstract:Studies on silty clay subjected to triaxial loading by using real-time computed tomography(CT) scanning experiment are carried out. Based on the CT-number and CT images,it is shown that the stress-strain curve of soil can be divided into four stages¾micro-defects closing stage,initial damage stage,rapid damage development stage,and softening failure stage. Silty clay is a typically nonuniform and original damaged material. During loading process,local deformation is formed;and the failure of soil is caused by local deformation and formation of shear band. Macro-fissure will be completely generated at the peak and post-peak of strength.