A series of undrained tests is carried out on Hangzhou soft clay with hollow cylinder apparatus. The stress paths which include shearing test under different-fixed principal stress directions for the intact soft clay and principal stress rotation for intact and remolded soft clay are designed to study the non-coaxial development behavior of soft clay as well as the influence of intermediate principal stress parameter b
initial deviatoric stress and induced anisotropy on non-coaxiality. The results show that the non-coaxiality of soft clay is similar to that of sand
but they are far from identical. The non-coaxial angle is quite small in fixed shear tests; and it is dependent on the loading directions; however
affected by the development of deviatoric stain
the non-coaxial angle is not 0° when the specimen is close to failure. Regardless of intact soft clay or remolded soft clay
the non-coaxial angle fluctuates with the increase of principal stress orientation α
of which the cycle period is 90°. The non-coaxial angle basically decreases with the increase of coefficient of intermediate principal stress b
but this effect is not quite remarkable. The deviatoric stress has certain effect on the angle of non-coaxial as well as its development trend. As to the test of remodeled soft clay
it shows that the non-coaxiality is not only entirely determined by the inherent anisotropy