Abstract: The drained triaxial compression creep tests were conducted on the dispersive soil of Ningmute Hydraulic Project by using a stress triaxial creep meter to investigate the creep deformation law under different initial conditions and to develop a creep model and its parameters. Experimental results show that the dispersive soil is a typical creep material and its creep deformation characteristics are quite obvious. It experiences three creep stages which include instantaneous creep deformation, attenuation creep deformation and constant speed creep deformation. The data also indicate that the creep rate and creep magnitude of dispersive are significantly governed by the water content of soil, confining pressure and deviatoric stress level, and stress-strain curves exhibit obvious nonlinear. Mesri model and Singh-Mitchell model are employed to describe creep properties of dispersive soil. By comparing with experimental results, it is found that the creep properties of dispersive soil can be described more accurately and easily by Mesri model than Singh-Mitchell model. Moreover, Mesri model has the characteristic of less parameters and strong applicability.

Key words: dispersive soil, triaxial creep tests, creep properties, creep functions