Creep characteristics of lacustrine sedimentary peaty soil

By using the SLB-1 stress-strain controlled triaxial shear permeability tester, the triaxial consolidation undrained creep tests on lacustrine sedimentary peaty soil are carried out to study its creep process under different confining pressures and partial stresses, and the creep curve under graded loading is obtained by the Chen's method. The results of the triaxial creep tests show that the strain-time relationship of the undisturbed samples exhibits obvious attenuation creep characteristics when the confining pressure is 50 and 100 kPa, while it exhibits obvious non attenuation creep characteristics when the confining pressure is 200 kPa and the deviating stress is 129 kPa. The remolded sample can bear less loads than the original one. The Chen's method is more suitable for processing the creep data than the Boltzmann's linear superposition method. Taking the creep tests under the confining pressure of 100 kPa as an example, by combining with the fitting analysis of the least square method, the generalized Kelvin model and the improved fractional Maxwell creep model are established. The obtained creep model has the characteristics of few parameters and strong applicability.