Experimental research on creep properties of two typical soft clays in coastal region of Tianjin

The non-linear creep characteristics of two typical clays, which are muddy clay and silt clay in the coastal region of Tianjin, are studied by means of triaxial creep tests. The tests are carried out by the step loading method, and the creep curves of the soft clays under different stress states are got from the raw data by Mr. Chen’s method. Considering with the change law of the stress-strain isochronal curves, the results of the creep tests are fitted by the Merchant model based on the creep curves. The model parameters are confirmed, and then a non-linear rheological model suitable for these soft clays in the coastal region of Tianjin is established. Based on the comparative analysis of the change law of model parameters, the empirical formulas for the relation of these main parameters with the stress are confirmed finally. It is shown that the modulus of Hooke spring’s elasticity with stress difference increases in a negative exponent way; and the modulus of Kelvin component’s elasticity with stress difference increases in a linear way at the same time.