A non-linear rheological model for typical soft clay in Tianjin coastal areas

In this paper, the non-linear creep property of typical soft clay, which is mucky clay in Tianjin coastal areas, is investigated though indoor triaxial creep tests. The tests are carried out by step loading method, and the creep curves of soft clay in different stress states are acquired from the test data. Combined with the variation laws of the stress-strain isochronal curves, which are created according to the creep curves, the results of creep tests are fitted by Merchant model. The model parameters are confirmed and a non-linear rheological model for the soft clay in Tianjin is established. Based on comparative analysis about variation laws of parameters in the model, it is concluded that the relationship between the main parameters and stress states could be expressed with empirical formulas. It is shown that the elastic modulus of Hooke spring increases in a negative exponent way, and the elastic modulus of Kelvin component decreases in a linear way, with the stress increasing.