Experimental study and statistical theory of creep behavior of warm frozen silt

Abstract

To investigate the soil parameters and stochastic mechanical characteristics of warm frozen silt, a series of triaxial compression tests were conducted on frozen silt at the temperature of -1.5°C under confining pressures of 0.5, 1.0, and 2.0 MPa. The results indicate that the creep properties of warm frozen silt are affected considerably by stress levels. The creep show present primary and secondary creep stages under low stress level and indicate that the specimen is destroyed quickly under high stress levels. Based on phenomenological theory, a unified creep constitutive model of warm frozen silt was proposed. The results predicted by the proposed model agree well with corresponding experimental data. Investigation of the random distribution has revealed that the parameters of the proposed creep model could be better described by a normal distribution. Based on the dynamic theory of frozen soil strength, the long-term strength of warm frozen silt was obtained, and was found to exhibit nonlinear behavior with increasing confining pressure. The Weibull function can represent the random distribution well, and the reliabilities of long-term strength were given under different confining pressures.