A New One-Dimensional Thermal Elastic-Viscoplastic Model for the Thermal Creep of Saturated Clayey Soils

Temperature significantly affects the mechanical properties of geomaterials, particularly the creep behavior of soft clayey soils. Thus, an appropriate constitutive model to describe the time-dependent stress-strain behavior of clayey soils at various temperatures is necessary. This study performed temperature-controlled oedometer tests on two clayey soils: Hong Kong marine deposit (HKMD) and kaolinite clay (kaolin). The thermally-induced strain and creep strain rates under different temperature paths were investigated and discussed. A novel one-dimensional (1D) thermal elastic viscoplastic (TEVP) model was developed based on an existing 1D elasto viscoplastic (EVP) model. In the proposed model, the viscoplastic strain rate of soils can be described using three state variables: effective stress, strain, and temperature. The proposed model can be conveniently implemented in creep analysis with the equivalent time concept. The prediction results of the TEVP model were consistent with the experimental data for HKMD and kaolin.