Abstract:

Triaxial creep tests on Q₂ loess of different moisture contents were carried out to explore the creep properties of water-containing Q₂ loess. Test results show that the rheological property of Q₂ loess strengthens with the increase of moisture content. Furthermore, since the soft-matter element built by fractional calculus could simulate the material between ideal solid and ideal fluid, a four-element nonlinear creep model which contains the soft-matter element was applied to fit data, and the model parameters under different moisture contents were analyzed. The results suggest that instantaneous deformation modulus E_H and viscoelastic coefficient ξ₁ have a negative relationship with moisture content with an exponential decline. A water damage evolution equation of each creep parameter was obtained by introducing the water damage variable D_(ω), which was further used to establish a nonlinear creep model in consideration of water damage effect. The nonlinear creep model was verified by test data. It was proved that the nonlinear creep model considering water damage could effectively characterize the overall rheological property of Q₂ loess,and has a good application prospect.

Key words: Q₂ loess, creep test, moisture content, nonlinear, damage, creep model