Abstract:Based on the creep test results, a nonlinear viscoelastic-plastic intrinsic model describing the whole creep process of silty mudstone was established, and the proposed creep intrinsic model was verified for its rationality and feasibility by taking the creep test results at 7 MPa as an example. The results show that: the steady-state creep rate of the specimen conforms to the exponential function relationship with the partial stress; the creep rate in the accelerated creep stage is significantly larger than that in the decelerated creep and steady-state creep at low stress level, and the creep damage occurs in a very short time; a nonlinear viscoelastic-plastic instrinsic model is proposed to describe the whole creep process of the silty mudstone, which can describe the creep-deformation process of the silty mudstone. This model can describe the creep-deformation law of the whole process of creep-damage of silty mudstone, and reflects the creep characteristics of silty mudstone under different levels of partial stress.