Abstract:A circular increment step load and unload method with many advantages is employed;and a set of creep experiments are performed to study the viscoelasto-plastic characteristics of soft and intricate ore-rock in Jinchuan Mine III. The experimental data were analyzed according to the retrievable instantaneous elastic strain and lagged viscoplastic strain,and the post-retrievable instantaneous plastic strain and viscoplastic strain,and the essential rules of viscoelasto-plastic characteristic of the soft and intricate ore-rock are obtained. Based on scientific analysis and comparative study,Burgers creep model was combined with Mohr-Coulomb criterion;and a new viscoelasto-plastic model was formed to study the characteristics of soft rock creep under intricate conditions. Some programs about Burgers model were developed to deal with the experimental data. The creep characteristic curves were obtained;and the model parameters and the values were achieved through weighted means. The test results show that the creep testing curves of the ore-rock of Jinchuan Mine III are coincident well with the theoretic curves;and the modified Burgers creep model can be applied to characterize the creep of Jinchuan ore-rock.