A new superlinear viscoplastic shear model for accelerated rheological deformation

Abstract

Abstract The rheological properties of rocks are closely related to long-term stability and safety in geotechnical engineering. After analysing the shear rheological test curve of granite samples taken from the mining slope in the Bangpu Mining Area of Tibet, a superlinear viscoplastic model (named the SLVP model) is developed based on the constitutive Nishihara model. It is found that the SLVP model can satisfactorily describe the three shear rheological stages of the granite and fit the rock properties in the accelerated rheological stage. For the 1–1 profile of the slope excavated in the Bangpu Mining Area of Tibet, stabilities of the excavated slope are calculated and analysed. The results show that, at the middle-upper step and the toe of the excavated slope, the displacement and the plastic zone are considerably different for cases with and without rheological deformation. The maximum displacement considering rheological deformation is 14.1 times greater than that without rheological deformation. The slope is not stable in general and serious failure at the excavated slope is possible. Early warning measures should be taken and the middle-upper step and the toe areas of the excavated slope should be strengthened, and the early warning and monitoring measures should be taken in relevant areas.