Abstract: Shear rheology experiments were carried out for the shale in Longtan Hydropower Project by using a servo-controlled shear rheology testing machine. The variation law of shear displacement of shale with the time is analyzed. The variation tendency of shear rheological rates under different stress states is discussed. At the same time, the variation of shear strength of rock with the time is discussed. When the proposed nonlinear rheological component (NRC model) by the author is parallel connected with Kormanura model; so that a new nonlinear rheological model can be gained, which can describe the accelerating rheological properties. Using the shear rheological curves of shale, the proposed nonlinear viscoelastoplastic shear rheological model of rock is identified, which gets the viscoelastoplastic rheological parameters of the shale. The comparison between the rhelogical model and experimental result shows that the proposed rheological model behaves reasonably well.

Key words: rock mechanics, shale, shear rheology, nonlinear rheological component (NRC model), nonlinear shear rheological model