A non-linear damage rheological constitutive model and its application to a giant slow-moving landslide

Generation of a landslide is a typical aging process of rock and soil deformation. Therefore, it is a basic method and also a difficult problem to build constitutive models that reflect the deformation process of landslides and furthermore to use the models for prediction. However, many classical rheological models can only be used to describe the first and second creeping stages and are unable to describe the third accelerated stage. Base on the non-linear and aging characteristics of the slip zone soil during the shear creeping development and the damage theory, this paper attempts to construct a non-linear damage rheological constitutive model by combining a non-linear damage visco-plastic element with the CVISC rheological model built-in FLAC3D, namely the modified CVISC model. For implementing this modified CIVSC model in 3D numerical simulations, its 3D difference equations are developed. The numerical codes for the difference equations are programmed following the roles of the FLAC3D’s user interface program. This model is applied to simulation of the Xieliupo landslide, which is a long-term slow-moving landslide with intermittently intense movement. The results show that the modified CVISC model can disclose accelerated creeping of the landslide, which is roughly consistent with the movement history of the landslide. This gives an indication of the validity of the modified CVISC model based on non-linear damage theory.