When using a general finite element analysis, it is impractical to consider only the elastoplastic constitutive model to simulate the landslide problem. Even when the reservoir and groundwater levels were stable, its deformation continued to increase. For example, the deformation of the Bazimen and Shuping landslides in the China Three Gorges reservoir area showed obvious rheological properties, such as the stepwise Global Positioning System displacement of the surface with a decrease of the reservoir water level. The understanding of the influence of water-level changes on the deformation of reservoir landslides has developed and changed over time. The stability coefficient of the landslide calculated by the strength reduction method, considering the rheological properties, is smaller than the coefficient calculated without considering rheological properties.
![using flac3d to model triaxial test clay using flac3d to model triaxial test clay](http://www.earth-science.net/fileDQKX/journal/article/dqkxzx/2021/11/dqkxzx-46-11-4033-4.jpg)
It can be found that the landslide displacement calculation is significantly smaller when the rheological properties are not considered. A numerical simulation of rheological properties is conducted on a landslide and compared with conventional viscoelastic constitutive results.
![using flac3d to model triaxial test clay using flac3d to model triaxial test clay](https://www.frontiersin.org/files/Articles/497324/feart-07-00345-HTML/image_m/feart-07-00345-g002.jpg)
A strength reduction method that considers rheological properties is proposed.
#Using flac3d to model triaxial test clay software#
This paper uses FLAC3D, a finite-element software platform, for secondary development and to verify the accuracy of the model and program. In this paper, the three-dimensional state equation of the extended Burgers model is derived based on the creep test results of slip-surface soil and the Mohr–Coulomb elastoplastic model. Soil creep properties are not considered, often rendering inaccurate results.
![using flac3d to model triaxial test clay using flac3d to model triaxial test clay](https://geomatlab.com/itasca/flac3d6.0help/source/_images/modelcamclay-1.png)
Landslide deformations have predictable rheological properties, but, when using finite element analysis, only the elastoplastic constitutive equation of soil is considered.