Dec 24 2014
Mechanical property of granular materials in landslide is of great significance. A recent research demonstrates that the numerical triaxial apparatus based on discrete element method is able to simulate and reproduce the triaxial tests in laboratory, which is published in Science China: Physics Mechanics & Astronomy 2014 vol.57(12) by professor Jiachun Li from Institute of Mechanics, Chinese Academy of Sciences. The title is "Simulation of triaxial response of granular materials by modified DEM".
A landslide is a catastrophic hazard often taking place worldwide. Due to the complicated geological environment and different sort of particles, the mechanical properties vary a lot in different sites, which bring about the difficulties in quantifying the mechanical parameters of granular materials either by experiment or field test. This study proposed a numerical triaxial apparatus based on rolling type contact discrete element method, which is able to simulate and reproduce both triaxial compression and triaxial extension tests in laboratory.
The non-spherical shape effect of real particle is simplified as a rolling resistance contact model. It is demonstrated that taking account of both computation efficiency and physical mechanism, the modified discrete element model could reflect the main mechanism of both friction and dilatancy if this rolling model is carefully calibrated by reliable experiments. And then, the modified discrete element model is able to reproduce the stress-strain behavior in other conditions, such as different confining stresses, different stress path. As a result, the method can provide detail information of the mechanical properties of the granular material including friction angle, dilatancy angle and etc.
In the future, this model could be used to consider other factors such as particle size distribution, pore water effect and etc. Hopefully, this method can help understand failure mechanism of landslides and provide reliable mechanical parameters for engineering calculation in landslide study.