Multiscale Modelling of the Slope Stability of Block-in-Matrix Materials

The soil tends to be evaluated as a homogeneous material and rocks as solid or continuous media. However, there has always been a great uncertainty when evaluating materials with a high degree of heterogeneity; such materials are referred as bimrocks. In this paper the implementation of multiscale numerical modeling is shown for the study of materials with discontinuous nature. Triaxial tests using DEM were developed, where the resistance variation parameter, according to the block volumetric proportion (BVP) and the blocks shape was shown. Slopes in FEM were modeled with the inclusion of individual blocks and compared with limit equilibrium slope analysis using parameters from homogenized resistance. It was established that it is possible to define the parameters of homogenized resistance as dependent exponential functions of the surface area ratio of the blocks. It was showed a decreasing friction angle trend as the sphericity of the blocks decreased, in addition to conventional friction angle increase and decrease in cohesion with increasing volume ratio of blocks. A comparison of the factor of safety obtained by finite elements and limit equilibrium is performed. Finally, the need of a multiscale approach for heterogeneous materials analysis is established.