Stability fem analysis of rock masses modeling pattern of joints

Abstract

In the south of the city of Morelia, Mexico, there is a geological normal fault denominated "La Paloma". It has a height of 180 m and has limited the growth of the city. To improve the connectivity of the city, an urban road is building and it includes the digging of a tunnel that goes through this fault. Due to the presence of an ancient landslide in the exit tunnel, it is imperative to verify the stability of a slope in this zone. The geological structures founded “in situ” make complex the stability analyses, but the used of more realistic representation helps to understand the mechanism of failure. The data collected in geotechnical explorations helped to construct several models for slope stability analysis. Rocks and soils were identified in the interest area. In this way, an elastoplastic Finite Element Analysis (FEA) was carried out to verify the slope stability, considering a strength reduction by a safety factor. Stability was revised in static and seismic conditions. The rock structure is represented by using the Modified Hoek and Brown constitutive model and patterns of the joints with a Mohr-Coulomb constitutive model. The fragments of rock were emulated with joint patterns according to the geologic structure. The slope stability results show a stable slope considering static and pseudo-static FEA analysis. The failure mechanism could be appreciated with the slope stability analysis realized.