Failure in geomaterials : continuous and discrete analyses

International audienceVarious modes of failure in geomaterials have been observed in practice. Different criteria have been proposed to analyse these failures. In particular, Hill's Condition of Stability and diffuse modes of failure are considered in this paper in a dual framework: continuum mechanics and discrete mechanics. With the assumption of continuous media, experiments have shown that q constant loading paths (q characterizes the second stress invariant. For axisymmetric conditions, q is equal to: q = sigma(1) - sigma(3), where sigma(1) is the axial stress and sigma(3) the lateral stress) can exhibit non-localized failure modes and are analyzed by the second order work criterion. With the assumption of discrete media, grain avalanches are considered, and spatial and temporal correlations between bursts of kinetic energy and peaks of negative values of second order work are demonstrated from discrete computations. It is concluded that the second order work criterion (under its dual form: continuous and discrete) can be a proper tool to analyse diffuse modes of failure in geomaterials

Hydro-mechanical modelling of landslides with a material instability criterion

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A Comparison Study between Traditional and Finite Element Methods for Slope Stability Evaluations

Landslides are amongst the major disasters that have occurred in Karabük, Turkey. Due to the rapid increase in population movement to new habitats in urban areas, the need for engineering structures will increase. This condition has led to the construction of arts, cultural facilities and housing in insecure regions these days. The excavations to prepare the construction site, the external loads due to heavy structures and the changes in coverage of the earth surface are among the reasons for landslides in such areas. In this study, the landslides that occurred due to unsupported excavation for the construction of Karabük university stadium were analyzed using the three softwares like Plaxis, Geoslope and Slide. The study area is critical in terms of slope problems. Mass movement in the stadium occurred in high plasticity clay units containing sand and silt. For this reason, it is necessary to carry out detailed studies before the construction of engineering structures. The landslide considered in the study were analyzed using finite element (FE) analysis and slice method. These approaches are used for evaluating the stability of natural slope by considering a failure mechanism, which is known as the plastic limit condition. Regarding safety factors calculated using the different numerical solutions confirm that the results obtained are similar. In addition, the landslide area is close to the predicted simulation results. © 2018, Geological Society of India