Comparative study of P2PSand and Mohr-Coulomb constitutive models using FLAC3D for the seismic modeling of a tailings dam in Chile

Abstract

The trend in the dynamic analysis of tailings deposits is to use advanced constitutive models in order to properly capture the cyclic behavior of the materials and thus have a better estimation of the physical stability of these structures. In this context, the main objective of this research is to compare the results of numerical simulations performed with a constitutive model used in current practice, such as the Mohr-Coulomb elastoplastic model, and an advanced constitutive model based on the critical state theory. This model, P2PSand, has the ability to represent the contractive and dilatant behavior of soils and the essential characteristics of the cyclic behavior of sands. From the results of the numerical analysis, the following conclusions can be drawn: P2PSand is able to adequately simulate the dynamic behavior of the sand in the tailing dam subjected to a measured earthquake of medium intensity (M_w = 5.4). P2PSand and Mohr-Coulomb constitutive models have the capability to analyze a maximum credible earthquake of magnitude 8.0 (M_w = 8.0), even if the earthquake is increased by 1.5 and 2 and if an advanced constitutive model is not used, the use of an elastic-plastic model with the addition of hysteretic damping is recommended.