Coupled numerical simulation of a tailings deposit by FEM

Ana Luiza Coelho Braga,Christianne De Lyra Nogueira

doi:10.1590/0370-44672016720047

Ana Luiza Coelho Braga, Christianne De Lyra Nogueira

Open Access

https://doi.org/10.1590/0370-44672016720047

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Abstract

Abstract Researchers have found that a valuable alternative for predicting the mechanical behavior of landfill construction is numerical simulation based on the finite element method. The results of such a numerical simulation for a sandy tailings deposit from the iron mining coupling flow and deformation are presented herein. This study investigates the influence of the construction rate, drainage system, and anisotropy of permeability on the magnitude of pore pressures generated during the construction process. The study also presents the results from different analyses considering different constitutive models including elastic, nonlinear elastic and nonlinear elastoplastic. In obtaining the constitutive parameters, the numerical results highlight the importance of having a more detailed set of conventional triaxial compression tests. Also highlighted by the numerical results is the importance of having an efficient drainage system and the necessity of taking into account the water level variation in the hydro-mechanical behavior of numerical simulations of landfills that are hydraulically constructed.

Highlights

The construction of tailings deposits gives rise to displacements and pore pressure in soil mass
Several numerical simulations were conducted by ANLOG using the finite element mesh illustrated in Figure 3
At point EJ, the presence of the drain affects the magnitude of the excess pore pressure, both during the starter dike construction stage (ET1) as well as during the tailing deposit construction stages (ET2-ET20)

Summary

Introduction

The construction of tailings deposits gives rise to displacements and pore pressure in soil mass. To help ensure the safety of such work, it is of fundamental importance that engineers be able to predict hydromechanical behavior. This study makes use of the computational program ANLOG - Nonlinear Analysis of Geotechnical Works (Nogueira, 1998) to analyze the hydromechanical behavior of a tailings deposit from iron mining. The study analyzes this deposit in the plane strain state, in the field of small displacements and takes no account of the presence of the water level throughout the construction process. The geotechnical characteristics of the materials and the deposit geometry have been obtained from Rezende (2013) as described by Braga (2016)

Numerical modeling of landfill construction

Numerical simulation

Results and discussion

Conclusion