Abstract

In practice, tunnels design uses analytical methods and numerical models. The last methods are because tunnels need solutions that provide a high level of security given their complexity and civil use. In this paper the study of the influence of the geometric and the mechanical soil properties on the tunnel displacements is presented, when it is used the finite element method (FEM) in two (2D) and three (3D) dimensions. Validation of results was through of the displacements comparison with an elastic analytical method. The constitutive model used was the Mohr-Coulomb and the soil parameters are of a soil in Mexico. Results shows a convergence towards a similar behavior for the elastic case and a difference when a perfect elasto-plastic behavior is considered in design. As fundamental conclusions, it is observed that it is possible to speed up the time using the 2D-FEM method, as well as the feasibility of quickly reviewing a 3D tunnel using a 2D program. '''Key words: '''Finite elements; two-dimensions; three-dimensions; tunnels.