The influence of fissured material on tunnel stability (a numerical study)

Abstract

Purpose. To understand the effect of fissured material on tunnels. These infrastructure tunnels must be safe in all respects, including construction, materials, and more. One of the challenges which engineers face is the need to consider material types as well as fissured material. As a result, in order to ensure the safety of the tunnel, it is important for us to anticipate possible precipitation, displacements, stresses and strains caused by the construction of tunnels in fractured environments. Methodology. The OPTUMG2 software was used for thisnumerical study, the tunnel was modeled applying the hypothesis of two-dimensional plane deformation with the use of the finite element method, which is used to model continuous media. The Mohr-Coulomb criterium was considered to simulate the elastoplastic nonlinear behaviour of this model. Findings. The ndings demonstrate that the orientation of weakness planes can have a major impact on tunnel stability. Thus, it was observed that 45, and 60 for angle 1, and 110, and 135 for the second angle 2 present the most critical situations. The influence of fissured material (soil) on civil engineering projects such as tunneling should be taken into consideration. Originality. The tunnels stability is determined by the measuring of the displacement (settlement), stresses, and deformation, under the effect of the fissured material in the environment. In this paper we simulated a model with various crack angles. As for the orientation of plane, for the angl3e 1 the values are changed to 0, 20, 45, 65, and 90, the second angle 2 was changed from 110, 135, 155, 175, to 180. Practical value. The number of tunnels and infrastructure projects is constantly increasing. This is because they are important for the development of countries and for accelerating economic growth, shortening distances and travel time by linking urban areas that have natural obstacles such as mountains. We found that the orientation planes can have a major impact on tunnel stability. Thus, it was observed that 45, and 60 for first angle, and 110, and 135 for the second angle present the most critical situations.