Assessment of tunnel instability—a numerical approach

This paper outlines the application of numerical modeling to predict deformation and stability of tunnel to be excavated in Bansagar, M.P., India. To meet the ever-increasing demand of transportation, energy, and other infrastructure projects, a large volume of rock tunneling is being carried out throughout the world. The geotechnical properties along the route of the 1,800-m long tunnel in the Bansagar region of India have been studied. The rock mass rating and rock mass quality systems were employed for empirical rock mass quality determination. Numerical analysis for the stress–strain distribution of the tunnel excavation and support systems was also carried out. In order to simulate the excavation of tunnel (NATM) at a depth of 150 m below the ground , a series of finite element analyses using Mohr-coulomb elasto-plastic constitutive model has been carried out using PLAXIS 2D. The stability of tunnel has been analyzed, and stress pattern have been discussed.