Finite Element Analysis of Twin Tunnels in Granitic Rock

Tunnels are risky and complex geotechnical structures. Long tunnels have been built with proper design ensuring proper stability, safety and have proved to be a boon to humans. Tunnels have been constructed successfully to pass the inter-state traffic and various other reasons. Use of underground space for tunnels leaves the land resource for other human activities. With the fast advancing world, globalization and urbanization has uplifted the life standard of people which has in turn led rapid consumption as well as deterioration of conventional resources. In the present paper, analysis of twin tunnels in granitic rock for Karwar-Kundapura highway is taken up. Rock found at the site is of variable strength which is classified based on rock mass rating (RMR) value. Midas GTS NX software is used to develop 3D model with parameters like terrain, rock properties, and support system like umbrella reinforcement and rock bolts with shotcrete. The analysis is carried out for the tunnel at the time of construction and also post-construction to know various deformation on tunnel.