Design Analysis of an Underground Tunnel in Tamilnadu

Underground structures have gained importance in recent times all over the globe. Successful completion of such ventures hinges on accurate and realistic design which is neither optimistic nor conservative, and a balanced design is the need of the hour. The present work shows a comparative study on support design, such as Terzhagi’s load theory and quantitative methods of Rock mass quality (Q), Rock Mass Rating of Bieniawski, and PLAXIS-2D Numerical modeling. The results obtained show that final support measures such as shotcreting, thickness, rock bolting, length, frequency, and requirements of steel supports are better. Based on engineering judgment and analytical approaches, realistic support measures were obtained for an access tunnel to be excavated in Nilagiri, Tamil Nadu.