Excavation Method Implemented in Atal (Rohtang) Tunnel: Case Study

Structurally dynamic, youthful collapsed mountains; The Himalayas are loaded with full of geological surprises, involving issues, folds, shear zones and so forth that shows their quality because of progressing structural exercises in the Himalayas. In feature of Atal tunnel, these issues increments multifold due to high overburden of the material and also careful topographical and geotechnical investigations at different scales. This makes vulnerability in planning a specific emotionally supportive network and requests for "structure as you go" approach for whole passage length (8.8km). DRESS (Drainage-Reinforcement-Excavation-Support-Solution) philosophy of excavation is very powerful in water bearing issue zones of delicate Himalayan district. DRESS includes pre-seepage of ground in front of face with long waste gaps and adjustment of the crown in front of passage face by steel pipe umbrella curve, up to a foreordained length, trailed by exhuming in little strides by mechanical methods and backing thereof. Numerous troublesome issues have been experienced during construction which was unpredicted initially. One such issue is an experience of Seri Nala. Due to differing conduct of rock mass, continuous update of rock mass is constantly required. NATM is dependent on disfigurement observing information to assess amount and nature of emotionally supportive network, has end up being a fitting apparatus for tunneling in the youthful Himalayas. This paper depicts the consolidation of NATM as well as DRESS method in the unearthing of Atal Tunnel, Himachal Pradesh, India