Analysis of support system for a conveyance tunnel in the higher Himalayan zone: A case study on Upper Tamakoshi HEP, Nepal

After excavation, insitu stress conditions are changed which lead deformation due to the concentration. For stability in excavated tunnel profile, appropriate support system is essential. To recommend system, site specific data used from Higher Himalayan Region of Nepal. Study focused on 3 m and 6 size inverted D Shaped with three different overburden thickness. analysis system: Empirical method, Analytical method Numerical Modeling performed. Result obtained approaches for heights as well both tunnels compared finally required recommended. It was found significant change deformations while increase tunnel. Overburden thickness also playing vital role this parameter but effect more prominent.