Design and support optimization of tathali-raviopi roadway tunnel

Abstract

Nepal's mountainous terrain poses significant challenges in transportation of goods and people necessitating the development of roadway tunnels to improve connectivity. The Tathali-Raviopi Roadway Tunnel is a proposed solution to enhance connectivity to the China border and mid-hill highway significantly reducing the travel time and enhancing road safety by avoiding steep and geologically unstable areas. This project on �DESIGN AND SUPPORT OPTIMIZATION OF TATHALI-RAVIOPI ROADWAY TUNNEL� focuses on the design and support optimization of the tunnel. To ensure structural stability and cost-effectiveness, suitable tunnel alignment and cross section was selected based on topographic and geological assessment, following relevant guidelines and codes. This study involves use of different classification systems and empirical formulas to assess the rock mass properties, in-situ conditions and strength of the rock mass. Numerical modelling, and empirical analysis were employed to determine suitable support system. Using 2D finite element modelling, stress distribution and deformation characteristics were analysed before and after support installation at different chainages to design an efficient and economic support system. The results indicate that an optimized support configuration significantly enhances tunnel stability while minimizing construction costs. This project provides critical insights into tunnel engineering in Nepal, offering a framework for future tunnelling projects in similar geotechnical conditions.