ABSTRACT
Steel fiber reinforced concrete (SFRC) is gaining popularity for tunnel linings due to its superior mechanical properties, sustainability, durability, and cost-effectiveness compared to traditional reinforced concrete (RC). By reducing reinforcing steel, SFRC lowers project costs and carbon emissions, making it an attractive alternative. This study evaluates the use of SFRC as the final lining for a NATM-bored, cast-in-situ rail tunnel in the Himalayas. Structural verification of SFRC linings is conducted for tunnel sections and cross-passages under static and seismic loads, using 2D and 3D models based on tunnel geometry, support conditions, and ground classes. Results indicate that SFRC performs well under specific support classes, while less competent ground conditions and critical areas, such as niches and junctions, still require steel bar reinforcement. Numerical analysis and monitoring data confirm that SFRC ensures stability and durability, making it a viable option for tunnel linings under appropriate conditions.
