DESIGN OF TUNNEL FINAL LINING UNDER FIRE LOAD

The safety and resilience of tunnel constructions against fire accidents are crucial since they are essential parts of transportation networks. The design of tunnel lining under fire load is the main topic of this thesis, which concentrates on the final lining's composition, design considerations for precast and cast-in-place concrete lining, and the rehabilitation of fire-damaged tunnels. This study intends to improve the fire resistance and rehabilitation tactics of tunnel structures using a literature review, experimental analysis, and numerical simulations and effective solutions for the issues faced via the French-Italian tunnel project with Pini Company's expertise. The research will help in the creation of improved design and rehabilitation techniques, ensuring the security and endurance of tunnels under fire load. The literature study examines the present level of knowledge on tunnel fire loads, tunnel lining fire resistance, and final lining design. The evaluation establishes the framework for further studies and indicates areas where developments might be made by pointing out gaps in existing research. This assessment provides the basis for the available concerns, which will focus on the conditions and requirements of the French-Italian tunnel project. Experimental analysis and numerical modeling strategies are used in the methodology. Fire-resistant materials are tested, and their performance is assessed under controlled circumstances through extensive experimental procedures. Then, to simulate fire scenarios and examine the structural behavior of various lining configurations, advanced numerical simulations are used. The objective of the research is to improve the fire resistance of tunnel linings and optimize design parameters. This thesis includes a section specifically devoted to evaluating the situation of fire-damaged tunnels, rehabilitation techniques, and investigating remodeling procedures for the fire-damaged tunnel lining. This is done to recognize the significance of addressing the rehabilitation of fire-damaged tunnels. The findings of this case study give useful suggestions and solutions for the construction and rehabilitation of tunnel linings subject to fire loads within the structure of the French-Italian tunnel project. The collaboration with Pini Company improves the findings' relevance and application by addressing specific challenges faced in this project.