The final lining, a fundamental stage The final lining is the most important stage in the construction of a tunnel. It represents the final reinforcement which determines the durability and structural strength of the underground works, as well as being the support for the service installations such as final ventilation, aeration and lighting.

A number of technical considerations. There are a series of technical solutions for this stage, with special attention paid to an increase in the final quality, durability, safety and also appearance from an architectural point of view.