ABSTRACT
Permanent sprayed concrete tunnel linings waterproofed with bonded membranes have been used at a number of important projects. The layout of this lining gives fundamentally different system properties compared to the traditional lining systems. The current understanding of the function and properties of such lining structures is presented based on review of recent research carried out in Norway, as well as field observations and monitoring carried over several years. The influence of the water exposure on the final condition of the concrete and membrane materials has proven to be of vital importance for proper material testing and acceptance, assessments of the mechanical contribution of the bonded membrane, as well as assessments of the longterm durability of such linings. Finally, some recent results from ongoing research on such linings, particularly the hydraulic response of the rock mass and the long term behavior of the concrete and membrane materials are presented.
