A method for repairing in-ground tunnel structures including the steps of: a) cleaning the structure to be lined; b) installing a suspension cable along the top of the tunnel; c) suspending sheets of liner composite along the suspension cable; d) applying resin to one side of the tunnel; e) bedding the liner composite into the applied resin; f) removing suspension cable once the top edge of the resin and liner composite becomes self-supporting; g) applying resin to the other side of the tunnel; and h) bedding the liner composite into the resin. The process can then be repeated along the length of the tunnel in a sheet by sheet fashion.