|There are more than 10,000 road tunnels in Japan, and every year, more and more tunnels reach the end of their service lifetimes. These tunnels include some in which their lining concrete has been deformed by external force so that they require reinforcement measures. The authors have developed a reinforcement method that can guarantee adequate load-bearing capacity by using precast concrete linings (PCL) panels which are members with partially thin cross-sections. Even in cases where there is no clearance in tunnel cross section, this method enables the tunnel refurbishment to widen the cross-section without obstructing road traffic and without digging down into the roadbed of the tunnel. Full-scale test of partially-thin PCL panels installed on damaged lining was carried out to grasp their mechanical properties. The effectiveness and safety during its execution of this method was confirmed through the application to the actual road tunnel.