Grouting Performance Evaluation of the Double Injection Method for Settlement Restoration of Concrete Rail Tracks
For the construction of concrete tracks, strict settling control standards are applied. However, settlement inevitably occurs owing to the construction conditions, climate, and geographical conditions. When settlement occurs beyond the limited value, recovery work is performed by using a restoration method. During restoration processes, the concrete track must maintain its support stiffness and not develop non-uniform stress to ensure proper functioning of interface systems between the track and roadbed and geometric settlement recovery. To satisfy these conditions, the track must be tightly filled to prevent voids from occurring at the bottom. This paper proposes a double-injection-type method for cement grouting to secure filling, considering the injection material, pressure, and interval. In this study, the filling performance was evaluated through field tests using visual inspection and the impact echo technique, which are non-destructive investigation methods.