Full-Scale in-Situ Validation of a Spatial TDR-Based Real-Time Quality Control Tool for Inner Tunnel Lining Construction

Key Points

• To quantify the filling status of fresh concrete in tunnel lining to prevent construction defects.
• Utilized spatial distribution detection TDR method for continuous real-time measurement.
• Installed coated parallel two-wire electrodes within the formwork.
• Applied step pulse waves from TDR equipment to monitor changes in material around electrodes.
• Successfully measured the concrete filling height and condition continuously.
• Observed reflection phenomena indicating changes in the filling state.
• Validated the technology during tunnel lining construction at the Shibayama Tunnel (tentative name).