Abstract
Monitoring system of Japan expressway corporation (NEXCO) consists two stages. The first stage is the screening system by using tunnel lining photo image at the periodic tunnel health inspection. The second stage is the onsite detailed inspection by engineer. The main evaluation item of both system is called evaluation value effected by external force and exfoliation based on Tunnel lining Crack Index (TCI). In this research, inspection results over 85,000 lining spans managed by NEXCO was analyzed for the purpose of high accuracy and efficiency of tunnel health monitoring system for expressway. In the data analysis, it was found that there is a high relationship with tendency between the first and second stage. In addition, a comparative analysis of the both stage is performed. The practicality of the current inspection system is high, the efficiency of detailed inspection needs to be examined in the future.
