Infrastructure has been managed by precise diagnosis and repair․rehabilitation. Generally, more than 0.3mm cracks are repaired by injection method regardless of the time of repair and location of crack. In this papar, considering the feature of crack variation at three tunnels, it suggested that current diagnosis and repair methods should be improved.

• 윤태국(한국시설안전공단 진단본부, 차장) | Yoon, Tae Gook
• 이태종(한국시설안전공단 진단본부, 대리) | Lee, Tae Jong Corresponding Author
• 추진호(한국시설안전공단 진단본부, 대리) | Choo, Jin Ho
• 임대웅(한국시설안전공단 진단본부, 사원) | Lim, Dae Woung
• 신용석(한국시설안전공단 진단본부, 팀장) | Shin, Yong Suk