The clogging of transverse drainage pipes in NATM tunnel is attributed to the hydraulic pressure generated on the outside of lining concrete and affects the safety of the whole structure in the long term, necessitating a keen attention in terms of its maintenance.
Accordingly, this paper will introduce an analysis on the effect of the clogging of transverse drainage pipes on the lining structure based on the comparison between the inspection of the clogging of transverse drainage pipes and the visual inspection (leakage, efflorescence).

Abstract
 1. 서 론
 2. 현장조사
 3. 조사결과 분석 및 고찰
 4. 결 론
 참고문헌

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