터널은 지하수 처리방법에 따라 배수형 및 비배수 방수형식으로 구분된다. 배수형 방수형식 터널은 콘크리트 라이닝 배면의 지하수에 대한 수압을 고려하지 않으므로 대단면 터널 및 얇은 라이닝 콘크리트 두께 등 터널형상 선정에서 자유롭고 경제적인 장점이 있다. 하지만 터널의 배수시스템에 문제가 생기는 경우 라이닝 콘크리트 배면에 지하수로 인한 수압으로 장기적인 측면에서 터널의 구조적 안전성에 영향을 주기 때문에 터널의 내구연한 동안 배수시스템에 대한 유지관리와 문제 발생 시 적절한 보수, 보강 방법의 적용이 필요한 실정이다.

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).

The latest precise inspection for safety and diagnosis has found the clogging of transverse drainage pipes in NATM tunnel, resulting in hydraulic pressure generated on the outside of lining concrete that poses a safety threat to the tunnel structure. Accordingly, this paper aims to conduct a safety analysis on using NATM tunnel that currently suffers the clogging of transverse drainage pipes based on its numerical analysis.

For the last several years, climatic changes have led to the increase of natural disaster attributed to climatic abnormality, for instance, sweltering heat, heavy snow, or heavy rain. Particularly, localized guerrilla heavy rain mostly occurring in summer often results in flood damage. Such damage may lead to fatal damage to the safety of underground structures having the water level as the load. Accordingly, this study is going to introduce the cases of safety analysis grounded on numerical analysis in order to understand the structural behavior of riverbed tunnels according to water level fluctuations.

In reinforced concrete structures, carbonation phenomena associated with deterioration is important. So, this study conducted a visual inspection and a concrete durability test in Precise Safety Diagnosis, analyzed the result, and tried to suggest a reasonable repair method and range of concrete carbonation.

reinforced concrete structures, carbonation phenomena associated with deterioration is important. So, this study conducted a visual inspection and a concrete durability test in Precise Safety Diagnosis, analyzed the result, and tried to suggest a reasonable repair method and range of concrete carbonation.

Recently, the problem about a structural safety of the tunnel lining concrete is much raised. Thus, in this paper, We introduce a safety analysis case about an insufficient filling of the road tunnel(NATM) lining concrete for numerical analysis.

In this study, the behavior of the existing tunnel was measured by automation system to analyze the characteristics of lining longitudinal cracks. The characteristic of the infusion material which it is applicable to crack repairing was considered by grasping the overall behavior including the temperature and the crack width change, and etc., From this, the reasonable repair period for the complement efficiency enhancement was trying to be determined.

Recently, in the tunnel precise inspection, the problem of the lining concrete cracks is much concerned. Thus, in this study, the behavior of the existing tunnel was measured by automation system to analyze the characteristics of lining cracks.

Generally, Seismic design has not been applied for the existing('now-using' means) railway tunnel. therefore, In this case study, We introduce a case of seismic performance evaluation for tunnels. It is evaluated by comparing capacity with demand for tunnel linings.

Recently, it is more concerned about securing of its seismic safety, as underground structures are significantly recognized. Especially, it is very important that underground structures such as the tunnel of urban railroad or subway ensure the seismic safety of its, because it can be caused an enormous loss of lives and a economical damage by earthquake. When the subway tunnel of cut-and-cover box type is constructed, grounds are excavated and refilled. In this study, the parametric study is performed and analyzed about factors affecting seismic analysis of cut-and-cover tunnel, such as soil type, refilled range, tunnel location, etc. Consequently, it is hoped to provide the preliminary data for a better reasonable review on seismic design and seismic performance assessment of underground structures.