PURPOSES : This study investigates the factors affecting extra-long tunnel accidents by integrating data on tunnel geometry, traffic flow, and traffic accidents and derives the underlying implications to mitigate the severity of accidents. METHODS : Two processes centered on three key data points (tunnel geometry, traffic flow, and traffic accidents) were used in this study. The first is to analyze the spatial characteristics of extra-long tunnel traffic accidents and categorize them from multiple perspectives. The other was to investigate the factors affecting extra-long tunnel traffic accidents using the equivalent property-damage-only (EPDO) of individual accidents and the aforementioned data as the dependent and independent variables, respectively, by employing an ordered logistic regression model. RESULTS : Gyeonggi-do, Gyeongsangnam-do, and Gangwon-do are three metropolitan municipalities that have a significant number of extra-long tunnel accidents; Busan and Seoul have the most extra-long tunnel accidents, accounting for 23.2% (422 accidents) and 18.6% (339 accidents) of the 1,821 accidents that occurred from 2007 to 2020, respectively. In addition, approximately 70% of extra-long tunnel traffic accidents occurred along tunnels with lengths of less than 2 km, and Seoul and Busan accounted for over 60% of the top 20 extra-long tunnels with accidents. Most importantly, the Hwangryeong (down) tunnel in Busan experienced the most extra-long tunnel traffic accidents, with 77 accidents occurring during the same period. As a result of the ordered logistic regression modeling with EPDO and multiple independent variables, the significant factors affecting the severity of extra-long tunnel traffic accidents were determined to be road type (freeway, local route, and metropolitan city road), traffic flow (speed), accident time (year, summer, weekend, and afternoon), accident type (rear end), traffic law violations (safe distance violation and center line violation), and offending vehicles (van, sedan, and truck). CONCLUSIONS : Based on these results, the following measures and implications for mitigating the severity of extra-long tunnel traffic accidents must be considered: upgrading the emergency response level of all road types to that of freeways and actively promoting techniques for regulating high-speed vehicles approaching and traversing within extra-long tunnels are necessary. In addition, the emergency response and preparation system should be reinforced, particularly when the damage from extra-long tunnel traffic accidents is more serious, such as during the summer, weekends, and afternoons. Finally, traffic law violations such as safe distance and centerline violations in extra-long tunnels should be prohibited.

When constructing tunnels, it is important to understand structural, geological and hydrogeological conditions. Geumgeong tunnel that has been constructed in Mt. Geumjeong for the Gyeongbu express railway induced rapid drawdown of groundwater in the tunnel construction area and surroundings. This study aimed to analyze groundwater flow system and baseflow using long-term monitoring and groundwater flow modeling around Geumgeong tunnel. Field hydraulic tests were carried out in order to estimate hydraulic conductivity, transmissivity, and storativity in the study area. Following the formula of Turc and groundwater flow modeling, the annual evapotranspiration and recharge rate including baseflow were estimated as 48% and 23% compared to annual precipitation, respectively. According to the transient modeling for 12 years after tunnel excavation, baseflow was estimated as 9,796 - 9,402 m3/day with a decreasing tendency.

본 연구에서는 초/장대 철도터널 및 철도사고와 관련하여 기존 국내 소방대응체계 및 해외 소방대응체계를 분석하고 Golden time안에 소방관이 신속히 사고현장으로 접근하여 인명 구조 및 소방대응활동이 가능하도록 하는 시스템을 개발하는 것이 주목표라 할 수 있다. 국외 선진국에서는 매해 철도사고(도심철도 및 일반철도, 고속철도)가 빈번하게 발생하고 있어 철도사고에 대응하기 위하여 초장대터널 주변에 화재진압열차를 배치해 두고 있으며 일반 철도 사고발생시 출동이 가능하도록 Rail road형 특수소방차량이 개발되어 철도인근 소방서에서 즉각적인 대응을 하도록 시스템이 구축되어있다. 그러나 국내 고속철도 및 일반철도는 구조적으로 외부접근을 차단하기 위해서 방벽 및 고가다리에 위치하고 철도터널의 경우 소방법규에 적용을 받지 않아 소방 설비가 미 구축되어 터널내부에서 화재사고발생시 대형인명사고 발생할 가능성이 높다. 도심철도 또한 대부분이 지하에 설치된 초/장대터널 구조로 되어 있어 사고발생시 탈출하는 인원과 농연으로 인한 시야제한, 다양한 장애물로 인하여 외부에서의 소방관의 접근이 어려운 상황이다. 따라서, 국내에서도 국외에서처럼 철도 및 철도터널사고에 대응할 수 있는 특수소방차량의 개발이 필요한 상황이며 특히 노후화된 도심철도에 대한 소방대응기술의 개발 및 적용이 시급하다.