• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.8
• /
• pp.1597-1603
• /
• 2017

The incidence of fire in underground utility tunnel is lower than other fires, but the damage caused by fire can cause social loss due to social management paralysis as well as economic loss. Hereupon, this paper presents the results of an empirical test on the construction of the underground utility tunnel condition monitoring system using the leakage coaxial cable installed in the underground utility tunnel. For this reason, a verification test was conducted by connecting a inductive coupler 200 Mbps power line communication modem with insertion loss characteristics of $-6{\pm}2dB$ to the installed the leakage coaxial cable installed in the underground utility tunnel. As a result, We confirmed sending/receiving of IP cameras up to 500 m. Therefore, it is judged that it is possible to construct a condition monitoring system for underground utility tunnel by using the leakage coaxial cables installed in the underground utility tunnels without installing additional communication lines for data transmission.

• Fire Science and Engineering
• /
• v.15 no.4
• /
• pp.71-77
• /
• 2001

The pipes and cables buried below ground which may have helped to improved city landscapes is becoming direct and indirect cause for various disaster in Korea due to potential possibility of fire. Various types of fire in utility tunnels should be analysed in order to improve its fire safety level, therefore mail problems and shortcomings are checked out as a result of this analysis. By performing both tunnel fire risk analysis and fire safety level comparison in advanced countries, effective measure and approach to required standardization may be presented to bath tunnel structure and its containing cables in order to diminished up to a desirable rate in a near future.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.25 no.1
• /
• pp.11-20
• /
• 2021

The seismic deformation method is conventionally used as a seismic design for a multi-utility tunnel in Korea. In the seismic deformation method, the soil ground's natural period is one of the most critical factors for calculating the ground displacement using cosine functions. Correction factors for the natural period and shear wave velocity have been used to consider the non-linearity of dynamic soil properties. However, the correction factors have been issued because the correction factors have not been sufficiently studied to consider Korea's regional conditions. This paper aims to evaluate the natural periods for the seismic deformation method considering Korea's ground conditions. Ground response analysis was performed using seven real earthquake records on twelve sites with different soil conditions where actual multi-utility tunnels are installed. As a result, natural periods of the sites were analyzed and new correction factors were proposed according to seismic performance and Korea's regional conditions.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.3
• /
• pp.106-115
• /
• 2007

The size and length of road tunnels have been gradually expanded as industry developed. Consequently, the risk has been increased. The decision making process for ventilation system for road tunnels involves a large amount of information on economic feasibility, construction methods, and safety etc. In situation where systematically structured decision making process is unavailable, almost decisions about ventilation systems are made based on engineers' private knowledge and experiences. Procedure and criteria to choose the best optimized ventilation system among many alternatives are proposed, breaking away from the economic dependency-oriented decision making. This paper presents a Multi-Attribute Utility Theory and AHP based function with which planners can calculate overall utility of each alternative. It is anticipated that the effective use of the proposed methodology for decision making on ventilation systems ould be able to reduce the likelihood of the occurrence of potential safety risks as well as increase the overall ventilation performance.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.19 no.2
• /
• pp.231-248
• /
• 2017

Government plans to construct a double-deck tunnel under a portion of Gyeongbu Expressway that will solve traffic problems and could also be used as a flood storage facility. Divergence tunnels connect the main tunnel to the urban areas and their construction effects on adjacent structures at shallow depth need to be analyzed. This study primarily includes the numerical analysis of construction effects of divergence tunnels on utility tunnels. The utility tunnel was analyzed for three cases of volume loss applied to the divergence tunnel and two cases of the angle between main tunnel and divergence tunnel ($36^{\circ}$ and $45^{\circ}$). The results show that the more the volume loss was applied and the shorter the distance was between utility tunnel and divergence tunnel, the more the utility tunnel was affected in terms of induced displacements, angular displacement and stability. The worst scenario was found out to be the one where the angle between main tunnel and divergence tunnel was $36^{\circ}$ and the distance between divergence tunnel and utility tunnel was 10 m, resulting in the largest displacement and differential settlement at the bottom of the utility tunnel. A relationship between the angular displacement and the distance to diameter ratio was also established.

• Journal of the Korean Institute of Gas
• /
• v.20 no.5
• /
• pp.89-95
• /
• 2016

Keeping the gas pipelines in the common utility tunnel is useful because it has a lower risk of corrosion than conventional burial, and can prevent from excavating construction. But, explosions in common utility tunnels can cause greater damage from the blast overpressure compared to outdoor explosions, due to nature of the confined environment. Despite this fact, however, research on common utility tunnels has been limited to fire hazard and little has been studied on the dangers of explosions. This study developed scenarios of methane gas explosion caused by gas leak from gas piping within the common utility tunnel followed by unknown ignition; the study then calculated the extent of the impact of the explosion on the facilities above, and suggested the needs for designing additional safety measures. Two scenarios were selected per operating condition of safety devices and the consequence analysis was carried out with FLACS, one of the CFD tools for explosion simulation. The overpressures for all scenarios are substantial enough to completely destroy most of the buildings. In addition, we have provided additional measures to secure safety especially reducing incident frequency.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.6
• /
• pp.715-724
• /
• 2022

With the enforcement of the infrastructure management act, the importance of utility tunnels that jointly accommodate life-lines such as electricity, communication, water supply, and heating facilities has increased. The currently applied utility tunnel maintenance system is managed in an accident-preventive safety-based evaluation method. However, this evaluation method has limitations in effective maintenance. In this study, performance evaluation items were derived through the Delphi method to suggest a criterion for quantitatively evaluating the performance of utility tunnels, and the weights for each item were calculated through the Analytic Hierarchy Process (AHP) method. In the future, it is judged that a more reasonable performance evaluation standard of utility tunnel can be prepared if modifications and supplements are made through field application.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.32 no.6D
• /
• pp.549-556
• /
• 2012

Longitudinal tunnels are defined as tunnels with length of over 1km. Because of Korea's topographical conditions and as safety measures for linear design, many tunnels are inevitably being constructed in Korea. The number of longitudinal tunnels constructed on expressways amounted to 104 as of the end of 2010 with a total length of 192km. Given the increasing demand for tunnels and the increasing length of tunnels, a safety evaluation of longitudinal tunnels needs to be conducted. As such, this study selected design elements, transportation environment and delineation system as elements to check and tried to determine factors influencing road crashes. For this, tunnels have been classified based on history of crashes; ones with crashes and ones without crashes and statistically meaningful explanatory variables were selected. By using these variables, a logit model was development in order to better grasp the factors that directly and strongly influence crashes. The result, related to crashes as well as the analysis were utility tunnel interior materials of driving lane and passing lane, which are related to driver's visibility, lateral width widening to consolidate space in a tunnel, and annual average daily traffic (AADT) per lane. These results may be used in the future as analysis indicators when drawing up plans to prevent crashes in longitudinal tunnels.

• Tunnel and Underground Space
• /
• v.13 no.1
• /
• pp.1-5
• /
• 2003

The United States Antarctic program (USAP) through its principal Support Contractor Raytheon polar Services Co. (RPSC), has recently finished a 3 years projects, almost 936m length of underground utility tunnels at Amundsen-Scott station. It accommodates the piping that conveys fresh water from current well sites, as well as waste water to repositories in abandoned wells. The under snow tunnels allow year-round access for system operations and maintenance.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.1
• /
• pp.83-94
• /
• 2016

Utility tunnels have been employed in Korea since the 1970s and start to make trouble with structural safety and serviceability. Recently, tunnel enlargement has consequently been proposed due to the impending problems. However there are little study on box type utility tunnels except traffic tunnels. A 2D finite element analysis was conducted to evaluate ground behavior which depends on enlargement size and stiffness by one-side enlargement of the utility tunnel. Settlement scale increased with larger enlargement size and less stiff ground conditions. The observed settlement characteristics due to enlargement are similar to that suggested by Clough & Schmidt (1981). The settlement width is more affected by enlargement size than ground condition.