• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.637-644
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• 2016

This paper is a follow-up to previous papers entitled, "Development of Tunnel-Environment Monitoring System and Its Installation" I [1] and II [2]. The target tunnel of these studies is the Solan Tunnel, which is a loop-type, single-track, 16.7-km-long tunnel located in mountainous terrain and passing through the Baekdudaegan mountain range. It is an ordinary railway tunnel designed for both freight and passenger trains. We analyzed the environmental conditions of the tunnel using temperature and humidity data recorded over approximately one year. The data were recorded using the Tunnel Rough Environment Measuring System (TREMS), which measures environmental data in subway and high-speed train tunnels and is installed in three locations inside the tunnel. Previous studies analyzed environmental conditions inside tunnels located in or near a city, whereas the tunnel in this study is located in a mountainous area. The tunnel conditions were compared with those measured outside the tunnel for each month. Hourly changes during summer and winter periods were also analyzed, and the environmental conditions at different locations inside the tunnel were compared. The results are widely applicable in studies on the thermal environment and air quality of tunnels, as well as for computer analysis of tunnel airflow such as tunnel ventilation and fire simulations.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.655-660
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• 2005

Recently, the crossing tunnel has been constructed to maintain the operation highway as well as railroad. The advantages of adopting RPS method in crossing tunnel construction are needed a little space and easy to change the direction of cutting shoe during the construction of pipe roof. The numerical analysis of RPS was performed for the application in the crossing tunnel under railroad. The earth pressure distribution and settlement were predicted when the RPS method was applied during the excavation for crossing tunnel construction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.516-521
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• 2016

In this study, we investigated the operation of railroad fire fighting vehicles against fires on trains in a long railway tunnel. In recent years, long railway tunnels (more than 10 km in length) have been built and the number of such tunnels, such as the Geumjeong tunnel (20.3 km in length) on the Gyeongbu high speed line, Solan tunnel (16.7 km in length) on the Yeongdong line and Yulhyeon tunnel (50.3 km in length) on the Suseo high speed line which is scheduled to be opened in the second half of 2016, is increasing. Significant damage is to be expected, due to the increased evacuation time and limited accessibility of fire services when the train is stopped by an urgent fire in the tunnel. Special fire fighting vehicles capable of running on rails have been developed and operated in overseas advanced countries. Therefore, a fire-response system using Unimog vehicles, which can run on road and rail, instead of road vehicles, is necessary. The characteristics of the railway tunnel and thermal environmental change caused by a train fire in a tunnel were analyzed in this study. Also, the operational requirements of the railroad fire fighting vehicles were evaluated by taking into account the specifications of the railroad fire fighting vehicles under development.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1796-1803
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• 2015

Unlike commercial LTE network, LTE-R railway network is arranged along a railroad track and the base stations of the network (RUs) are also installed on the waysides. For urban railway systems that are composed of underground tunnels, the leakage coaxial cables are widely used due to the radio propagation characteristics in tunnels. In theory, the tunnel sections are interpreted as the waveguide with blank spaces and for this reason, the tunnel sections are expected to be better than open ground sections in terms of the radio propagation characteristics. In this paper, we analyze the radio propagation characteristics based on this theory by replacing the leakage coaxial cables in the network with Yagi antennas. The test has been carried out in the 2.2km tunnel in the Daebul test track of KORAIL with 2.6GHz LTE-R Network. The LTE-R applicability in urban railways has been tested through the analysis on the radio propagation characteristics with the unmanned train operation system in Daebul tunnel.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1083-1088
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• 2004

Several possibilities on the stability analysis of the railroad tunnels passing through the abandoned mining area are considered in this paper. Previous works on the influence zone due to cavities are investigated to study the effect of the safety deterioration near the cavities which are normally unknown to the engineers. Additional works on the numerical analysis of the influential zone are also performed in 3D space. The praximity of railroad tunnel and unexpected cavities is critical to influence the stability of railroad tunnel under construction. Futhermore, the study on the influence of underground condition like joint and faults should be significantly controlled under both design and construction stage.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.454-461
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• 2005

There are many cross tunnelling methods such as NTR, TRCM, Messer Shield, Front Jacking, and Pipe Roof Method. The advantages of adopting RPS(Roof Panel Shield) method in crossing tunnel construction with comparing other existing cross tunnelling method are needed a little space and easy to change the direction of cutting shoe during the construction of pipe roof. The 3-dimensional numerical analysis of RPS was performed for the application in the crossing tunnel under railroad. The earth pressure distribution and settlement were predicted when the RPS method was applied during the excavation for crossing railroad tunnel construction.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.10
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• pp.1069-1077
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• 2015

In tunnel excavation using blast, the wire saw rock cutting method generates a discontinuity perimeter around the center cut, and thus prevents blast vibration propagation to reduce vibration and noise. Therefore, the method is expected to be easy to use and economical compared with other methods. In this paper, the cutting mechanism of wire saw in tunnel excavation is investigated. A model describing the changes in cutting depth and wire saw shape inside a rock during cutting is established and validated for this purpose. Through a simulation using the model, the important characteristics of wire saw cut are investigated, and the influences of cutting conditions, such as wire saw tension, wire saw speed, feed speed, depth, and diameter of boring, on cutting performance are also examined. A method to improve the cutting performance is proposed based on the results.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.4
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• pp.295-304
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• 2005

The smoke propagating distances are measured in case that a fire occurs within the subway railroad tunnel. The tunnel is 800m long and the dimension of the cross-section is. Three vertical shafts exist for smoke ventilation. The experiments are performed using the 1/50 reduced-scale model. The smoke propagating distances are measured by thermocouples and by visualization for the accuracy. In order to understand the effect of a fire size and ventilation capacity of the shafts on the smoke propagating distance, 9 test scenarios are chosen. Based on the results, the smoke propagating distance is shown to be important criteria for the ventilation design of the tunnel.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.436-441
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• 2012

Pressure waves are generated and propagate in tunnel when train enters a tunnel with high speed. Compression wave due to the entry of train head propagates along the tunnel and is reflected at tunnel exit as expansion wave. While expansion wave due to the entry of train tail propagates along the tunnel and is reflected at tunnel exit as compression wave. These pressure waves are repeatedly propagated and reflected at tunnel entrance and exit. Severe pressure change per second causes ear-discomfort for passengers in cabin and micro pressure wave around tunnel exit. It is necessary to analyze the transient pressure phenomena in tunnel qualitatively and quantitatively, because pressure change rate is considered as one of major design parameters for an optimal tunnel cross sectional area and the repeated fatigue force on car body. In this study, we developed the characteristics method analysis based on fixed mesh system and compared with the results of real train test. The results of simulation agreed with that of experiment.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.578-584
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• 2001

Purpose of the present study is to investigate the aerodynamic performances of air-shafts with different inner diameters in a single track tunnel for reducing pressure fluctuations and micro pressure waves. Three configurations of air-shafts with different inner diameters were examined for comparison of aerodynamic performances. Experiments were performed with a 1/61-scale moving model rig for the tunnel of 0.764 km length and the train of 4 cars per 1 unit. The results showed the reduction effect of the maximum pressure fluctuations in tunnel and micro-pressure waves radiating towards the surroundings from the tunnel exit according to the increase of the diameter of 10 air-shafts spaced equally.