• Proceedings of the KSR Conference
• /
• 2007.11a
• /
• pp.337-344
• /
• 2007

This paper is about the examination and selection of the special method applied to the railway tunnel which will lie under the road. Moreover, the road was constructed on the weak ground. Eventually, we select DSM, considering geological condition, stability during construction of the railway tunnel, and economic efficiency. The 3D-analysis, performed with PENTAGON-3D and MIDAS CIVIL-3D, shows that allowable standards are all satisfied. In the design of the railroad tunnel under the road at low depth, this paper will give useful data for the selection of the tunneling method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.121-124
• /
• 2014

Many of research on noise reduction techniques have been progressed for the improvement of noise environment in subway train. There are many way to noise reduction techniques in the tunnel, but it has been reported as an alternative to attach sound absorption material on tunnel wall. For this reason sound absorption material has been studied for application of tunnel. The objective of this study is to investigate design parameters on a Helmholtz resonator with built-in sound absorption panel for the reduction of the tunnel noise in the subway. Sound absorption panel composed of the perforated panel with sub-millimeter holes and the airspace backed a rigid wall or between panels. The experiment is performed through the change of number of perforated panel, cross sectional area and the depth of airspace of the sound absorption panel under the normal incidence sound.

• Proceedings of the KSR Conference
• /
• 2003.10c
• /
• pp.479-483
• /
• 2003

In general, urban railroad in Korea is constructed as a tunnel type under ground due to the various restricted conditions. Passengers in train running through underground tunnel compare to open space are exposed to severe noise environment. In this study, various performance characteristics of many candidate materials are surveyed and analyzed. And some important characteristics are tested. From this study, various performance requirement for noise reduction in railway tunnel were suggested.

• Journal of the Korean Society of Safety
• /
• v.31 no.2
• /
• pp.57-63
• /
• 2016

Recently, subways in the city are formed a vast underground network which is interfered with construction when large-scale infrastructure will be planned to nearby existing subway tunnels. Researches have been restricted to estimate stability of existing subway tunnel due to adjacent excavation causued by small construction such as buildings. In this paper, OO underpass is planned on the top of existing subway tunnel, which will be need large-scale excavation, is selected as a subject of study. And the purpose of this study is to analyze the effects on existing subway tunnel due to excavation by stages on construction of underpass. The 3D-numerical analysis was performed by using the MIDAS/GTS program. The stability on existing subway tunnel caused by sequential excavation is analysed using numerical results. Based on the analysis, the excavation orders and reinforcement methods was suggested for stability of exiting subway tunnel.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.980-987
• /
• 2006

Recently, twin-tunnel is often designed considering the aspects of disaster prevention and economic reasons. However, the design cases and the studies are relatively insufficient. By the twin-tunnel excavation, deviate stresses of pillar between tunnels are increased and the increased stresses induce the instability of the twin-tunnel. In this study, numerical analyses about the twin-tunnel behaviour are conducted while varying ground strength, width of pillar and depth of earth cover and a series of regression analyses are carried out by using the results of numerical analyses for the twin-tunnel. Based on the numerical analyses, an estimation method of derived stresses is suggested though the regression analyses. Also, based on the results of regression analyses, an quantitative estimation method considering the reinforcement effects is also suggested. Then various parametric studies are conducted to be considered the reinforcement type and various design parameters. Finally, the efficiency of the suggested method is verified through the results of parametric studies.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.127-132
• /
• 2004

The third double-track construction part of work, called Chung Ang Railroad line(Deok-So$\∼$Won-Ju) is in progress and the personal museum located 330m from the starting point of Pal-Dang Tunnel(length=4,470m) line in the canyon is to be effected by rock blasting during the tunnel excavation work, especially museum articles and building itself. This paper is the example of application suitable tunnel rock blasting pattern for excavation after the case study about the investigation and analysis of rock blasting noise pollution during tunnel excavation work. The museum is a three-story building, RC concrete structure and is located 17m from the top of the tunnel, in the center of the double-track line. Comparing estimate vibration frequency with site vibration one, it can be verified the reasonable rock blasting noise pollution as improving the application of tunnel excavation rock blasting pattern. The above pattern has been selected economically and effectively and applied to our construction field.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.12
• /
• pp.782-789
• /
• 2020

The demand for the development of rolling stock technology to maintain the best performance in various climatic environments has increased to expand the overseas market of rolling stock. In this study, international and domestic standards that must be applied to build a harsh climatic environment test system were investigated and compared. The way of improvement for domestic standards is proposed. The wind velocities and temperatures are specified in the UIC, EN, and IEC standards for climatic wind tunnel, and EN 50125-1 provides the velocity test up to 180km/h, the largest wind speed. UIC and EN provide the lowest temperature of -45℃, and IEC 62498-1 provides the highest temperature 55℃. The solar radiation test was specified up to 1200W/m2 in the UIC, EN, and IEC. The IEC, EN, and KS R 9145 provide the water tightness standards, which are different from each other in water capacity, pressure, and methods. The snow test method was not well specified. KRTS-VE-Part 31 provides pressurization test methods. The airtightness standards for high-speed rolling stock are defined and regulated for internal pressure change rate in UIC 660 and 779-11. The domestic standard for the wind tunnel test was not well prepared, and the solar radiation test and snow test do not exist in Korea. Therefore, it is necessary to improve domestic standards to an international level for the climatic wind tunnel test of rolling stock.

• Journal of the Korean Geotechnical Society
• /
• v.38 no.11
• /
• pp.69-86
• /
• 2022

The railway is widely used to transport passengers and freight due to its punctuality and large transport capacity. The recent remarkable development in construction technology enables various subsea railway tunnels for continent-continent or continent-island connectivity. In Korea, design and construction experience is primarily based on the successful completion of the Boryeong subsea tunnel (2021) and the Gadeok subsea tunnel (2010). However, frequent earthquakes with diverse magnitudes, globally induced and continuously increased the awareness of seismic risks and the frequency of domestic earthquakes. The effect of an earthquake on the subsea tunnel is very complicated. However, ground conditions and seismic waves are considered the main factors. This study simulated four ground types of 3-dimensional numerical models, such as soil, rock, composite, and fractured zone, to analyze the effect of ground type and seismic wave. A virtual subsea railway shield tunnel considering external water pressure was modeled. Further, three different seismic waves with long-term, short-term, and both periods were studied. The dynamic analyses by finite difference method were performed to investigate the displacement and stress characteristics. Consequently, the long-term period wave exhibited a predominant lateral displacement response in soil and the short-term period wave in rock. The artificial wave, which had both periodic characteristics, demonstrated predominant in the fractured zone. The effect of an earthquake is more noticeable in the stress of the tunnel segment than in displacement because of confining effect of ground and structural elements in the shield tunnel. 

• Journal of the Korean Society for Railway
• /
• v.18 no.6
• /
• pp.513-521
• /
• 2015

When a GTX travels through a deep-level underground tunnel at a speed of 180km/h, ear-discomfort in passengers due to the pressure wave generated could be an issue due to the small cross-sectional area. Therefore, appropriate pressure-tightness values for GTX trains must be secured as a countermeasure. In this paper, a 1D numerical analysis was conducted to determine the pressure-tightness coefficient which allows a pressure change meet the criteria. The pressure transients in a tunnel and in a passenger car are predicted considering an A-line underground tunnel with a length of 37km and its operation schedule. The required pressure-tightness of the car is predicted to be three seconds and 6 seconds respectively for a single track and a double- track tunnel to prevent aural discomfort in passengers. The result of this study are expected to serve as useful information to those involved in the development of various solutions to improve air-tightness of GTX passenger cars.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.24 no.6
• /
• pp.679-697
• /
• 2022

Having an awareness of the ongoing conception of Honam-Jeju, Korea-Japan, and Korea-China subsea tunnels for accommodating the railway, this paper investigates immersion tube tunnel technology, one of the underwater tunnel construction methods. This paper analyses the current status of immersed tube tunnels according to their location and function. This paper summarises the dredging methods and briefly introduces the muck disposal facility. Also introduced are the case studies where measures were taken to mitigate the impact of dredging on the surrounding marine environment. This paper also explains how the tunnel elements are connected underwater using an immersion joint. This paper classifies the foundation methods into bedding and ground improvement methods and provides summaries, including their environmental impact associated with drill cuttings and cementitious binders.