• Tunnel and Underground Space
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• v.28 no.6
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• pp.620-634
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• 2018

The NTR(New Tubular Roof) method was used to secure the stability of the tunnel and minimize the subsidence of the road. The tunnel was constructed at about 7.5 meters deep below the highway. with a width of about 21 meters. Following the NTR method, 13 steel pipes with a diameter of 2.3 meters were digged and pushed in longitudinally along the tunnel profile and cut out sides of pipes to connect to adjacent pipes, then filled the inside of pipes and the connected space between pipes with concrete to complete the lining of the tunnel to be excavated. As the steel pipes were digged in sequentially, the area of relaxation was connected to each other and behaves like a gradually widening tunnel. When the steel pipes were digged in to the widest points of the tunnel, the settlement rate of the road surface was increasing to the maximum as 2.2 mm and the total settlement until the lining construction was approximately 7.7 mm. After that, by excavating a tunnel inside the pre-installed lining, an additional settlement of about 4.3 mm was occurred, resulting in the total settlement of about 11.8 mm after completing of tunnel construction.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.887-890
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• 2008

Shindorim Station is the most important transfer station which is crossed Seoul Metro Line-2 and national rail traffic Kyungbu, Honam and Kyungin Line etc.. There is the lagest transfer passengers and the greatest rail traffic. Therefore to solve the congeted station problem, Shindorim station extension project has been planned. This project has very difficult many problems. One of them is undercrossing the national rail traffic ground without open-cut excavation. There are many undercrossing construction methods in our country. But this project is required the best safety. So the best applicable methods are investigated, which are Front-Jacking, NTR and TRcM. In Design stage Front-Jacking with PRS method which is gound reinforcing is applied.

• Journal of Korean Society of societal Security
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• v.2 no.4
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• pp.49-57
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• 2009

The development and use of underground space in the city have been expanded considerably worldwide due to the growing population and traffic. Because the construction of underground causes some problems including traffic jam and safety accidents, the non-open excavation construction method are commonly used. NTR (New Tubular Roof) method which is one of the non-open excavation method is investigated in this study. The structural safety of underground structures by using NTR method is evaluated by ANSYS 9.0. The tubular roof according to diameters are analysed by ANSYS 9.0 at critical construction step. Finally, according the diameter and thickness of tubular roof the stress nad dispacement are analyzed and then the The efficient use of tubular roof is suggested from relationship between tubular's thickness and stress condition.

• Journal of the Korean Society for Railway
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• v.9 no.2 s.33
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• pp.174-179
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• 2006

Recently, the crossing tunnel has been constructed frequently to connect the separated area by highway and railroad. The construction of crossing tunnel must be progressed while maintaining the existing traffic of the highway as well as railroad. There are many cross funnelling 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 funnelling methods are needed a little volume of concrete and easy to change the direction of cutting shoe during the construction of pipe roof, The 3-dimensional numerical analysis of RPS to consider the arching effect 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.

• 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.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2439-2449
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• 2011

Existing grade crossings between railway and roadway area gradually changed to grade separation systems by the law. In the case of new roadway construction which crosses railways, it shall be grade separation system in principle. With the railway underground crossing method, many practices have been developed which can minimize rail displacements and avoid rail release. With these methods, the effects to the train can be reduced. The underground crossing methods can be identified as open-cut methods and non open-cut methods. The open-cut methods include temporary support methods and special rail construction methods. Also the non open-cut methods includes pipe roof methods, front jacking methods, messer shield methods, NTR methods and JES methods. Among these, the most suitable method is applied considering safety, economy, class of each rail system (train passing frequency and velocity), etc. In the non open-cut methods, the cost and duration shall be increased to keep existing rail system during construction. In the open-cut methods which use plate girders, the rail speed shall be restricted due to the displacement and vibration of the girder. In this study new grade separation methods were developed. With this method, the safety during construction can be increased. This method refines temporary support methods, but pc slab girder with huge stiffness is applied instead of plate girders. With this method, the rail displacement can be reduced and higher safety can be obtained during construction. Also construction cost and duration can be minimized because the temporary work and the overburden soil depth can be reduced.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.591-600
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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 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.