• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1999-2004
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• 2009

Since 2003, the domestic ground signalling system of the Kyeongbu and Honam lines has been steadily improving with the introduction of the ATP system and application of the system to the train is actively being pursued for 2009 target. Therefore, new ground signalling systems are being installed to the trains and track conditions to control the train speed to a maximum of either 80km/h, 120km/h, 150km/h, or 160km/h. As well, considering safe breaking distance, block signalling has been installed and also the change over times of the track switching device has been adjusted according to the train speed. Since the new Tilting trains will be running faster than present trains, at speeds over 180 km/h, we anticipate that there will be problems with present signalling facilities. Therefore this paper attempts to examine the various problems with the interface between the ATP signalling system and the new Tilting trains and also it will propose the most effective operating plan based upon case studies of successful foreign operations.

• 한국측량학회지
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• 제39권5호
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• pp.329-341
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• 2021

This study derives the risk-Influence factors for subway structures, the basis for the transition from the current subway disaster recovery-oriented maintenance system to a preemptive disaster management system, to reduce risk factors for existing subway structures. To apply reasonable risk assessment techniques, risk influence factors for subway underground structures using statistical information(spatial information) and risk influence factors according to frequency of accidents were selected to derive the risk factors. The significant risk factors were verified through ground subsidence (SI: Subsidence Impact)-based correlation analysis. This process confirmed that the subsidence of the ground was a risk influence factor for the subway structure. The main result of this study is that derive the risk factors to improve the risk factors of subway structures due to the rapid increase in disaster risk factors. The derived risk factors that were expected to affect the depression around subway stations and track structures did not show a noticeable correlation, but the cause of this may be that there is no physical connection between them, but on the other hand, the accumulated data may not accurately record the surrounding depression. Accordingly, in order to evaluate the risk of depression around the station and track, more intensive observation and data accumulation around the structure are required.

• 한국철도학회논문집
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• 제19권2호
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• pp.195-203
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• 2016

최근 경부고속철도 2단계와 호남고속철도에 적용된 콘크리트궤도는 초기 건설비는 기존 자갈궤도에 비하여 불리하나, 유지관리비용은 유리한 것으로 검토되었다. 이와 같은 이유로 콘크리트궤도는 일반철도 신설구간을 중심으로 점점 더 적용구간이 늘어나고 있는 실정이다. 그러나 콘크리트궤도의 가장 큰 문제점 중의 하나는 침하로 인한 궤도 보수와 관계된 문제이다. 궤도의 하부 노반침하 및 이로 인한 궤도 안정성 저하는 콘크리트궤도의 가장 큰 단점이고, 고속철도 설계기준에는 허용잔류침하량을 25mm로 제시하고 있다. 콘크리트궤도의 안정성을 위해서는 2차 압축침하량을 기준치 이내로 관리하여야 한다. 본 연구에서는 2차 압축침하에 대한 이론을 토대로 연약지반의 2차 압축지수 및 연약지반 층의 두께 그리고 궤도수명에 따른 2차 압축침하량을 산정하여 궤도구조 선정에 활용하도록 제시하였다. 또한 국내 연약지반의 2차 압축계수의 확률분포 특성을 분석을 통하여, 콘크리트궤도 부설이 불가능한 지역이 10% 이상 나타남을 알 수 있었다.

• 한국해양공학회지
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• 제28권2호
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• pp.167-176
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• 2014

This paper proposes an optimum curve driving method for adeep-seabed mining robot(MineRo) in deep-sea soft ground. MineRo was designed as afour-row tracked vehicle. A study on the turning methods for the four-row tracked vehicle was conducted using three case by changing the velocity profile of each track. The configuration of the four-row tracked vehicle and soft ground equation are introduced, along with the dynamics analysis models of MineRo and soft ground, which were constructed using the commercial software DAFUL. Because the purpose of this study was to investigate a driving method on soft ground, the marine environment of the deep sea was not considered.

• 한국철도학회논문집
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• 제20권5호
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• pp.602-611
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• 2017

철도시스템에서 이동 중인 열차와 지상과의 정보교환은 위치검지, 열차제어 등 다양한 분야에서 매우 중요한 역할을 수행하고 있다. 열차와 지상간의 정보전송을 위한 매체로 대부분 궤도회로가 사용되어 왔으나, 궤도회로는 지상에 선로를 따라 연속적으로 설치되어야 하므로 설치 및 유지보수 비용의 증대를 초래한다. 이러한 문제를 해결하고자 최근에는 연속적인 정보전송(무선통신)과 불연속적인 정보전송(트랜스폰더)을 혼합하는 방식으로 변화되고 있다. 본 연구에서는 400km/h의 고속으로 이동하는 열차에서 지상과 차상간 정보전송이 가능한 트랜스폰더 시스템을 개발하기 위하여, 현장설치 및 유지보수가 효율적인 수동형 태그에 구동전원을 공급하기 위한 무선전력전송용 리더 및 태그 안테나를 설계하고, 시뮬레이션 및 시작품 제작을 통하여 그 성능을 확인하였다.

• Wind and Structures
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• 제35권6호
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• pp.405-418
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• 2022

The aerodynamic behaviour of a CRH high-speed train under three infrastructure scenarios (flat ground, embankment, and viaduct) in the presence of a crosswind was simulated using a 1/8th scaled train model with three cars and the IDDES framework. The time-averaged and instantaneous flow field around the model were examined. The employed numerical algorithm was verified through a wind tunnel test, and the grid and timestep resolution analyses were conducted to ensure the reliability of the data. It was noted that the flow around the rail line was different under different infrastructure scenarios, especially in the case of the embankment, which degraded the aerodynamic performance of the train under the crosswind. The flow around the train on the flat ground and viaduct was different, although the aerodynamic performance of the train was similar in both cases. Moreover, the viaduct accidents were noted to have the most critical consequences, thereby requiring the most attention. The aerodynamic performance of the train on the windward track of the embankment under the crosswind was worse than that of the train on the leeward track. But for the other two infrastructure scenarios, the aerodynamic performance of the train on the windward track is relatively dangerous, which is mainly caused by the head car. These observations suggest that the aerodynamic behaviour of the train on an embankment under a crosswind must be carefully considered and that certain wind protection measures must be adopted around rail lines in windy areas.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 봄 학술발표회 논문집
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• pp.323-330
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• 1999

Daylight collapse have been occurred by about 5.0m deep at ground surface and collapse of the crown head part of the tunnel have connected to the ground surface during first step of shotcrete work after blasting of upper half section of the tunnel driving at two-way double track tunnel face section on highway construction. This study is for a successful illustration case for the earth improvement method through applying such strengthening methods as cement milk grouting, S.G.R grouting,, steel pipe reinforced multi-step grouting etc. for the purpose of earth strengthening of loosened earth block occurred by tunnel collapse.

• Journal of Positioning, Navigation, and Timing
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• 제1권1호
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• pp.15-21
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• 2012

For a GNSS receiver's robustness against RFI and the high accuracy of navigation solution in GNSS, interference source detection and mitigation are needed. In this paper, an adaptive lattice IIR notch filter is employed to track single-tone continuous wave and swept continuous wave interference signals, and an interference detection method is proposed. Furthermore, this paper presents interference source characterization algorithm using multiple ground stations' interference detection results. The measurement of the signal powers from each ground station is used to build weighting factors to estimate the type of the interference. The performance of interference detection algorithm is simulated for scenarios of GPS signal in the presence of single-tone continuous wave interference and swept continuous wave interference.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 연약지반처리위원회 학술세미나
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• pp.14-22
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• 1999

Daylight collapse have been occurred by about 6.$^{0}$ m deep at ground surface which connected to the ground surface and excessive overbreak have been occurred by the space and height of 3.$^1$~6.$^2$m at crown head part of the tunnel during tunnelling of lower-half part after completing upper-half part on tunnelling of a phyllite mountain by NATM method at the construction work of two way-double track national road. This study is a successful illustration case of earth improvement by confirming structural safety of the tunnel in a whole through solving the cause of the tunnel collapse and the work have completed successfully through applying such earth strengthening method as cement mortarㆍcement milk injection, S.G.R, steel pipe reinforced multi-step grouting etc.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.366-370
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• 2014

Considering a countermeasure against vibration along the existing line, in many cases, it may be the most efficient method to replace existing fasteners with high resilient fasteners because of the restriction of the construction of a new track type. There are many types of high resilient fasteners which are different in price and performance. Therefore it is important to choose the high resilient fastener which has best vibration-proof performance per price. In this study, a prediction method which can exactly evaluate the performance of a fastener in the reduction the ground borne noise in the existing line is presented, which is constructed based on the combination of the measurement and the simulation. A numerical example using the presented method is introduced to evaluate the vibration-proof performance for the solution of the vibration problem in the existing line.