• Structural Engineering and Mechanics
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• 제63권6호
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• pp.713-723
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• 2017

As a new type of ballastless track, longitudinal continuous slab track (CST) has been widely used in China. It can partly isolate the interaction between the ballastless track and the bridge and thus the rail expansion device would be unnecessary. Compared with the traditional track, CST is composed of multi layers of continuous structures and various connecting components. In order to investigate the performance of CST on a long-span bridge, the spatial finite element model considering each layer of the CST structure, connecting components, bridge, and subgrade is established and verified according to the theory of beam-rail interaction. The nonlinear resistance of materials between multilayer track structures is measured by experiments, while the temperature gradients of the bridge and CST are based on the long-term measured data. This study compares the force distribution rules of ballasted track and CST as respectively applied to a long span bridge. The effects of different damage conditions on CST structures are also discussed. The results show that the additional rail stress is small and the CST structure has a high safety factor under the measured temperature load. The rail expansion device can be cancelled when CST is adopted on the long span bridge. Beam end rotation caused by temperature gradient and vertical load will have a significant effect on the rail stress of CST. The additional flexure stress should be considered with the additional expansion stress simultaneously when the rail stress of CST requires to be checked. Both the maximum sliding friction coefficient of sliding layer and cracking condition of concrete plate should be considered to decide the arrangement of connecting components and the ultimate expansion span of the bridge when adopting CST.

• 한국철도학회논문집
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• 제12권3호
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• pp.405-411
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• 2009

고속철도 신호시스템은 ATC시스템을 이용하여 열차의 제한속도를 송신하고, 일부 도시철도 신호시스템은 이동가능거리를 전송한다. 열차제어정보전송은 직접 궤도를 이용하여 차상에 전송하는 방식, 궤도상에 기기를 설치하여 전송하는 방식, 선로변에 기기를 전송하는 방식이 있다. 직접궤도를 도체로 활용하여 궤도를 회로일부로 구성하고, 궤도에 신호를 전송하여 열차가 궤도에서 열차제어 정보를 획득하는 방법으로, 궤도회로를 사용하며, 고속철도, 지하철에서 사용하고 있다. 궤도회로를 사용하는 방식은 반송신호에 정보를 실어서 보내며, 차상장치는 자기결합에 의해서 정보를 획득한다. 콘크리트 슬래브궤도에는 많은 철근을 사용하기 때문에 자갈도상의 궤도에서는 발생되지 않았던 레일과 철근간의 상호작용이 발생한다. 레일과 철근간의 상호작용이 발생하여 레일의 전기적 특성이 변화된다. 본 논문에서는 경부고속철도 2단계 구간에서 사용되는 콘크리트 슬래브궤도에서 레일과 철근 사이의 모델을 이용하여 콘크리트 슬래브궤도의 모델로부터 레일과 철근 사이의 결합계수를 수리적으로 해석하고, 레일과 철근간의 상호작용이 일어나지 않는 경우, 즉 철근에 의한 레일의 전기적 특성의 변화가 없는 결합계수를 정의하였다.

• 한국전기전자재료학회논문지
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• 제22권10호
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• pp.864-869
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• 2009

The measurement of contact wire uplift in electric railways is one of the most important test parameters to accepting the maximum permitted speed of new electric vehicles and pantographs. The contact wire uplift can be measured over short periods when the pantograph passes monitoring stations. In this paper, a high-speed image measurement system and its image processing method are being developed to evaluate dynamic uplift of overhead contact wires caused by pantograph contact forces of Korea Tilting Train eXpress (TTX) and Korea Train eXpress (KTX). The image measurement system was implemented utilizing a high-speed CMOS (Complementary Metal Oxide Semiconductor) camera and gigabit ethernet LAN. Unlike previous systems, the uplift measurement system using high speed camera is installed on the side of the rail, making maintenance convenient. On-field verification of the uplift measurement system for overhead contact wire using high speed camera was conducted by measuring uplift of the TTX followed by operation speeds at the Honam conventional line and high-speed railway line. The proposed high-speed image measurement system to evaluate dynamic uplift of overhead contact wires shows promising on-field applications for high speed trains such as KTX and TTX.

• 한국자동차공학회논문집
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• 제15권1호
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• pp.186-192
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• 2007

In general, pulsation damper is installed in fuel rail for conventional MPI engine to decrease undesirable noise in vehicle cabin room. However, pulsation damper is so expensive that there are prevailing studies to reduce fuel pressure pulsations with integrated damping effect. This paper is one of basic studies for development of fuel rail to abate pulsations with self-damping effect. Primarily, the pressure pulsation characteristics was investigated with aspect ratio of cross section, wall thickness, and materials of fuel rail. A high aspect ratio or thin wall was found to absorb the pressure pulsations effectively. But volume effects on the fuel pressure pulsation reductions were not especially significant than cross section effects because volume increment rate is larger than pressure pulsation reduction rate. The fuel rail made of aluminum is effective for reduction of pressure pulsation than that of low-carbon steel. Pressure change period increases on the basis of same lengths of supply line and fuel rail as the volume is enlarged and/or the thickness of wall is thinned.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1370-1378
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• 2007

고속철도 교량은 고속주행 열차의 차축 주기하중 효과와 교량 고유의 동적특성에 의한 동적 증폭 효과로 인하여 구조물의 안전성에 영향을 받는다. 그리고 교량의 과도한 변형으로 인하여 차륜과 레일의 접촉력 감소, 궤도틀림 등의 윤중 변동이 일어나 열차의 주행안전성 및 승차감을 저해할 수 있다. 이러한 궤도 안전성을 확보하기 위하여 동적거동에 대한 교량상판수준의 수직가속도 제한, 차륜-레일간의 접촉과 열차주행 안전성 확보를 위한 상판 면틀림 제한, 단부 회전각 변위 제한, 차량하중에 의한 교량의 수직 처짐 제한을 반드시 만족시켜야 하며, 필수적으로 공진에 대한 검토도 이루어져야 한다. 신설되는 호남고속철도에서는 기존의 경부고속철도와 다른 콘크리트 도상을 적용하고, 궤도간격, 설계열차하중 등이 변경되어 적용되므로 새로운 동적안정성 요구조건을 적용하게 된다. 본 연구에서는 콘크리트교량에 비해 진동특성이 취약한 것으로 알려진 강합성 거더 고속철도 교량의 동적거동 분석을 수행하였다.

• 한국항공운항학회지
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• 제20권1호
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• pp.26-33
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• 2012

Competition between air transportation and railways has grown fiercer in major countries around the world with the rise of high-speed railways. In South Korea, air passenger travel has been rapidly decreasing since the initial launch of the Seoul-Pusan KTX line in 2004 and second opening that followed in 2010. Further expansion of the high-speed railway is expected. At present, research efforts to verify the validity of constructing an underwater express railway tunnel between Ho-nam and Jeju Island are taking place. Considering the possible high speed railway connection between Seoul and Jeju Island, this thesis has analyzed the choice behavior of existing passengers of the major and low-cost carriers. For this, Stated Preference (SP) research has been performed for three variables, including fare, travel time and the number of runs, to estimate the substitution rate of each of the three variables. Binomial Logit Model has been estimated with the obtained data. The estimation of the model has found that airline passengers of major and low-cost carriers are willing to pay approximately 7,200 KRW and 5,000 KRW, respectively, to reduce travel time by one hour. If the number of runs in one day increases, it has been estimated that the passengers are willing to pay additional fares of about 390 KRW and 30 KRW, respectively. On the other hand, the substitution rate between the number of runs and the travel time was found to be somewhat insignificant. If the construction of the Seoul-Jeju line progresses in the future, this study could be used as preliminary data for determining fares, travel time and the number of runs.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.318.1-318
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• 2002

In this paper, the results of an analysis of the dynamic behavior of the eddy current brake(ECB) system are presented. The measured irregularity of the track in Korean high speed line and the track irregularity given by ERRI(high level) were used for simulation. The wheel-rail profile combination were analyzed with different rail gauges. A model of the bogie with an substitute body fur the carbody was implemented in the Multi-Body-Simulation Program Simpack. (omitted)

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.340-346
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• 2000

The vibration induced by high speed train running on rail is dealt with as an environmental problem. The train induced vibration is characterized by moving loads of specific frequency contents and soil conditions. In fact various sources are involved the wheal distance, number of cars, speed of operation, drift of rails, structural form vibration, etc. In this paper the characteristics of transferring vibration induced by the operational high-speed train is discussed. And the field measurements was conducted at region from Chungnam Yungi So-jung-myan to Chungbuk Chungwon hyun-do-myun. In the future is would be proposed the fundamental data for establishment of the countermeasure for vibrational reduction of high speed train using the results of the field measurements and quantitative prediction of the vibration level

• 한국소음진동공학회논문집
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• 제20권8호
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• pp.774-781
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• 2010

In Korea, the high-speed train is one of the most important mass transportation. Due to its fast speed, the interior noise level is high and it is one of major reason for passenger complaints. In this study, the response of passengers to interior noise was evaluated using sound quality parameters. The effects of various parameters, such as train types, travel speed, rail road, on the calculated sound quality were investigated. The characteristics of interior noise were identified. The obtained results were compared to auditory experimental data. For precise comparison of noises of similar loudness but with different characteristics, paired comparison method was used. From the comparison, important parameters that have influence on the annoyance and loudness of the noise were determined.

• Structural Engineering and Mechanics
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• 제59권2호
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• pp.277-290
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• 2016

This paper investigates the ground vibration induced by high-speed trains moving on multi-span continuous bridges. The dynamic impact factor of multi-span continuous bridges under trainloads was first determined in the parametric study, which shows that the dynamic impact factor will be large when the first bridge vertical natural frequency is equal to the trainload dominant frequencies, nV/D, where n is a positive integer, V is the train speed, and D is the train carriage interval. In addition, more continuous spans will produce smaller dynamic impact factors at this resonance condition. Based on the results of three-dimensional finite element analyses using the soil-structure interaction for realistic high-speed railway bridges, we suggest that the bridge span be set at 1.4 to 1.5 times the carriage interval for simply supported bridges. If not, the use of four or more-than-four-span continuous bridges is suggested to reduce the train-induced vibration. This study also indicates that the vibration in the train is major generated from the rail irregularities and that from the bridge deformation is not dominant.