• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.470-473
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• 2006

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1113-1118
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• 2004

Ballasted track is constructed in consideration of the maintenance. The application time and frequency of MTT(Multiple Tie Tamper) and BS(Ballast Cleaner) depend on track geometry measurements. This paper presents the application of Ground Penetrating Radar(GPR), Falling Weight Deflectometer(FWD), and Portable Ballast Sampler (PBS) to evaluate the effects of track geometry due to substructure deterioration and to build a reliable substructure evaluation system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1090-1095
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• 2008

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, which determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from the characteristics of measuring device. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolley. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is EM-120, measures versine with 10m of symmetrical chord length.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.268-274
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• 2011

In railway, Ballast plays an essential role as intermedium in transmitting train load to subgrade safely. Gyoung-Bu HSL 1st phase consists of ballasted track except for over 5km long tunnels. Ballast track occurred track irregularity by train loads and requires periodic maintenance work. However, Repetitive train operation and tamping work cause to accelerate track irregularity and ballast deterioration such as abrasion and crushing. For these reason, Track irregularity areas had occurred ballast cleaning work to improve track quality. However, for the train to run safety, ballast cleaner working area needs train speed reduction and track stabilization work due to ballast relaxation and initial settlement. In this study, according to train speed-up and cumulative traffic tonnage, we measured and analyzed the track settlement and acceleration of sleepers to evaluate of track stabilization in order to keep the ballast condition stable after cleaning work.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2000년도 춘계학술대회 논문집
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• pp.431-438
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• 2000

In recent years. the destructive force acting on the ballasted track is on the increase with the speed-up of trains and the number of trains, requiring more labor and expenditure to maintain the track in goof condition. Slab track has been developed to decrease the track maintenance work on earthworks. One type of slab track Rheda has Prefabricated track grid, consisting of rails. Prestressed concrete sleepers and reinforcement rods are aligned into position. and then concrete is then placed to integrate the sleepers into a reinforced concrete track slab. In this paper, a new analysis model for the system analysis of the slab track is presented. Then the analysis results are compared with requirements for slab track.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.435-441
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• 2011

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies in Korea use various track recording equipments to measure track irregularity. But this various equipments output different data due to their geometrical structure even measured at same location. In this report, the correlation of various track recording data used in Korea was reviewed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.310-314
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• 2010

Track geometry changes by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies in Korea use normal distribution as probability distribution of track irregularity. But some countries use non-normal distribution according to their own track recording system. In this report, reviewed probability distribution of Kyung-Bu high-speed line and tested normality.

• 한국철도학회논문집
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• 제5권1호
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• pp.48-54
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• 2002

This research estimated decreased vibration level as quantitative according to change of track system on Seoul Subway Line No. 1 from existing ballasted track system(Pandrol type clip) to concrete track system(Youbgdan type isolation rubber clip). Following change to concrete system, vibration level at tunnel floor decreased between 4-8dB(V). Vibration equations suggested in this paper consider the velocity of train and can estimate quantitative vibration response. These are divided by ultimate limit state($\beta$=0), serviceability limit state($\beta$=1.28) and safety state($\beta$=3), respectively. The reliability index, $\beta$=0, means 50％ data line obtained by least squares best-fit line. The reliability index $\beta$=1.28 and 3 represent boundaries below 90％ and 99.9％ respectively.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.382-388
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• 2005

SMSC(Seoul Metropolitan Subway Corporation) is substantially taking the core role of mass transit system in Seoul Metropolitan area. When it was built, the design had challenged to sharp curved tracks less than 250m radius considering the protection of buildings and cultural properties as well as the connection to ground roads. Such circumstances have required a certain extent of slack in track geometry and therefore led to the construction of ballasted track with wooden sleepers. However, the dynamic force from running on sharp curved track has caused the misalignment and abnormal failure of track geometry, and it has resulted in a frequent maintenance and repair works which require a lot of cost and manpower. In this paper, we present the construction case of maintenance-free track system by using of concrete sleeper and elastic rail fastening system to ensure the safety of both passengers and trains, and to contribute the effective maintenance for track facilities of SMSC.

• 한국철도학회논문집
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• 제16권2호
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• pp.85-92
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• 2013

철도 전동 소음은 철도에서 발생하는 대표적인 소음으로서 차륜과 레일의 음향 조도에 의해 유기된다. 철도 전동 소음의 주요 소음원으로는 침목, 레일 그리고 차륜을 들 수 있다. 따라서 철도의 전동 소음을 해석하기 위해서는 차륜의 진동 특성과 함께 궤도의 진동을 해석하고 그 특성을 이해하는 작업이 수행되어야 한다. 본 논문에서는 전동 소음의 관점에서 레일의 진동을 해석하기 위한 이론적 궤도 모델링에 대해 기술하고, 국내의 대표적인 세 가지 철도 궤도에 대해 진동 해석을 수행하였다. 해석에 사용한 궤도로는 기존선 자갈 도상 궤도, KTX 자갈 도상 궤도, KTX 콘크리트 궤도를 선정하였으며, 각 궤도 별로 레일을 따라 진행하는 파동의 전파 특성을 해석하고 그 결과를 비교하였다. 해석 시 궤도는 이산 지지를 가진 Timoshenko 보로 모델링하였으며, 레일의 평균 진동 속도를 이용해 세 궤도 레일의 방사 소음 특성을 간접 비교하였다.