• 한국철도학회논문집
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• 제15권2호
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• pp.109-115
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• 2012

허본 논문에서는 도상자갈 비산에 의한 GFRP 복합재 대차프레임의 구조안전성을 평가하기 위해 대차프레임의 스킨부를 구성하는 유리섬유/에폭시 적층 복합재의 충격시험과 충격 후 잔류압축시험을 수행하였다. 충격시험은 충격시험장비를 사용하여 5J, 10J, 그리고 20J의 충격에너지에 대해 수행하였고, 선로상의 도상자갈 비산을 모사하기 위해 구형, 육면체형, 그리고 원뿔형의 충격체를 설계하여 충격시험을 수행하였다. 충격손상을 갖는 적층 복합재의 잔류압축강도를 평가하기 위해 충격 후 압축시험을 수행하여 충격에 의한 재료의 물성저하 여부를 판단하였다. 본 연구를 통하여 충격에너지가 증가함에 따라 적층 복합재의 충격손상영역과 압축강도저하가 증가하는 것을 확인하였으며, 원뿔형 형상의 도상자갈이 다른 형상에 비해 재료의 손상을 가중시키는 것을 확인하였다.

• 문화기술의 융합
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• 제5권1호
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• pp.389-394
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• 2019

본 연구에서는 무도상 궤도가 부설된 국내 도시철도의 철도 교량상 목침목에 대한 선로검사내규의 점검사항 및 불량판정 기준을 개선하여 목침목의 손상유형에 따른 상태등급체계를 분류하고 침목별 이력관리대장 시스템 도입을 통해 목침목의 유지관리체계를 개선하고자 하였다. 이를 위해 본 연구의 대상 철도교량에 부설되어 있는 목침목의 손상현황을 분석하여 손상별 코드를 구축하였으며, 침목별 손상 및 유지관리이력을 관리할 수 있는 유지관리시스템 도입을 통해 단면형상 및 침목 고정장치가 다양하고 유지관리가 복잡한 무도상 철도교량상 목침목의 체계적인 유지관리가 가능할 것으로 판단되었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.3147-3155
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• 2011

Railway bridges are highly susceptible to resonance due to the equidistant axle load with constant speed of train. Thus, it is inevitable verify dynamic characteristics and quantities against dynamic guidelines. Recently, various new-type bridges are developed and applies to medium span length between 30m and 40m. However, just steel box girder bridge is under review for span length between 45m and 50m without development any new technologies. This study investigate the dynamic properties and safety of steel box railway bridge having span length 45m in alternative girder hight and kind of ballast. Numerical analysis is performed time series analysis by mode superposition using calculated natural vibration frequency and mode after carry out a free vibration analysis and extract modal parameter to higher modes. The results are then compared to various dynamic stability standards toward target bridge's dynamic stability analysis. The result of this study is expected as a reference for design railway bridges.

• 한국건설순환자원학회지
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• 제18권3호
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• pp.18-23
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• 2023

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.229-234
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• 2004

When trains run over a snow-covered track at high speed, the snow accereted under car bodies may drop during train running. The dropped snow lumps scatter the ballast on the track damaging the car body and the environment along the track in snowy regions. In this study, various countermeasures to prevent the ballast from scattering has been investigated and compared. Furthermore, the implementation of the ballast-flying prevention methods to passing-by station has been examined through which the KTX train passes about 300km/h speed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.498-503
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• 2005

In this paper, an experimental study is carried out to analyze the vibration characteristics of components of the ballast track and the slab track layed in HSL tunnels. According to vibration level test of ballast tracks and concrete tracks on HSL, the vertical vibration level of rails on concrete tracks is 6.2dB more than that on ballast tracks, and especially on $50{\sim}80Hz$ frequency band, the difference is more than 6dB. The orther track components according to track type are appeared to be smaller on the slab track than on the ballast track. Regarding car body vibration, 80Hz component, which was not remarkable while running on open tracks, is considerably amplified in tunnels where concrete tracks are laid.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.303-310
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• 2001

The railroad under operation has very sharp curves and the state of ballast is somewhat deteriorated due to the traffic loads, which put some constraints in converting the conventional rails into CWR. In making CWR, the determination whether the ballast has sufficient capacity for resisting buckling must be made, quantitatively and qualitatively, and schemes to guarantee the required lateral resistance of ballast should be proposed. In this study, using the in-situ investigated data, the probability of buckling of CWR is given for several installation temperatures for CWR. The effect of tamping, DTS, and sleeper spacing are taken into account. The buckling probability is given as a function of curvature and installation temperature of CWR and works used to increase the ballast resistance capacity after tamping, i.e., DTS and reduction of sleeper sparing.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.1241-1247
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• 2005

The ballast-flying, induced by strong underbody train gust, may damage train underbody, wheel and even cause the safety problems. For this reason, a heighter is being used to prevent the ballast-flying phenomenon through underbody now reduction. In this research, flow field around a heighter is numerically simulated. And the parametric study of various heighter shapes is performed to find out more effective heighter shape. Also the ballast-flying probabilities are calculated for various ballast types and train speeds.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.707-716
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• 2011

It has been applied using cranes or insertion methods to install heavy structures to strengthen existing railway bridges. These methods are uneconomical because of two reasons. The first one is it is required to construct approach roads for heavy equipment and/or working yard. The second one is the electric lines shall be cutoff during construction. Both require additional construction cost and duration. In this study, new transport equipment was developed which can be applied to heavy structures up to 100 ton. Using this method, the heavy structure can be loaded into the new transport equipment at working yard and transported to the working site. This method can be applied, but not limited to railway bridge or roadbed rehabilitation. It was found that the precious construction can be achieved to install heavy structure using this method. The experimental construction to make non-ballast girder bridge composite with new pc deck slab using this method was carried out for Jewon bridge. The example bridge is in extreme condition because it locates above national road #38 within extreme transition curve and has 10 ‰ slope and skew. The experimental construction results were satisfactory both for safety and construction precision.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.697-706
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• 2011

There are more than 800 railway steel plate girder bridges which are in use and the total length is approximately 50 km. Among these, it shall be pointed out that non-ballast rail systems which lay on wood sleepers are the most critical members. To strengthen this type of structures, mainly two methods have been applied. The first one is the most typical method which is to replace the girders with slab girder system or steel composite girders and to add ballast. It is not uncommon that the construction cost of substructure is more than ten time higher than that of superstructures and even in this case, the structural uncertainty for the substructures is not diminished. To resolve above mentioned problems, new method was developed to rehabilitate railway steel girder bridge by adding PC-slab using transport equipment. Using this method, substructure strengthen is rarely required because the additional weight to the bridge superstructure is only up to 1.0t/m. Also it was possible to save the construction cost by reducing construction duration and by simplifying the construction process. Experimental construction was performed for Jewon bridge and measurements were performed before and after construction to verify the bridge capacity.