• Title, Summary, Keyword: 도상

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A Study on Effect of Vibration Reduction with Ballast Mat of Ballasted Track in Tunnel (터널내 자갈도상제도의 자갈도상매트 시공 후 진동 저감 효과에 대한 연구)

  • You, Chung-Jun
    • Journal of the Korean Society for Railway
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    • v.12 no.1
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    • pp.167-174
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    • 2009
  • Due to the travelling of the train with high speed the period of maintenance activities of the ballasted track is coming to be short, and more from the residential area of the ballasted track tunnel circumference the civil appeal is increasing with railroad vibration problem. To reduce the vibration problem and a maintenance cost establishes the ballast mat in the tunnel within part segment. In this study, to estimate the vibration reduction effect of the ballast mat we have done a comparative analysis with the vibration field test by the transit train by at the ballasted track with ballast mat and the standard ballasted track without vibration protection in tunnel.

A Study on the Crushing Characteristic of the Ballast Gravel at High-Speed Railroad (고속선 도상자갈의 파쇄특성에 관한 연구)

  • Lee, Choon-Kil;Kim, Nam-Hong;Woo, Byoung-Koo;Lee, Sung-Uk
    • Journal of the Korean Society for Railway
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    • v.11 no.4
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    • pp.384-389
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    • 2008
  • The ballast, one of track components, plays an essential role as intermedium in transmitting train load to subgrade safely, and the deterioration of ballast directly effects the growth of track irregularity. In this study, we determined the main factor of ballast deterioration was miniature of ballast gravel caused MTT (Multiple Tie Tamper) works and accumulated traffic loads. To estimate the deterioration characteristics of ballast, we carried out field test (Chap.2) through track construction for test and the model test (Chap.3) simulating the actual operation environment, have done a comparative analysis with the sample's result (crushing rate) of high-speed railroad running actually.

Aggregate Criterion for Paved Track Considering Recycling of Railway Ballast (도상자갈 재활용을 고려한 포장궤도용 골재 기준)

  • Lee, Il-Wha
    • Journal of the Korean Society for Railway
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    • v.12 no.4
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    • pp.481-487
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    • 2009
  • On the paved track, the railway ballast is used as aggregate for the filling layer using the pre-packed concrete method. The condition of ballast as the paved track aggregate ensure that the compressive strength, particle distribution size for the pouring and surface clearance to increase the adhesive strength with mortar. It is profitable to recycle the existing railway ballast as a economical supply. In order to increase recycling characteristic, it is necessary to apply the similar criterion which does not exceed the conventional railway ballast criterion. Consequently, this paper was to investigate physical characteristics of existing ballast, particle size distribution, compressive and flexural strength, bearing capacity and filling capacity to prepare the aggregate's recycling. As a result, optimized aggregate criterion is suggested.

Numerical Analysis of ballastbed stress distribution depending on the grain size distribution (도상자갈 입도분포에 따른 도상응력분포에 관한 수치해석적 연구)

  • Kim, Dae-Sang
    • Proceedings of the KSR Conference
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    • pp.85-91
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    • 2003
  • 본 연구에서는 원과 선분을 이용하여 복잡한 형상의 입자를 표현할 수 있는 2차원 개별요소법(DEM) 알고리즘에 3종류(균등분포, 정규분포, 대수정규분포)의 입도분포를 구현할 수 있도록 하였다. 개발된 프로그램을 이용하여 다양한 반지름을 갖는 원형요소를 구현하고 도상자갈을 원하는 입도분포로 모델링할 수 있었다. 그리고 우선적으로 균등분포에 대하여 변위제어 하중 재하 방식에 의하여 도상으로부터 노반으로 전달되는 응력을 파악하였다.

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Optimization of Ballast Depth of Ballasted Track Bridges to Improve Ride Comfort (승차감 향상을 위한 유도상교량의 도상두께 최적화)

  • Kim, Kwan-Hyung;Kwon, Soon-Jung;Kim, Yun-Tae
    • Journal of The Korean Society of Civil Engineers
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    • v.31 no.6D
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    • pp.867-874
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    • 2011
  • The ballast abrasion occurs on the ballasted track upon bridges more than soil roadbed because the track vibration occurs a lot in the ballasted track upon bridges due to girder vibration when a train's weight is loaded onto track even though the identical ballast is used. The phenomena of mud pumping especially, which occurs when drainage is not properly secured for heavy rain, leads to the increase of maintenance work load and the decline of ride comfort. The ballast thickness range in domestic railroad construction rule is uniformly set up according to the design speed of railroad and passing tonnage of train without considering field conditions which is considered in foreign railroad companies. The purpose of this study is to verify the effect of vibration decrease by measuring the acceleration, displacement and ride comfort of ballasted track with the change of ballast thickness on the ballast tracked bridges and to suggest the optimal height of ballast on the Yocheon Bridge built for the test in Honam Line.

A study on the 'Fun' in Hangul Iconicity (한글 도상성에 나타난 '재미'에 관한 연구)

  • Park, Young-Won
    • 기호학연구
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    • no.54
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    • pp.65-92
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    • 2018
  • Hangul 's iconicity based on the scientific creation principle makes it possible to expand into various designs. 'Fun' is a factor for success in the cultural contents industry. Through the design process, it is possible to apply fun elements to the design of cultural contents to meet the purpose. The characteristics of Hangul icons that can be used in cultural contents design, the concept of 'fun', the inducing factors of fun and the production methods of visual fun are summarized. The production method of visual fun has suggested the same way as the design humor creation method in visual communication design. 10 types of examples of Hangul in relation to visual 'fun' have been analyzed by the semiotic approach. This suggests a design methodology for the creation of fun elements that utilize Hangul Iconicity in cultural contents design in the future.

A Fundamental Study on Analysis of Electromotive Force and Updating of Vibration Power Generating Model on Subway Through The Bayesian Regression and Correlation Analysis (베이지안 회귀 및 상관분석을 통한 지하철 진동발전 모델의 수정과 기전력 분석)

  • Jo, Byung-Wan;Kim, Young-Seok;Kim, Yun-Sung;Kim, Yun-Gi
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.2
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    • pp.139-146
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    • 2013
  • This study is to update of vibration power generating model and to analyze electromotive force on subway. Analysis of electromotive force using power generation depending on classification of locations which are ballast bed and concrete bed. As the section between Seocho and Bangbae in the line 2 subway was changed from ballast bed to concrete bed, it could be analyzed at same condition, train, section. Induced electromotive force equation by Faraday's law was updated using Bayesian regression and correlation analysis with calculate value and experiment value. Using the updated model, it could get 40mV per one power generation in ballast bed, and it also could get 4mV per one power generation in concrete bed. If the updated model apply to subway or any train, it will be more effective to get electric power. In addition to that, it will be good to reduce greenhouse gas and to build a green traffic network.

An Estimate of Ballast Track Condition on Dynamic Behavior of Railway Bridge (철도교량의 동적거동 특성을 고려한 자갈도상궤도의 상태추정에 관한 연구)

  • Kweon, Oh-Soon;Choi, Jung-Youl;Kang, Myoung-Seok;Lee, Hee-Up;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.480-493
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    • 2007
  • Many railway-advanced countries are using the various types of track to reduce the track maintenance and repair cost according to the improvement of velocity. It spends on much maintenance and repair cost for ballast track due to abrasion of ballast, track irregularity and unisotropical ballast-support stiffness. The ballast track on railway bridge is accelerating the deterioration of ballast according to interaction of railway bridge and track. As continuing the deterioration, it is caused dynamic loads. Due to these effects, it increases negative loads of track and bridge. However, when designing the railway bridge, the effect of ballast track was applicate only dead load, so elastic behavior effect of ballast track is not influenced. Therefore, this paper presumes the stiffness of ballast track on railway bridge considering dynamic behavior of railway bridge, it was evaluated that effect on dynamic behaviors of railway bridge according to ballast track stiffness.

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Influence of Lateral Ballast Resistance on the Buckling Fragility Curve of the Continuous Welded Rail Tracks (장대레일 궤도의 좌굴 취약도 곡선에 대한 도상횡저항력의 영향)

  • Bae, Hyun Ung;Choi, Jin Yu;Lee, Chin Ok;Lim, Nam Hyoung
    • 한국방재학회:학술대회논문집
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    • pp.185-185
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    • 2011
  • 기존 장대레일 궤도의 안정성 평가는 궤도 매개변수에 대하여 고정된 안전측의 값을 사용하는 결정론적인 해석에 의존해서 평가되어져 왔다. 그러나 실제현장의 궤도조건은 많은 영향인자들에 의해 그 특성이 불확실하게 변하고 있다. 따라서 온도하중에 의한 궤도 좌굴에 영향을 미치는 궤도 구성인자들의 불확실성 및 임의성을 보다 합리적으로 고려하기 위해서 확률론적 기법을 적용하는 것이 필수적이다. 본 연구에서는 기존 본 연구진에 의해 개발된 장대레일 궤도의 좌굴확률 평가시스템을 이용하여 좌굴 취약도 곡선을 나타내었으며, 궤도 좌굴에 영향을 미치는 주요변수 중 하나인 도상횡저항력에 대한 영향을 분석하였다. 좌굴확률 평가시스템에서는 장대레일 궤도의 좌굴확률을 산정하기 위하여 구조물의 안정과 파괴를 판단할 수 있는 기준을 한계상태방정식으로 표현하고, 이 한계상태방정식으로부터 확률론적 기법 중 하나인 AFOSM(Advanced First Order Second Moment) 방법을 이용하여 파괴확률의 간접적인 지표인 신뢰도지수(${\beta}$)를 통해 좌굴확률을 계산한다. 한계상태방정식에서 구조물의 강도(보유성능)에 해당하는 부분은 궤도의 허용좌굴온도이고, 하중(요구성능)에 해당하는 부분은 레일온도하중으로써 현재 레일온도와 중립온도의 차로 반영된다. 허용좌굴온도 산정에 고려되는 주요변수는 곡선반경(Radius), 도상횡저항력(Lateral Ballast Resista nce), 연직도상강성(Vertical Ballast Stiffness), 궤도 틀림량(Misalignment), 틀림길이(Half Wave Length), 열차운행속도(Velocity)이다. 각 확률변수들이 갖는 확률분포는 모두 정규분포로 가정하였다. 궤도의 기하학적 특성은 곡선반경 5,000m에 대해 고려하였으며, 열차는 KTX의 제원을 사용하여 정지된 상태에서 고려하였다. 틀림량과 틀림길이는 이에 대한 통계적 특성자료가 부족하여 확률변수로 고려하지 않고 결정론적 값으로 취급하였다. 레일온도의 통계적 특성치는 본 연구진에 의해 구축된 기후요소 및 레일온도 DB를 근거로 결정하였으며, 중립온도는 선로관리지침에 따라 $25{\pm}3^{\circ}C$를 기준으로 결정하였다. 또한 도상횡저항력은 실측 데이터를 참고로 하여 평균값에서 10%의 변동량을 갖는 것으로 보고 통계적 특성치를 결정하였다. 도상횡저항력이 좌굴확률에 미치는 영향을 매우 큰 것을 알 수 있었으며, 레일온도 $60^{\circ}C$일 때 도상횡저항력이 증가하면서 감소되는 좌굴확률이 도상저항력이 커질수록 그 감소량이 작아지는 것을 알 수 있었다.

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Evaluation of the Influence Factors on the Ballast Settlement by using the Discrete Element Method (개별요소법을 이용한 도상자갈 침하 영향인자 평가)

  • Kim, Ki Jae;Lee, Sung Jin;Jang, Seung Yup;Hwang, Sung Ho
    • Journal of The Korean Society of Civil Engineers
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    • v.36 no.4
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    • pp.715-722
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    • 2016
  • Most of the domestic railroad tracks are ballast track and repetitive maintenance is required in this track. Therefore, it is necessary to optimize maintenance process for maintenance cost reduction and more effective maintenance. For this, it is important to develop a reasonable settlement progressive model of ballast layer. However, the behavior of ballast is different to that of soils, since ballast is composed of large coarse gravel. Thus, in this study, we carried out numerical analysis by using the discrete element method (PFC 2D) for better understanding of ballast settlement and development of reasonable settlement progressive model. And, we evaluated the settlement of ballast according to particles shape, porosity and loading conditions.