• Title, Summary, Keyword: 궤도틀림

Search Result 100, Processing Time 0.042 seconds

Kinematic Modeling of a Track Trolley Using Extended Kalman Filter (확장 칼만필터를 이용한 궤도틀림 트롤리의 운동학적 모형화)

  • Lee, Jun S.;Choi, Il Yoon;Kim, Sun Hee;Um, Ju Hwan
    • Journal of the Korean Society for Railway
    • /
    • v.18 no.5
    • /
    • pp.447-456
    • /
    • 2015
  • Continuous as well as discrete measurement of the track geometry based on a track trolley are investigated to enhance the efficiency of the trolley and to minimize the measurement errors. A new kinematic model based on the track coordinates involving transition and circular curves is developed to improve the accuracy of the measurement; a nonlinear Extended Kalman Filter (EKF) is employed to linearize the governing equations. The proposed model is verified with the ideal track geometry in terms of both discrete and continuous measurement. Comparison with the previous models is also made to prove the applicability of the kinematic model.

Evaluation of Track Irregularity Effect due to Adjacent Excavation on Serviced Railway Line (철도시설물 인접굴착공사에 따른 운행선 궤도의 궤도틀림 영향 평가)

  • Choi, Jung-Youl;Park, Dong-Ryong;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.5 no.4
    • /
    • pp.401-406
    • /
    • 2019
  • The three-dimensional precision numerical analysis was performed using the finite element model applied with the railway track model consisting of rails, sleepers, and track elastic springs(ballast, rail pad). As a result of analyzing the track deformation level of the existing tracks due to the excavation work adjacent to the railway facilities, it was found that the track irregularity evaluation criteria (allowed values) of both conventional and high-speed railways lines were satisfied. Based on the numerical analysis using the track model, it was analyzed that the results of the prediction of the track irregularity due to the excavation work and the level of the track deformation occurring at the actual site could be approximated as closely as possible.

유지 보수의 입장에서 본 궤도 기술의 현상과 과제

  • 서사범
    • Journal of the Korean Society for Railway
    • /
    • v.5 no.2
    • /
    • pp.27-33
    • /
    • 2002
  • 궤도의 역할은 열차 하중을 지지하고, 이것을 분산시켜 구조물에 전달함과 동시에 열차의 주행을 위한 원활한 (안전하고 승차감이 좋은) 안내로를 제공하는 것이다. 그러나, 궤도는 열차의 반복 주행에 의하여 구성 재료의 열화ㆍ손상이나 궤도 틀림의 진행이 부득이 하므로 일상적인 궤도정비 작업이나 재료교환 작업을 피할 수 없기 때문에 될 수 있는 한 적은 보수비로 열차 주행에 필요한 궤도 품질을 실현하는 기술의 확립이 궤도 기술에 관한 연구 개발의 최대 사명이다. 궤도 보수에 관계하는 비용은 크게 세 가지로, 즉 궤도 재료의 교환ㆍ보수 작업, 궤도 틀림의 정비 작업, 각종 검사나 유간 정정 등의 기타 작업으로 대별할 수 있다. (중략)

Evaluation of Track irregularity due to Adjacent Excavation Work on Serviced Urban Transit (도시철도 인접굴착공사에 따른 운행선 궤도의 궤도틀림 분석)

  • Choi, Jung-Youl;Lee, Ho-hyun;Kang, You-Song;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
    • /
    • v.6 no.2
    • /
    • pp.481-487
    • /
    • 2020
  • In this study, finite element analysis was performed to evaluate the track irregularity of the existing track system on urban transit according to the large-scale excavation work that is constructed adjacent to the serviced line. Based on the numerical analysis, the effect of track irregularity generated during the step-by-step construction process was analytically derived, and the stability in terms of track deformation was evaluated through comparison with related standards. As the results, in the case of track irregularity items evaluated based on the relative displacement difference at a certain distance, such as alignment and vertical irregularity, it occurred most clearly at the location where deformation of the existing structure begins, such as the end point of adjacent excavation work. On the other hand, the overall vertical and horizontal displacement of the track was the largest deformation at the center of the construction section. The vulnerable position of the deformed side of the existing structure due to adjacent excavation is analytically proven that the both of the end point section and the center of the construction can be a vulnerable position in terms of track irregularity.

Determination of Upper Limit of Rail Pad Stiffness for Ballasted and Concrete Track of High-Speed Railway Considering Running Safety (주행 안전을 고려한 고속철도 자갈궤도 및 콘크리트궤도 레일패드의 강성 상한 결정)

  • Yang, Sin-Chu;Jang, Seung-Yup;Kim, Eun
    • Journal of the Korean Society for Railway
    • /
    • v.14 no.6
    • /
    • pp.526-534
    • /
    • 2011
  • In this study, proposed is the methodology to determine the upper limit for stiffness of rail pad for the ballasted and concrete track in high-speed railway in the viewpoint of running safety, considering the dynamic characteristics of train and track and the operation environment. For the track irregularity, one of the most important input parameters for traintrack interaction analysis, the reference vertical track irregularity PSDs(power spectral densities) for the ballasted and concrete track in a wide range of frequencies were proposed based on those presented in France and Germany and that obtained from the measured data at Kyeong-Bu 1st phase high-speed railway line. Using these reference PSD models, the input data for the vertical track irregularity data were regenerated by random generation process, and then, the wheel load reduction rates according to the stiffness of the rail pads have been calculated by the train-track interaction analysis technique. Finally, by comparing the wheel load reduction rates calculated with the derailment criteria prescribed in the Korean standards for railway vehicle safety criteria, the upper limits for the stiffness of rail pad have been proposed.

Track Stability Assessment for Deep Excavations in Adjacent to Urban Railways (도시철도 인접지반 깊은 굴착 시 궤도 안정성 평가)

  • Jeon, Sang-Soo;Lee, Sang-Seung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.6
    • /
    • pp.614-627
    • /
    • 2018
  • Urban railway lines have been constructed adjacent to residential buildings and urban areas. The expansion of transportation networks and reconstruction of residential buildings in highly populated urban areas require deep excavations in areas adjacent to urban railways. Mobilized soil stresses and changes in the groundwater level induced by deep excavations results in track irregularities in urban railways. In this study, a three-dimensional finite difference model using the commercial program FLAC3D was adopted to estimate the horizontal displacements of earth retaining structures, settlements of backfill, the stability of track irregularity and underground box structure based on the criteria of each railway organization and its relationships. In deep excavations, a change in groundwater level induces relatively very small differences for track gauge irregularities, whereas relatively large differences for longitudinal irregularities of 72.5%, twist irregularities of 83.3%, cross level irregularities of 61.9%, and alignments of 43.3% were found to be the maximum differences when the horizontal displacement of earth retaining wall and settlement of backfill were 65.1% and 21.4%, respectively, because the groundwater level (GWL) on the ground surface-mobilized tensile strength of the underground box structure exceeds the allowable value. Therefore, three-dimensional numerical analysis was performed in this study. Overall, real-time monitoring should be carried out to prevent railway accidents in advance when a deep excavation adjacent to urban railway structures is constructed.

Correlation Analysis Between Crack and TQI in RC Slab Track (철도콘크리트 슬래브 궤도상의 균열과 TQI 상관성 분석)

  • Kwon, Sae Kon;Park, Mi Yun;Kim, Doo Kie;Park, Jae Hak
    • Journal of Korean Society of Disaster and Security
    • /
    • v.5 no.2
    • /
    • pp.71-79
    • /
    • 2012
  • Recently, in the total railroad construction field, the concrete slab track is adapted, not ballast track. Because the ballast track have the characteristics doing the ongoing maintenance and difficult to handle increasing maintenance costs, eventually the concrete slab track is selected as an alternative. However, owing to the hydration heat reactions and temperature affected shrinkage cracks related to concrete itself, a variety of studies to solve maintenance problems related to concrete slab track are underway. This study analysed characteristics of TQI values evaluating the track irregularity, searched the relationship between crack progress and TQI, and then evaluated of the correlation between the two values. Through this method, there is a need to complete the problems of the current method, only TQI is the main decision making tool in track maintenance, and also the need for the development of evaluation index considering the crack.

Sensitivity of the ballast resistance and track irregularity on the track stability (궤도 안정성에 대한 도상저항력과 궤도틀림의 민감도)

  • Lim, Nam Hyoung;Choi, Sang Hyun;Lee, Chin Ok;Sung, Ik Hyun
    • Journal of Korean Society of Steel Construction
    • /
    • v.17 no.5
    • /
    • pp.519-526
    • /
    • 2005
  • During summer, very high compressive force occurs on the continuous welded rail (CWR) track because of the increase of rail temperature (max. $60^{\circ}C$). This extreme temperature stress can cause the CWR track to buckle. Among many CWR parameters affecting the track buckling, the influence of the lateral and longitudinal ballast resistance was investigated on the stability of the CWR track in this study. Also, the sensitivity of the track irregularity such as the alignment defect and the gauge irregularity was investigated.

Train-Structure Dynamic Interaction Analysis of The Bridge Transition Considering Track Irregularity (궤도틀림을 고려한 교대접속부의 열차상호동적거동해석)

  • Choi, Chan-Yong;Kim, Hun-Ki;Chung, Keun-Young;Yang, Sang-Beom
    • Journal of the Korean Geotechnical Society
    • /
    • v.31 no.9
    • /
    • pp.29-38
    • /
    • 2015
  • In this study, track dynamic interaction characteristics caused by the vehicle running through transitional section such as bridge abutments were studied using the finite element analysis program. The geometric condition of track was generated by trigonometric function and allowable maximum track irregularity is determined by KORAIL track maintenance criteria. The sub-infrastructure under rail fastener system was modelled by 3D solid elements. To reduce computational cost only half track line is numerically considered and the roller boundary condition was applied to each side of model. In this study, the vehicle-track dynamic interaction analysis was carried out for standard Korean transition section of concrete track and the dynamic behaviors were investigated. The dynamic characteristics considered are wheel load variation, vertical acceleration at body, and maximum Mises stress at each part of transitional section.