• Title/Summary/Keyword: Railroad bridge

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Track Longitudinal Irregularities at Bridge Deck Expansion Joint with ZLR(Zero Longitudinal Restraint) (활동체결장치가 설치된 교량상판 신축이음부에서의 궤도고저틀림에 미치는 영향)

  • Eom, Jong-Woo;Kim, Si-Chul;Kim, In-Jae
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1093-1098
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    • 2007
  • In designing the high-speed railroad track, it is important to utilize appropriate track components to maintain uniform stiffness and ensure track alignment within the tolerance set for that system. In this regard, continuous welded rails (CWRs) were introduced to the Korean railways. Yet the installation of CWRs can result in an adverse impact due to the track/structure interaction on bridge sections yielding variations in the stiffness at the expansion joints. It may also impose additional axial force, generate excessive stress or deflection on track, and loosen the ballast at the ends as a bridge deck contracts or expands owing to a thermally-induced dynamic response. The risk is even greater in a long bridge deck, resulting in track longitudinal irregularities, deteriorating passenger's comfort, and increasing maintenance efforts. This study evaluates the performance of ZLR and their impact on track longitudinal irregularities through the track measuring results on a test section installed the ZLR in order to minimize the thermally-induced responses and the maintenance efforts for the high speed railway bridges.

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An analysis of bridge perimeter of river channel change and sediment concentration distribution characeristic (교량 주변 하도구간에서 하상변동 및 유사농도 분포 특성분석)

  • Lee, Hyo-Jung;Jung, Do-June;Ahn, Seung-Seop
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.207-210
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    • 2008
  • Recently many studys have been continued Nak-Dong river. This study recognized the importance about a rivers floor change. The Nak-Dong main river of railroad bridge(2.423Km) waegwan-eup, Cilgok-gun, Gyeongsangbuk-do analyzed to the SED2D-WES model. This study recognized the difference of the model according to the existence and nonexistence of the bridge piers. At a result of mean velocity current is higher in bridge option appeared in this case. As well sediment transportation model show that river bed change appear the part of velocity is low.

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Effects of Bridge Bearings by Structure-Track Interaction for Continuous Bridge applied CWR with Rail Expansion Joint under Temperature Load (레일신축이음 설치된 장대레일 적용 연속교의 구조물-궤도 상호작용에 의한 온도하중이 교량 받침에 미치는 영향)

  • Chung, Jee-Seung;Lee, Jong-Soon
    • Journal of the Korean Society of Safety
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    • v.25 no.5
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    • pp.54-61
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    • 2010
  • The additional axial force of CWR(continuous welded rail) is occurred by structure-track interaction, in reverse, fixed supports of structure are applied the large load by that. Ratio of load which transferred on support through the bridge superstructure with one-side REJ by acceleration and braking load are stated in High-Speed Rail Design Criteria(2005). On the other hand the horizontal forces of support delivered to the load due to thermal loads has been no report about the criteria. Therefore, this study was performed the review of the reaction and displacement on support by structure-track interaction in a special bridge(composite brdiges, 45+55+55+45=200m) with REJ acting on the temperature load. As a result, because fixed support of a special bridge or a continuous bridge with REJ under the temperature load which is constant load has been acted the large lateral load by structure-track interaction, when determining the fixed bearing capacity of structure should be reflected in the results to secure the safety of structures was confirmed.

Lightweight Design of a Modular Bridge for Railway Infrastructure Systems (철도 인프라 적용 교량형 조립식 모듈의 경량화 설계)

  • Im, Jae Moon;Shin, Kwang Bok;Park, Jae Hyun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.25 no.6
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    • pp.471-478
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    • 2016
  • This paper describes a method to design a lightweight modular bridge for a railway infrastructure system. A lightweight design was achieved using the material selection method. Aluminum extrusions and honeycomb sandwich composites were selected as the best materials to reduce the weight of the upper structure of a conventional modular bridge made of carbon-steel material. The structural integrity of the lightweight modular bridge was evaluated under vertical and wind loads. The twisting and bending natural frequencies were also evaluated to investigate its dynamic characteristics. The results showed that the structural integrity and natural frequencies of the lightweight modular bridge, made of aluminum extrusion and sandwich composites, satisfied the design requirements. Moreover, it was found that the weight of the conventional modular bridge made of carbon steel could be reduced by a maximum of 47% using lightweight materials.

Damage Potential of a Domestic Metropolitan Railway Bridge subjected to 2016 Gyeongju Earthquake (2016년 경주지진에 의한 국내 도시철도 교량의 잠재적 손상평가)

  • Lee, Do Hyung;Shim, Jae Yeob;Jeon, Jong-Su
    • Journal of the Earthquake Engineering Society of Korea
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    • v.20 no.7_spc
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    • pp.461-472
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    • 2016
  • Damage potential has been investigated for a domestic metropolitan railway bridge subjected to 2016 Gyeongju earthquake which has been reported as the strongest earthquake in Korea. For this purpose, nonlinear static pushover analyses for the bridge piers have been carried out to evaluate ductility capacities. Then, the capacities have been compared with those suggested by Railway Design Standards of Korea. This comparison shows that all piers possess enough safety margins. Nonlinear dynamic time-history analysis has also been conducted to estimate both displacement and shear force demands for the bridge subjected to ground motions recorded at stations in near of Gyeongju. Maximum demands reveal that response under the ground motions remains essentially in elastic. In addition, for a further assessment of the bridge under the Gyeongju earthquake, fragility analyses have been performed using those ground motions. The fragility results indicate that the recorded earthquakes do not significantly affect the damage exceedance probability of the bridge piers.

Evaluation of Railroad Restoration Technology using Quick-reaction Expansible Resins (급속 팽창성 수지를 이용한 철로침하 복원공법의 평가)

  • Shin, Eun-Chul;Son, Won-Ik;Kim, Sung-Hwan;Kan, Hyoun-Hoi
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1789-1795
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    • 2007
  • Railroad, the structure maintenance and restoration project was increased and widely performed in concrete pavement road and airport, building at downtown area, bridge abutment, and other concrete structures. Especially, the ground reinforcement technique by quick-reaction expansible resins is the most effective countermeasures against differential settlement and undesired deformation of structure. In this paper, the unconfined compressive strength and some environmental related tests were conducted to evaluate compressive strength and environmental effect of quick-reaction expansive resins and soil mixtures. Also, three case histories of concrete structure and railroad restoration project are presented. Based on the laboratory test, the quick-reaction expansible resins and soil mixture represent the sufficient compressive strength and the leachate material is satisfied the environmental regulation limits. As a result of this study, the structure restoration technology using quick-reaction expansible resins is very effective for restoration of differential settlement and deformation, and it is environmentally sustainable technology.

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Data throughput measurement for Wireless LAN of IEEE 802.11g In Train environment (열차내 무선 통신을 위한 AP 설치 방안 연구)

  • Song, Yong-Soo;Han, Sung-Ho;Lee, Su-Gil
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.395-396
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    • 2007
  • Recently the application area of wireless LAN has been increased, rapidly. The application area was limited in indoor, but as the data throughput and performance of wireless LAN becomes better the application is to extend to the Internet connection and wireless bridge in outdoor. In this paper, the data throughput of wireless LAN in mobile environment is measured, and the usability of wireless LAN for Train, Telematics, and LBS is confirmed.

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The Study on the Archives Held in Railroad Stations in Busan (부산지역 철도역 소장 기록의 잔존양태 분석)

  • Lee, Ju-Yeon;Kim, Hee-Young
    • Journal of Korean Society of Archives and Records Management
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    • v.11 no.1
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    • pp.299-326
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    • 2011
  • This paper surveyed records and archives which the railroad stations in Busan possesses and illustrated the status of them. Also we examined whether records and archives of railroad stations contain the memories of localities or not. We visited 17 railroad stations in Busan and we found that 1) the archives in railroad station are fugitive archives 2) the records or archives are classified into five categories, 'station's history', 'report on station-adjacent area', 'report of drive and transport', 'photos', and 'other materials' 3) the volume of such archives in 17 stations are different because of disposal or missing 4) Each archives in same category have same form. Especially the descriptions and images in 'station's history', 'report on station-adjacent area' represent much to memories of locality, but we also must examine the public records, private records related railroad station in Busan for documenting localities. To bridge the gap we suggest to collect oral records by relevant persons.

Research of Remote Inspection Method for River Bridge using Sonar and visual system (수중초음파와 광학영상의 하이브리드 시스템을 이용한 교각 수중부 원격점검 기법 연구)

  • Jung, Ju-Yeong;Yoon, Hyuk-Jin;Cho, Hyun-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.330-335
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    • 2017
  • This study applied SONAR(Sound Navigation And Ranging) to the inspection and evaluation of underwater structures. Anactual river bridge was chosen for inspection and evaluation. SONAR and an optical camera were operated together to analyze the underwater image of the bridge. SONAR images were obtained by various methods to remove the environmental variables from the field experiment, and it was confirmed that the reliability of detecting damaged areas on piers was decreased when using SONAR alone. The SONAR equipment and the optical camera can be used simultaneously to overcome the limitations of SONAR in inspecting underwater structures.These results can be used as basic data for the development of similar technologies for underwater structure inspection.

Flexural Reliability Assessment of PSC-I Girder Rail Bridge Under Operation (사용중 PSC-I 거더 철도 교량의 휨모멘트에 대한 신뢰도 분석)

  • Kim, Ki Hyun;Yeo, Inho;Sim, Hyoung-Bo
    • Journal of the Korean Society for Railway
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    • v.19 no.2
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    • pp.187-194
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    • 2016
  • It is necessary to determine reliability indexes of existing railway bridges prior to setting up a proper target reliability index that can be used to introduce a reliability based limit state design method to design practice. Reliability is evaluated for a six PSC-I girder railway bridge, which is one of many representative types of double-track railway bridges. The reliability assessment is carried out for an edge girder subjected to bending moment. In the assessment, the flexural resistance and the fixed-load effect were obtained using existing statistical values from previous research on the introduction of limit state design to road bridge design. On the other hand, the live-load effect was determined using statistical values obtained from field measurement for the Joong-ang corridor, on which heavy freight trains are frequently passing. The reliability assessment is performed by AFOSM(Advanced First Order Second Moment method) for the limit state equation, and a sensitivity analysis for the reliability is performed for each factor of the load and resistance effects.