• Title, Summary, Keyword: ballast

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Breakage Characteristics of Ballast (도상자갈의 마모/파쇄 특성)

  • 정근영;김현기;이종득
    • Journal of the Korean Society for Railway
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    • v.2 no.3
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    • pp.61-69
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    • 1999
  • The durability of ballast plays an important role in track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several scholars. The deterioration characteristics is very important factor in the behaviour of track and its life. In this paper, abrasion/breakage characteristics of ballast is studied to see the effect of physical ballast characteristics on ballast life. To reveal breakage characteristics of ballast, the ballast box test and the MTT field test were carried out. The breakage characteristics studied in this paper is applied to the ballast life prediction in various conditions, such as LA abrasion, annual tonnage, tamping number per year, etc

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An Experimental Study of Diminution of Ballast Track Bridges Vibration due to the Variation of Ballast Depth (도상두께 변화에 따른 유도상교량 궤도 진동저감의 실험적 연구)

  • Kwon, Soon-Jung;Lee, Sang-Bae;Hong, Cheng-Hi
    • Proceedings of the KSR Conference
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    • pp.1222-1229
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    • 2011
  • Railway bridges are divided into ballastless and ballast track bridges. The ballast abrasion occurs on the ballast track upon bridges more than soil roadbed because the track vibration occurs a lot in the ballast 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. There are countermeasures such as ballast change, installation of cross-drainage for poor drainage, gutter establishment, ballast lifting methods, ballast mats and resilient sleepers laying for the mud pumping. 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 ballast track with the change of ballast thickness on the ballast track bridges and to suggest the optimal height of ballast on the Yocheon Bridge built for the test in Honam Line.

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Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

  • Sadeghi, J.M.;Zakeri, J. Ali;Najar, M. Emad Motieyan
    • International Journal of Railway
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    • v.9 no.2
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    • pp.27-35
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    • 2016
  • In spite of recent advances in ballasted railway track, the correct choice of ballast for rail track is still considered critical because aggregates progressively deteriorate under traffic loading and environmental exposures. Various ballast requirements, functions and duties have been defined by researchers, railway companies and countries' regulations even though it needs to be integrated to make following proper decision during track operation and maintenance. A proper understanding of ballast properties and suitable tests are prerequisites for minimizing maintenance costs. This paper presents a capable classification for ballast characteristics which need to be investigated beforehand to such a way, firstly to assign ballast functions, secondly need to clarify ballast requirements, thirdly to map appropriate tests to evaluate ballast characteristics and then it must be such that if ballast cannot carry out one of these duties, be able to call there is ballast defect. The paper is structured in order to achieve these objectives.

Variation of Lateral Ballast Resistance due to Ballast Work (도상직업에 의한 도상 횡저항력 변화)

  • Lim Nam-Hyoung;Hwang Sung-Ho;Lee Jee-Ha;Yang Shin-Chu
    • Proceedings of the KSR Conference
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    • pp.961-966
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    • 2004
  • Lateral ballast resistance is one of track components that causes much effects in track buckling. Ballast work or tie renewal if is done the ballast original lateral resistance lose. Reduction of lateral ballast resistance may significantly reduce the stability of track. Lateral ballast resistance that is decreased by these work increases slowly according to the increase of train passing tonnage. We measured the ballast lateral resistance in Okchon station neighborhood in Seoul-Busan line to grasp fluctuation phenomenon of ballast resistance by ballast class-2 work. The rate of decrease of ballast lateral resistance shortly after ballast work and the rate of increase by increase of train passing tonnage were investigated.

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A Study of the Technical Treatment within an Environmental Appetency for the Ballast Water

  • Nam, Chung-Do
    • Journal of the Korean Society of Marine Engineering
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    • v.28 no.8
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    • pp.1313-1323
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    • 2004
  • In accordance with adoption of new convention for the control of ship's ballast water at the diplomatic conference held in London Feb, 2004, every country has to regulate the ballast water and deposit matters. When this Resolution comes into effect in 2009, all vessels engaged in international voyage must have ballast water control program, ballast water records, equipments which are suitable to the standard of exchange and performance for the ballast water. This study estimates objectively their performances, merits and demerits of the ballast water treatment technique and exchanging techniques for safe operation of ships. It is desirable to design an equipment to control the ballast water using the brush-type vacuum suction nonstop reverse cleaning system to overcome the clogging phenomenon and the direct disc filtering to maximize filtering area for the optimum process considering biological availabilities. It will be expected to protect against marine pollution and to maintain clean sea if it is secured to develop new ballast water treatment techniques. And it will also be expected to cope with the Resolution and each regulation of the developed countries from the ballast water.

Electronic Ballast for HPS Lamps with Intrinsic Power Regulation over Lamp Life

  • Dehghani, Majid;Saghaiannejad, Seid Mortaza;Karshenas, Hamid Reza
    • Journal of Power Electronics
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    • v.9 no.4
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    • pp.526-534
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    • 2009
  • This paper introduces the electronic ballast for high pressure sodium (HPS) lamps which provides power regulation during the whole lamp life without using a closed-loop power control system, in spite of large variations of lamp characteristics resulting from lamp aging. The structure of the electronic ballast and the parameters of HPS lamps are described. A mathematical model for the ballast is developed and used for the design and analysis of the ballast. A design procedure is presented to design the ballast which provides intrinsic power regulation over the whole lamp life. To improve the technical specifications of the ballast, the practical and standard constraints are considered in the design. According to the design procedure, an electronic ballast for 250-W HPS lamps is designed. All theoretical analyses are verified with the help of a semi-industrial experimental setup. The results validate that the designed ballast provides power regulation during the whole lamp life.

Numerical Simulation of Ballast Water Exchange

  • Kamada, Koichi;Minami, Kiyokazu;Shiotani, Shigeaki;Shoji, Kuniaki
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.157-165
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    • 2006
  • In February,2004, at International Maritime Organization (IMO), LONDON, a new international convention 'International Convention fur the Control and Management of Ship's Ballast Water and Sediment 2004' was adopted. It is called 'Ballast Water Management Convention (BWM)'. Ballast water means charged seawater or fresh water in ship's special tanks (ballast tank) to keep safety navigation and ship's maneuverability. However, from 1980, it was point out the serious problem for marine ecosystem and human life that ballast water includes harmful marine species (and small organisms) and these species are also discharged along with ballast water. These species were released with discharged ballast water in water areas, where species are different from discharged ballast water. The problem is that released species increase when released species are more powerful than native species and consequently, marine ecological system is destroyed in released water area. Authors have inspected the validity of the ballast water exchange using pumping-through method that is one of the methods of ballast water management. In this paper, the numerical simulation of the motion and density of the fluid at the time of exchange of the fluid in a 2-dimensional tank using the pumping-through method was carried out by using two different type numerical methods. One method is MPS method that is one of the particle methods. Other one is Finite Different Method (FDM). Authors were compared with result of two numerical method calculations and experiment result and reported some knowledge from these results.

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Filtering System Design and Structural Analysis for Intake Water of Ship's Ballast Tank (선박 밸러스트 탱크 유입수 필터링 시스템 설계 및 구조해석)

  • Yun, Sang-Kook;Park, Byung-Geun
    • Journal of the Korean Society of Marine Engineering
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    • v.33 no.2
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    • pp.282-287
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    • 2009
  • As current international guideline and IMO regulation give severe restrictions for ships to manage ballast water to reduce unintentional organism transfers, several ballast water treatment systems recently have been being developed together with filtration. That is because discharging ballast water from ships causes many pollutions by foreign biological invasive species. The primary treatment system being considered in this study was based on fine screen filtration technology applied to ballast water filter in ballast tank in order to reduce the load of ballast water treatment system. New ballast water filtration system was invented and analysed. The structural stress and strain analysis for ballast filtration systems which are current and invented filters were carried out using UGS and Ansys. The results showed that the structure of current filtering module was not designed to meet the requirement of sea water filtration during ballasting operation. The studies also showed that the invented design of filtration system equipped with back washing and automatic scrapper for eliminating cake of bio-species might be a potentially effective technology for ballast water management of ship's ballast tank.

A review on modelling and monitoring of railway ballast

  • Ngamkhanong, Chayut;Kaewunruen, Sakdirat;Baniotopoulos, Charalampos
    • Structural Monitoring and Maintenance
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    • v.4 no.3
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    • pp.195-220
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    • 2017
  • Nowadays, railway system plays a significant role in transportation, conveying cargo, passengers, minerals, grains, and so forth. Railway ballasted track is a conventional railway track as can be seen all over the world. Ballast, located underneath the sleepers, is the most important elements on ballasted track, which has many functions and requires routine maintenance. Ballast needs to be maintained frequently to prevent rail buckling, settlement, misalignment so that ballast has to be modelled accurately. Continuum model was introduced to model granular material and was extended in ballast. However, ballast is a heterogeneous material with highly nonlinear behaviour. Hence, ballast could not be modelled accurately in continuum model due to the discontinuities nature and material degradation of ballast. Discrete element modelling (DEM) is proposed as an alternative approach that provides insight into constitutive model, realistic particle, and contact algorithm between each particle. DEM has been studied in many recent decades. However, there are limitations due to the high computational time and memory consumption, which cause the lack of using in high range. This paper presents a review of recent ballast modelling with benefits and drawbacks. Ballast particles are illustrated either circular, circular crump, spherical, spherical crump, super-quadric, polygonal and polyhedral. Moreover, the gaps and limitations of previous studies are also summarized. The outcome of this study will help the understanding into different ballast modelling and particle. The insight information can be used to improve ballast modelling and monitoring for condition-based track maintenance.

A Study on the Dynamic Behaviors of Ballast Track using Field Test (현장측정을 통한 자갈도상 궤도의 동적 거동 분석)

  • Choi, Jung-Youl;Park, Kyun-Seo;Ryu, Joong-Youl;Park, Jeong-Gun;Ryu, Kyoung-Sik;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.494-507
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    • 2006
  • The major objective of this study is to investigate the dynamic behaviors of track due to the deterioration characteristics of ballast for servicing tracks by the field test. The durability of ballast plays an important role in the track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several scholars. The deterioration characteristics of ballast is one of the most important factor in the dynamic behaviour of track and its life. In this paper abrasion/breakage characteristics of ballast is studied to predict the effect of physical ballast characteristics on ballast track. To reveal deterioration characteristics of ballast, the field test were carried out. The deterioration characteristics, studied in this paper, is applied to the dynamic behaviour of track in various conditions.

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