A review on modelling and monitoring of railway ballast

Ngamkhanong, Chayut,Kaewunruen, Sakdirat,Baniotopoulos, Charalampos Techno-Press 2017 Structural monitoring and maintenance Vol.4 No.3

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 Feasibility Review for an Uneven Baseline Basis Minimal Ballast Ship

강희진,Kwang-Soo Kim,Jin Choi,이영연,안해성,Geun-Tae Yim 한국해양공학회 2020 韓國海洋工學會誌 Vol.34 No.1

Although there are many kinds of advanced ballast water management systems, pioneering studies for ballast-water free ship and minimal ballast water ship concepts are in progress. In this study, the existing alternatives of ballast water are reviewed and a new design concept is studied on the basis of the existing bulk carrier hull form. To develop a new design alternative which has minimal ballast for ballast water discharge free operation, the new concept should have technical feasibilities that are related to the role of the ballast water, berth access, loading constraints, etc. For this purpose, a simplified systems engineering basis design approach is adopted using a business model as the system analysis and control tool. To check the performance feasibility of the new concept, ship resistance performance is reviewed based on a model scale ship resistance performance analysis.

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

Majid Dehghani,Seid Mortaza Saghaiannejad,Hamid Reza Karshenas 전력전자학회 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4

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 elcctronic 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 proccdure 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 thc design. According to the design procedure, an electronic ballast for 250-W HPS lamps is designed. All theoretical analyses are verificd with thc help of a semi-industrial experimental setup. The results validate that the designed ballast providcs power regulation during the whole lamp life.

An experimental study on the characteristics of polyurethane-mixed coarse aggregates by large-scale triaxial test

Lee, Su Hyung,Lee, Sung Jin,Park, Jeung Geun,Choi, Yeong-Tae Elsevier 2017 Construction & building materials Vol.145 No.-

<P><B>Abstract</B></P> <P>The two main functions of ballast are train-load distribution and track-water drainage. Repeated train passage subjects ballast aggregates to abrasion and, eventually, breakage. Mixing of bonding materials such as polyurethane into aggregates can effectively mitigate ballast degradation. In the present study, large-scale triaxial tests were carried out to investigate the characteristics of polyurethane-mixed ballast materials. The stiffness and strength of the materials could be predicted in terms of the polyurethane contents, and the linear relationships could be established. According to those relationships, the performance of polyurethane-mixed aggregates as enhanced railway ballast materials can be simply but reasonably estimated.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper focuses on the behavior of ballast aggregates induced by train loading. To improve performance of the ballast, polyurethane is added. The moduli and strength are investigated according to content of polyurethane. </LI> <LI> A large scale triaxial testing equipment was applied to evaluate the behavior of ballast accurately. The large triaxial tests lead to the correlation between polyurethane content and stiffness of polyurethane mixed ballast. The large scale triaxial tests provide with predictive model for strength as well. </LI> <LI> These simple models are believed to help design the ballast with polyurethane without expensive and cumbersome testing. </LI> </UL> </P>

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

Dehghani, Majid,Saghaiannejad, Seid Mortaza,Karshenas, Hamid Reza The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.4

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.

누적통과톤수와 도상횡저항력과의 상관관계에 대한 연구

박경태(Kyung-Tae Park),김영철(Young-chul Kim),김성일(Sung-Il Kim),박용걸(Yong-Gul Park) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.10

궤도구성 요소 중 하나인 도상자갈은 연직방향, 종방향, 횡방향의 힘에 저항한다. 특히 횡방향 힘에 저항하는 도상횡저항력은 궤도 좌굴강도와 밀접한 관계가 있는 요소로 궤도의 안정성을 결정하는 중요한 인자이다. 그러나, 수시로 2종 기계작업, 침목교환 등 도상을 교란하는 궤도 유지보수작업 시행으로 인해 도상횡저항력은 감소되며 궤도강도 또한 저하되어 열차운행의 안정성을 위협하고 있다. 본 연구에서는 2종 기계작업 후 도상횡저항력의 증감량을 측정하고 누적통과톤수를 산정하여 누적통과톤수에 따른 도상횡저항력의 복원 특성을 파악하고 상관관계에 대해 분석 및 고찰을 하고자 한다. One of the ballast in track component resists the force of vertical direction, longitudinal direction and lateral direction. In particular, lateral resistance of ballast is closely related to buckling strength. therefore the lateral resistance of ballast is important element to determine the track stability. But, the reduced lateral resistance of ballast and track strength threaten the stability of train operation because track maintenance-class 2 machine work and sleeper exchange- disturbs the ballast. This study find that it measures the variations in the amount of lateral resistance of ballast regarding to class2 machine work ballast cleaning. It realizes the restoring force characteristic of lateral resistance of ballast based on cumulative passing tonnage after calculating the cumulative passing tonnage and analyze correlation between the cumulative passing tonnage and the lateral resistance of ballast.

철도교량의 동적거동 특성을 고려한 자갈도상궤도의 상태추정에 관한 연구

권오순(Kweon Oh Soon),최정열(Choi Jung Youl),강명석(Kang Myoung Seok),이희업(Lee Hee Up),박용걸(Park Yong Gul) 한국철도학회 2007 한국철도학회 학술발표대회논문집 Vol.- No.-

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.

Bayesian ballast damage detection utilizing a modified evolutionary algorithm

Hu, Qin,Lam, Heung Fai,Zhu, Hong Ping,Alabi, Stephen Adeyemi Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.4

This paper reports the development of a theoretically rigorous method for permanent way engineers to assess the condition of railway ballast under a concrete sleeper with the potential to be extended to a smart system for long-term health monitoring of railway ballast. Owing to the uncertainties induced by the problems of modeling error and measurement noise, the Bayesian approach was followed in the development. After the selection of the most plausible model class for describing the damage status of the rail-sleeper-ballast system, Bayesian model updating is adopted to calculate the posterior PDF of the ballast stiffness at various regions under the sleeper. An obvious drop in ballast stiffness at a region under the sleeper is an evidence of ballast damage. In model updating, the model that can minimize the discrepancy between the measured and model-predicted modal parameters can be considered as the most probable model for calculating the posterior PDF under the Bayesian framework. To address the problems of non-uniqueness and local minima in the model updating process, a two-stage hybrid optimization method was developed. The modified evolutionary algorithm was developed in the first stage to identify the important regions in the parameter space and resulting in a set of initial trials for deterministic optimization to locate all most probable models in the second stage. The proposed methodology was numerically and experimentally verified. Using the identified model, a series of comprehensive numerical case studies was carried out to investigate the effects of data quantity and quality on the results of ballast damage detection. Difficulties to be overcome before the proposed method can be extended to a long-term ballast monitoring system are discussed in the conclusion.

외부 후긴장으로 보강한 강철도교에 대한 실험 및 해석적 연구

박용걸 서울産業大學校 2005 논문집 Vol.54 No.4

It analyzed the mechanical behaviors of non-ballasted railway bridge(steel plate girder type) with ballast reinforced on the finite element analysis, field test and laboratory test for the static and dynamic responses. The major objective of this study is to investigate the effects and application of reinforcement for steel plate girder railway bridge by the external post-tensioning method. The reinforcement of non-ballast railway bridge had obviously stable dynamic behaviors due to the additional dead force which was ballast. But in case of static behaviors, static displacements and stresses had increased nearly the allowable values. Therefore we analyzed the mechanical behaviors of non-ballasted railway bridge with ballast reinforced and external post-tensioning reinforced on the finite element analysis and laboratory test for the static and dynamic behavior. As a result, the reinforcement of ballasted railway bridge the external post-tensioning method are obviously effective for the additional dead force which is ballast. The analytical and experimental study are carried out to investigate the post-tension force decrease bending behavior and deflection in composite bridge for serviceability. The servicing railway bridge with ballast reinforced has need of the reasonable reinforcement measures which could be reducing the effect of additional dead load that degradation phenomenon of structure by an unusual stresses and a drop durability.

강철도교에 대한 외부 후긴장 보강공법의 적용에 관한 실험 및 해석적 연구

박용걸(Yong-Gul Park),박영훈(Young-Hoon Park),조선규(Sun-Kyu Cho),최정열(Jung-Youl Choi) 한국철도학회 2006 한국철도학회논문집 Vol.9 No.2

It analyzed the mechanical behaviors of non-ballasted railway bridge (steel plate girder type) with ballast reinforced on the finite element analysis, field test and laboratory test for the static and dynamic responses. The major objective of this study is to investigate the effects and application of reinforcement for steel plate girder railway bridge by the external post-tensioning method. The reinforcement of non-ballast railway bridge had obviously stable dynamic behaviors due to the additional dead force which was ballast. But in case of static behaviors, static displacements and stresses had increased nearly the allowable values. Therefore we analyzed the mechanical behaviors of non-ballasted railway bridge with ballast reinforced and external post-tensioning reinforced on the finite element analysis and laboratory test for the static and dynamic behavior. As a result, the reinforcement of ballasted railway bridge the external post-tensioning method are obviously effective for the additional dead force which is ballast. The analytical and experimental study are carried out to investigate the post-tension force decrease bending behavior and deflection in composite bridge for serviceability. The servicing railway bridge with ballast reinforced has need of the reasonable reinforcement measures which could be reducing the effect of additional dead load that degradation phenomenon of structure by an unusual stresses and a drop durability.