scholarly journals Railway superstructure for high-speed rails

2021 ◽  
Vol 31 ◽  
pp. 53-57
Author(s):  
Lukáš Týfa ◽  
Jan Kruntorád ◽  
Ondřej Tomaschko
Keyword(s):  
Research And Development ◽  
High Speed ◽  
Track Structure ◽  
High Speed Rail ◽  
Track Geometry ◽  
Advantages And Disadvantages ◽  
Ballastless Track ◽  
Present Experience ◽  
Long Time

The construction of the track is solved as a conventional (with track ballast) or as a ballastless track (without track ballast). When deciding on the choice of the most suitable track design for high-speed rail, it is necessary to emphasize that with increasing line speed, the requirements for the quality of the track geometry increase, including the size of the deviations of individual geometric parameters of the track from the projected values. When assessing the choice of track structure – especially for high-speed rails – it is therefore necessary and correct to assess the total costs (investment and operational) for a sufficiently long time. DB Netz AG’s present experience with a ballastless track since its first implementation in 1972 in Rheda station, for almost 50 years, shows that the required lifetime of 60 years has its real justification. In addition, current research and development in the field of ballastless track is moving towards extending the life of ballastless track well beyond this limit. The paper is focused on the comparison a ballasted and ballastless track construction. It deals in more detail with evaluation of the advantages and disadvantages of a ballastless track construction. The main objective is to assess the use of ballastless track structure for the construction of high-speed lines.

The Calculation of the Supporting Stress of Track Plate in Ballastless High-Speed Rail Structure

2011 ◽  
Vol 97-98 ◽  
pp. 3-9
Author(s):  
Yang Wang ◽  
Quan Mei Gong ◽  
Mei Fang Li
Keyword(s):  
Stress Distribution ◽  
High Speed ◽  
Design Theory ◽  
Moving Load ◽  
Structure Design ◽  
Track Structure ◽  
Beam Model ◽  
High Speed Rail ◽  
Slab Track ◽  
Ballastless Track

The slab track is a new sort of track structure, which has been widely used in high-speed rail and special line for passenger. However, the ballastless track structure design theory is still not perfect and can not meet the requirements of current high-speed rail and passenger line ballastless track. In this paper, composite beam method is used to calculate the deflection of the track plate and in this way the vertical supporting stress distribution of the track plate can be gotten which set a basis for the follow-up study of the dynamic stress distribution in the subgrade. Slab track plate’s bearing stress under moving load is analyzed through Matlab program. By calculation and analysis, it is found that the deflection of track plate and the rail in the double-point-supported finite beam model refers to the rate of spring coefficient of the fastener and the mortar.The supporting stress of the rail plate is inversely proportional to the supporting stress of the rail. The two boundary conditions of that model ,namely, setting the end of the model in the seams of the track plate or not , have little effect on the results. We can use the supporting stress of the track plates on state 1to get the distribution of the supporting stress in the track plate when bogies pass. Also, when the dynamic load magnification factor is 1.2, the track plate supporting stress of CRST I & CRST II-plate non-ballasted structure is around 40kPa.

scholarly journals Diagnostics of Track Quality of Ballastless Track and Transition Areas in Vicinity of Portals of Tunnel Turecky vrch

2016 ◽  
Vol 12 (1) ◽  
pp. 2-12 ◽  
Author(s):  
Michal Šmalo
Keyword(s):  
Track Structure ◽  
Track Geometry ◽  
Ballastless Track ◽  
Ballasted Track ◽  
Transition Areas ◽  
Track Quality

Abstract The paper deals with the partial results of diagnostics of experimental sections of ballastless track Rheda 2000® and transition areas between ballastless and ballasted track structure around portals of tunnel Turecky vrch after six measurement cycles. The paper presents differences between each operational measurement and the measurement before putting sections into operation, which indicates a development of track geometry quality.

scholarly journals Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2876
Author(s):  
Yingying Zhang ◽  
Lingyu Zhou ◽  
Akim D. Mahunon ◽  
Guangchao Zhang ◽  
Xiusheng Peng ◽  
...  
Keyword(s):  
High Speed ◽  
Thermal Loading ◽  
Mechanical Performance ◽  
Track Structure ◽  
Box Girder ◽  
High Speed Railway ◽  
Ballastless Track ◽  
Track System ◽  
Girder Bridge ◽  
Track Slab

The mechanical performance of China Railway Track System type II (CRTS II) ballastless track suitable for High-Speed Railway (HSR) bridges is investigated in this project by testing a one-quarter-scaled three-span specimen under thermal loading. Stress analysis was performed both experimentally and numerically, via finite-element modeling in the latter case. The results showed that strains in the track slab, in the cement-emulsified asphalt (CA) mortar and in the track bed, increased nonlinearly with the temperature increase. In the longitudinal direction, the zero-displacement section between the track slab and the track bed was close to the 1/8L section of the beam, while the zero-displacement section between the track slab and the box girder bridge was close to the 3/8L section. The maximum values of the relative vertical displacement between the track bed and the bridge structure occurred in the section at three-quarters of the span. Numerical analysis showed that the lower the temperature, the larger the tensile stresses occurring in the different layers of the track structure, whereas the higher the temperature, the higher the relative displacement between the track system and the box girder bridge. Consequently, quantifying the stresses in the various components of the track structure resulting from sudden temperature drops and evaluating the relative displacements between the rails and the track bed resulting from high-temperature are helpful in the design of ballastless track structures for high-speed railway lines.

scholarly journals Optimization of presser foot and needle bar driving mechanism based on the complex method principle

2021 ◽  
Vol 16 ◽  
pp. 155892502110603
Author(s):  
Lei Zhang ◽  
Zhien Zhang ◽  
Jianneng Chen ◽  
Shouzhi Huang ◽  
Yibin Zhai
Keyword(s):  
Research And Development ◽  
High Speed ◽  
Pause Time ◽  
Complex Method ◽  
Driving Mechanism ◽  
Drive Mechanism

The rod presser foot and needle bar driving mechanism of the embroidery machine cannot achieve accurate parking time and position at high speed, which limits the development of high speed embroidery machine and make the quality of embroidery decline. Aiming at solving this bottleneck problem, the characteristics of the embroidery machine presser foot and needle bar driving mechanism based on analyzing the mechanism kinematics is developed. These characteristics and influences of each linkage parameters on the presser foot parking time and position are analyzed. Six main parameters are selected to optimize by using the complex method. Taking the parking position and linkage parameters as constraints, the parameters of the main linkages was optimized in order to obtain the maximum parking time of the presser foot mechanism. The results show that the optimized parameters is more reasonable and effective, the pause time of the presser foot mechanism is increased by 15.5%, and the parking position of the embroidery machine is at 100° ± 0.5° as required by the technological requirements, which satisfies the requirements of the coordinate movement of the needle bar-presser foot drive mechanism of the high-speed embroidery machine. The study also provides a method reference for the follow-up high-speed embroidery machine research and development.

Impact of Spatial Filtering on the Least Cost Path Method

2010 ◽  
Vol 1 (4) ◽  
pp. 32-44
Author(s):  
Amy E. Rock ◽  
Amanda Mullett ◽  
Saad Algharib ◽  
Jared Schaffer ◽  
Jay Lee
Keyword(s):  
Land Cover ◽  
High Speed ◽  
Least Cost Path ◽  
High Speed Rail ◽  
Highway Infrastructure ◽  
Advantages And Disadvantages ◽  
Passenger Rail ◽  
The Face ◽  
Cost Paths ◽  
Cost Factors

In the face of renewed interest in High-Speed Rail (HSR) projects, Ohio is one of several states seeking federal funding to relieve pressure on aging, overburdened highway infrastructure by constructing passenger rail routes between major cities. This paper evaluates the creation of a new rail route in Ohio’s 3-C Corridor utilizing GIS. The authors consider two primary cost factors in construction, slope and land cover, to generate alternative least-cost paths. To assess the importance of the cost factors, two separate paths are created using two different weighting methods for the land cover layer. The land cover is weighted first by difficulty of construction, and second by relative acquisition costs. These two paths are then compared against a path selected by the Ohio Hub Project which uses existing track lines, advantages and disadvantages of each are discussed.

scholarly journals A Grey-BPNN Model for Evaluating the Competitiveness of Chinese Contractors in the High-Speed Rail Market in Europe

2019 ◽  
Vol 2019 ◽  
pp. 1-19
Author(s):  
Yi-Hsin Lin ◽  
Biling Shi ◽  
Po-Han Chen ◽  
Zhao Xu ◽  
Huimin Liu
Keyword(s):  
High Speed ◽  
Rolling Stock ◽  
High Speed Rail ◽  
The Sustainable Development ◽  
Advantages And Disadvantages ◽  
Management Ability ◽  
Study Results ◽  
Grey Relational ◽  
Technology Level ◽  
Bpnn Model

With the planning and progress of the construction of the trans-Eurasian high-speed rail (HSR) network, it becomes an important issue for Chinese contractors to enter the European HSR market. Facing the world’s most competitive contractors and their high technology levels, Chinese contractors will need to know their advantages and disadvantages, so as to make necessary improvements. In this study, contractors for HSR are divided into two groups: construction contractors and rail equipment suppliers. In order to evaluate the competitiveness of HSR contractors, a Grey-BPNN model that combines the grey relational analysis and backpropagation neural network (BPNN) is proposed. The Grey-BPNN model is expected to analyze the overall competitiveness of Chinese contractors in the European HSR market and provide informative decision support for them. The study results show the following: (1) in the field of HSR construction, the competitiveness gap between the top-tier Chinese contractors and the most competitive international contractors is small. Chinese contractors’ competitive advantages lie in medium- and low-technology-level projects, with a strong development potential. However, they highly depend on Chinese domestic market and lack in intangible resources, like management ability and market development ability; (2) for rail equipment suppliers, China Railway Rolling Stock Corporation (CRRC) ranks among the top-tier leaders of the international market. CRRC’s greatest competitor in the European HSR market is Siemens, and CRRC is much more competitive than others in the sustainable development capability. However, CRRC needs to increase the quantity of patents and Research and Development (R&D) expenditures in transportation. As a weak transportation patent holder, CRRC has a potential risk of getting intellectual property litigations in the European HSR market.

scholarly journals Technical parameters of high speed lines as the determinant for selection of rolling stock

2018 ◽  
Vol 180 ◽  
pp. 06007
Author(s):  
Jan Raczyński
Keyword(s):  
High Speed ◽  
Point Of View ◽  
Rolling Stock ◽  
High Speed Rail ◽  
Technical Parameters ◽  
Rail Vehicle ◽  
Railway Infrastructure ◽  
The One ◽  
Selection Of

Choosing a high-speed rail vehicle depends on many factors. On the one hand, there are requirements for ensuring the quality of service for passengers, on the other hand, there are constraints resulting from the parameters of available infrastructure. Also a relation of the benefit and financial costs associated with the purchase and the operation of rolling stock is essential. Technical characteristics of vehicles selected for operating a particular system is a compromise between the three groups of requirements. In this article technical parameters of railway infrastructure and rolling stock are classified and then analysed from the TSI requirements point of view.

scholarly journals Track Maintenance Scheduling and Its Interactions With Operations: Dedicated and Mixed High-Speed Rail (HSR) Scenarios

2010 ◽  
Author(s):  
Hamed Pouryousef ◽  
Paulo Teixeira ◽  
Joseph Sussman
Keyword(s):  
Preventive Maintenance ◽  
High Speed ◽  
Maintenance Scheduling ◽  
Track Structure ◽  
Maintenance Planning ◽  
Critical Feature ◽  
High Speed Rail ◽  
Track Maintenance ◽  
Operations And Maintenance ◽  
Technical Specifications

HSRs are a complex system not only in terms of technical specifications, but also with respect to operations and maintenance over the track structure. Also, track structure is basically considered as the most important and costly railway asset. Its maintenance is vital to assure safety and operating practices are also of great importance to assure that a good level of service is provided. Considering track maintenance considerations over a new HSR line, one important and critical feature is the operational regime and the question of whether the line will be operated as mixed (passenger and freight) or dedicated only to passenger traffic. This can influence the maintenance patterns: preventive maintenance planning, maintenances scheduling and assignment issues. This will be different for the dedicated and mixed HSR traffic scenarios. In this research, the main approach is focused on the interactions between track maintenance planning and operational concerns and influences in these two scenarios. With this aim and within the current paper, a model of the preventive maintenance scheduling problem (PMSP) has been selected initially from Budai (2006) and then an upgraded revision of this model (Multi-segment assignment and scheduling of preventive maintenance problem) is introduced. Furthermore, the upgraded model of PMSP has been run over a given HSR line (Tehran-Qom HSR corridor in Iran) based on the comparison between the two scenarios of dedicated HSR and upgraded mixed HSR patterns. The main requirements, similarities and differences between these two scenarios are analyzed based on preventive maintenance scheduling and assignment requisites and interactions over the operating restrictions and considerations such as track possession patterns for maintenance activities. We conclude that decision making between these two scenarios through PMSP modeling are quite complicated and depends on the technical and operational specifications of the given HSR corridor, although some general comments on tradeoffs are possible.

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