Статті в журналах: "BALLASTLESS RAILWAY TRACK"

1

Týfa, Lukáš, Jan Kruntorád, and Ondřej Tomaschko. "Railway superstructure for high-speed rails." Acta Polytechnica CTU Proceedings 31 (July 14, 2021): 53–57. http://dx.doi.org/10.14311/app.2021.31.0053.

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Анотація:

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.

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2

Zhai, Wanming, Kaiyun Wang, Zhaowei Chen, Shengyang Zhu, Chengbiao Cai, and Gang Liu. "Full-scale multi-functional test platform for investigating mechanical performance of track–subgrade systems of high-speed railways." Railway Engineering Science 28, no. 3 (September 2020): 213–31. http://dx.doi.org/10.1007/s40534-020-00221-y.

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Abstract Motivated by the huge practical engineering demand for the fundamental understanding of mechanical characteristics of high-speed railway infrastructure, a full-scale multi-functional test platform for high-speed railway track–subgrade system is developed in this paper, and its main functions for investigating the mechanical performance of track–subgrade systems are elaborated with three typical experimental examples. Comprising the full-scale subgrade structure and all the five types of track structures adopted in Chinese high-speed railways, namely the CRTS I, the CRTS II and the CRTS III ballastless tracks, the double-block ballastless track and the ballasted track, the test platform is established strictly according to the construction standard of Chinese high-speed railways. Three kinds of effective loading methods are employed, including the real bogie loading, multi-point loading and the impact loading. Various types of sensors are adopted in different components of the five types of track–subgrade systems to measure the displacement, acceleration, pressure, structural strain and deformation, etc. Utilizing this test platform, both dynamic characteristics and long-term performance evolution of high-speed railway track–subgrade systems can be investigated, being able to satisfy the actual demand for large-scale operation of Chinese high-speed railways. As examples, three typical experimental studies are presented to elucidate the comprehensive functionalities of the full-scale multi-functional test platform for exploring the dynamic performance and its long-term evolution of ballastless track systems and for studying the long-term accumulative settlement of the ballasted track–subgrade system in high-speed railways. Some interesting phenomena and meaningful results are captured by the developed test platform, which provide a useful guidance for the scientific operation and maintenance of high-speed railway infrastructure.

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3

Li, Xiang Min, Suo Yan Zhang, and Jun Liu. "Research on CRTSIII Ballastless Track Slab Cracks of High-Speed Railway." Applied Mechanics and Materials 443 (October 2013): 69–73. http://dx.doi.org/10.4028/www.scientific.net/amm.443.69.

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Анотація:

At present ballastless track has been widely applied to railway line for passenger in our country, therefore it has broad prospect. Cracks in ballastless track slabs are inevitable in the construction and operation of high-speed railway. Based on comprehensive investigation of documents, and taking cracks in ballastless track slabs as the main object, systematic and deep research has been done within this paper. The main research contents are as follows: First of all, the structure characteristics of CRTSIII ballastless track in high-speed railway are briefly introduced; Secondly, the paper mostly introduces the impacts what cracks make, the characteristics of cracks and how they form. Subsequently the paper introduces what are made to prevent cracks.

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4

Zhu, Shengyang, Jun Luo, Mingze Wang, and Chengbiao Cai. "Mechanical characteristic variation of ballastless track in high-speed railway: effect of train–track interaction and environment loads." Railway Engineering Science 28, no. 4 (November 30, 2020): 408–23. http://dx.doi.org/10.1007/s40534-020-00227-6.

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Анотація:

AbstractDue to the fact that ballastless tracks in high-speed railways are not only subjected to repeated train–track dynamic interaction loads, but also suffer from complex environmental loads, the fundamental understanding of mechanical performance of ballastless tracks under sophisticated service conditions is an increasingly demanding and challenging issue in high-speed railway networks. This work aims to reveal the effect of train–track interaction and environment loads on the mechanical characteristic variation of ballastless tracks in high-speed railways, particularly focusing on the typical interface damage evolution between track layers. To this end, a finite element model of a double-block ballastless track involving the cohesive zone model for the track interface is first established to analyze the mechanical properties of the track interface under the loading–unloading processes of the negative temperature gradient load (TGL) followed by the same cycle of the positive TGL. Subsequently, the effect of wheel–rail longitudinal interactions on the nonlinear dynamic characteristics of the track interface is investigated by using a vehicle-slab track vertical-longitudinal coupled dynamics model. Finally, the influence of dynamic water pressure induced by vehicle dynamic load on the mechanical characteristics and damage evolution of the track interface is elucidated using a fluid–solid coupling method. Results show that the loading history of the positive and negative TGLs has a great impact on the nonlinear development and distribution of the track interface stress and damage; the interface damage could be induced by the wheel–rail longitudinal vibrations at a high vehicle running speed owing to the dynamic amplification effect caused by short wave irregularities; the vehicle dynamic load could produce considerable water pressure that presents nonlinear spatial–temporal characteristics at the track interface, which would lead to the interface failure under a certain condition due to the coupled dynamic effect of vehicle load and water pressure.

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5

Zheng, Weiqi, Xingwang Sheng, Zhihui Zhu, Tianjing Luo, and Zecheng Liu. "Experimental Study on Vibration Characteristics of Unit-Plate Ballastless Track Systems Laid on Long-Span Bridges Using Full-Scale Test Rigs." Sensors 20, no. 6 (March 20, 2020): 1744. http://dx.doi.org/10.3390/s20061744.

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Анотація:

In this work, we present a series of hammering tests on full-scale unit-plate ballastless tracks used for long-span bridges. There is no denying that it is a new attempt to pave ballastless tracks on high-speed railway long-span bridges; the related issues deserve to be studied, and especially the vibration characteristics. Hence, the vibration characteristics and transmission rules of the ballastless track with geotextile or rubber isolation layers are explored, and the vibration reduction effect of the rubber isolation layer is analyzed. The main conclusions are as follows: the isolation layers change vibration modes and transmission characteristics of ballastless tracks; the introduction of the rubber isolation layer makes the excited vibration frequency range of the ballastless track concentrated; and the vibrations of the ballastless track with the rubber isolation layers are stable. Moreover, the rubber isolation layer has an obvious attenuation effect on vibration transmission in ballastless track structures. When the vibration is transmitted from the rail to the bridge deck, the vibration level differences of the ballastless track with rubber isolation layers are 20 dB larger than that of the ballastless track with the geotextile isolation layers. The vibration attenuation rate of the rubber isolation layer is about ten times larger than that of geotextile isolation layer.

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6

Xu, Qing Yuan, and Bin Li. "Study on Spatial Mechanical Characteristic of High-Speed Railway Ballastless Slab Track on Subgrade." Advanced Materials Research 503-504 (April 2012): 1010–15. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.1010.

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By using beam element to model rail, spring element to model fastener, solid element to model different components of ballastless track, contact element to model the connection between each component of ballastless track, a statics three-dimensional nonlinear finite element mechanical model for calculating the forces transmission among rail, fastening and different component of ballastless slab track on subgrade was established. Experimental data of Suining-Chongqing railway line was given to validate the calculation model. Force of ballastless slab track on subgrade under gravity load, train load, uneven settlement load, temperature gradient load as well as combined load was analyzed. Results show that: spatial forces characteristic of ballastless slab track is very notable under train load; uneven settlement load as well as temperature gradient load has significant influence on the mechanical characteristic of ballastless slab track; force of ballastless slab track increases significantly under combined load than that of under any single load.

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7

Bel'tyukov, Vladimir, and Andrey Andreev. "Substantiation for Maintenance and Repair System for Promising Structure of High-Speed Railway Tracks." Bulletin of scientific research results 2022, no. 3 (September 22, 2022): 128–36. http://dx.doi.org/10.20295/2223-9987-2022-3-128-136.

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Objective: To create proposals on the system of maintenance for track facilities on the sections with ballastless constructions because the experience in maintaining of such structures is absent. Methods: During the study, the analysis of being predicted life cycle cost of track structure was made. This analysis is based on the study of indicators such as defectiveness of track superstructure elements (rails, fasteners, sleepers), the analysis of being estimated costs on repairing the track using expert evaluation methods. The expert assessment provides for the application of special correction factor. This factor for each maintenance job shows the ratio of job volumes on ballastless track to job volumes on ballast railway track. Results: On the basis of cost calculations and technologies for maintenance, an analysis was pursued of overhaul schemes for sections with ballast railway and for ones with ballastless construction and conclusions were made on required overhaul scheme for a ballastless track structure. Practical importance: The study results are intended to develop a system for planning technical maintenance and repairs of a ballastless superstructure track.

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8

KOLOS, Alexey F., and Ksenia I. IVANOVA. "Elastic characteristics of the underrail base of a ballastless railway track." Proceedings of Petersburg Transport University 2021, no. 4 (December 2021): 469–79. http://dx.doi.org/10.20295/1815-588x-2021-4-469-479.

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Objective: Experimental determination track modulus and the coeffi cient of relative stiffness of underrail base and the rail, which are the main elastic characteristics that determine the stresses in the structural elements of track superstructure under the impact force from the train. The values of these parameters for a track with a ballast layer are well studied, in contrast to a ballastless track. Comparison of the elastic characteristics of a ballastless railway track with analogs of a track on ballast, as well as an assessment of their effect on the stress-strain state of the superstructure elements of a ballastless track. Methods: When carrying out full-scale tests, strain-gauge methods for measuring stresses in the elements of the track superstructure were used. The obtained values were processed by the methods of mathematical statistics. One statistical series included the values of stresses corresponding to one type of rolling stock, fi xed axle load and train speed, changing by no more than 10 km/h. The probability level in processing the results was taken in all cases equal to 0,994. Results: The values of track modulus and the coeffi cient of the relative stiffness of the underrail base and the rail were obtained for a ballastless structure of the RHEDA 2000 type. Practical importance: The results allow us to consider the rail as a beam lying on a solid elastic foundation in relation to the ballastless track and use the existing calculation methods for the design of ballastless track structures depending on the operating conditions.

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9

Liu, Jing, Yuanqing He, Jiahai Zhang, Jian Hong, Xihua Wen, Jianhong Xiao, Feng Wang, and Xinguo Zheng. "Polymer Injection Rehabilitation Technology for Lifting Differential Settlement of Turnout Ballastless Track." MATEC Web of Conferences 199 (2018): 07013. http://dx.doi.org/10.1051/matecconf/201819907013.

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Анотація:

The turnout ballastless track is an advanced track structure with high stability and integrity. However, due to complicated geological conditions, local groundwater level declined, and many other unavoidable objective reasons, the roadbed foundation of some railway lines appeared large uneven settlement deformation, so the above turnout ballastless track concrete structure also experienced uneven settlement accordingly. Compared with ballast track which could be restored by increasing the ballast under the sleepers simply, the smoothness of turnout ballastless track could only be restored by adjusting the thickness of the base plates of fastener system accordingly. But if continuous settlement deformation exceeded the specified allowed adjustable range of the fastener system, the smoothness of ballastless track diminished, the speed of passing trains had to be limited to ensure the safety. In order to solve this global challenging problem, we systematically studied polymer injection rehabilitation technology through a series of indoor reduced scale tests and field full scale simulations with real ballastless track concrete structure. We verified the effect of uplift rehabilitation and filling quality of grouting material through destructive experiment inspection. And combined with engineering practices and its coring samples strength test, the Polymer injection rehabilitation technology for turnout ballastless track in settlement roadbed sections had been studied and developed. This technology could restore the smoothness of railway and the adjustable range of fastening systems without affecting the normal daily operation of the railway lines. Compared with traditional cement grouting technology, this rehabilitation technology possessed significant advantages including small light construction equipment, simple logistics, flexible organization, high uplifting precision, and little additional load. This technology provided valuable technical support and useful references for restoring the smoothness of turnout ballastless track which appeared large uneven settlement deformation.

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10

Yan, Bin, Limei Yu, Zhe Li, and Zhiping Zeng. "Vulnerability Analysis of Catenary-Bridge-Track System." Shock and Vibration 2023 (August 29, 2023): 1–12. http://dx.doi.org/10.1155/2023/6667171.

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Continuous welded rails on bridges are extensively employed in high-speed railways, where trains are predominantly electrically powered, and the open-air catenary represents the weakest link in the system. Despite the widespread use of continuous welded rail on bridges for high-speed railways, there exists a relative dearth of research on their vulnerability, particularly regarding seismic vulnerability studies that consider the catenary, track type, and bridge collectively. The vulnerability of fasteners and catenary on bridges under the longitudinal resistance of the line was investigated by constructing a 7−32 m high-speed railway double-line simply-supported box girder bridge. It reveals, for the first time, the influence of the longitudinal resistance of the line on the vulnerability of fasteners and catenary under seismic action. The study indicates that both the fasteners’ and catenary’s vulnerability increases with the intensity of ground shaking, with the catenary being more susceptible. The longitudinal resistance of the line has a greater impact on the fasteners’ vulnerability than the catenary. When the degree of damage is minimal, the order of damage to the fasteners is the ballasted track, small resistance fastener, and ballastless track when the probability of exceedance is 5%. The ballastless track can significantly increase the probability of no damage to the fasteners, and it is recommended that the ballastless track be used when designing high-speed railway bridges in earthquake-prone regions.

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11

Köllő, Szabolcs Attila, Attila Puskás, and Gavril Köllő. "Ballasted Track versus Ballastless Track." Key Engineering Materials 660 (August 2015): 219–24. http://dx.doi.org/10.4028/www.scientific.net/kem.660.219.

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First concrete sleepers were made of normal reinforced concrete and used during the 1930s and 1940s. Concrete railroad ties became popular in Europe after World War II because of the advances in design, material quality and production of pre-stressed concrete. Now as before, concrete sleepers on ballast represent the primary basis of track construction, around the world, but the twin block concrete sleepers are also popular and widely used. The continuously increasing operational loads and speeds forced the railway companies to update their technical and economic system to keep their vital role in transporting passengers and merchandise. In this development a very important role played the superstructure of the railroad system, and this modernization process led to appearing of the ballastless track system approximately 60 years ago. The article presents a comparison of two main types of track systems, including technical and economic aspects.

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12

Gailienė, Inesa, and Vaidas Ramūnas. "Usage Analysis and Evaluation of Slab Track Constructions." Baltic Journal of Road and Bridge Engineering 14, no. 3 (September 26, 2019): 285–303. http://dx.doi.org/10.7250/bjrbe.2019-14.444.

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Анотація:

Slab track is one of the technical possibilities to achieve the following goals: increase the conductivity of a railway, increase the highest permitted train speed, reduce the cost of railway maintenance, and increase the railway lifetime. However, the abundance of slab road constructions that occurred during the development stages presents a challenge to railway operators, designers and researchers, about the selection of a right slab track and establishing requirements to it. The present article analyses the ballastless track constructions that are used in the European Union and other world countries. The market is analysed, and a comparative evaluation of the ballastless track construction is carried out, based on the quality and price, by rating and providing the evaluation of usability and recommendations.

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13

Koh, Taehoon, and Moochul Shin. "Field Tests on Eco-Friendly Railway Precast Concrete Slab." Applied Sciences 10, no. 12 (June 16, 2020): 4140. http://dx.doi.org/10.3390/app10124140.

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This study focuses on evaluating the field performance of a newly developed eco-friendly precast concrete slab track structure for railway/subway systems in Seoul, South Korea. Although Ballasted railway track structures are one of the most common track structures in the railway industry, they have some drawbacks including higher maintenance cost, un-uniform supports, and a high level of noise and vibration. However, a ballastless (slab-based) track structure system requires less maintenance and uniform support conditions, as well as several ballastless structure systems developed for high-speed trains. The Seoul Metro subway in South Korea has developed a ballastless reinforced concrete (RC) slab railway system using a type of conventional concrete. This study presents a ballastless precast concrete slab using a newly developed eco-friendly concrete, which can significantly improve structural performances and the manufacturability of a railway track structure system. This study evaluates the field performance of the eco-friendly concrete slab system deployed in one of the existing tunnel sections of the Seoul Metro subway system. A total of 10 m long slab sections including a 5 m long eco-friendly “ballasted track to slab track (B2S)” panels section and a 5 m long conventional B2S panels section are installed and monitored side by side. Field tests are performed to measure the level of noise, vibration, dynamic wheel load, rail displacement, and rail stress. The field measurements from the eco-friendly B2S section are compared to those of the conventional reinforced concrete slab track systems. The results show that the performance of the new B2S system using the eco-friendly concrete is comparable and/or superior to the conventional system.

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14

Fu, Jun, Yu Qin, You Yun Yu, Meng Jun Ye, and Lian Xin Li. "Temperature Field Analysis on CA Mortar Ballastless Track of High-Speed Railway." Key Engineering Materials 531-532 (December 2012): 163–67. http://dx.doi.org/10.4028/www.scientific.net/kem.531-532.163.

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As an important cushion layer, CA mortar ballastless track is crucial to the durability, safety of high-speed railway and the high-speed railway is influenced by the external environment. The regulation of temperature field evolvement of ballastless track is analyzed in this paper through a two-dimensional, transient finite element model built by ANSYS. The results show that the temperature of structure section caused by solar radiation and circumstances temperature is decreasing along depth in sunlight, and the internal temperature of structure is higher than the surface temperature at night. The integral temperature field of structure reaches the maximum at 1:00 p.m. and the vertical difference of the temperature inside the structure is also the largest, causing the most obvious temperature stress, which provides theoretical data for systematic research on ballastless track of high-speed railway.

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15

Li, Ziqiang, Weiwei Huang, Zhifan Xu, Xiao Tang, Mingnian Wang, Li Yu, and Zheng Li. "Analysis of the Mechanical Characteristics of Different Track Bed Types in Heavy-Haul Railway Tunnels." Mathematical Problems in Engineering 2021 (May 23, 2021): 1–11. http://dx.doi.org/10.1155/2021/5527073.

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Анотація:

Based on field measurement data from the Fuyingzi Tunnel and Hongshila Tunnel on the Zhangtang Railway, a comparative analysis was conducted on the characteristics of a ballast bed and ballastless slab track, which are commonly used in the track structures of heavy-haul railway tunnels. According to the relevant domestic standards and the theory of the stress diffusion angle, a wheel-rail sharing ratio and theoretical calculation method for the added value of the trainload on the surface and bottom of different track bed types was proposed. In accordance with the measured data, the dynamic load thresholds and distributions on the surface and bottom of different track bed types were analysed and compared with the theoretical results. The results show that the theoretical equation has high accuracy and good applicability. The ballast bed can better cushion the heavy loads, while the ballastless slab track is better able to accomplish train load attenuation. In addition, the distribution on the bottom of the ballastless slab track is “triangular”, while the distribution at the surface or bottom of the ballastless track and ballast bed is “saddle-shaped.” The ballast bed is subjected to a greater load from the vehicle, and the long-term effect is more pronounced. These results can provide a theoretical basis for the stress analysis and design parameters of heavy-haul railway tunnel track beds.

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16

Polyakov, V. Yu, and N. T. Dang. "BALLASTLESS BRIDGE DECK FOR HSR." World of Transport and Transportation 16, no. 2 (April 28, 2018): 36–55. http://dx.doi.org/10.30932/1992-3252-2018-16-2-4.

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Анотація:

For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version). ABSTRACT The article is devoted to the study of oscillations of ballastless bridge deck, concrete slabs, conduct of rail fastenings, gasket layer under a rail slab of a high-speed railway. The objective of research was to achieve reduction of forces in concrete slabs and rational stiffness of elastic elements in the structure of a carrying system, depending on load, speeds and features of the model «bridge-track- vehicle». Keywords: railway, ballastless track, high-speed railway, bridge deck, dynamic studies, modeling, wheel, rail, vehicle, beam, span structure.

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17

Fang, Hongyuan, Yingjie Su, Xueming Du, Fuming Wang, and Bin Li. "Experimental and Numerical Investigation on Repairing Effect of Polymer Grouting for Settlement of High-Speed Railway Unballasted Track." Applied Sciences 9, no. 21 (October 23, 2019): 4496. http://dx.doi.org/10.3390/app9214496.

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Uneven settlement of high-speed railway subgrade leads to the irregularity of high-speed railway line, which seriously affects high-speed train operation. The skylight point of high-speed railway operation is short and the maintenance time is limited. Therefore, how to quickly lift and repair the ballastless track slab in the subsidence section is an urgent problem to be solved in the maintenance of high-speed railways. The two-component non-aqueous reactive polymer material has the advantages of strong expansive force, fast reaction speed, and wide application range, which is extremely suitable for the repair of high-speed railway track slab subsidence and lifting. In this study, the expansion force characteristics of different density polymer materials and the stress-deformation curves at corresponding density are tested in laboratory to propose the mechanical parameters of polymer. Then, a three-dimensional finite element (FE) model of high-speed railway train ballastless-track subgrade is established based on ABAQUS. The mechanical characteristics of CRTS III ballastless track under different repair materials, different elevation, and different density of polymer grouting materials are analyzed. The results show that, under the dynamic load of the train, the stress value of polymer repairing material is less than that of cement slurry, presenting a compressive stress state, which is similar to that of the complete subgrade surface. In addition, within a certain thickness range, increasing the thickness of polymer is beneficial to reducing the difference of stress variation between polymer filling layer and complete pavement. Once beyond this range, the thickness of polymer has little effect on the force variation.

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18

Ivanova, Kseniya, and Aleksey Kolos. "Dynamic Forces of Wheel Impact on Rail at Ballastless Track Structure RHEDA 2000." Bulletin of scientific research results 2023, no. 1 (March 27, 2023): 197–205. http://dx.doi.org/10.20295/2223-9987-2023-1-197-205.

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Purpose: Experimental determination of vertical dynamic forces of wheel impact on a rail at ballastless construction of railway track RHEDA2000 upper structure with subsequent analysis of obtained data; definition of main factors affecting vertical dynamic force value; identification of dependence of change in the value of wheel vertical dynamic force impact on a rail from motion speed and rolling stock type; calculation of coefficients of vertical dynamics at ballastless construction of rail upper structure. Methods: Measurement of wheel vertical dynamic force impact on a rail was carried out by strain-gauge method (Schlumpf method). Numerical values of those, obtained in the course of experiment, were processed by mathematical statistics method, in its turn, probability level was taken equal to 0.994. Results: The values of vertical dynamic forces of wheel impact on a rail for ballastless structure of RHEDA2000 type at rolling stock different types and various ranges of motion speed have been determined. The dependence of change in the value of wheel vertical dynamic force impact on a rail from motion speed and rolling stock type has been graphically built. Comparison of vertical dynamics coefficients of ballastless construction of railway RHEDA2000 upper structure with the construction of a track on a ballast has been carried out. Practical significance: The obtained results can be used in projection, construction, reconstruction and repair of railway track where track ballastless upper composition is provided.

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19

Qian, Yue Lei, and Xin Ming Li. "Application of Ballastless Track CP III Control Network Measure Method in the Building of High Speed Railway." Applied Mechanics and Materials 204-208 (October 2012): 1817–21. http://dx.doi.org/10.4028/www.scientific.net/amm.204-208.1817.

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In the process of building the ballastless track of the high speed railway from Wuhan to Guangzhou, the measuring method of the CPⅢ control network has played an extremely critical role. In this article, the form layout, measuring method, precision requirements and some other contents of the high speed railway ballastless track CP Ⅲ have been proposed. It has been proved that this control network has reliable technology basis and meets the construction requirements, which is available for other similar engineering.

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20

Shi, Li, Xiaoqiang Ye, Pengfei Zhang, and Lin Guo. "A Comparative Study on Vertical Dynamic Responses of Three Types of Elevated Railway Tracks Subjected to a Moving Train." Mathematical Problems in Engineering 2019 (August 25, 2019): 1–11. http://dx.doi.org/10.1155/2019/3290958.

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Анотація:

A theoretical model incorporating the moving train, the railway track, and the elevated viaduct is established and then solved using periodic theory in this paper. The vertical wheel/rail forces and the dynamic responses of track and viaduct girder are obtained and compared for three different types of tracks, i.e., the double-block ballastless track, the rubber-pad floating slab track, and the steel-spring floating slab track. It is observed that the rubber-pad and steel-spring floating slab tracks can reduce more than 10% of the wheel/rail force and the reaction force at girder supports, when compared to those of the double-block ballastless track. Especially, the steel-spring floating slab track develops an uplifting force larger than the installation force of the fastening clip, which may cause failure of the rail fastening system.

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21

Yu, Zhiwu, Ying Xie, and Xiuquan Tian. "Research on Mechanical Performance of CRTS III Plate-Type Ballastless Track Structure under Temperature Load Based on Probability Statistics." Advances in Civil Engineering 2019 (June 26, 2019): 1–16. http://dx.doi.org/10.1155/2019/2975274.

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Анотація:

CRTS III (China Railway Track System III) slab ballastless track structure is one of the high-speed railway ballastless track structures which has Chinese independent intellectual property rights. The mechanical performance of CRTS III slab ballastless track structure under temperature load has not been clear yet. Therefore, through temperature field model and temperature load values selected by statistics analysis based on long-term meteorological data, the mechanical performance of ballastless track structure is studied under two typical working conditions with different safety probability. It is found that the daily extreme values of monthly axial uniform temperature and the daily maximum temperature gradient obey certain statistical laws. In addition, the maximum tensile stress of the self-compacting concrete layer is located in the middle and edge of the slab bottom and the side of the slab. The maximum tensile stress of the base plate is located at the edge of the surface of the layer and the inner edge of the limiting groove. The interface normal tensile stress is located at the end and corner of the interface. Furthermore, maximum stress increases with the increase of safety probability.

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22

Kosarev, A. B., A. V. Barch, and E. N. Rozenberg. "Ensuring electrical safety of power supply systems of electrified AC railways for highspeed lines." Vestnik of the Railway Research Institute 77, no. 6 (December 30, 2018): 337–46. http://dx.doi.org/10.21780/2223-9731-2018-77-6-337-346.

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Abstract. High-speed railways are fast-growing and promising type of traffic. In Russia development of high-speed railway service is associated with the solution of a number of problems, including infrastructure. Authors propose to use earth connection of the railway catenary with the help of an artificial earthing switch on currently designed high-speed line Moscow—Kazan for 2×25 kV power supply system. Taking into account requirements for electrical safety conditions for maintenance of the track and earthed catenary supports, paper justifies method for calculating allowable voltages of rail—earth points and supports of catenary. Methods takes into account structural features of ballastless track superstructure used for high-speed lines. It is estimated that the voltages admissible under the electrical safety conditions are random in nature and distributed logarithmically normal. When calculating probability of safe operation, one should take into account random nature of both permissible stresses and those actually occurring on the track. It is estimated that the probability of safe operation in traction networks of sections with ballastless track superstructure does not exceed a similar value in electrified sections with the conventional structure of a ballast prism. Feasibility of using a 2×25 kV earth system using an artificial earth connection is confirmed, recommendations on its use are given. Authors substantiate allowable values of the rail—earth voltage and catenary supports, which practically exclude the occurrence of hazardous situations for personnel maintaining the track in sections with ballastless track superstructure.

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Yang, Jian, Jin Sheng Wang, and Xin Peng. "Design and Behavior of RPC Slab Track." Applied Mechanics and Materials 587-589 (July 2014): 1100–1105. http://dx.doi.org/10.4028/www.scientific.net/amm.587-589.1100.

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Reactive Powder Concrete is proposed to be used in the ballastless track for its excellent material properties due to existing problems of high speed railway ballastless track. Three different unit types of RPC frame slab track were proposed through optimization design and the mechanical behavior of these frame slab track was analyzed. The results show that the RPC slab track meet the requirements of bearing capacity, the suggested type of RPC slab track is a frame slab with increased thickness because of its higher techno-economic advantages.

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24

Xue-Ning, Ma, Hao Zi-Xiang, Liu Chang, Wang Xu, and Wang Bo-Lin. "Study of Problems Related to Laying Ballastless Track in the Turnout of Ballasted Track at High-Speed Railway Stations." Advances in Materials Science and Engineering 2022 (May 28, 2022): 1–16. http://dx.doi.org/10.1155/2022/8446392.

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Due to the complex dynamic interactions of the vehicle-track system in the turnout of high-speed railway stations on a ballasted track, the geometric position of the line changes rapidly. In order to improve the stability of the line, the ballasted track in the turnout area of the stations can be replaced by a ballastless track. Based on the engineering background of laying ballastless track in the turnout area of Zhonglan’s high-speed railway station, this paper studies the subgrade reinforcement scheme, subgrade settlement prediction, and ballasted-ballastless track transition section setting. The result shows that, in order to meet the requirements of laying ballastless track in the turnout area, a reinforcement scheme of subgrade impact rolling, surcharge preloading, and closed water isolation on the subgrade surface is proposed. Based on the commonness and individuality of the grey Verhulst, hyperbola, and Deng Yinger prediction model, this paper optimizes the combination of the three models. The sum of squares of the minimum errors of the combined model is used as the objective function to solve the optimal weighting coefficient, and in this way the combined prediction model is constructed. Through the prediction comparison, we found that the accuracy of the three-model combination prediction model is better than any single- or two-model combination, and its adaptability and reliability are stronger and more reliable. This dynamic analysis model of vehicle tracks was established to carry out the dynamic response analysis under the conditions of fastener stiffness grading transition and ballast glue grading curing ballast bed transition. The results show that the dynamic response indexes under the two transition modes meet the requirements for the smooth running of trains. Due to the convenience of fastener stiffness transition construction and easier replacement, this measure is recommended.

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25

Zhou, Lingyu, Yahui Yuan, Lei Zhao, Akim Djibril Gildas Mahunon, Lifan Zou, and Wenqi Hou. "Laboratory Investigation of the Temperature-Dependent Mechanical Properties of a CRTS-Ⅱ Ballastless Track-Bridge Structural System in Summer." Applied Sciences 10, no. 16 (August 9, 2020): 5504. http://dx.doi.org/10.3390/app10165504.

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To study the mechanical properties of the China Railway Track System type II (CRTS-II) ballastless slab track structure, a 1/4-scale specimen of a CRTS-II slab ballastless track-32-m standard prefabricated simply supported box girder bridge with three spans and two high-speed railway lines was developed. The mechanical properties of the structure under the action of daily natural temperatures were studied under the natural environmental conditions. The structural strain and relative interlayer displacements were analyzed. The results show that the temperature of the CRTS-II ballastless track-bridge structural system changes periodically every 24 h. The strain of the structural layers of the track system first increases and then decreases sinusoidally, and the internal strain of the track system lags along the vertical depth direction. The relative displacement between the layers of the ballastless track bridge structure system increases with the increase in temperature. The extreme value of the vertical relative displacement appears between the track bed and the bridge at section 1/4 in the span, so it should be paid attention to by the maintenance personnel. Due to the constraint of the shear slots, the structural strain and relative displacement at the fixed end near the shear slots are smaller than those at the sliding end. The mid-span deflection is the largest, and the overall deflection during the cooling phase is more significant than that during the heating phase.

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26

Wang, Ping, Jinhui Xu, Li Wang, and Kai Wei. "Calculation model of the vehicle – CRTS II coupling system with symplectic method." Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 232, no. 4 (April 21, 2017): 959–69. http://dx.doi.org/10.1177/0954409717703470.

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In this paper, the vibrations of the vehicle – CRTS II (abbreviation for China Railway Track System II) slab ballastless track vertical coupling system for high-speed railways were studied. Based on the structural characteristics of the CRTS II ballastless track, a dynamic model of the CRTS II ballastless track was established, and an effective calculation method was applied to determine the frequency response of the system. In this method, the track structure was divided into innumerable substructures by fastener spacing. Four substructures under the wheel–rail force were chosen as the subject while the transmission of simple harmonic waves in such track substructures were solved using the symplectic method. In addition, the transfer function between the track irregularities and the dynamic response of the coupling system was solved, and with these results, the coupling system’s frequency response was obtained. Furthermore, the method was proven accurate and efficient (see examples in this paper). The effects of track parameters on the coupling system’s frequency response were also studied, which provide a basis for the optimization of the design of the CRTS II ballastless track. As shown in the study, with respect to the desired track geometry and dynamic displacement, the application of the fastening system featuring low stiffness and large damping can effectively reduce the frequency response of the coupling system, while the elastic modulus and damping of the cement asphalt mortar exert the least impact on the frequency response. In addition, the subgrade stiffness shall be managed at an appropriate level, and greater subgrade damping can effectively minimize the coupling system’s vibrations.

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27

Zhu, Huai Liang, Ying Dong Fang, and Li Feng Yu. "Dynamic Simulation of Ballastless Railway Track System with Local Invalid Sleepers." Applied Mechanics and Materials 423-426 (September 2013): 1217–20. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.1217.

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Considering local sleepers supported invalidly, the dynamic analysis is presented for ballastless railway track system subjected to moving loads. The track is modeled as an infinitely Euler-Bernoulli beam with Kelvin viscoelastic foundation. The restrain conditions of system change suddenly at unsupported sleepers. Numerical simulating was carried out by the finite element discrete and Newmarks-method. Dynamic responses of system were analyzed in the case of single or multi-sleeper to be not working properly. Results show that the maximum value of displacement of track is going up 50% approximately due to an invalid sleeper occurring. The amplitude of vibration is two times increase when three sleepers to be hung up. Hence, there would be a bad effect on the vibration control of ballastless railway track system as some sleepers lose efficacy continuously.

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Tsypin, P. E., and A. D. Razuvaev. "ADVANTAGES OF BALLASTLESS TRACK DESIGN FOR LARGE TRANSPORT OBJECTS." World of Transport and Transportation 15, no. 3 (June 28, 2017): 132–38. http://dx.doi.org/10.30932/1992-3252-2017-15-3-12.

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[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT The article assesses the possibility of using a ballastless (or slab) track design (BTD) in implementation of large transport facilities in the city. BTD is the only alternative to a traditional track on ballast. Such an option has a number of advantages, but at the same time, certain shortcomings that restrain its mass application today. Based on foreign experience and comparison of two designs (track on ballast and BTD), taking into account costs for repair and current maintenance, the authors offer their understanding of economic arguments and benefits derived from operation of the ballastless track. Keywords: railway transport, track superstructure, ballastless structure, high-speed traffic, costs, payback, economic effect.

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29

Zheng, Zhihui, Peng Liu, Zhiwu Yu, Yachuan Kuang, Lei Liu, Sasa He, Xiaoqiang Zhang, Qianghui Li, Wen Xu, and Maofeng Lv. "Numerical Investigation of Interlaminar Stress of CRTS II Slab Ballastless Track Induced by Creep and Shrinkage of Concrete." Materials 15, no. 7 (March 27, 2022): 2480. http://dx.doi.org/10.3390/ma15072480.

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The secondary development of ABAQUS was carried out to calculate the shrinkage and creep of concrete, and a finite element model of the China Railway Track System (CRTS) II slab ballastless track was established. Then, the interlaminar stress of CRTS II slab ballastless track at different ages of the track slab during laying (AOTSL) caused by concrete shrinkage and creep was studied. The obtained results showed that the stress redistribution occurred in the sliding layer, which resulted in the generation of a gap. Although the gap length was slightly reduced due to the shear cogging, the sliding layer at the slab edge is more prone to produce gaps. Under the effect of shrinkage and creep of the ballastless track, large additional shear stress, up to 0.676 MPa, was induced at the interface between CA mortar and the track slab. Meanwhile, the appearance of additional vertical and lateral forces of the shear cogging was caused by the shrinkage and creep of the ballastless track. Additionally, by further analysis, the recommended AOTSL ranges from 120 days to 180 days.

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30

Kraśkiewicz, Cezary, Wojciech Oleksiewicz, Monika Płudowska-Zagrajek, and Cezary Lipko. "Overview of vibroacoustic isolators used in railway tracks." MATEC Web of Conferences 219 (2018): 05001. http://dx.doi.org/10.1051/matecconf/201821905001.

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The paper presents an overview of vibroacoustic isolators used in railway tracks to reduce negative effects from railway traffic. These include single components or their assemblies, with different material characteristics and location in the track structure due to track structure type (ballasted or ballastless track system). The reduction of negative effects relates mainly to the reduction of vibration and structure-borne noise. The practical solutions for railway structures include various components that perform different functions at the same time: vibroacoustic isolation and mechanical function to ensure safe and durable use of rail track (i.e. rail fastening systems, rail supporting structures). The main goals of this paper are systematization and description of basic material characteristics of vibroacoustic isolators applied sufficiently close to the place of vibration generation during the movement of rail vehicles.

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31

He, Li Jing Wen, and Quan Mei Gong. "PFC’s Application on the Dynamic Response Analysis of High Speed Railway Ballastless Subgrade." Applied Mechanics and Materials 505-506 (January 2014): 9–14. http://dx.doi.org/10.4028/www.scientific.net/amm.505-506.9.

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The biaxial test on ballastless track subgrade material of surface layer and bottom layer of subgrade was established using the particle flow code(PFC). Based on the micro parameter gotten from the biaxial test, a two-dimensional discrete element model of slab Ballastless Track subgrade is modeled. The dynamic response under dynamic load was calculated. A comparison of simulation results and the field measured data shows goodness of fit which provides a new way of simulation on dynamic response of high speed railway subgrade.

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32

Illarionova, Lilia A., and Alexey A. Loktev. "Modeling of anisotropic base plate of a ballastless railway track under dynamic influences." Vestnik MGSU, no. 8 (August 2020): 1105–14. http://dx.doi.org/10.22227/1997-0935.2020.8.1105-1114.

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Introduction. Due to dynamic loading, the upper structure of the railway track is subject to deformation over the entire construction and operation period. This paper focuses on the development of a mathematical model of the base plate of a general-type ballastless railway track structure without relying on specific existing technological solutions used for such elements. The effect of the actually given vertical component of the rolling stock velocity arising from the deviation from the design position of the long-welded rails on the dynamic deflection of the plate and the contact force of cylindrical anisotropy and the initial rate of dynamic interaction is studied. The proposed model makes it possible to take into account the effect of elastic waves originating in the contact area between the wheel and the rail that move at their final speeds after contact. The actual issue researched in this paper is the reinforcement of the ballastless railway base plate for the prevention of severe damage in the base plate. Materials and methods. A mathematical model has been developed to describe the dynamic behavior of a reinforced concrete plate of a ballastless railway track taking into account the specifics of load application from rolling stock wheel sets. Results. Detailed presentation of the research results in the form of analytical expressions and dependence diagrams of dynamic and kinematic parameters of the structure behavior can have practical application when designing rapid transit and high-speed railway lines both in Russia and abroad. Conclusions. The obtained results can be used for carrying out full-fledged research of dynamic behavior of the track bed under mobile loading, for checking the local durability of plates under shock impact, for researching and selecting optimal rigidity parameters for the track bed.

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33

Zhang, De, Junhua Xiao, and Xiao Zhang. "Effects of Pier Deformation on Train Operations within High-Speed Railway Ballastless Track–Bridge Systems." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 10 (May 23, 2018): 96–105. http://dx.doi.org/10.1177/0361198118776525.

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The deformation of a bridge foundation (i.e. pier) for a ballastless track of a high-speed railway may cause additional irregularities within the track, thereby affecting train operation. By using a unit slab ballastless track bridge system as the research object, this study built a finite element model and a train–track dynamic interaction model. The additional rail deformation caused by the vertical or lateral deformation of a bridge pier was calculated by the finite element model, and then the effects on train operation due to the additional rail deformation were analyzed by the train–track dynamic model. It was found that the lateral deformation of a single pier should be of the most concern for the management and control of a high-speed railway. Specifically, when a pier suffered settlement and lateral deformation concurrently, the evaluation indices of train operation were primarily affected by the magnitude of the lateral deformation, and were only slightly affected by the settlement.

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34

Xie, Haoran, Bin Yan, and Jie Huang. "Vertical Dynamic Analysis of Ballastless Tracks on Train-Track- Bridge System." MATEC Web of Conferences 306 (2020): 02003. http://dx.doi.org/10.1051/matecconf/202030602003.

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In order to investigate the vertical dynamic response characteristics of train-track-bridge system on CWR (Continunously Welded Rail) under dynamic load of train on HSR (High-Speed Railway) bridge. Based on the principle of vehicle train-track-bridge coupling dynamics, taking the 32m simply supported bridge of a section of Zhengzhou-Xuzhou Passenger Dedicated Line as an example, the finite element software ANSYS and the dynamic analysis software SIMPACK are used for co-simulation, and bridge model of the steel spring floating slab track and the CRTSIII ballastless track (China Railway Track System) considering the shock absorbing steel spring, the limit barricade and the contact characteristics of track structure layers are established. On this basis, in order to study the dynamic response laws of the design of ballastless track structure parameters to the system when the train crosses the bridge and provide the basis for the design and construction, by studying the influence of the speed of train on the bridge, the damage of fasteners and the parameters of track structure on the train-track-bridge system, the displacement of rail, vertical vibration acceleration and wheel-rail force response performance are analyzed. Studies have shown that: At the train speed of 40 km/h, the displacement and acceleration of the rail and track slab in the CRTSIII ballastless track are smaller than the floating slab track structure, but the floating slab track structure has better vibration reduction performance for bridges. The acceleration of rail, track slab and bridge increases obviously with the increase of train speed, the rail structure has the largest increasement. Reducing the stiffness of fasteners could decrease the vertical acceleration response of the steel spring floating slab track system, the ability to absorb shock can be enhanceed by reducing the stiffness of the fastener appropriately. Increasing the density of the floating slab can increase the vertical acceleration of the floating slab and the bridge, thereby decreasing the vibration amplitude of the system.

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35

Wang, Ping, Hao Xu, and Rong Chen. "Effect of Cement Asphalt Mortar Debonding on Dynamic Properties of CRTS II Slab Ballastless Track." Advances in Materials Science and Engineering 2014 (2014): 1–8. http://dx.doi.org/10.1155/2014/193128.

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The debonding of cement emulsified asphalt mortar (CA mortar) is one of the main damage types in China railway track system II slab ballastless track. In order to analyze the influence of mortar debonding on the dynamic properties of CRTS II slab ballastless track, a vertical coupling vibration model for a vehicle-track-subgrade system was established on the base of wheel/rail coupling dynamics theory. The effects of different debonding lengths on dynamic response of vehicle and track system were analyzed by using the finite element software. The results show that the debonding of CA mortar layer will increase the dynamic response of track. If the length of debonding exceeds 1.95 m, the inflection point will appear on the vertical displacement curve of track. The vertical vibration acceleration of slab increases 4.95 times and the vertical dynamic compressive stress of CA mortar near the debonding region increases 15 times when the debonding length reaches 3.9 m. Considering the durability of ballastless track, once the length of debonding reaches 1.95 m, the mortar debonding should be repaired.

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36

Chen, Long, Jinjie Chen, and Jianxi Wang. "Calculation of Reasonable Tension Value for Longitudinal Connecting Reinforcement of CRTSII Slab Ballastless Track." Applied Sciences 8, no. 11 (November 2, 2018): 2139. http://dx.doi.org/10.3390/app8112139.

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There is confusion in the original design concept for the tensioning of longitudinally connected reinforcement of the CRTSII (China Railway Track System) slab ballastless track. In order to clarify the effect of tension value of longitudinal reinforcement on the mechanical characteristics of the ballastless track, a three-dimensional finite element model, considering the nonlinear interaction between the track slab and cement-emulsified asphalt (CA) mortar of the CRTSII slab ballastless track, was established. The mechanical characteristics of the track structure under longitudinal tension load and temperature gradient load of the longitudinal joint were calculated. A method of applying prestress to post-pouring concrete was proposed according to the concept of prestress loss of pretensioning prestressed concrete, a reasonable tensile force value was proposed after the crack width, and the reinforcement stress of the ballastless track in the operation stage was checked and calculated according to the concrete design principle. When the tension force is greater than 300 kN, it is harmful to the bonding between the slab and mortar layer, which is prone to interlayer damage. In order to add prestress to concrete with wide joints to ensure the longitudinal stability of the ballastless track, and that the reinforcement stress and crack width meet design requirements, it is suggested that the tension force value should be 230 kN. Further, the temperature difference between reinforcement and concrete should be 30 °C before the initial curdle of wide joint concrete.

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37

Yi, Qiang, Cai-you Zhao, Ping Wang, Xin Gao, Liu-cong Wang, and Wen-hua Ke. "Estimation of Rail Axial Force in High-Speed Railway Ballastless Track Based on Wave Modes." Mathematical Problems in Engineering 2019 (July 17, 2019): 1–11. http://dx.doi.org/10.1155/2019/4329830.

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To estimate the rail axial force of high-speed railway ballastless track, the reasonable index without complex measuring or error correction process is proposed. Taking the ballastless track structure in high-speed railway as the research object, the wave motion of periodic ballastless track is studied using the wave finite element method. It is found that some standing wave modes are linearly correlated with the rail axial force and thus can be considered as the basic indices for rail axial force estimation. A further in situ experiment according to the modal test method is performed and the feasibility of different wave modes for estimating rail axial force is discussed. Experiment results show that the lateral wave mode coincides well with the theoretical result while there is a large difference for the vertical wave mode. To explicate the difference, the temperature-dependent properties of the fastening are tested additionally. Parametric analysis shows that the frequency shift of vertical wave mode is greatly affected by the fastening temperature-dependent characteristics including the rail pad, elastic pad, and fastener clamping force, while the frequency shift of lateral wave mode is mainly determined by the rail axial force.

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38

Chen, Jin, Ying Zhou, Guangxin Zhou, and Bo Fu. "Experimental Vibration Investigation on High-Speed Railway Ballastless Track-Subgrade Structure." International Journal of Structural Stability and Dynamics 20, no. 07 (July 2020): 2050081. http://dx.doi.org/10.1142/s0219455420500819.

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With the development of high-speed railways, the double-line mode of ballastless tracks is being adopted increasingly worldwide. In some sections where subgrades need to be laid, this type of line mode is also applied above the subgrade, thus forming double-line track-subgrade structure. In this structure, the subgrade on one side of the double-line is subjected to the eccentric pressure of the load when the unidirectional train is running (the most common operating condition in actual operation). When the subgrade contains embankment layer, the complexity of the problem is increased. Therefore, a 1:4 scale test model of the double-line ballastless track-subgrade system was constructed in this paper in order to study the dynamic responses of the double-line track-subgrade structure with embankment layer under the unidirectional high-speed train loads. By considering the similarity of shear wave velocities, a new uniform dynamic similarity method was adopted to design the track, subgrade and foundation models. The effects of a series of sine waves with 1–30[Formula: see text]Hz excitation frequency and three kinds of loading modes on the speed, soil stress and acceleration response of the track and subgrade were systematically investigated. The relationship between the effective composite values of velocity beneath the track and the depth was finally obtained. The results show that the dynamic stress attenuation of the subgrade bottom layer under larger axle loads are relatively faster. It is found that the dynamic stress attenuation of the subgrade bottom layer is relatively fast under the high-frequency uniform excitation of large axial heavy load.

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39

Zhang, Yingying, Lingyu Zhou, Akim D. Mahunon, Guangchao Zhang, Xiusheng Peng, Lei Zhao, and Yahui Yuan. "Mechanical Performance of a Ballastless Track System for the Railway Bridges of High-Speed Lines: Experimental and Numerical Study under Thermal Loading." Materials 14, no. 11 (May 27, 2021): 2876. http://dx.doi.org/10.3390/ma14112876.

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Анотація:

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.

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40

Prabhakaran, Priyanka, Anandakumar Subbaiyan, Dineshkumar Gopalakrishnan, Harsha Vardhana Balaji.M, S. Ramkumar, Suresh Veluswamy, Dinesh Kumar Murugesan, et al. "Maintenance Methodologies Embraced for Railroad Systems: A Review." Advances in Materials Science and Engineering 2022 (September 14, 2022): 1–15. http://dx.doi.org/10.1155/2022/7655245.

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Анотація:

Congestion on land, hike in fuel costs, and critical need to cut down environmental emissions have generated the urge to shift from conventional rail transit systems to metro rail and high-speed rail for a mass mode of transportation. The conventional railway network especially in India stages an effective space in the means of mass transit systems. Subsequently, periodic inspection of the state of railway tracks is vital for ensuring rail safety, as tracks are critical components of train transportation networks. Tracks are designed to withstand zero critical incidents, and with the advent of new high-speed train services, there is a greater need to focus on track performance. Track maintenance methods are customized to suit local conditions for enhancing safety and reducing disruptions while guaranteeing the resilience and sustainability of any rail system. In recent years, various aspects of the TMSs (track maintenance systems) have been introduced within the railway industry for both ballasted and ballastless track systems. This study reviewed various approaches to track maintenance measures using traditional methods, statistical methods, and geometry-based methods based on track deterioration. Among all the reviewed methods, track maintenance based on the geometry is said to cater to the needs of the maintainers. The outcomes of this study are expected to support and assist in track maintenance decisions in the railway industry.

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41

Zhu, Wen-Fa, Guo-Peng Fan, Xiang-Zhen Meng, Yao Cheng, Hai-Yan Zhang, Li-Ming Li, Wei Shao, Xing-Jie Chen, and Han-Fei Zhang. "Ultrasound SAFT imaging for HSR ballastless track using the multi-layer sound velocity model." Insight - Non-Destructive Testing and Condition Monitoring 63, no. 4 (April 1, 2021): 199–208. http://dx.doi.org/10.1784/insi.2021.63.4.199.

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Accurate detection of void defects in ballastless track structures has become a core problem that needs urgent resolution for the maintenance and repair of high-speed railway (HSR) line structures in China. In this study, the root mean squaresynthetic aperture focusing technique (RMS-SAFT) ultrasound imaging method, which is suitable for the void defects of multi-layer structures, is proposed by combining the RMS velocity method and SAFT ultrasound imaging. First, a multi-layer sound velocity model (the relationship model between sound propagation time and sound propagation distance) of the HSR ballastless track is established. The sound propagation time is expressed as a function of the RMS of sound propagation speed as an independent variable. Second, the propagation time of the sound wave in the HSR ballastless track is calculated in accordance with the multi-layer sound velocity model and the obtained propagation time is substituted into the SAFT ultrasound imaging method for imaging. Lastly, the accuracy of the method is verified through a finite element simulation and an experiment. The results show that for the HSR ballastless track with minimal differences in the sound propagation speed at each layer, the sound propagation time calculated by the multi-layer sound wave model has high accuracy. The proposed RMS-SAFT ultrasound imaging method improves the accuracy of traditional SAFT imaging and realises accurate imaging of the void defects of HSR ballastless track.

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42

Zhao, Caiyou, Ping Wang, Qiang Yi, and Duo Meng. "Application of Polyurethane Polymer and Assistant Rails to Settling the Abnormal Vehicle-Track Dynamic Effects in Transition Zone between Ballastless and Ballasted Track." Shock and Vibration 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/826362.

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This paper describes tests on a transition section between ballasted and ballastless tracks in the Liupanshui-Zhanyi railway in China. The originally unsettled transition zone is exposed to sudden car shaking and a series of track transition problems during train passage. As an example, the influences of polyurethane polymer and a combination of polyurethane and assistant rails to increase track stiffness distribution and track transition decay rates on the dynamic vehicle and track behaviour were investigated. The measured results indicate using only polyurethane and using both polyurethane and assistant rails not only effectively makes the track stiffness change more even but also increases the track decay rate at the target frequencies. These positive effects further reduce the wheel-rail interaction forces and vehicle and rail vertical acceleration, which decreases more when combining polyurethane and assistant rails than when using only polyurethane because the former outperforms the latter for smoothing the track stiffness distribution and increasing the track decay rate. Based on abating wheel-rail impact during the transition from ballasted to ballastless track and improving traffic operation and passenger comfort, combining polyurethane and assistant rails had the greatest effect and may be an effective remedy.

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Zeng, Zhiping, Ji Hu, Xudong Huang, Weidong Wang, Zhibin Huang, Abdulmumin Ahmed Shuaibu, Yu Yuan, Zhonglin Xie, and Xianfeng He. "Research on Fatigue Damage Evolution of the Base Plate Structure of China Railway Track System III Type Slab Ballastless Track under Heavy Haul Train Load." Applied Sciences 12, no. 3 (February 7, 2022): 1694. http://dx.doi.org/10.3390/app12031694.

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To meet the transportation requirements of heavy-haul trains, it is necessary to consider the use of prestressed reinforced concrete ballastless tracks. Therefore, the CRTSIII SBT (China Railway Track System III-type slab ballastless track) has been considered for its convenient construction and geometric adjustment. Considering the problems existing in the base plate of CRTSIII SBT in heavy-haul applications, an indoor test and simulation were conducted to explore the cracking phenomenon of the base plate concrete under fatigue load. The reliability of the simulation was verified through the experimental results. A fatigue crack development law of the base plate structure was established. Furthermore, the influence of the load position, the thickness of self-compacting concrete and axle loads on the fatigue damage of the base plate structure were investigated. For the CRTSIII SBT subjected to heavier axle loads, it is appropriate to thicken the self-compacting concrete layer and strengthen the concrete and steel reinforcement at the plate end to reduce fatigue damage and cracks. The research results can serve as a basis for the optimization of the CRTSIII SBT base plate structure in heavy-haul railway applications.

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44

YANG, Fei, WanMing ZHAI, JianMin GAO, HongYan LI, Xiong KANG, and XiuBo LIU. "PSD of ballastless track irregularities of high-speed railway." SCIENTIA SINICA Technologica 44, no. 7 (July 1, 2014): 687–96. http://dx.doi.org/10.1360/n092014-00088.

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45

Dudkin, Evgeni, Nariman Sultanov, and Maksim Malakhov. "Application of ballastless construction of the railroad track in the Arctic zone." E3S Web of Conferences 383 (2023): 01014. http://dx.doi.org/10.1051/e3sconf/202338301014.

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Abstract: the article provides a calculation justification of the proposed railway structure on a reinforced concrete sleeper-free base, for which an analysis of the existing methodology for calculating the railway track for strength is carried out, according to which for a railway track on a sleeper-free base, dynamic loads acting from the rolling stock on the track are determined. The analysis of the applied sleeper-less structures of the railway track and the results of measurements of emerging stresses in the substructure, the measured depth of the core are carried out. Using the previously obtained results of studies of the depth of the core, the justification of the required height of the embankment and the calculation of the parameters of the subplate base is carried out. Next, the finite element method calculates the bending stresses arising in the bearing plate, where the maximum is 1.82 MPa and is compared with the permissible value, which is much greater for a reinforced concrete slab. Also, the result is the obtained elastic vertical movements, which indicate a more uniform distribution of the load from the rolling stock on the roadbed.

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46

Zhang, Hanhua, Jun Li, Jun Zou, Zhixin Wang, and Jin Yang. "Fast approach to calculate the ballastless track impedance." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 1 (January 2, 2018): 176–88. http://dx.doi.org/10.1108/compel-01-2017-0008.

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Purpose The track impedance is one of the most important parameters in designing the track circuit which is widely used in the railway signal control system to detect the presence of a train. This paper aims to calculate the ballastless track impedance by taking account of the influence of reinforcement bars. Design/methodology/approach This paper proposes a two-step decomposition approach to calculate the ballastless track impedance. The basic idea is evaluating the track impedance without the reinforcement bars by using two-dimensional (2D) finite element method (FEM), and the incremental impedance, because of the reinforcement bar, is calculated by the partial element equivalent circuit (PEEC) method. Findings The numerical examples show that the proposed approach can guarantee the accuracy and largely reduce the computing time, at least 20 times, compared with the direct three-dimensional (3D) FEM method. Research limitations/implications The study provides a fast approach to calculate the ballastless track impedance. However, compared with the 3D FEM method, the results are less accurate because of the approximation and assumption adopted in the method. A future study should pay more attention to improve accuracy of the model. Originality/value A fast approach is proposed to calculate the ballastless track impedance taking account of the influence of the reinforcement bars. The computing time can be largely reduced by using the method. With the proposed approach, the influence of insulation of the reinforcement bars on track impedance can be analyzed.

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47

Chen, Xianhua, Yu Zhu, Degou Cai, Gang Xu, and Tao Dong. "Investigation on Interface Damage between Cement Concrete Base Plate and Asphalt Concrete Waterproofing Layer under Temperature Load in Ballastless Track." Applied Sciences 10, no. 8 (April 12, 2020): 2654. http://dx.doi.org/10.3390/app10082654.

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The interfacial bond between cement concrete base plate (CCBP) and asphalt concrete waterproofing layer (ACWL) is a weak portion in the newly developed Chinese high-speed railway ballastless track. The interface damage caused due to fluctuating temperature load and dynamic train load is one of the most critical problems in Northern China. This paper aims to investigate the interface damage evolution process under temperature load via experimental and simulation analysis. Full-scale transverse shear tests were performed to explore the interface bond-slip mode of the adjacent ACWL and CCBP. Then, a finite element model of a ballastless track structure was built and a cohesive zone model (CZM) was utilized to model the interface damage initiation, crack propagation, and delamination process under uniform/gradient temperature load. Furthermore, the dynamic response of the ballastless track where CCBP and ACWL were partly/totally debonded was investigated and compared with the perfectly bonded structure. The results demonstrate that bilinear CZM is capable of revealing the interface damage initiation, crack propagation, and delamination process under temperature load. The interface state between the adjacent CCBP and ACWL was greatly affected by temperature changes and the interface bonding state had a great impact on the dynamic response of ballastless track.

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48

Chen, Wei, Chao Wang, Linhong Fang, Chao Liu, Zhiping Zeng, Ping Lou, and Tianqi Zhang. "Line Shape Analysis and Dynamic Response of Ballastless Track during Jacking Rectification Fixing." Materials 15, no. 22 (November 21, 2022): 8265. http://dx.doi.org/10.3390/ma15228265.

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In order to study the railway line deformation and dynamic response of ballastless track structure under train load during jacking rectification fixing, a three-dimensional numerical model of the CRTS II slab ballastless track on subgrade is established by using the finite element method. The line deformation rule and local damage rule of ballastless track under jacking force are analyzed. The dynamic response laws of track structure and subgrade bed are compared considering four different connection modes between the base plate and subgrade bed under different train speeds in the process of jacking rectification fixing. The results show that jacking force and dissociation length have a small influence on the deviation value and the critical jacking force should be smaller than 375 kN in single point jacking. Under the condition of multi-point jacking, when the jacking loading length equals to 5 slabs, the critical jacking force should be smaller than 275 kN and the maximum lateral deviation value is about 22.11 mm. It is necessary to restrict the speed of passing trains to no more than 150 km/h during the jacking rectification fixing for dissociation condition without temporary restraint. When temporary restraint is applied, the speed of the train can be increased appropriately according to the actual situation. The above study results could be used as a theoretical reference for the ballastless track deviation correction.

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49

Biancardo, Salvatore Antonio, Francesco Avella, Ernesto Di Lisa, Xinqiang Chen, Francesco Abbondati, and Gianluca Dell’Acqua. "Multiobjective Railway Alignment Optimization Using Ballastless Track and Reduced Cross-Section in Tunnel." Sustainability 13, no. 19 (September 26, 2021): 10672. http://dx.doi.org/10.3390/su131910672.

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The increasing need for railway planning and design to connect growing cities in inland mountainous areas has pushed engineering efforts toward the research of railway tracks that must comply with more restrictive constraints. In this study, a multiobjective alignment optimization (HAO), commonly used for highway projects, was carried out to identify a better solution for constructing a high-speed railway track considering technical and economic feasibilities. Then, two different and innovative scenarios were investigated: an unconventional ballastless superstructure, which is more environment-friendly than a gravel superstructure, and a reduced cross-section in a tunnel, which enables a slower design speed and then, less restrictive geometric constraints and earthmoving. The results showed that the first solution obtained a better performance with a slight increase in cost. Moreover, both scenarios improved the preliminary alignment optimization, reducing the overall cost by 11% for the first scenario and 20% for the second one.

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50

Cao, Jian An, Mei Xin Ye, and Wen Qi Hou. "Long Term Deformation Control of Long-Span Pre-Stressed Concrete Continuous Rigid Frame Bridge with Ballastless Track." Advanced Materials Research 163-167 (December 2010): 1515–19. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.1515.

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Aiming to Ronggui Bridge (RGB) on Guangzhou-Zhuhai Intercity Rapid Rail Transit (GZIRRT), long term deformation control of long-span pre-stressed concrete continuous rigid frame bridge with ballastless track was studied. Comparing with the non-controlled deformation, extend track laying six months later after bridge construction, reserve 48 post-tensioned cables in middle spans and tension 12 external tendons after tracking laying were all effective in decreasing the long term deformation of RGB with individual application. Taking bridge construction and railway service in consideration, applying the foregoing three measures in combination, deformation of RGB 20 years later after track laying was effectively controlled within 12.8mm in the side spans and 21.9mm in the middle spans, which is less than the deformation limitation of bridges with ballastless track. The combined measure has been adopted in the actual construction of RGB.

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