THE EFFECTS OF LOCAL PRELOAD ON THE FOUNDATION STIFFNESS AND VERTICAL VIBRATION OF RAILWAY TRACK

1999 ◽  
Vol 219 (5) ◽  
pp. 881-904 ◽  
Author(s):  
T.X. Wu ◽  
D.J. Thompson
2014 ◽  
Vol 1041 ◽  
pp. 432-435
Author(s):  
Leopold Hudeček ◽  
Jiří Svoboda ◽  
Jan Kramný

The paper discusses measures to reduce the negative effects of tram traffic on residential house in Ostrava, where the tram line passes through the street area located under the structure of the house see Figure 1.Fig.1HouseNo.1340inOstravaaffectedbyvibrationsfromrailtransportThe lines of urban railways are often kept at densely built-up areas, often in close proximity to the buildings. It is necessary to put a high emphasis on protection against noise and vibration. In case of structures for residential buildings it has a negative effect on residents. An efficient way to reduce the vibration levels of the protected structure and thus the secondary noise is elastic foundation structure as a whole to its support structure. But in practice, we need to solve the problem of the ex post, i.e. when the structure of a residential building already exists.To reduce the transmission of vibrations to the structure was carried out technical measures for vibration attenuation along the route of the spread it is the path from the source to the protected structure. Railway track was imposed on rubber anti-vibration mats under gravel bed of tram line. Furthermore, the test sections were established in order to test the application of different materials used as a grout space between the rails and the surrounding environment and the reference section to compare the resulting data.Subsequently was held the measurement of noise and vibration. Vibrations were measured on the own construction of the house, also on the communication - vertical vibration near the track (30 cm far from the running rail track), these data present the transmission of vibration from the rail and sleepers in the immediate surroundings, measuring the vertical vibrations of the road (150 cm far from the running rail track in place that was not affected by reconstruction), these data present the transmission of vibration to the subsoil neighborhood.


2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ricard Sanchís ◽  
Salvador Cardona ◽  
Jordi Martínez

This paper presents a mathematical model used to obtain the vertical vibration of a ballasted railway track when a wheel is passing at a certain speed over a fixed location of the rail. The aim of this simulation is to compare calculated root-mean-square (RMS) values of the vertical vibration velocity with measured RMS values. This comparison is the basis for a proposed time domain methodology for detecting potential wheel flats or any other singular defect on the wheel rolling bands of metropolitan trains. In order to reach this goal, a wheel–rail contact model is proposed; this model is described by the track vertical impulse response and the vertical impulse response of the wheel with the primary suspension, both linked through a Hertz nonlinear stiffness. To solve the model for obtaining the wheel–rail contact force, a double convolution method is applied. Several kinds of wheel flats are analyzed, from theoretical round edged wheel flats to different real wheel profile irregularities. Afterward, the vertical vibration velocity at a fixed point on the rail is obtained using a variable kernel convolution method. Running different simulations for different wheel flats, a study of the vertical vibration attenuation along the rail is carried out. Finally, it is proceeded to obtain the temporary evolution of the RMS value for the rail vertical vibration velocity in order to be used as a reference for detecting wheel flats or any other defect. This last aspect will be presented in more detail in a second paper.


Author(s):  
S Kaewunruen ◽  
A M Remennikov

Concrete railway sleepers in ballasted track are laid on ballast and subgrade supporting systems. Full contact between sleepers and ballast is typically assumed for analysis and design purposes. Often, voids and pockets in the sleeper/ballast contact interface form between sleepers and the ballast underneath that could cause problems to both the sleepers and the track system as a whole. The current paper investigates the effects of ballast voids and pockets on free vibration response characteristics of in situ railway concrete sleepers. Finite-element modelling was employed to develop a dynamic model of the railway track incorporating concrete sleepers. This model includes the dynamic interaction of sleepers and ballast as part of the free vibration analyses of the in situ railway concrete sleepers. Several patterns of voids and pockets underneath railway sleepers were studied. The emphasis was placed on partial and full interaction between sleepers and ballast. The information on the vertical vibration modes provides an important insight into the dynamic response of concrete railway sleepers in different void-and-pocket configurations.


2014 ◽  
Vol 134 (11) ◽  
pp. 1716-1723 ◽  
Author(s):  
Akihiro Torii ◽  
Mitsuhiro Nishio ◽  
Kae Doki ◽  
Akiteru Ueda
Keyword(s):  

2020 ◽  
Vol 24 (04) ◽  
pp. 1690-1697
Author(s):  
Arun Francis ◽  
Priyadharshini V ◽  
Dhanyasri N
Keyword(s):  

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