Effects of model scale on lateral resistance characteristic of sleepers in railway ballasted tracks

Fundamental study on rapid detection of the insufficient lateral resistance of ballasted railway tracks by dynamic loading

“…Ballast, sleepers and rails used for the track models were also 1/9 of full-scale. Based on the previous studies [12][13][14], the scaled model tests were expected to hold the similarity law such that the load on the 1/9-scale model was 1/9 3 = 1/729 of the actual load.…”

Developing a Novel Superstructure System for the Ballasted Railways Using RRP235special Stabilized Clayey Soil

“…Lateral resistance has influenced by various factors such as environment conditions, applied loads, track components, track geometry, and maintenance procedure. The lateral resistance between ballast and sleeper usually is conducted using the tests with single or multiple sleepers in full-scale or scaled model in laboratory or in situ [12]. The ballast layer geometry and interaction between the ballast and the sleeper is the main factor of lateral resistance [13].…”

Comment on: Toughness of Railroad Concrete Crossties with Holes and Web Openings. Infrastructures 2017, 2, 3

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The present brief comment is regarding the technical note "Toughness of railroad concrete crossties with holes and web opening", by Erosha K. Gamage, Sakdirat Kaewunruen, Alex M. Remennikov, and Tetsuya Ishida [1].I judge from my experience (please see some of my relevant publications [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] about loading and dimensioning of concrete sleepers; uploaded in http://giannakoskonstantinos.com/wp) that their technical note is of little value since it does not include dynamic testing of the sleepers/crossties, but it is based only on static tests. I briefly describe the research performed with me as the coordinator, for a period of over twenty years.

The investigation of railway matters in Greece had been undertaken during the development of the Greek Railways' network and the design, construction, and maintenance of new and upgraded (high-speed) lines planned for operational speeds of up to 250 km/h (155 m/h) and axle-load max = 22.5 t; this development has been co-financed by European Union/EU and the Greek Government, since the 1980s, and it is performed according to the EU's regulations and technical specifications.

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“…I judge from my experience (please see some of my relevant publications [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] about loading and dimensioning of concrete sleepers; uploaded in http://giannakoskonstantinos.com/wp) that their technical note is of little value since it does not include dynamic testing of the sleepers/crossties, but it is based only on static tests. I briefly describe the research performed with me as the coordinator, for a period of over twenty years.…”

“…One factor with a decisive influence on the value of the dynamic component of the actions is the value of the Non-Suspended (Unsprung) Masses/NSM of the vehicles and their behavior due to the dip of the (vertical) displacement of the track, the static stiffness coefficient of the track, the condition of the rail running table, etc. Two more parameters, that highly influence the value of the dynamic component of the actions, are the static and the dynamic stiffness coefficients of the pads of the fastenings; the static The results from Figure 1 led to a more exhaustive investigation of the extensive appearance of cracks on sleepers, which would lead to the development of a new methodology (Giannakos 2004 method) for the calculation of the actions on sleepers, which would be able to simulate and explain the phenomena that were observed in the Greek network (see [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]). One factor with a decisive influence on the value of the dynamic component of the actions is the value of the Non-Suspended (Unsprung) Masses/NSM of the vehicles and their behavior due to the dip of the (vertical) displacement of the track, the static stiffness coefficient of the track, the condition of the rail running table, etc.…”