Analysis of Track Bending Stiffness and Loading Distribution Effect in Rail Support by Application of Bending Reinforcement Methods

Abstract

Railway track is a linearly inhomogeneous object that consists of geometrical and elastic discontinuities such as bridges, transition zones, rail joints and crossings. The zones are subjected to the development of local instabilities due to quicker deterioration than the other tracks. Until now, there have been no efficient approaches that could fully exclude the problem of accelerated differential settlements in the problem zones. Many structural countermeasures are directed at controlling the sleeper/ballast loading with the help of fastenings/under-sleeper pad elasticities, sleeper forms and additional bending stiffness reinforcements. However, the efficiency of the methods is difficult to compare. The current paper presents a systematic approach in which the loading distribution effect in the rail support by application of two bending reinforcement methods is compared: auxiliary rail and under-sleeper beam. The study considers only the static effects to reach a clear understanding the influence of the main factors. The track equivalent bending stiffness criterion is proposed for comparing reinforcement solutions. The analysis shows that the activation of the bending stiffness of the reinforcement beams depends on the relative ratio of the rail fastenings stiffness and track support stiffness under sleepers (or under the under-sleeper beam). The comparison demonstrates that conventional auxiliary rail reinforcement solutions are ineffective due to their weak bending because of the high elasticity of fastening clips and the main rail fastenings. The share of an auxiliary rail is maximally 20% in the track bending stiffness and cannot be significantly improved by additional rails. The under-sleeper beam-based reinforcement solutions show noticeably higher efficiency. The highest effect can be achieved by the activation of the horizontal shear interaction between the under-sleeper beam and the rail. The additional track bending stiffness of the under-sleeper-based solutions is about 3.5 times more of the rail one and could be potentially increased to 6–10 times.

Keywords

Track bending stiffness / Rail support stiffness / Loading distribution / Transition zones / Auxiliary rails / Under-sleeper beam / Shear interaction

References

[1] Marx L, Moßmann D (2011) Arbeitsverfahren für die Instandhaltung des Oberbaus. DB-Fachbuch. Bahn Fachverlag GmbH, Berlin, 796 s. ISBN: 978-3-9808002-8-0

[2] Lichtberger B. Track compendium: formation, permanent way, maintenance, economics, 2005, Hamburg: Eurailpress

[3] Sañudo R, Jardí I, Martínez J-C, Sánchez F-J, Miranda M, Alonso B, dell’Olio L, Moura J-L. Monitoring track transition zones in railways. Sensors, 2022, 22: 76

[4] Shi J, Burrow MPN, Chan AH, Wang YJ. Measurements and simulation of the dynamic responses of a bridge-embankment transition zone below a heavy haul railway line. Proc Inst Mech Eng Part F J Rail Rapid Transit, 2013, 227(3): 254-268

[5] Shahraki M, Warnakulasooriya C, Witt KJ. Numerical study of transition zone between ballasted and ballastless railway track. Transp Geotech, 2015, 3: 58-67

[6] Wang HY, Markine VL. Methodology for the comprehensive analysis of railway transition zones. Comput Geotech, 2018, 99: 64-79

[7] Çati Y, Gökçeli S, Anil Ö, Korkmaz CS. Experimental and numerical investigation of usp for optimization of transition zone of railway. Eng Struct, 2020, 209: 109971

[8] Wang HY, Markine V. Dynamic behaviour of the track in transitions zones considering the differential settlement. J Sound Vib, 2019, 459: 114863

[9] Ngamkhanong C, Ming QY, Li T, Kaewunruen S. Dynamic train-track interactions over railway track stiffness transition zones using baseplate fastening systems. Eng Fail Anal, 2020, 118: 104866

[10] https://rhombergbahntechnik.rhomberg-sersa.com/de/services/produkte-universelles-uebergangsmodul-v-tras. Accessed 26 August 2022

[11] Kurhan D, Kurhan M, Husak M. Impact of the variable stiffness section on the conditions of track and rolling stock interaction. IOP Conf Ser Mater Sci Eng, 2020, 985(1): 012005

[12] Asghari K, Sotoudeh S, Zakeri J-A. Numerical evaluation of approach slab influence on transition zone behavior in high-speed railway track. Transp Geotech, 2021, 28: 100519

[13] Hodás S, Pultznerová A. Numerical modeling of freezing of structural objects in transition zones of railways. IOP Conf Ser Mater Sci Eng, 2021, 1015: 012049

[14] Indraratna B, Babar Sajjad M, Ngo T, Gomes Correia A, Kelly R. Improved performance of ballasted tracks at transition zones: a review of experimental and modelling approaches. Transp Geotech, 2019, 21: 100260

[15] Uranjek M, Štrukelj A, Lenart S, Peruš I. Analysis of influential parameters for accelerated degradation of ballast railway track. Constr Build Mater, 2020, 261: 119938

[16] Sakhare A, Farooq H, Nimbalkar S, Dodagoudar GR. dynamic behavior of the transition zone of an integral abutment bridge. Sustainability (Switzerland), 2022, 14(7): 4118

[17] Hodas S, Izvoltova J, Chromcak J, Bacova D. Monitoring the geometric position of transition zones to increase the quality and safety of railway lines. Appl Sci (Switzerland), 2022, 12(12): 6038

[18] Izvolt L, Harusinec J, Smalo M. Optimisation of transition areas between ballastless track and ballasted track in the area of the Tunnel Turecky Vrch. Commun Sci sLett Univ Žilina, 2018, 20(3): 67-76

[19] Sadri M, Lu T, Steenbergen M. Railway track degradation: the contribution of a spatially variant support stiffness—local variation. J Sound Vib, 2019, 455: 203-220

[20] Chumyen P, Connolly DP, Woodward PK, Markine V. The effect of soil improvement and auxiliary rails at railway track transition zones. Soil Dyn Earthq Eng, 2022, 155: 107200

[21] Liu JX, Xiong ZW, Liu ZY, Chen R, Wang P. Static and cyclic compressive mechanical characterization of polyurethane-reinforced ballast in a railway. Soil Dyn Earthq Eng, 2022, 153: 107093

[22] Fischer S. Geogrid reinforcement of ballasted railway superstructure for stabilization of the railway track geometry—a case study. Geotext Geomembr, 2022, 50(5): 1036-1051

[23] Sañudo Ortega R, Pombo J, Ricci S, Miranda M. The importance of sleepers spacing in railways. Constr Build Mater, 2021, 300: 124326

[24] Sañudo R, Miranda M, Alonso B, Markine V. Sleepers spacing analysis in railway track infrastructure. Infrastructures, 2022, 7: 83

[25] Rampat T, Le Pen L, Powrie W, Harkness J. Importance of bending stiffness of different track forms. Lect Notes Civ Eng, 2021, 165: 125-137

Funding

Rhomberg Sersa Deutschland GmbH