Mechanical characteristic variation of ballastless track in high-speed railway: effect of train–track interaction and environment loads

Abstract

Due 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.

Keywords

Ballastless track / High-speed railway / Mechanical characteristic / Interface damage / Train–track interaction / Temperature gradient / Dynamic water pressure / Cohesive zone model

References

[1.] Gautier PE. Slab track: review of existing systems and optimization potentials including very high speed. Constr Build Mater, 2015 92 9-15

[2.] Matias SR Ferreira PA. Railway slab track systems: review and research potentials. Structu Infrastructu Eng, 2020 16 12 1635-1653

[3.] Zhao G Gao L Zhao L Zhong Y. Analysis of dynamic effect of gap under CRTS II track slab and operation evaluation. J China Railw Soc, 2017 39 1 1-10

[4.] Zhong Y Gao L Zhang Y. Effect of daily changing temperature on the curling behavior and interface stress of slab track in construction stage. Constr Build Mater, 2018 185 638-647

[5.] Zhang Y Cai X Gao L Wu K. Improvement on the mechanical properties of CA mortar and concrete composite specimens in high-speed railway by modification of interlayer bonding. Constr Build Mater, 2019 228 116758

[6.] Peng H Zhang Y Wang J Liu Y Gao L. Interfacial bonding strength between cement asphalt mortar and concrete in slab track. J Mater Civ Eng, 2019 31 7 1-11

[7.] Wang J Zhou Y Wu T Wu X. Performance of cement asphalt mortar in ballastless slab track over high-speed railway under extreme climate conditions. Int J Geomech, 2019 19 5 1-11

[8.] Yu Y Tang L Ling X Cai D Ye Y Geng L. Mitigation of temperature-induced curling of concrete roadbed along high-speed railway: in situ experiment and numerical simulation. KSCE J Civil Eng, 2020 24 4 1195-1208

[9.] Chen R Yang K Qiu X Zeng X Wang P Xu J Chen J. Degradation mechanism of CA mortar in CRTS I slab ballastless railway track in the Southwest acid rain region of China–Materials analysis. Constr Build Mater, 2017 149 921-933

[10.] Cai X-P Luo B-C Zhong Y-L Zhang Y-R Hou B-W. Arching mechanism of the slab joints in CRTSII slab track under high temperature conditions. Eng Fail Anal, 2019 98 2018 95-108

[11.] Li Y Chen J Wang J Shi X Chen L. Study on the interface damage of CRTS II slab track under temperature load. Structures, 2020 26 224-236

[12.] Zhu S Cai C. Interface damage and its effect on vibrations of slab track under temperature and vehicle dynamic loads. Int J Non-Linear Mech, 2014 58 222-232

[13.] Zhu S Wang M Zhai W Cai C Zhao C Zeng D Zhang J. Mechanical property and damage evolution of concrete interface of ballastless track in high-speed railway: experiment and simulation. Constr Build Mater, 2018 187 460-473

[14.] Ren J Wang J Li X Wei K Li H Deng S. Influence of cement asphalt mortar debonding on the damage distribution and mechanical responses of CRTS I prefabricated slab. Constr Build Mater, 2020 230 116995

[15.] Zhao P Liu X Yang R Guo L Hu J. Experimental study of temperature load determination method of bi-block ballastless track. J China Railw Soc, 2016 38 1 92-97(in Chinese)

[16.] Zhang Y Wu K Gao L Yan S Cai X. Study on the interlayer debonding and its effects on the mechanical properties of CRTS II slab track based on viscoelastic theory. Constr Build Mater, 2019 224 387-407

[17.] Xiao H Zhang Y-R Li Q-H Jin F Nadakatti MM. Analysis of the initiation and propagation of fatigue cracks in the CRTS II slab track inter-layer using FE-SAFE and XFEM. Proc Inst Mech Eng F J Rail Rapid Transit, 2019 233 7 678-690

[18.] Cao S Yang R Su C Dai F Liu X Jiang X. Damage mechanism of slab track under the coupling effects of train load and water. Eng Fract Mech, 2016 163 160-175

[19.] Zhu S Cai C Zhai W. Interface damage assessment of railway slab track based on reliability techniques and vehicle-track interactions. J Transp Eng, 2016 142 10 04016041

[20.] Alfano G Crisÿeld MA. Finite element interface models for the delamination analysis of laminated composites: mechanical and computational issues. Int J Numer Methods Eng, 2001 50 2000 1701-1736

[21.] Camacho GT Ortiz M. Computational modelling of impact damage in brittle materials. Int J Solids Struct, 1996 33 20 2899-2938

[22.] Geubelle PH Baylor JS. Impact-induced delamination of composites: a 2D simulation. Compos B Eng, 1998 29 5 589-602

[23.] Needleman A. An analysis of tensile decohesion along an interface. J Mech Phys Solids, 1990 38 3 289-324

[24.] Tvergaard V Hutchinson JW. The relation between crack growth resistance and fracture process parameters in elastic-plastic solids. J Mech Phys Solids, 1992 40 6 1377-1397

[25.] Camanho PP, Davila CG (2002) Mixed-Mode Decohesion Finite Elements for the Simulation of Delamination in Composite Materials. NASA/TM-2002–2117372002. pp 1–37.

[26.] TB 10621–2014 (2014) Code for Design of High Speed Railway. Beijing: The National Railway Administration of China. (in Chinese).

[27.] Zhai W. Vehicle-track coupled dynamics: theory and application, 2020 Singapore Springer

[28.] Zhai W Wang K Cai C. Fundamentals of vehicle-track coupled dynamics. Veh Syst Dyn, 2009 47 1349-1376

[29.] Luo J Zhu S Zhai W. Theoretical modelling of a vehicle-slab track coupled dynamics system considering longitudinal vibrations and interface interactions. Veh Syst Dyn, 2020

[30.] Zhai W. Two simple fast integration methods for large-scale dynamic problems in engineering, . Int J Numer Meth Eng, 1996 39 4199-4214

[31.] Luo J Zeng Z. A novel algorithm for longitudinal track-bridge interactions considering loading history and using a verified mechanical model of fasteners. Eng Struct, 2019 183 52-68

Funding

National Natural Science Foundation of China(51708457, 11790283, 51978587); State Key Laboratory of Traction Power(2019TPL-T16); China Association for Science and Technology(2018QNRC001); State Administration of Foreign Experts Affairs (CN)(B16041)