Effect of cyclic loading frequency on the permanent deformation and degradation of railway ballast

Sun, Qideng; Indraratna, Buddhima; Nimbalkar, Sanjay

doi:10.1680/geot.14.t.015

Cited by 133 publications

(41 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In Phase 3, however, further particle rearrangement occurred much less within the now sufficiently packed or stabilized ballast layer. This only resulted in a marginal increase of vertical deformation that could be characterized as "stable shakedown" (Sun et al 2014). The relationship between vertical deformation and the number of load cycles can be empirically modelled as…”

Section: )mentioning

confidence: 99%

“…This often causes significant cumulative deformation as well as the loss of stability and geometry of conventional tracks. Such degradation under repetitive wheel loads results mainly from a loss of stability in the ballast layer through particle breakage, fouling, cyclic densification and associated deformations, as well as settlement of the underlying layers of subballast and subgrade (Neidhart 2001;Suiker et al 2005;Aursudkij et al 2009;Kennedy et al 2012;Sun et al 2014;Indraratna et al , 2015. Further degradation can also occur from impact loads induced from wheel-rail irregularities as well as abrupt changes in track stiffness (Jenkins et al 1974).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved Performance of Ballasted Rail Track Using Geosynthetics and Rubber Shockmat

Nimbalkar

Indraratna

2016

J. Geotech. Geoenviron. Eng.

109

View full text Add to dashboard Cite

Large repetitive wheel loads from heavy haul and passenger trains can cause significant track deformation that leads to poor track geometry and safety issues. The inclusion of geosynthetics and rubber mats (i.e., shockmat) in critical sections in the track for reducing these adverse effects was further examined through an extensive field trial in the town of Singleton, New South Wales (NSW), Australia. Four types of geosynthetics and a shockmat were installed below the ballast layer in selected sections of track constructed on three different subgrades (soft alluvial clay, hard rock, and concrete bridge), and the performance of the instrumented track was monitored for five years under in-service conditions including tamping operations. The measured stress-deformation response indicates that the geosynthetics effec-tively control the long-term and transient strains in the ballast layer, with the obvious benefit of reducing maintenance costs. The study also showed that the aperture size of geogrids in the range of 1.1 times the mean particle size of the ballast was most effective. The placement of shockmat on a concrete bridge contributed to reduced ballast breakage. The dynamic amplification of stresses induced by moving trains was observed, and it became more pronounced at higher axle loads and train speeds. The dynamic track modulus was evaluated adopting the concept of modified beam on an elastic foundation (BOEF), and this approach was found to be largely influenced by the axle load, train speed, placement of synthetic inclusions, and type of subgrade. Abstract: Large repetitive wheel loads from heavy haul and passenger trains can cause significant track deformation that leads to poor track geometry and safety issues. The inclusion of geosynthetics and rubber mats (i.e., shockmat) in critical sections in the track for reducing these adverse effects was further examined through an extensive field trial in the town of Singleton, New South Wales (NSW), Australia. Four types of geosynthetics and a shockmat were installed below the ballast layer in selected sections of track constructed on three different subgrades (soft alluvial clay, hard rock, and concrete bridge), and the performance of the instrumented track was monitored for five years under in-service conditions including tamping operations. The measured stress-deformation response indicates that the geosynthetics effectively control the long-term and transient strains in the ballast layer, with the obvious benefit of reducing maintenance costs. The study also showed that the aperture size of geogrids in the range of 1.1 times the mean particle size of the ballast was most effective. The placement of shockmat on a concrete bridge contributed to reduced ballast breakage. The dynamic amplification of stresses induced by moving trains was observed, and it became more pronounced at higher axle loads and train speeds. The dynamic track modulus was evaluated adopting the concept of modified beam on an elastic foundation (BOEF), and this approach was foun...

show abstract

Section: )mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improved Performance of Ballasted Rail Track Using Geosynthetics and Rubber Shockmat

Nimbalkar

Indraratna

2016

J. Geotech. Geoenviron. Eng.

109

View full text Add to dashboard Cite

show abstract

“…Khalili et al [7] and Liu et al [16] studied the cyclic behaviour of gravelly soil under cyclic loading with low frequency. Suiker et al [10] and Indraratna et al [17,18] investigated the deformation and degradation behaviours of both ballast and subballast under static and cyclic loading, from which the influences of loading history and confining pressure as well as loading frequency were observed. These notable contributions provide fundamental tools for further constitutive modelling of the cyclic behaviour of granular soils.…”

Section: Introductionmentioning

confidence: 99%

Modelling long-term deformation of granular soils incorporating the concept of fractional calculus

et al. 2015

View full text Add to dashboard Cite

Many constitutive models exist to characterise the cyclic behaviour of granular soils but can only simulate deformations for very limited cycles. Fractional derivatives have been regarded as one potential instrument for modelling memory-dependent phenomena. In this paper, the physical connection between the fractional derivative order and the fractal dimension of granular soils is investigated in detail. Then a modified elastoplastic constitutive model is proposed for evaluating the long-term deformation of granular soils under cyclic loading by incorporating the concept of factional calculus. To describe the flow direction of granular soils under cyclic loading, a cyclic flow potential considering particle breakage is used. Test results of several types of granular soils are used to validate the model performance. Abstract Lots of constitutive models exist to characterise the cyclic behaviour of granular soils but can only simulate deformations for very limited cycles. Fractional derivatives have been regarded as one potential instrument for modelling memory-dependent phenomena. In this paper, the physical connection between the fractional derivative order and the fractal dimension of granular soils is investigated in detail. Then a modified elasto-plastic constitutive model is proposed for evaluating the long-term deformation of granular soils under cyclic loading by incorporating the concept of factional calculus. To describe the flow direction of granular soils under cyclic loading, a cyclic flow potential considering particle breakage is used. Test results of several types of granular soils are used to validate the model performance.

show abstract

“…To address these problems, granulometric evolution has been incorporated into constitutive models for soils [12,23,36,37,39,44,50,56,62]. Such models are inspired by an increasingly large database of laboratory investigations which, despite notable experimental difficulties, document the behaviour of crushable soils [20,26,30,33,40,42,46,53,63,65,67].…”

Section: Introductionmentioning

confidence: 99%

Micromechanical inspection of incremental behaviour of crushable soils

Ciantia

Arroyo²,

O’Sullivan

et al. 2019

Acta Geotech.

View full text Add to dashboard Cite

In granular soils grain crushing reduces dilatancy and stress obliquity enhances crushability. These are well-supported specimen-scale experimental observations. In principle, those observations should reflect some peculiar micromechanism associated with crushing, but which is it? To answer that question the nature of crushing-induced particle-scale interactions is here investigated using an efficient DEM model of crushable soil. Microstructural measures such as the mechanical coordination number and fabric are examined while performing systematic stress probing on the triaxial plane. Numerical techniques such as parallel and the newly introduced sequential probing enable clear separation of the micromechanical mechanisms associated with crushing. Particle crushing is shown to reduce fabric anisotropy during incremental loading and to slow fabric change during continuous shearing. On the other hand, increased fabric anisotropy does take more particles closer to breakage. Shear-enhanced breakage appears then to be a natural consequence of shear-enhanced fabric anisotropy. The particle crushing model employed here makes crushing dependent only on particle and contact properties, without any pre-established influence of particle connectivity. That influence does not emerge, and it is shown how particle connectivity, per se, is not a good indicator of crushing likelihood.

show abstract

Effect of cyclic loading frequency on the permanent deformation and degradation of railway ballast

Cited by 133 publications

References 16 publications

Improved Performance of Ballasted Rail Track Using Geosynthetics and Rubber Shockmat

Improved Performance of Ballasted Rail Track Using Geosynthetics and Rubber Shockmat

Modelling long-term deformation of granular soils incorporating the concept of fractional calculus

Micromechanical inspection of incremental behaviour of crushable soils

Contact Info

Product

Resources

About