Influence of particle breakage on the resilient modulus of railway ballast

Indraratna, Buddhima; Vinod, Jayan S.; Lackenby, J.

doi:10.1680/geot.2008.t.005

Cited by 38 publications

(16 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This trend is analogous to the dominant effect of stress level on the resilient modulus employed in pavement engineering (e.g. Indraratna et al, 2009). Fig.…”

Section: Design Lateral Backfill Stiffnesssupporting

confidence: 54%

Lateral soil stiffness adjacent to deep integral bridge abutments

Lehane¹

2011

Géotechnique

View full text Add to dashboard Cite

Our understanding of the performance of integral bridge abutments subjected to cyclic loading has been improved using well-designed laboratory experiments, and by observation of abutment performance in the field. However, there remains significant uncertainty on how the increase in lateral stress that arises due to cycling of the backfill may be assessed for abutment design. Such uncertainty is addressed in this paper by drawing on results from a series of experiments performed using the University of Western Australia (UWA) beam centrifuge. The experimental results shed light on the effects, for granular backfill, of initial density, retained height, cyclic history and particle shape. These results, as well as observations made from tests involving overconsolidated clays, are used in conjunction with the existing database of lateral stress measurements to assist in the development of recommendations for assessment of design lateral stresses on deep integral bridge abutments.

show abstract

“…This trend is analogous to the dominant effect of stress level on the resilient modulus employed in pavement engineering (e.g. Indraratna et al, 2009). Fig.…”

Section: Design Lateral Backfill Stiffnesssupporting

confidence: 54%

Lateral soil stiffness adjacent to deep integral bridge abutments

Lehane¹

2011

Géotechnique

View full text Add to dashboard Cite

show abstract

“…Indraratna et al (2008) highlighted the influence of particle breakage on the resilient modulus which is summarised below.…”

Section: Resilient Modulus Of Ballastmentioning

confidence: 99%

“…The percentage increase of M R in this zone was found to be 16% for q max of 500 kPa. An increased ′ σ 3 in the CSDZ will increase the stress level where the particles touch whilst restricting internal sliding and rolling (Lackenby et al 2007;Indraratna et al 2008), and contribute towards an increase in the resilient modulus. Lackenby et al, 2007 has shown that the resilient modulus (M R ) increases with an increasing number of cycles, and a maximum deviator stress magnitude (q max,cyc ) and confining pressure, as shown in Figure 12.…”

Section: Resilient Modulus and Ballast Breakagementioning

confidence: 99%

The performance of rail track incorporating the effects of ballast breakage, confining pressure and geosynthetic reinforcement

Indraratna¹,

Nimbalkar²,

Christie³

2009

Bearing Capacity of Roads, Railways and Airfields

View full text Add to dashboard Cite

Rail tracks are often placed on ballast which offers the desirable resiliency to cyclic loads. However ballasted beds need periodic maintenance due to deformation and degradation associated with breakage and fouling. A proper understanding of load transfer mechanisms and their effect on ballast breakage are prerequisites for minimizing maintenance costs. Recycled ballast is a cheaper and environmentally viable option but its strength characteristics need to be investigated beforehand. This paper demonstrates the analytical, numerical and laboratory investigations carried out to investigate the geotechnical behavior of ballast, including shear strength, ballast breakage, and confining pressure. The potential use of geosynthetics for improving the stability and drainage of railway tracks under high monotonic and cyclic loading is also studied. Field tests were carried out to measure the in-situ stresses of ballast on a section of instrumented track funded and built by RailCorp, Australia.

show abstract

“…Therefore, this study could not capture the role of train speed (directly proportional to frequency) on the permanent deformation of ballast. Indraratna et al (2009) concluded that the particle breakage has a significant influence on the resilient modulus of the railway ballast. However, none of these studies was able to capture the effect of decreasing confining pressure on the permanent deformation of ballast due to the increasing train speed.…”

Section: Introductionmentioning

confidence: 99%

Effect of confining pressure and frequency on the deformation of ballast

Thakur¹,

Vinod²,

Indraratna³

2013

Géotechnique

Self Cite

View full text Add to dashboard Cite

Increasing the speed and frequency of trains with the same static axle weight imparts higher dynamic axle loads more frequently. When this occurs on existing track which has not been designed for such loading there can be increased rates of ballast degradation, characterised by unacceptable deformation and lateral spread, leading to more frequent requirements for track maintenance. Recent studies carried out at the University of Wollongong highlighted that confining pressure and frequency have a significant influence on the permanent deformation and degradation of ballast. However, confinement required to keep the deformation and degradation of the ballasted track to an acceptable limit will depend on the train speed (frequency). In this context, a series of cyclic triaxial tests was conducted on latite basalt samples having an initial confining pressure of 120 kPa. After every 25 000 cycles, the confining pressure was decreased in steps to simulate the drop of confining pressure during heavy traffic. This test procedure was adopted to replicate the influence of train speed on the stability of ballast. Test results indicated that both the frequency and confining pressure have a significant influence on the permanent deformation of ballast. Resilient modulus is found to increase with an increase in confining pressure and number of cycles, but to decrease with increasing frequency. The results also showed that the ballast layer requires a minimum level of confinement for preventing an excessive amount of track deformation. An empirical equation is formulated to determine the required confining pressure and resilient modulus of the ballast layer for an allowable limit of track deformation at a given train speed.

show abstract

Influence of particle breakage on the resilient modulus of railway ballast

Cited by 38 publications

References 3 publications

Lateral soil stiffness adjacent to deep integral bridge abutments

Lateral soil stiffness adjacent to deep integral bridge abutments

The performance of rail track incorporating the effects of ballast breakage, confining pressure and geosynthetic reinforcement

Effect of confining pressure and frequency on the deformation of ballast

Contact Info

Product

Resources

About