The effect of coal dust fouling on the cyclic behaviour of railtrack ballast

Budiono, D. S.; McSweeney, Tim; Dhanasekar, Manicka; Gurung, N.

doi:10.1201/9781439833452.ch73

Cited by 20 publications

(15 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, due to progressive degradation and the infiltration of fine particles and mud-pumping from the lower subgrade , ballast becomes fouled, which adversely affects the strength and deformation of ballasted tracks (Budiono et al 2004;Lackenby et al 2007;Tutumluer et al 2008;Fortunato et al 2010;Indraratna et al 2013). Given the typical Australian coal freight tracks, Feldman and Nissen (2002) reported that dry coal fines are responsible for 70-95% of the fouling materials in rail tracks.…”

Section: Introductionmentioning

confidence: 99%

Modelling geogrid-reinforced railway ballast using the discrete element method

Ngo

Indraratna

Rujikiatkamjorn

2016

Transportation Geotechnics

View full text Add to dashboard Cite

Rail ballast is an unbounded granular material that spreads laterally when subjected to train loading. Railroads can be reinforced by geogrids to reduce lateral movement and to optimize track performance. This paper presents a study of the behaviour of geogrid-reinforced ballast subjected to monotonic and cyclic loading using a large-scale direct shear box and a novel Track Process Simulation Apparatus (TPSA). The shear stressstrain response of fresh and fouled ballast reinforced by geogrid was investigated using large-scale direct shear tests subjected to normal stresses from 15 kPa to 75 kPa, where the levels of fouling varied from 20% to 95% Void Contamination Index (VCI). Cyclic tests for fresh and fouled ballast were conducted using the TPSA to realistically simulate real track conditions. The experimental results showed that a geogrid provides extra internal confinement and interlocks the aggreagtes in its apertures, hence reduces ballast deformation. The discrete element method (DEM) was used to model geogrid-reinforced fresh and fouled ballast subjected to monotonic and cyclic loading. Irregularly-shaped particles and geogird were simulated by clumping spherical balls together, while the coal fines were simulated by adding 1.5mm diameter spheres into the pore spaces of ballast. The predicted stress-displacement responses obtained from the DEM were in good agreement with those measured in the laboratory, where the peak shear stress of fouled ballast decreased and the dilation of fouled ballast increased with an increasing level of fouling. The contact force distributions and the orientations of normal and shear force were analyzed to provide more insight into the behaviour of ballast subjected to shearing. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ABSTRACTRail ballast is an unbounded granular material that spreads laterally when subjected to train loading. Railroads can be reinforced by geogrids to reduce lateral movement and to optimize track performance. This paper presents a study of the behaviour of geogrid-reinforced ballast subjected to monotonic and cyclic loading using a large-scale direct shear box and a novel Track Process Simulation Apparatus (TPSA). The shear stress-strain response of fresh and fouled ballast reinforced by geogrid was investigated using large-scale direct shear tests subjected to normal stresses from 15 kPa to 75 kPa, where the levels of fouling varied from 20% to 95% Void Contamination Index (VCI). Cyclic tests for fresh and fouled ballast were conducted using the TPSA to realistically simulate real track conditions. The experimental results showed th...

show abstract

Section: Introductionmentioning

confidence: 99%

Modelling geogrid-reinforced railway ballast using the discrete element method

Ngo

Indraratna

Rujikiatkamjorn

2016

Transportation Geotechnics

View full text Add to dashboard Cite

show abstract

“…frictional resistance). Budiono et al (2004) and Giannakos (2010) showed that fine particles adversely affect the strength and stiffness of the track. Also, the increased fines content may lead to excess pore water pressure generation upon saturation (Indraratna et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Behaviour of clay-fouled ballast under drained triaxial testing

Indraratna¹,

Tennakoon²,

Nimbalkar³

et al. 2013

Géotechnique

126

View full text Add to dashboard Cite

Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail ballast of volcanic origin, commonly used in Australia. Consolidated drained triaxial tests were conducted under three different levels of confining pressure and varying degrees of clay fouling. Stress-strain degradation characteristics are discussed in detail. This paper also describes the non-linear strength envelope and a novel empirical relationship to capture the detrimental effects of clay fouling on the performance of ballasted tracks. Contamination or fouling of rail ballast with external fines, including slurried and pumped subgrade material (e.g. clay and silt), is one of the primary reasons for track deterioration. Fouling causes differential settlement of the track, and also decreases the load-bearing capacity, owing to the reduction in the friction angle of the granular assembly. In certain circumstances, fouled ballast needs to be cleaned or replaced to maintain the desired track stiffness, load-bearing capacity and track alignment, all of which influence safety. This paper presents and discusses the results of a series of large-scale triaxial tests conducted on latite basalt, a rail ballast of volcanic origin, commonly used in Australia. Consolidated drained triaxial tests were conducted under three different levels of confining pressure and varying degrees of clay fouling. Stress-strain degradation characteristics are discussed in detail. This paper also describes the non-linear strength envelope and a novel empirical relationship to capture the detrimental effects of clay fouling on the performance of ballasted tracks.

show abstract

“…Under this condition, significant excess pore water pressure can be generated under fast moving trains (i.e., high cyclic loading), thereby reducing the track resiliency and stability apart from enhanced clay pumping (Ni et al 2014). In cases where the entrapment of fines into the ballast aggregates becomes significant, this would reduce the drainage capacity of the tracks, increase the excessive pore water pressure and thus decrease the effective bearing capacity of the track (Budiono et al 2004;Tutumluer et al 2008;Indraratna et al 2011a).…”

Section: Introductionmentioning

confidence: 99%

“…Budiono et al (2004) and Tutumluer et al (2008) stated that fine particles decreased the stiffness of track substructure and when the degree of fine particles becomes excessive, it can govern the strength of the ballast and ultimately cause the track to become unstable. Dombrow et al (2009) and Ebrahimi et al (2014) carried out large-scale tests of fouled ballast and reported that as the level of fouling increased the shear strength steadily decreased.…”

Section: Introductionmentioning

confidence: 99%