Using impulse response testing to examine ballast fouling of a railway trackbed

Bold, Robert De; Connolly, David; Patience, S.; Lim, Malcolm; Forde, M. C.

doi:10.1016/j.conbuildmat.2020.121888

Cited by 15 publications

(11 citation statements)

References 7 publications

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“…However, the suitable ballast resources (parent rock) are increasingly tight, and it is very difficult to find qualified ballast material for high-speed railways due to the high standards [ 20 ]. In addition, one challenge of applying ballasted tracks for higher speed trains is that fouling is rapidly generated in the ballast layer during service [ 21 ]. Therefore, developing a reasonable ballast layer maintenance plan, improving the inspection means, reducing ballast consumption, and controlling maintenance costs are the main development directions for ballast layers.…”

Section: Introductionmentioning

confidence: 99%

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

Wang

Liu

Jing

et al. 2022

Sensors

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In the past 20 years, many studies have been performed on ballast layer inspection and condition evaluation with ground penetrating radar (GPR). GPR is a non-destructive means that can reflect the ballast layer condition (fouling, moisture) by analysing the received signal variation. Even though GPR detection/inspection for ballast layers has become mature, some challenges still need to be stressed and solved, e.g., GPR indicator (for reflecting fouling level) development, quantitative evaluation for ballast fouling levels under diverse field conditions, rapid GPR inspection, and combining analysis of GPR results with other data (e.g., track stiffness, rail acceleration, etc.). Therefore, this paper summarised earlier studies on GPR application for ballast layer condition evaluation. How the GPR was used in the earlier studies was classified and discussed. In addition, how to correlate GPR results with ballast fouling level was also examined. Based on the summary, future developments can be seen, which is helpful for supplementing standards of ballast layer evaluation and maintenance.

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Section: Introductionmentioning

confidence: 99%

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

Wang

Liu

Jing

et al. 2022

Sensors

View full text Add to dashboard Cite

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“…Infrastructure monitoring during construction and service has made significant progress in recent decades [1][2][3][4], benefitting from the rapid advances in sensing techniques [5][6][7] and signal-processing algorithms [8][9][10]. As important infrastructure, tunnel construction has attracted much attention in monitoring technology to mitigate geological challenges, such as those from the karst environment, which accounts for 10% of the environment in the world.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Quantitative Recognition of Filler Materials Ahead of a Tunnel Face via Time-Energy Density Analysis of Wavelet Transforms

Zhang

et al. 2022

Minerals

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Advanced geological prediction of tunnels has become an indispensable task to ensure the safety and effectiveness of tunnel construction before excavation in karst areas. Geological disasters caused by unfavorable geological conditions, such as karst caves, faults, and broken zones ahead of a tunnel face, are highly sudden and destructive. Determining how to predict the spatial location and geometric size of unfavorable geological bodies accurately is a challenging problem. In order to facilitate a three-dimensional quantitative analysis of the filler material ahead of the tunnel face, a biorthogonal wavelet with short support, linear phase, and highly matching waveform of ground penetrating radar (GPR) wavelet is constructed by lifting a simple and general initial filter on the basis of lifting wavelet theory. A method for a time–energy density analysis of wavelet transforms (TEDAWT) is proposed in accordance with the biorthogonal wavelet. Fifteen longitudinal and horizontal survey lines are used to detect void fillers of different heights. Then, static correction, DC bias, gain, band-pass filtering, and offset processing are performed in the original GPR profile to enhance reflected signals and converge diffraction signals. A slice map of GPR profile is generated in accordance with the relative position of longitudinal and horizontal survey lines in space. The wavelet transform analysis of a single-channel signal of each survey line is performed by adopting the TEDAWT method because of the similar rule of the single-channel signal of GPR on the waveform overlay and the ability of the constructed wavelet basis to highlight the time-frequency characteristics of GPR signals. The characteristic value points of the first and second interfaces of the void fillers can be clearly determined, and the three-dimensional spatial position and geometric sizes of different void fillers can be obtained. Therefore, the three-dimensional visualization of GPR data is realized. Results show that the TEDAWT method has a good practical application effect in the quantitative identification of void fillers, which provides a basis for the interpretation of advanced geological prediction data of tunnels and for the construction decision.

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“…Apart from the internal conditions, some external agents such as non-subgrade fines can induce mud pumping. These include but are not limited to fines from ballast breakage, sleeper wear, coal spillage, wind, and waterborne dust, which reduce the drainage capability and adversely affect the ballast's mechanical functions [2,26,27]. It has been quantified that a majority (76%) of fouling material in ballast is contributed by ballast breakage, followed by migration of fines from sub-ballast and subgrade (16%) and a small amount (7%) is infiltrated from the surface [28].…”

Section: Introductionmentioning

confidence: 99%

Internal Instability and Fluidisation of Subgrade Soil under Cyclic Loading

et al. 2022

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Rapid globalisation and the rise in population have substantially increased the demand for rail infrastructure which have been critical in transporting passengers and freight across landmasses for over a century. The surge in demand often leads to the construction of railway lines along with unfavourable soil conditions which result in different forms of substructure challenges such as uneven track deformations, ballast degradation, and subgrade mud pumping. A widespread site investigation along the eastern coast of New South Wales, Australia, indicated the prevalence of mud holes or bog holes along the tracks. The field studies suggest that low-to-medium plasticity soils are highly susceptible to mud pump when subjected to heavy axle loads under impeding drainage conditions. Subsequent laboratory investigations conducted on the remoulded soil samples collected from the sites indicated the sharp rise in cyclic axial strains and excess pore pressures along with the internal redistribution of moisture content as the governing mechanism for mud pumping. Numerical simulations performed using discrete element method coupled with computational fluid dynamics show that at a high hydraulic gradient, there is a substantial loss of soil contact network which leads to the upward migration of soil particles. The role of plastic fines and the inclusion of geosynthetic layer between the ballast and subgrade are also discussed in this paper. It was observed that the addition of 10% of cohesive fines increased the resistance of subgrade soils to mud pumping. On the other hand, geosynthetic inclusions not only assist in dissipating high cyclic excess pore pressures but also inhibit the upward migration of fine particles.

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Using impulse response testing to examine ballast fouling of a railway trackbed

Cited by 15 publications

References 7 publications

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

State-of-the-Art Review of Ground Penetrating Radar (GPR) Applications for Railway Ballast Inspection

Three-Dimensional Quantitative Recognition of Filler Materials Ahead of a Tunnel Face via Time-Energy Density Analysis of Wavelet Transforms

Internal Instability and Fluidisation of Subgrade Soil under Cyclic Loading

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