Effect of grading category on the roundness of degraded and abraded railway quartzites

Ballast degradation: Effect of particle size and shape using Los Angeles Abrasion test and image analysis

“…Recently, ballast degradation was studied and determined from the digital or X-ray images system by various researchers [21,[25][26][27]. Detailed measurements of particle's shape and roughness using the image analysis method have been successfully used for quantifying particle morphology [28,29]. Ballast particle abrasion and breakage by LAA tests with fouling index, and a relationship between the fouling index and the flakiness and elongation index change, sharp corner loss and surface texture reduction of the ballast particles, and the ballast shape factors evolution in different LAA test stages were studied in [21].…”

Image analysis for morphology, rheology and degradation study of railway ballast: A review

“…Also for better image acquisition, in the image analysis systems, the apparatuses are combined with some other facilities (e.g. transparent trays [60], green backlight [61]). each apparatus has the advantages and the disadvantages, as shown in Table 1.…”

“…To overcome the low efficiency limitation, the whole sample is placed in a proper position and photographed [61,[64][65][66][67][68], and many particle image segmentation algorithms are proposed for precise and automatic extraction, especially with the cutting-edge computer technology. For example, based on the convolutional neural networks (CNN), Tong presents an efficient and automatic PA method to evaluate particle angularity through digital images [69].…”

“…Instead of measuring the sizes of particles one by one, more efficient methods for measuring the particle sizes are proposed. The method is taking a photo of the entire particle sample, and then drawing the particle size distribution of the sample [61].…”

Relating fragmentation, plastic work and critical state in crushable rock clasts

“…Important breakage can also occur under low confining stress, particularly if the grains are fragile and present irregular shape (e.g., Nakata et al, 1999). Grain breakage is a fundamental issue for the stability of earth dams, embankments and railway ballasts, and for the bearing capacity of piles (e.g., Daouadji et al, 2011;Okonta, 2015;Winter et al, 2017). Quantitative information about the shearing history can be retrieved from glacial sediments (Altuhafi and Baudet, 2011) and landslide granular deposits (Zhang and McSaveney, 2017), and can be crucial for understanding the likelihood of the latter to exhibit further instability (Hu et al 2017(Hu et al , 2018a(Hu et al , 2018b(Hu et al , 2018cFan et al, 2018).…”