Gradation and Rheological Characteristics of Glacial Debris Flow along the Kangding–Linzhi Section of Sichuan–Tibet Railway

To date, most research on the characteristics of glacial debris flow along the Sichuan–Tibet railway has focused on numerical simulations and remote sensing, resulting in a lack of direct experimental data from debris flow samples. Therefore, in the present study, a field investigation was conducted along the Sichuan–Tibet railway, and 55 samples of glacial debris flow deposits were systematically analyzed to determine their grading and rheological properties. This is the first systematic experimental study on glacial debris flow deposits. The results showed that the proportion of coarse particles was high and the proportion of fine particles was low in the glacial debris flow along the Sichuan–Tibet railway. The average gravel and sand contents were 37.8% and 58%, respectively, and the average contents of silt and clay were 3.7% and 0.47%, respectively. The average fractal dimension was 2.1507, which is much greater than that of viscous debris flow. Under the same gravity and shear rate, the stress of typical glacial debris flow was significantly less than that of viscous debris flow, whereas the variability of the stress was more significant. These findings will contribute to revealing the movement rules and disaster risk of glacier debris flow along the Sichuan–Tibet railway and have considerable theoretical and practical significance for ensuring safety during both its construction and later operation.