Abstract Debris flows are flowing mixture of water and sediments (from clay to boulder-sized particles). The sediments control both occurrence and characteristics of debris flows, however, the relevant literature has concentrated mainly on fine debris. Considering their large fractions in debris flows, the significance of coarse clasts (≥0.005 mm) is investigated by comparing the crude debris (CD, the fractions of Aggregation of data collected in 39 tested debris-water mixtures leads us to conclude that the coarse clasts can greatly affect the slurrying susceptibility of debris masses and bulk behavior of slurries. The debris-flow indices (Id) from the CD to RD slurries with maximum grain sizes of 10 and 5 mm decrease by 29% and 17%, respectively. The CD slurries possess higher yield strength and viscosity than their RD counterparts with the same solid volumetric concentrations (Cvs). The areas inundated by 10 CD slurries with maximum grain sizes of 10 and 5 mm are approximately 17%–39% of those of their RD counterparts. The excess pore pressures in the RD slurries dissipate more quickly than those in the CD slurries. The shape and surface texture of coarse clasts regulate slurrying of debris masses, as well as influence their liquefaction potential, which in turn has an impact on the mobility and persistence of subsequent slurries. The platy/flaky debris-producing mountain catchments generally experience lower-magnitude/higher-frequency, lower Cv debris flows of relatively less destructive power, and the debris flows dominated by equidimensional clasts are often more powerful and hazardous, despite their potentially lower frequency.

中文翻译：

---

粘性泥石流中粗碎屑的意义

摘要 碎屑流是水和沉积物（从粘土到巨石大小的颗粒）的流动混合物。沉积物控制泥石流的发生和特征，但相关文献主要集中在细碎屑。考虑到它们在泥石流中的很大一部分，粗碎屑（≥0.005 mm）的重要性通过比较粗碎屑（CD，在 39 个测试的碎屑 - 水混合物中收集的数据聚合的分数使我们得出结论，粗碎屑（≥0.005 mm）最大粒径为 10 mm 和 5 mm 的泥浆从 CD 到 RD 泥浆的泥石流指数（Id）分别降低了 29% 和 17%。在固体体积浓度 (Cvs) 相同的情况下，CD 浆液比 RD 浆液具有更高的屈服强度和粘度。被 10 种最大粒径分别为 10 和 5 毫米的 CD 泥浆淹没的面积约为 RD 泥浆的 17%–39%。RD 泥浆中的超孔隙压力比 CD 泥浆中的超孔隙压力消散得更快。粗碎屑的形状和表面纹理调节碎屑块的淤浆化，并影响它们的液化潜力，进而影响后续淤浆的流动性和持久性。产生片状/片状碎屑的山区集水区通常经历较低震级/较高频率、较低 Cv 的碎屑流，其破坏力相对较小，