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Calculating rockslide movement and deposit characteristics is challenging due to the complex interactions of various physical factors. This study investigates the effects of rockslide volume, slope angle, and material strength on fragmentation and deposit patterns through laboratory experiments using homogeneous and non-homogeneous specimens. Specimens were tested on sloping chutes at angles of 41.5°, 45.1° and 48.6°. Results showed that increasing the chute angle led to a reduction in specimen completeness. Specifically, as the chute angle increased from 41.5° to 45.1°, the completeness for specimens with heights of 5 cm, 10 cm, and 15 cm decreased by approximately 29.6%, 7.4%, and 32.8%, respectively, with the largest specimen showing the most significant reduction. For non-homogeneous specimens, strength differences between the upper and lower layers significantly influenced fragmentation; a lower-strength bottom layer resulted in increased fragmentation and longer leading-edge distances. A dimensionless parameter Ψ , defined as the ratio of the largest fragment’s travel distance to the farthest debris, to quantify the relationship between fragment travel distance and flow mobility in rockslides. The results demonstrated a positive linear correlation between Ψ and specimen completeness. Greater completeness is associated with larger fragment travel distances. Additionally, a logarithmic correlation was found between Ψ and the apparent friction coefficient, reinforcing the relationship between fragmentation behavior and the potential risk of rockslide events. These findings offer predictive models for assessing rockslide risks based on slope angle, rockslide volume, and apparent friction coefficient. [ABSTRACT FROM AUTHOR]

Landslide dams formed by successive rock slides in the same location may cause severe and long-term destruction to affected areas. However, studies on the formation of landslide dams that result from successive rock slides are still at early stages. In this paper, a flume test that could model rock fragmentation and the flow of fragmentary material is used to study the formation of landslide dams triggered by successive long-runout rock slides. The tests assess the effects of number of blocks, the number of times the blocks are released, and the initial arrangement of blocks before release on the dam geometry. The maximum and minimum landslide dam heights rise with the increasing number of blocks in each series of tests, while there is minimal or even no growth in the dam length for some series. Additionally, more block releases produce larger minimum dam height but smaller maximum dam height. Together, these results indicate that more releases are prone to fully block the flow channel by forming a steep dam. Furthermore, the initial block arrangement is also found to influence the landslide dam formation. In this study, landslide dams caused by successive rock slides are divided into two types: the stable type, namely, the landslide dam(s) already formed by the previous slide event(s) maintains general stability before the next slide lands on the dam surface; the unstable type, namely, the landslide dam(s) by the previous slide episode(s) has failed before the next damming slide occurs. Field investigations showed that slide episodes in both types of successive landslide dams are influential for the dam formation and river morphology. [ABSTRACT FROM AUTHOR]

Calculating rockslide movement and deposit characteristics is challenging due to the complex interactions of various physical factors. This study investigates the effects of rockslide volume, slope angle, and material strength on fragmentation and deposit patterns through laboratory experiments using homogeneous and non-homogeneous specimens. Specimens were tested on sloping chutes at angles of 41.5°, 45.1° and 48.6°. Results showed that increasing the chute angle led to a reduction in specimen completeness. Specifically, as the chute angle increased from 41.5° to 45.1°, the completeness for specimens with heights of 5 cm, 10 cm, and 15 cm decreased by approximately 29.6%, 7.4%, and 32.8%, respectively, with the largest specimen showing the most significant reduction. For non-homogeneous specimens, strength differences between the upper and lower layers significantly influenced fragmentation; a lower-strength bottom layer resulted in increased fragmentation and longer leading-edge distances. A dimensionless parameter Ψ , defined as the ratio of the largest fragment’s travel distance to the farthest debris, to quantify the relationship between fragment travel distance and flow mobility in rockslides. The results demonstrated a positive linear correlation between Ψ and specimen completeness. Greater completeness is associated with larger fragment travel distances. Additionally, a logarithmic correlation was found between Ψ and the apparent friction coefficient, reinforcing the relationship between fragmentation behavior and the potential risk of rockslide events. These findings offer predictive models for assessing rockslide risks based on slope angle, rockslide volume, and apparent friction coefficient. [ABSTRACT FROM AUTHOR]