Deposit morphology and structure under interactions of sliding mass and erodible layers: experimental insights

Abstract

Landslides are a kind of highly concerned geological disasters that occurring with complex motion processes and mechanisms. They often signi cantly affect the human life and properties located in their pathway. In some circumstances, the geological phenomena and structural features generated by the interactions between landslides and their substrates are still unclear, which makes it di cult to be forecasted and mitigated on its effects. In this study, a sandbox experiment was conducted to study the velocity and displacement of the sliding mass, the geometry of the deposit, and the internal and external structural characteristics of the deposit under the interactions between the sliding mass and erodible layer by varying the depth of the erodible layer. Results show that the motion process of sliding mass consists of three stages: falling, shovel push-extrusion, and push-nappe accumulation. In the rst stage, the velocity of the sliding mass increases sharply to a peak velocity before colliding with the erodible layer. In the latter two stages, the mobility of landslide is greatly limited by the erodible layers at the foot of the inclined plate, and the secondary acceleration of the sliding mass is observed. The deposits were divided into three zones (I a , I b , and II), in terms of the morphological and structural characteristics of their positions. The action forms were mainly pushing and covering in the zone II and I respectively. There were phenomena such as strata inversion, pushover, and entrainment that occurred in the deposits; the folds, ridges, and bulge that occurred on the surface of deposits. These structural characteristics re ect the stress states of laboratory landslides in motion from compressing to shearing. The results of this research will provide a valuable theoretical reference for the calculation of the disaster range when erodible layers exist in landslides' motion paths.