Author(s): Valentin Heller; Deep Roy; Sazeda Begam

Linked Author(s): Valentin Heller

Keywords: Geohazards; Granular slides; Laboratory experiments; Scale effects; Similarity

Abstract: Granular slides are observed in nature as landslides, rock falls, avalanches and debris flows and can cause devastation and human losses in their runout path. Laboratory experiments are often used to investigate such granular slides. However, it is challenging to reliably extrapolate small-scale laboratory experimental results to larger-scale natural events due to scale effects. Hence, two Froude scale series of unconfined (3D) dry granular slide laboratory experiments have been conducted at scales 1: lambda = 1:1, 1:2 and 1:4, where lambda is the scale factor, to investigate and quantify scale effects. The smooth incline was 3 m long, up to 1.75 m wide and the run-out area was 3 m by 3 m. The 1:1 slides were 54.251 and 30.150 kg heavy, with an initial width of 0.500 m, and all experiments have been conducted 3 times (18 experiments in total). Large scale effects have been identified in the dimensionless slide deposits: the relative tail and front positions decreased by up to 17% with increasing lambda, and the maximum slide thickness increased by up to approximately 50% with increasing lambda. On the other hand, the relative slide expansion is insignificantly affected by lambda. Photogrammetric reconstruction of the slide footprint shows that the footprint area is affected by scale effects as well. These results assist in hazard assessment based on laboratory experiments. Future work will involve rough incline surfaces and relate the results to other studies and past events in nature.

DOI: https://doi.org/10.64697/978-90-835589-7-4_41WC-P1963-cd

Year: 2025