Research

Landslide Research

Department of

# Civil and Environmental Engineering

This research is supported by the U.S. National Science Foundation under Grant #CMMI-1453103 to investigate landslide mobility. 2-D flume experiments have been performed to study the impact force applied from a granular sliding mass to a rigid obstruction. The impact force is used to infer the effect of solid-like and fluid-like behaviors of a granular sliding mass. For the first series of experiments presented below, the effects of inclination angle, initial density of the sliding mass, and the sliding distance on the impact force are investigated.

Fig. 1 shows the flume that is used in this research. The flume has a dimension of
320 cm (L) × 43.2 cm (H) × 40 cm (W) which includes a 43.2 cm × 40 cm × 43.2 cm sand box for placement of sand. Standard uniform F-50 Ottawa sand with an average particle size of 0.25 mm is used as the sliding material.

Fig. 1. A photograph of the 2-D flume

Fig. 2
shows the load measurement device which is used as the rigid obstruction to measure the impact forces. It consists of six dynamic load cells that are attached to the fixed part of the load measurement device. In front of each of these load cells, a sliding plate is placed through attached bars and bearings. Using this load measurement device, the distribution of impact force from the granular sliding mass can be recorded.

Fig. 2. Load measurement device: (a) load cells attached to the fixed part; (b) movable plates; (c) a schematic of the load measurement device

Experiment parameters and results:

The first series of experiments were performed at the following inclination angles, initial relative densities, and sliding distances:
• Inclination Angles (θ): 30°, 40°, 45°, 50°, 55°, 60°
• Initial relative densities (DR): 35%, 55%, 96%
• Sliding distances (L): 0.65m, 1.83m, 2.49m
For each experiment, the measured impact forces from individual load cells and the combined total impact force are shown in the following table (the videos are linked to YouTube):

 Parameters Experiment Individual Impact Force Total Impact Force θ = 30° DR = 35%  L = 0.65m θ = 30° DR = 55% L = 0.65m θ = 30° DR = 96% L = 0.65m θ = 40° DR = 35% L = 0.65m θ = 40° DR = 55% L = 0.65m θ = 40° DR = 96% L = 0.65m θ = 45° DR = 35% L = 0.65m θ = 45° DR = 55% L = 0.65m θ = 45° DR = 96% L = 0.65m θ = 50° DR = 35% L = 0.65m θ = 50° DR = 55% L = 0.65m θ = 50° DR = 96% L = 0.65m θ = 55° DR = 35% L = 0.65m θ = 55° DR = 55% L = 0.65m θ = 55° DR = 96% L = 0.65m θ = 60° DR = 35% L = 0.65m θ = 60° DR = 55% L = 0.65m θ = 60° DR = 96% L = 0.65m θ = 30° DR = 35% L = 1.83m θ = 30° DR = 55% L = 1.83m θ = 30° DR = 96% L = 1.83m θ = 40° DR = 35% L = 1.83m θ = 40° DR = 55% L = 1.83m θ = 40° DR = 96% L = 1.83m θ = 45° DR = 35% L = 1.83m θ = 45° DR = 55% L = 1.83m θ = 45° DR = 96% L = 1.83m θ = 50° DR = 35% L = 1.83m θ = 50° DR = 55% L = 1.83m θ = 50° DR = 96% L = 1.83m θ = 55° DR = 35% L = 1.83m θ = 55° DR = 55% L = 1.83m θ = 55° DR = 96% L = 1.83m θ = 60° DR = 35% L = 1.83m θ = 60° DR = 55% L = 1.83m θ = 60° DR = 96% L = 1.83m θ = 30° DR = 35% L = 2.49m θ = 30° DR = 55% L = 2.49m θ = 30° DR = 96% L = 2.49m θ = 40° DR = 35% L = 2.49m θ = 40° DR = 55% L = 2.49m θ = 40° DR = 96% L = 2.49m θ = 45° DR = 35% L = 2.49m θ = 45° DR = 55% L = 2.49m θ = 45° DR = 96% L = 2.49m θ = 50° DR = 35% L = 2.49m θ = 50° DR = 55% L = 2.49m θ = 50° DR = 96% L = 2.49m θ = 55° DR = 35% L = 2.49m θ = 55° DR = 55% L = 2.49m θ = 55° DR = 96% L = 2.49m θ = 60° DR = 35% L = 2.49m θ = 60° DR = 55% L = 2.49m θ = 60° DR = 96% L = 2.49m