An Instrumented Flume to Characterize the Initiation Features of Flow Landslides

Rainfall-induced landslides are on the rise due to global warming but the associated initiation mechanisms remain unclear. To observe the local initiation features of flow landslides under different rates of water supply, a well-instrumented flume capable of tightly controlling the inflow from the groundwater supply pipes and upstream discharge was built. Basal porewater pressure transducers (PPT) were installed to monitor the water pressure evolution, and a simple method to retrofit pressure transducers into PPTs was introduced. Internal movement behaviors of the slope body prior to the onset of and during a full failure were monitored with low-cost and small-size MEMS (Micro-Electro-Mechanical-Systems) accelerometers. A MEMS sensing package, termed the Smart Soil Particle (SSP, first generation), was also developed in conjunction with the laboratory testing program for field implementation in the future. In a set of experiments designed to investigate the initiation mechanism of a loose soil sample under a small and slow constant groundwater inflow, the MEMS accelerometers and basal PPTs successfully captured the intricate internal movement features and porewater pressure patterns. This warrants more systematic studies of the flow landslide initiation mechanism using the newly developed flume instrumentation.