Centrifuge model test platform for rainfall simulation triggering shallow landslides

A centrifuge model test platform was designed and developed to verify the critical continuous rainfalls triggering shallow landslides in natural slopes. Based on literature reviews, in-situ dimensions of shallow landslides on natural slopes were determined to 40 m (Length) × 16 m (Width) × 2 m (Depth) on average. In consequence, considering the model mounting space of the centrifuge test facility, a gravity level was decided (N = 40g) so that the length of a model slope equals 1 m according to scaling law. The width and depth of the model slope were hence determined to 0.4 m and 0.05 m, respectively. On the other hand, a rainfall simulator comprised of a series of air-atomizing spray nozzles was designed and developed considering scaling laws of rainfall infiltration and subsurface water flows. As a simulation result in a 40g condition, rainfall dispersions reduced and its trajectory bending induced by Coriolis’ force was almost vanished. After the development of centrifuge model test platform, several 1g performance tests of the rainfall simulator were conducted to test the spatial uniformity of rainfall distributions and fit the conditions of applying water and air pressures to rainfall intensities. The study also presents preliminary test results of shallow landslides in a 1g condition conducted to find and solve errors and unexpected problems before mounting the platform to the centrifuge test facility.