EARTHQUAKE-INDUCED FAILURE OF VOLCANIC EMBANKMENTS SUBJECTED TO PREVIOUS RAINFALL
Keywords:Slope stability, Volcanic soil, Model test, Rainfall, Earthquake
Every year, slope failures such as landslides and debris flow on natural and artificial slopes cause great loss of life and property. The purpose of this study is to investigate the stability of the embankments constructed by coarse-grained volcanic soils under post-rainfall earthquakes like dual hazards in history (e.g., Typhoon Jebi and the 2018 Hokkaido Eastern Iburi earthquake). To accomplish the purpose, a series of 1g experiments on model slopes with Komaoka volcanic soils as material were performed using a spray nozzle and a shaking table. The experimental results showed that preceded rainfall greatly influences the stability of the embankment under subsequent earthquakes. Moreover, by comparing the result of this study with those of experiments on model embankments subjected to post-earthquake rainfall, it showed that the stability of the slope would change due to the different order of external force even if the previous shear strain induced is similar.