Experiment on landslide hazard mapping, based on AHP method, in consideration of point load strength of hydrothermally altered rock : －Example in the Ohekisawa－Shikerebenbetsugawa landslide area, Japan－

Abstract

  This study attempted landslides hazard assessment for hydrothermal alteration zone landslides of the Ohekisawa-Shikerebenbetsugawa landslide area in Teshikaga Town, eastern Hokkaido, Japan. The landslide hazard assessment system for landslides used here is based on topography, slope geology, geological structure, and the hydrothermal alteration zone. In addition to those we considered mechanical properties of hydrothermally altered rock based on irregular lump point load strength test results. The landslide hazard was evaluated based on analytic hierarchy process (AHP). A landslide hazard map was created based on the landslide hazard rank of I-V as follows. Rank I : stable hard rock slope, Rank II : stable soft rock slope, Rank III : unstable soft rock slope, Rank IV : potential landslide area, and Rank V : ancient landslide area.