Mechanism of Landslide Composed of Strongly Weathered Mudstone Induced by the 2004 Mid-Niigata Earthquake
This paper reports the mechanism of a landslide composed of strongly weathered mudstone induced by the 2004 Mid-Niigata Earthquake. The size of the landslide is 250 m long, 150 m wide and 15 ~ 20 m deep. Undisturbed soil samples of strongly weathered mudstone were obtained from the soil layer near the assumed sliding surface by boring. Cyclic undrained triaxial tests performed on the undisturbed soil specimens revealed the possibility of the landslide mechanism that the excess pore water pressure was induced in the soils near the sliding surface by the cyclic earthquake shaking and the safety factor of the slope became fairly less than 1.0, which led to the long-distance sliding of the landslide.
KeywordsEarthquake-induced landslide Geotechnical testing Landslide mechanism Weathered mudstone
The present study was conducted as a “Research project for utilizing advanced technologies in agriculture, forestry and fisheries” with support from the Ministry of Agriculture, Forestry and Fisheries of Japan.