Ground damage during large earthquakes: liquefaction and slope collapse

Abstract

Since the authors have already clarified the mechanism of liquefaction on the alluvium sedimentary ground and presented the results for 3rd Geotech-Hanoi 2016 and 15th WCEE, they tried to investigate the landsides on a gradual slope and the mountainous slope collapse covered with volcanic ash in Sulawesi Earthquake and Hokkaido Iburi East Earthquake in 2018. They found that the landslides and the slope collapse during earthquake happen based on the excess pore water pressure by a series of shear waves within the soft layers and on the high excess pore water pressure of a moment by impact waves in the vertical seismic waves. These phenomena were analyzed from the site photographs and the past knowledge of the authors.