Study on volcanic sediment embankment collapse in the 2011 Earthquake off the Pacific Coast of Tohoku

摘要

Alarge-scale slope failure of an embankment,which consists of volcanic sediment, in FukushimarnPrefecture of Japan occurred due to the 2011 off the Pacific Coast of Tohoku Earthquake. Some signatures ofrnliquefaction have been observed in the site. When investigating the embankment slope failure mechanism, it isrnnecessary to study the effects of particle breakage. In this study, some monotonic and cyclic triaxial tests werernconducted for the sampled soil to investigate the change of the particle size distribution caused by applyingrnvarious stress and the influence on the shear strength characteristics due to the particle breakage. From the testrnresults, it was revealed that the sampled soil, subjected to the effective isotropic consolidation stress of 100 kParnor less, increases the particle breakage amount rapidly and the shear resistance angle is significantly reducedrnwith the increase of the particle breakage amount.