Re-liquefaction characteristics of ground filled with volcanic ash soil

抄録

It is thought that the liquefaction resistance increases in the ground once liquefied because the ground becomes denser due to the drainage of pore water. However, it has been reported that re-liquefaction occurs in liquefied ground. In this study, liquefaction and re-liquefaction characteristics were evaluated using two kinds of undisturbed and its reconstituted samples collected from grounds filled with volcanic ash soil in Sapporo and Kitami Cities, Hokkaido, Japan. In addition, the change of stiffness due to liquefaction was investigated by the bender element test. Test results showed that; 1) In the reconstituted sample, the re-liquefaction strength increased slightly due to the density increase during liquefaction. On the other hand, the re-liquefaction strength of the undisturbed sample was lower than the first liquefaction strength. 2) The anisotropy of the sedimentary structure did not change before and after liquefaction in both the undisturbed and reconstructed samples. It wasthought that the contact force between particles decreased while the initial anisotropy was maintained.