International Session 国際セッション (1)

[CS2-05] Shear stress behavior of unsaturated undisturbed black volcanic ash soil under cyclic loading

*Putra Okri¹、Yasufuku Noriyuki¹、Ishikura Ryohei¹、Kawaguchi Yuko² (1. Kyushu University、2. NEXCO West)

Keywords:Black volcanic ash, Cyclic, Direct shear box, Shear stress

Recently Kumamoto earthquake 2016 triggered many slope failures around the Aso area. The black volcanic ash soils and orange-colored pumice deposits are the most common types of soils that experienced failure in the Aso area. In this paper, the shear stress behavior of unsaturated undisturbed black volcanic ash soil was evaluated. A series of cyclic tests using the constant volume direct shear box was performed. Furthermore, to consider the effect of over-consolidation ratio, normally consolidated and over-consolidated samples were tested.