Publication Abstract

Proceedings of the Deep Mixing 2015 Conference, (DFI)

Dynamic Centrifuge Model Tests on Pile-Type Deep Mixing Method Reducing Lateral Flow of Liquefied Ground
Yoshiyuki Morikawa, Port and Airport Reserach Institute, Japan; Hidenori Takahashi, Port and Airport Research Institute, Japan; Wakaki Tsuda, Sumitomo-Mitsui Construction Co., Japan; Natsuki Okuno, Sumitomo-Mitsui Construction Co., Japan; Naoki Takahashi, Sumitomo-Mitsui Construction Co., Japan; Ikuo Towhata, University of Tokyo, Japan

Deep mixing (DM) method has been increasingly employed as a countermeasure against subsoil liquefaction in recent years. Pile-type DM, however, is considered to have little effect as a liquefaction countermeasure, because the shear deformation of unimproved soil around the piles cannot be reduced. However, experimental results, which imply that shear deformation of unimproved soil around DM piles can be reduced, were reported. Furthermore, a new plane-arrangement of DM piles has been proposed to mitigate lateral flow induced by liquefaction. The DM piles in this arrangement confront the lateral flow in any direction, compared with the piles arranged in conventional pattern such as square and triangular arrangements. In this study, a series of dynamic centrifuge model tests was conducted to verify the lateral flow resistance of DM plies in the new arrangement. The results indicate that the DM plies can reduce the lateral flow of liquefied ground when the pile displacement and the pile head rotation are restricted. In addition, lateral load acting on DM pile from liquefied ground, which is required for design strength of the DM pile, was investigated.

 article #2058; publication #1013 (DM-2015)