The lateral flow of the ground due to liquefaction has caused severe damage to many varieties of facility. In past papers, the authors proposed a pile-type improvement method applying a new pile arrangement, wherein deep mixing piles were arranged with being shifted to prevent the lateral flow of liquefied ground in all directions. Additionally, the tops of the piles were connected by stabilised shallow ground. This method allows liquefaction, but the piles decrease the amount of lateral flow, and the stabilised shallow ground can be used immediately after the earthquake. However, the efficacy for ground behind quay walls has not been examined. In this study, the method’s efficacy behind quay walls was examined and the design method of the cement-treated piles was discussed. Centrifuge model tests showed that the lateral flow was dramatically restricted in the improved area, and the settlement of the ground surface could be reduced. The moments in the tests were significantly smaller than those of the proposed method for all piles and periods. It could be said that the proposed method calculates a safety-side moment. Although the strengths in the model were rather smaller than those of the proposed design, the cement-treated soil had no failures. Keywords: lateral flow, liquefaction, pile improvement, quay wall
Subjects: lateral flow, liquefaction, pile improvement, quay wall, strength design
Author: H. Takahashi, Head of Group, W. Tsuda, N. Takahashi, M. Fuchiyama, Y. Morikawa and I. Towhata
Publisher: DFI, EFFC