Effect of surface layer freeze to soil-pile interaction

¹ Civil Engineering Research Institute for Cold Region (CERI), 1-34-3 Hiragishi 1-jo, Toyohira-ku, Sapporo, Hokkaido 062-8602, Japan
² University of Tokyo, Principal Researcher, International Consortium on Landslides, 138-1 Tanaka-Asukai cho, Sakyo-ku, Kyoto 606-8226, Japan
³ Nagaoka University of Technology, 1603-1, Kamitomioka, Nagaoka, Niigata 940-2188, Japan

^* Corresponding author: taka4@ceri.go.jp

Abstract

To assess earthquake resistance of new or existing structures and predict earthquake damage of structures, it is important to properly evaluate the response of the structure at the time of the earthquake. In cold regions however, where the ground can freeze in winter, the dynamic soil-foundation interaction can change with the change in the density and stiffness of the frozen side soil. This paper examines in a quantitative manner, the influence of freezing of ground on the dynamic soil grouped piles interaction., It is shown herein that the grouped piles in the frozen ground tend to follow the motion of the ground over a wider range of frequency. Furthermore, it is shown that even when the freezing depth is much thinner than the characteristic length of piles determined by the stiffness ratio of the ground and the group pile, the pile cap stiffness at the time of freezing becomes noticeably large. It is confirmed that the freezing of the ground can greatly affect the interaction between the ground and the piles.