Influence of pulling out existing piles on the surrounding ground

Teardowns of social infrastructure, including civil structures, have been increasing in number in recent years because these structures have aged and their utilization has decreased along with the decrease in population. The number pile foundations being pulled out is now far greater than that being newly installed. However, after a pile foundation is pulled out, the mechanical characteristics of the surrounding ground may be affected by the existence of the resulting hole formed by pulling out. There are no regulations yet on injecting fillers into pull-out holes, and the influence of filler strength on the surrounding ground is yet to be elucidated. This study considers the influence of a pull-out hole on the static and dynamic characteristics of the surrounding ground using two-dimensional dynamic finite-element analysis. The special qualities required by fillers injected into such holes are also clarified.