Characteristics and Assessment of seismic behavior of improved ground by Sand Compaction Pile Method using iron and steel slag as base of Gravity Caisson Structure

Abstract

The Sand Compaction Pile Method (SCP) is a major method to improve soft clay ground. Natural sand is generally used as a filling material of SCP. In this study, the seismic deformation behavior of improved ground using solidified iron and steel slag as an alternate material was investigated. As a result of the cyclic loading tests using hollow cylindrical torsional test apparatus to composite ground consisting of improvement pile and clay, the dilatancy properties significantly appeared in improvement pile. As a result of dynamic centrifuge model tests, deformation behavior was similar in the case using solidified iron and steel slag and the case using sand, and residual deformation in the improvement area of the case using solidified iron and steel slag is smaller than that of the case using sand. And as the results of effective stress analysis to the model test, it has been confirmed that the consideration of the dilatancy properties of solidified iron and steel slag is important in the seismic performance evaluation.