Shielding effects of deep cement mixing column rows on an anchored sheet pile quay in soft clay: three-dimensional centrifuge and numerical modeling

As a preventative measure to increase the stability of an anchored sheet pile quay in soft clay, deep cement mixing (DCM) column rows erected at the active side behind the quay wall were suggested in the current study. The effect of DCM columns rows on the responses of the quay wall and ground movements was examined using a three-dimensional finite element numerical model of back analysis based on a centrifuge model test. The mechanism of soil arching and the stress transfer from the yielding soil to the stabilizing columns have also been studied using numerical analyses. A parametric study was also conducted to assess the effectiveness of DCM column rows. Results show that the shielding effect of DCM column rows can effectively reduce the negative effects on the quay wall. The effect was brought about by the compression of the lateral soil between the columns caused by stress redistribution, along with the resistance of the column rows in the direction opposite to the soil movement. On the basis of this analysis, some preliminary conclusions can be drawn for the stability improvement of quay wall using DCM column rows in soft clay at the design stage.