Numerical Investigation on Seepage Discharge Inside a Cylindrical Cut-off Wall

Recently, a cylindrical cut-off wall was proposed as a new technology for temporary offshore works. The cut-off wall has a cylindrical shape, so seepage analyses are necessary to analyze the effect of wall shape. In this study, a numerical analysis was performed to investigate the seepage discharge inside cut-off walls. The numerical modeling was verified by comparing with the theoretical solution for the cofferdam with double sheet piles. Two different flow conditions were compared between 2-dimensional flow and axisymmetric flow. The results showed that the discharge of the axisymmetric flow was about 1.55 times larger than that of 2-dimensional plain flow. A parametric study was carried out by varying wall radius, penetration depth of the wall, and total head difference between in and outside of the wall. The discharge decreased with the increase of the penetration depth and the wall radius. Finally, the design equations were suggested to determine the discharge for the preliminary design of the cylindrical cut-off wall.