Numerical Analysis on the Flow and Stability of Vertical Hydraulic Barrier at Offshore Containment Facility

Abstract

Preventing leakage and structural stability of vertical barrier at offshore containment facilities are very important. Two-dimensional numerical analysis were performed to evaluate seepage and flow characteristics regarding to different embedded depths and hydraulic permeability of vertical barrier. In addition, stress and displacement at corner of vertical barrier were evaluated by using 3-dimensional numerical analysis. The effluent flux in the case of vertical barrier with insufficient embedded depth was significantly increased by 200 ~ 240 times compared with the case of embedded barrier in low permeable clay layer. The effluent flux was increased by 4.5 and 45 times according to 10 and 100 times increase of hydraulic permeability of vertical barrier, respectively. The seepage and flow analysis results imply that the most important factor to prevent leakage is to embed the vertical barrier in low permeable layer. The 3-dimensional stress and displacement analysis results showed small displacement but large moment and shear stress at the corner of vertical barrier. Therefore, the stiffness and strength at the corner of vertical barrier compared with other parts should be increased to secure stability of vertical barrier at offshore disposal facilities. Keywords: offshore containment facility, waste disposal, vertical hydraulic barrier, PLAXIS