Stability analysis of breakwater in terms of seepage flow using DDA

Massive tsunami caused serious damage to breakwater. There are two reasons for a breakwater destroyed by tsunami. The one is wave pressure, and other is seepage flow. Seepage flow makes a rubble-mound unstable and piping. There are few studies of seepage flow. For this reason, this study aims at analyzing stability of breakwater in terms of seepage flow by using the Discontinuous Deformation Analysis and Shear Strength Reduction. This study analyzed breakwater in Kamaishi. The safety factor is calculated by checking displacement in the rubble-mound blocks. As the result from this study, the following conclusions have been obtained. (1) Safety factor can be calculated by change of the maximum displacement in the rubble mound blocks. (2) Safety factor improved by covering rubble-mound of the port side.