Numerical analysis of the effects of clay blanket and cut-off wall on reducing seepage from earth dam foundation

Water level difference on both sides of earth dam provides seepage of water from body and foundation of dam. Various methods such as the implementation of a clay blanket, cutoff wall and combination of them are used to reduce seepage from the foundation of earth dam. In present study, Seep/w software was used to investigate the seepage from the foundation of earth dam under the influence of clay blanket, cut-off wall and combined method of them. The results showed that combination of clay blanket and cut-off wall with full height by the end of permeable layer was not significantly effective compare to case without clay blanket and reduction in seepage (percentage) was almost identical in the both cases. But if clay blanket is used with incomplete cut-off wall, reduction in seepage will be doubled compared to the use of incomplete cut-off wall without clay blanket.