Investigation of Relief Wells Performance in Decreasing Uplift Pressure in Foundation of Embankment Dams

The design of relief wells includes determination of the distance of relief wells from each other, their distance from the dam upstream, the well diameter and discharge into each wells. This study tends to investigate these factors effect on uplift pressure in earth dams. For this purpose, finite elements method (FEM) was used for different configuration of relief wells in downstream of an earth dam. For validation, a comparison between analytical equation for simple condition and FEM showed good agreement for uplift pressure prediction. It was found that by increasing the diameter of pressure reducing wells, the seepage flow increases to each well. Reducing of the distance among relief wells or increasing of the wells diameters, resulted in uplift pressure reduction. Two-row arrangements of relief wells showed that zigzag type was superior than the non-zigzag type. Simple linear and nonlinear regression relations were presented for uplift pressure prediction with reasonable accuracy. For future researches, it is suggested to consider un-isotropic effect of soil