Abstract
In this paper, finite element modelling is employed for simulating and analysing seepage and slope stability of earthfill
dam via GeoStudio software. Two products are employed, which are SLOPE/W for slope stability and SEEP/W for seepage
analysis. The behaviour of earthfill dam with four different types of sandy soils having different values of hydraulic
conductivity (K) has been studied. Different upstream (US) slopes of 1:2, 1:2.5, 1:3 and 1:3.5 for the earthfill dam are
simulated. The downstream (DS) slope is constant at 1:2.
The results showed for all the four types of soils that when the US slope is increased, the amount of seepage from the
dam increases and the factor of safety (F) decreases. For each US slope, when K (type of soil) increases, both seepage and
F increase. Fine sand soil is associated with less seepage and less F. Sixteen equations are obtained to predict both seepage
and F with respect to US slope for each type of soil and K of the soil for US slope.
An experimental model for earthfill dam is constructed in the laboratory of hydraulics, Benha University to investigate
the seepage of water through earthfill dams. It is concluded that seepage decreased when K decreased, and when the US
slope for each type of soil decreased. The seepage increased when K increased for each US slope. Seven equations are obtained
to predict seepage with respect to US slope for each type of soil, and K for each US slope.