Effect of Inclined Clay Core on Embankment Dam Seepage and Stability Through LEM and FEM

Water seepage affects dam stability and loss of water from reservoirs. Consequently, seepage is an important problem in the design, implementation, and operation of embankment dams. One type of embankment dam is a non-homogeneous (zoned) dam with a clay core. Water passes through the core of the dam and loses much of its energy due to friction. Zoned embankment dams can be designed and implemented with inclined or vertical cores. In this study, the performance of inclined and vertical cores are compared using numerical models to simulate the seepage and hydraulic gradients. Also, the Limit of Equilibrium Method  is used to calculate slope stability. The permeability ratio of the dam shell to the clay core is a variable. The result of this study shows that seepage with a vertical core is less than that with an inclined core. Meanwhile, the factor of safety for upstream slope failure is higher (about 55.5%) for the embankment with an inclined core compared to the vertical core case. Also, comparisons were made using different methods to calculate the stability of the slope. The Bishop’s method showed the highest safety factor and the Fellenius’ method predicts the lowest safety factor.