Abstract
ABSTRACT
One of the main causes of the earth dam failure is the seepage. This seepage can cause weakening in the earth dam structure, followed by a sudden failure due to piping or sloughing. For this purpose a finite element method through a computer program, named SEEP2D, was used to determine the free surface seepage line, the quantity of seepage through the dam, the pore water pressure distribution, the total head measurements and the effect of anisotropy of the core materials of Duhok zoned earth dam. First, the accuracy of the program was tested via the data of experimental dam and the results showed an acceptable accuracy of the program. The effect of the ratio of the permeability in the horizontal direction to that in the vertical direction (Kx/Ky) on seepage was tested and results indicated an increase in seepage quantity as this ratio increased. The stability of Duhok zoned earth dam was analyzed using a slope stability computer program, named STABIL2.3. The program is verified through a dam example of known factor of safety (solved by hand calculations). The results of the verification indicated a good accuracy of the program. The slope stability analysis results showed that the factor of safety decreases with the increase of Kx/Ky ratio. The analysis of the results of this study showed that Duhok zoned earth dam is safe against the danger of piping and slope sloughing under the present operation levels. Also, the present study showed that the field piezometers readings of the dam are not accurate.
Keywords: Seepage, Stability, Duhok dam
