B Mahmoodkhani - MSc of Soil Mechanic’s department, Islamic Azad University-Zandjan Branch, Iran
MR Atrchian - M.Sc of Soil Mechanic’s department, Islamic Azad University-Zandjan Branch, Iran
GH Niazi - M.Sc of Soil Mechanic’s department, Islamic Azad University-Zandjan Branch, Iran

The soil slopes and walls, which are talented to slip and slide, are needed to be established with proper method. One of these methods is nailing approach; main aimis make relation between studied given slopes by earth dam’s body slopes. In this paper, according to all of the factors which effect on the soil slopes reinforcedusing nailing operations such as, slope's height, nail's length and angle, overburdens and soil mechanical characteristics, influence of the establishment optimum nail angleon the safety factor in slopes(earth dam's slopes) is being studied using the Finite Element Method via PLAXIS software. Finally, the establishment optimum angle and the nails proper length are being defined.Achieved results represent that nailing is more benefit at soil with lower cohesion andinternal friction angle.

Establishment, Earth dams, Finite Element, Nailing, Optimum angle, Slope