Stability Analysis of the rock slope of the Gabric Dam spillway trench head in south of Iran

Stability analysis is essential to ensure the stability of rock slopes. There are various methods for stability analysis of slopes, especially rock slopes. According to the geological studies, the considered slope which is in the spillway area of Gabric dam (south of Iran), is located in marl-sandstone layers’ question, with Eocene Oligocene age. Considering the height of this terrace and the gradual process of changing the nature of the layers from marl to sandstone, the considered parameters are equivalent parameters. In the analysis of the overall stability of a rock slope, the parameters of shear strength have been used based on the Hoek-Brown failure criterion. After the analysis of the overall stability and the design of the support system, the stability of the stone wedges has been analyzed and the adequacy of the support system for the stability of the wedges that have the potential to slip. has been investigated and also to consider the loading related to the earthquake, in addition to static analyses, quasi-static analyzes have been performed by applying horizontal acceleration corresponding to the design and use level of the roof to reach the appropriate reliability coefficients. According to the analysis, it shows that in the spillway of Gabric Dam, there is a planar rupture and a pit, which reduces the reliability factor due to saturation and earthquake.