عنوان مقاله [English]
Stability analysis is an important issue during designing and operation of earthfill dam. Importance of this issue is related to failure possibility and other risks for people who are living in downstream. The various sources of uncertainties exist in stability analysis of earthfill dam body, such as random parameters (Parameter Uncertainty) and randomness characteristic of stability model (Model Uncertainty). Therefore, the estimated stability safety factor is more accurate by considering the mentioned sources of uncertainty. There are many new methods of slope stability analysis that use statistical approach to the consideration and quantification of uncertainties. In this study, LHS and GLUE were used as sampling methods for extraction probability distribution of
stability safety factor. In this respect, stability safety factor of Parsian rockfill dam was estimated by considering the uncertainty of random variables in semi-static analysis with full reservoir. In addition, ``limit equilibrium general'' theory and ``method of components'' were used for estimating stability analysis of Parsian dam. In this respect, the randomness characteristic of the resistance parameters of different dam sections was quantified by considering the different probability distributions. The obtain result showed that, the uncertainty and variability of horizontal drain and filter geomechanical parameters has no main effect on safety factor variability. In addition, the comparison between derived probability distribution of safety factor using LHS and GLUE approach shows that, the LHS method is more conservative compared to GLUE approach in evaluating dam failure. The reliability indexes $(\beta)$ of GLUE and LHS were computed. The magnitudes of $(\beta)$ for GLUE and LHS are 1.36 and 0.93, respectively. So, according to obtain result, the estimated stability safety factor by GLUE approach is more reliable compared to LHS method. In addition, the average of safety factor in both LHS and GLUE methods is equal to 1.12 that is very close to allowable stability safety factor of Parsian dam.